REVIEW OF LITERATURE

CHAPTER 2

REVIEW OF LITERATURE

CHAPTER-2


PACKAGING AND STORGE TEMPERATURE If red sweet peppers (Capsicum annuum L.) stored for 21 days when packaged after hot water dipping (HWD) at 53˚C for 4 minutes in low density polyethylene (LDPE), packed in low density polyethylene with out applying hot water dipping and unpackaged one which was considered as control or check. HWD and packaged treatments were performed best as compared to unpackaged one. The weight loss was less than 1% in packaged and 10% in unpackaged. HWD had no significant effect on the quality of fruits (Raffo et al., 2006). Packaging material used for tomato postharvest quality was 20 mm (PE20) and 10 u (PE50) and (PP) 25 u and then sealed compared with unwrapped fruits considered as control. Results indicated that (PE50) and (PP) film, devoid off the development of red color up to 30 days of storage. They were also still firm even after 60 days of storage and these tomato also possessed lowest weight loss and highest soluble solid (Batu & Thompson, 1998). The harvested tomatoes were stored at 7, 15 and 25˚C, for a period of 10 days. The soluble phenolics and ascorbic acid contents of tomatoes showed slight increases during storage, regardless of temperature. The mean lycopene content of tomatoes stored at 15 and 25˚C on the 10th day of storage was, approximately, 2-fold (7.5mg/100g) than of the tomatoes stored at 7˚C (3.2mg/100g). The soluble antioxidant activity increased from 17–27% during the storage period of tomatoes (Ramandeep and Geoffrey, 2006). Antioxidant activity in 10 sweet pepper cultivars grown over 10 consecutive years and found that cv. Flamingo had the highest ascorbic acid content followed by Bombay and parker. All cv. fulfilled 100 % requirement of vitamin C, but there was no effect of harvest year on antioxidant activity (Deepa et al., 2006). Change in antioxidant compounds in pepper fruits at different ripening stages, as affected by salinity and harvested fruits at three maturity stages; green, breaker and red. For nutritional point of view the red stage was most appropriate state of maturation, since red stage pepper had the highest antioxidant activity for both hydrophilic and lipophilic fraction (Navarro et al., 2006). In another study found that highest amount of ascorbic acid was in green chillies greater than citrus and highest amount of carotenoids in red chillies greater than carrot. Red pepper had significantly total phenolic content than the green pepper. It is reported that green, yellow, orange and red colored pepper if analyzed for their antioxidant activity, red pepper contained a higher level of beta-carotene content 0.54 ug/ g the yellow pepper had lowest beta-carotene content 0.2 ug/ g. All four colored peppers 6

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had capacity of preventing the oxidation of cholesterol during heating. The green pepper showed slightly higher capability in preventing the oxidation of cholesterol or docosahexaenoic acid (DHA, C 22:6) compared to the other three peppers (Sim et al., 2007). Oxidative carotenoid degradation causes paprika color loss during storage. Ethoxyquin, a synthetic antioxidant is used in the spice industry to prevent carotenoid loss during postharvest handling but ethoxyquin treated paprika is unaccepted for some market and consumers. Naturally derived antioxidant i.e. ascorbic acid, δ-tocopherol and mixed tocopherol were tested as color protestants in two paprika cultivar. Extractable color, surface color and carotenoid concentration were determined before storage and then monthly. After four month storage at ambient temperature, the control treatment loss 63 % of initial extractable color, the δ-tocopherol treated sample lost 32 % and the ethoxyquin lost 6 % color (Osuna-Garcia et al., 1997). A 45 days storage experiment of citrus fruits conducted under polyethylene bags of 0.0256mm, 0.0508mm thickness and the unpackaged one considered as control and stored at controlled room temperature. Maximum weight loss observed in control and minimum weight loss in thick polyethylene packaging. The TSS increased during storage and ascorbic acid decreased from 1.59 to 0.63 % during storage. Organoleptic properties evaluation revealed that individual packaging had significant effect on the external appearance, taste and texture. Thick packaging performed significant effect in prolonging the shelf life of citrus fruits (Hussain et al., 2004). Postharvest quality parameters in fresh or transformed horticultural crops detected and found that conventional indicators of quality, sugars can be conveniently analyzed by several physico-chemical or biochemical methods. Vitamin represented the important nutritional quality factor in horticultural crops and the detection of ascorbic and/ or betacarotene is valuable in predicting vegetable shelf life. The activity of enzymes, such as ascorbate oxidase, polyphenol oxidase and peroxidase also represented sensitive parameters for quality control, since protein expression strictly depends on environmental conditions. This procedure reveals that there were consistent differences in composition regarding Phenolics or sugars in different tissues of the same vegetable and that one tissue may more prone than other to variations in the concentration of marker compounds. Continuous studies in the research of these parameters have provided deterioration ensuring the supply of fresh vegetable to the consumer (Ninfali & Bacchiocca, 2004) Tomatoes (Lycopersicon esculentum L.) and sweet peppers (Capsicum annuum L.) treated with vapors of methyl jasmonate (MeJA) or methyl salicylate (MeSA) had markedly increased resistance to chilling injury and decreased incidence of decay during and after low temperature storage. Accumulation of classes I and II small heat shock protein (HSP) mRNAs was increased significantly by treatment of tomato fruit with MeJA and MeSA. Treated fruit also accumulated higher levels of transcripts from the HSP 70 family as compared to untreated fruit. MeJA treatment also substantially enhanced mRNA levels of pathogenesis-related (PR)-2a, PR-2b and PR-3b. MeSA treated fruit had significantly increased accumulation of PR-2b and PR-3a mRNAs compared to the control fruit. Two transcripts, 1.5 kb and 3.5 kb, of alternative oxidase (AOX) were detected by Northern blot analysis from sweet pepper fruit stored at 0°C. Both transcripts reached maximal levels first in MeSA treated fruit, second in MeJA treated fruit and last

7

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in control fruit. These results suggest that the treatment of tomatoes and sweet peppers with MeJA or MeSA induces the synthesis of some stress proteins, such as HSP, PRproteins, and AOX, which leads to increased chilling tolerance and resistance to decay (Wang, Fung and Ding, 2005). Stomata of red hot chilli monitored under scanning electron microscopy. Stomata apertures observed only at the pedicel surface and were absolutely absent on the fruit surface. Hydro-cooled chilli at 0 and 2 oC resulted in significantly closing stomata while the same process at 4 oC was only partially closing them as compared to untreated. The darkening was significantly reduced by hydro-cooling whereas slightly decreased by forced-air cooling. These results suggest that hydro-cooling is a suitable technique for keeping the quality of red hot chili after harvest (Taksinamanee at el., 2006)[a]. Exporting of fresh chilli faces a big problem especially the darkening at pedicel. Chillies hydro-cooled at 0 oC were packed in plastic tray wrapped with 15 μm polyvinylchloride (PVC) film, 70 µm polyethylene (PE) bag and shell clam PE box then stored at 5ºC. Hydro-cooled chilli and packed in plastic packaging maintained the fruit firmness higher than control. However, there were no consistency patterns of changes in ascorbate peroxidase activity during storage of red hot chilli in each treatment. The overall quality of red hot chilli was highest in hydro-cooled chilli kept in shall clam PE box (Taksinamanee et al., 2006)[b]. If red sweet peppers (Capsicum annuum L.) stored for 21 days packaged in low density polyethylene (LDPE), unpackaged and hot water dipping (53 oC for 4 min.) then packaged in low density polyethylene. HWD and packaged treatments were performed best as compared to unpackaged one. The weight loss was less than 1 % in packaged and 10 % in unpackaged. HWD had no significant effect on the quality of fruits (Raffo et al., 2006). The harvested tomatoes were stored at 7, 15 and 25 oC, for a period of 10 days. The soluble phenolics and ascorbic acid contents of tomatoes showed slight increases during storage, regardless of temperature. The mean lycopene content of tomatoes stored at 15 and 25 oC on the 10th day of storage was, approximately, 2-fold (7.5 mg/100 g) than of the tomatoes stored at 7 oC (3.2 mg/100 g). The soluble antioxidant activity increased from 17–27% during the storage period of tomatoes (Ramandeep and Geoffrey, 2006). Peppers harvested at green stage and stored at 22 oC for only 10 days. If harvested at green ripe stage and stored at 22 oC, they stored for only 5 days. Green ripe fruits stored at 7 oC in perforated polyethylene bags maintained their shelf life for 20 days. Result indicated that optimum ripeness stage for harvest was green ripe as the peppers develop enhanced quality characteristics at this stage (González et al., 2005). There are no data for (Xanthomonas vesicatoria) and (Vermicularia capsici) but provided that CO2 is absent, the growth of other organism is suppressed by [O2] present in 7-13 oC water saturated air at pressure of 2.0-2.7 kPa. This low pressure range should be tested at non-chilling temperature as high as 12-13 oC to determine if decay in peppers can be controlled without causing low-[O2] or low-temperature injury. Peppers tolerated a 2-day exposure to a pressure of 2.67 kPa at 10 oC with no adverse effects (Burg, 2004), but longer exposure The storage of peppers was improved by treatments that restrict water loss, including pre-packaging in perforated polyethylene, modified atmospheric packaging and waxing (Hughes el al., 1981; Hardenburg et al., 1986).

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Packaging system was used to compare the atmospheric composition within sealed packs containing tomato fruits. The films used were 20 micron (PE20) and 50 micron (PE50) polyethylene, 10 micron polyvinylcholoride (PVC) and 25 micron polypropylene (PP) compared with unwrapped fruit as a control. Sealed packaging, especially using with PE50 and PP films, delayed the development of the red color of tomatoes until 30 days of storage and those tomatoes were also still very firm even after 60 days of storage. Tomatoes sealed within PE50 and PP films had also the lowest weight loss and the highest soluble solids after 60 days of storage (Batu and Thompson, 1998). Control atmospheres containing 2-5% oxygen and 10% carbon dioxide slightly extend storage life. Less than 2% oxygen causes low carbon dioxide damage, and more than 2-10% carbon dioxide eventually causes calyx discoloration (Hatton el al., 1975; Dilley, 1978; Leshuk and Saltveit, 1990). Bell pepper (C. annuum L.) at three maturation stages, were evaluated sensorily on flavor attributes. Green bell peppers scored mainly on the attributes bitterness, grassy and green bell pepper aroma, whereas the attributes sweetness, sourness, and red bell pepper aroma were distinctive for the red ones. Sugars and organic acids were determined by high performance liquid chromatography (HPLC); fructose, glucose, total sugar, and dry matter content were related to the attribute sweetness in the red maturation stage. Citric and ascorbic acid, as well as calculated concentrations of undissociated ascorbic and dissociated citric 1 and citric 2, showed close relationships with the attribute sourness. Moreover, pH and HPLC concentrations of malic, oxalic, fumaric, and pyroglutamic acid and calculated contents of dissociated malic 2, pyroglutamic 1, and oxalic 2 appeared to be negatively related with sourness (Luning et al., 1994). The main post harvest storage diseases of peppers are alternaria rot (Alternaria tenuis), anthracnose (Collectrotricum gloeosporioides), bacterial soft rot (Erwinia carotovora), Cladosporium rot (Collectrotricum herbarum), grey mould rot (Botrytis cinerea), bacterial spot (Xanthomonos versicatoria), phoma rot (Phoma destructor), sunken spot (Vermicularia capsici) and rhizopus rot (Rhizopus stolonifer) (McColloch et al., 1966; Ryall and Lipton, 1972; Eckert et al., 1975; Hardenburg et al., 1986). Chilling damage occurs below 7 oC (Hardenburg et al., 1986), and sometimes at less than 11.1-12.8 oC (Pushka and Srivastava, 1963). Chilling damage occurred at 7 oC in low pressure (LP), but only became apparent 1-2 days after peppers were removed (Burge, 1976a). No benefit resulted when pepper cultivar ‘Bellboy’ was stored at 8.8 oC in controlled atmospheric storage at 2% [O2] supplemented with 0, 3, 6 or 9% [CO2], or in LP at 20.3, 10.1 and 5.1 kPa, (Hughes et al., 1981). Normal atmospheric storage was compared to low pressure storage at pressure of 2.0, 5.3 and 10.7 Kpa. Peppers stored in normal atmospheric storage were pre-treated with chlorine and/or Benlate; the remainder and all peppers stored in low pressure storage were untreated and unwaxed. After 50 days, the percentage of saleable peppers was 80% at 5.3 kPa, 87% at 5.3-10.7 kPa, 47% at 2 kPa respectively; and none in normal atmospheric storage regardless of the pre-treatment (Jamieson, 1980). Direct relationship was found between ascorbic acid content and capsicum maturity. Total pigment contents increased between two and seventy fold as the result of transition from the immature to the fully ripe condition (Rahman et al., 1978). The storage temperature was not specified. Excellent results with peppers stored

9

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at 10.13 kPa (76 mm Hg) were reported by Staby (1976a). Low pressure storage was limited by decay. Respiration was reduced by as much as 67-75% at low pressure storage (Bangerth, 1974). Peppers began to deteriorate after 16 days in normal atmosphere were in poor condition by 21 days. Those kept at a pressure of 10.7 kPa were still in excellent conditions after 28 days, while at 6.7 and 16.0 kPa they were only in fair condition. Peppers were marketable with excellent taste and quality after 46 days in low pressure storage at 10.7 kPa, except for a trace of mould, which appeared on stem ends. Storage was limited by decay. A chlorine rinse prior to storage reduced the incidence of decay and a Benlate dip was effective for up to 7 weeks during low pressure storage. Storage of peppers in normal atmosphere and in low pressure storage at a pressure of 10 kPa was compared during a 23-day test at 10-12 oC. The peppers remained firmer and greener in low pressure with slightly higher ascorbic acid contents and significantly lower ethylene production (Bangerth, 1973). Non-waxed peppers were stored at 7.2 oC either in normal atmosphere or in low pressure storage at pressure of 6.7, 10.7or 16.0 kPa (Burg, 1970). Ripening limits the normal atmosphere (NA) storage of green peppers at 7.2-10 0 C for 2-3 weeks which is very good time to transport the green chillies for distant market within the country and abroad (Lutz and Hardenburg, 1968). At atmospheric pressure, film wrapping reduced wastage, mainly due to less water loss, while storage in 2% [O2] + 6% [CO2] resulted in a significant increase in decay during subsequent shelf life at 20 oC. Weight loss in LP was at least five times higher per day compared to normal atmosphere, and 7-10 times greater than that needed to remove respiratory heat by evaporative cooling indicated that the humidity was not properly maintained in this low pressure storage study. PACKAGING MATERIALS Pepper fruit were harvested at three ripeness stages: green; green ripe; and beginning changing to orange. Samples of all three stages were stored at room temperature (22°C) and evaluations made of quality changes to the fruit during a 15 day period. Ripe green peppers were stored at 7°C over a 35 day period in perforated polyethylene bags. Results indicate that optimum ripeness stage for harvest is green ripe as the peppers develop enhanced quality characteristics and have a longer, 10 day, shelf life at 22°C. Peak chilli quality under storage conditions was attained using refrigeration of green ripe fruits for 20 days followed by ripening for 5 days at 22°C (González et al., 2005). CHILLING INJURY Lutz and Hardenburg (1968) studies that ripening limits the normal atmosphere (NA) storage of green peppers to 2-3 weeks at 7.2-10 °C. Chilling damage occurs below 7 °C (Hardenburg et al., 1986), and sometimes at less than 11.1-12.8 °C (Pushka and Srivastava, 1963). Chilling damage occurred at 7 °C in low pressure (LP), but only became apparent 1-2 days after peppers were removed (Burge, 1976a) CA atmospheres containing 2-5% [O2] + 2-10% [CO2] slightly extend storage life. Less than 2% [O2] causes low [O2] damage, and more than 2-10% [CO2] eventually causes calyx discoloration (Hatton et al., 1975; Dilley, 1978; Leshuk and Saltveit, 1990).

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PACKAGING The storage of peppers was improved by treatments that restrict water loss, including pre-packaging in perforated polyethylene, MA packaging and waxing (Hughes et al., 1981; Hardenburg et al., 1986). Ali and Keith (1998) performed an experiment on packaging system was used to compare the atmospheric composition within sealed packs containing tomato fruits. The films used were 20 micron (PE20) and 50 micron (PE50) polyethylene, 10 micron polyvinylcholoride (PVC) or 25 micron polypropylene (PP) compared with unwrapped fruit as a control. Sealed packaging, especially using with PE50 and PP films, delayed the development of the red color of tomatoes until 30 days of storage and those tomatoes were also still very firm even after 60 days of storage. Tomatoes sealed within PE50 and PP films had also the lowest weight loss and the highest soluble solids after 60 days of storage. Non-waxed peppers were stored at 7.2 °C either in NA or in LP at pressure at 6.7, 10.7or 16.0 kPa 50, 80 or 120 mm Hg (Burg, 1970). Peppers began to deteriorate after 16 days in NA were in poor condition by 21 days. Those kept at a pressure of 12.7 kPa (80 mm Hg) were still in excellent conditions after 28 days, while at 6.7 and 16.0 kPa (50 and 120 mm Hg) they were only in fair condition. Peppers were marketable with excellent taste and quality after 46 days’ LP storage at 12.7 kPa (80 mm Hg), except for a trace of mould, which appeared on stem ends. Storage was limited by decay. A chlorine rinse prior to storage reduced the incidence of decay, and a Benlate dip was effective for up to 7 weeks during LP storage. Storage of Neusiedler Ideal peppers in NA and in LP at a pressure of 10 kPa (75 mm Hg) was compared during a 23-day test at 10-12 °C. The peppers remained firmer and greener in LP with slightly higher ascorbic acid contents and significantly lower ethylene production (Bangerth, 1973). LP storage was limited by decay. Respiration was reduced by as much as 67-75% at a low pressure (Bangerth, 1974). NA storage was compared to LP at lower pressure, 2.0, 5.3 and 10.7 Kpa (20, 40 and 80 mm Hg), in laboratory tests run by Grumman Allied Industries. Some of the peppers stored in NA were pre-treated with chlorine and/ or Benlate; the remainder and all peppers stored in LP were untreated and unwaxed. After 50 days, the percentage of saleable peppers was 80-87% at 5.3-10.7 kPa (40-80 mm Hg), respectively; 47% at 2 kPa (15 mm Hg); and none in NA regardless of the pre-treatment (Jamieson, 1980a). The storage temperature was not specified. Excellent results with peppers stored at 10.13 kPa (76 mm Hg) were reported by Staby (1976a). Hughes et al. (1981) reported that no benefit resulted when pepper cultivar ‘Bellboy’ was stored at 8.8 °C in CA at 2% [O2] supplemented with 0, 3, 6 or 9% [CO2], or in LP at 20.3, 10.1 and 5.1 kPa 9152, 76 and 38 mm Hg). At atmospheric pressure, film wrapping reduced wastage, mainly due to less water loss, while storage in 2% [O2] + 6% [CO2] resulted in a significant increase in decay during subsequent shelf life at 20 °C. Weight loss in LP was at least five times higher per day compared to NA, and 7-10 times greater than that needed to remove respiratory heat by evaporative cooling indicated that the humidity was not properly maintained in this LP study.

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Ramandeep and Geoffrey, (2006) studied that nutritional implication of storage on tomatoes. The harvested tomatoes were stored at 7, 15 and 25 °C, for a period of 10 days. The soluble phenolics and ascorbic acid contents of tomatoes showed slight increases during storage, regardless of temperature. The mean lycopene content of tomatoes stored at 15 and 25 °C on the 10th day of storage was, approximately, 2-fold (7.5 mg/ 100 g) than of the tomatoes stored at 7 °C (3.2 mg/100 g). The soluble antioxidant activity increased from 17–27% during the storage period of tomatoes. POSTHARVEST DISEASES The main storage disease of peppers are alternaria rot (A. tenuis), anthracnose (C. gloeosporioides), bacterial soft rot (E. carotovora), Cladosporium rot (C. herbarum), grey mould rot (B. cinerea), bacterial spot (X. versicatoria), phoma rot (Phoma destructor), sunken spot (Vermicularia capsici) and rhizopus rot (Rhizopus stolonifer) (McColloch et al., 1966; Ryall and Lipton, 1972; Eckert et al., 1975; Hardenburg et al., 1986). There are no data for X. vesicatoria and V. capsici, but provided that CO 2 is absent, the growth of other organism is suppressed by the [O 2] present in 7-13 °C watersaturated air at pressure of 2.0-2.7 kPa (15-20 mm Hg). This low pressure range should be tested at non-chilling temperature as high as 12-13 °C to determine if decay in peppers can be controlled without causing low-[O2] or low-temperature injury. Peppers tolerated a 2-day exposure to a pressure of 2.67 kPa (20 mm Hg) at 10 °C with no adverse effects (Burg, 2004), but longer exposure periods and higher temperatures have not yet been tested. SODIUM HYPOCHLORITE Green bell peppers were collected in bags and treated with 0, 5, 10, 20, and 50 mg L-1 ClO2 gas at 10 ± 0.5 °C for over 40 days, and the changes in postharvest physiology and preservation quality of the peppers were evaluated during the storage. The rot rates of the treated samples were 50 % lesser than those of the control after 40 days of storage. The highest inhibitory effect was obtained after 50 mg L-1 ClO2 gas treatment, where the peppers did not decay until day 30 and showed only one-fourth of the rot rate of the control at day 40 of storage. The respiratory activity of the peppers was significantly inhibited by 20 and 50 mg L-1 ClO2 treatments, whereas no significant effects on respiratory activity were observed with 5 and 10 mg L-1ClO2 treatments. Except for 50 mg L-1 ClO2, malondialdenyde (MDA) contents in the peppers treated with 5, 10, or 20 mg L-1 ClO2 were not significantly different from those in the control (Du et al., 2007). The effects of treatment of chlorine dioxide (CIO2) gas on postharvest physiology and preservation quality of green bell peppers were studied. Green bell peppers were collected in bags and treated with 0, 5, 10, 20, and 50 mg L−1 CIO2 gas at 10 ± 0.5 °C for over 40 days, and the changes in postharvest physiology and preservation quality of the peppers were evaluated during the storage. The inhibition of rot of the peppers was observed for all the tested CIO2 gas treatments. The rot rates of the treated samples were 50% lesser than those of the control after 40 days of storage. The highest inhibitory effect was obtained after 50 mg L−1 CIO2 gas treatment, where the peppers did not decay until 30 days and showed only one-fourth of the rot rate of the control at 40 days of storage.

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The respiratory activity of the peppers was significantly (P<0.05) inhibited by 20 and 50 mg L−1 CIO2 treatments, whereas no significant effects on respiratory activity were observed with 5 and 10 mg L−1 CIO2 treatments (P>0.05). Except for 50 mg L−1 CIO2, malondialdenyde (MDA) contents in the peppers treated with 5, 10, or 20 mg L −1 CIO2 were not significantly (P>0.05) different from those in the control. Degradation of chlorophyll in the peppers was delayed by 5 mg L−1 CIO2, but promoted by 10, 20, or 50 mg L−1 CIO2. The vitamin C content, titratable acidity and total soluble solids of the peppers treated by all the tested CIO2 gas did not significantly change during the storage. The results suggested that CIO2 gas treatment effectively delayed the postharvest physiological transformation of green peppers, inhibited decay and respiration, maintained some nutritional and sensory quality, and retarded MDA accumulation. In perspective of breeding high-yield hybrid pepper varieties, combining ability analysis of net photosynthesis rate at different phases of flowering and fruit setting in pepper was made with 15 cross combinations from 6 parents by (1/2) n (n-1) diallel crosses. There are relatively large differences not only in general combining ability (GCA) effect among different parents and at different phases of flowering and fruit setting, but also in specific combining ability (SCA) effect among different hybrids. There are relatively large GCA effects in late parents but relatively less GCA effects in early parents. No obvious laws have been found in the relationship between SCA effects and maturity of hybrids. Variances of SCA are larger than those of GCA. Heritability is less but influence of environment is larger. Correlation analysis of combining ability between net photosynthesis rate and agronomic character or resistances to main diseases has showed that correlation coefficients of GCA are relatively large at the medium phase and the late phase of flowering and fruit setting. Net photosynthesis rate is more relative to leaf characters and fruit characters. Correlation coefficients of SCA are relatively large at the early phase and the late phase of flowering and fruit setting. Net photosynthesis rate is more relative to leaf characters and plant characters at the early phase but to plant characters and fruit characters at the late phase. Correlation coefficients of SCA between net photosynthesis rate and resistances to main diseases are larger than those of GCA. The combining abilities of net photosynthesis rate at different phases of flowering and fruit setting are positively correlated with those of yield per plant. The combining ability is an important parameter of breeding of high photosynthesis hybrid pepper varieties. The respiration rates of fresh-cut bell peppers under diverse high and low O 2 levels, with or without 20 kPa CO2, at 2, 7 and 14 °C, were studied. Weight loss and offodor development were also monitored. A constant respiration rate of pepper dices throughout 3 days under different conditions was found. Fresh-cut peppers exposed to 0, 0.5, 1, 3 and 9 kPa O2 (all CO2-free), and to 0 kPa O2 + 20 kPa CO2, had a lower respiration rate than peppers in the range 20–100 kPa O2 with or without CO2. Under high O2, 20 kPa CO2 increased the respiration rate by about 20–40% compared to that in freeCO2 atmospheres, this effect being lower at low temperature. High O2 had little (at 14 °C) or no effect (at 2 and 7 °C) in stimulating both CO2 production and O2 consumption compared to normal air. High CO2 in the range 20–100 kPa O2 increased the respiratory activity of pepper dices, probably because physiological injury occurred at 14 °C. However, 20 kPa CO2 combined with superatmospheric O2 neither induced a poor visual appearance nor off-odors. Consequently 50–80 kPa O2 combined with 20 kPa CO2 could

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be used in innovative modified atmosphere packaging of pepper dices to avoid fermentation and inhibit growth of spoilage microorganisms. Chilling Injury Occurrence (Lutz and Hardenburg, 1968) studies that ripening limits the NA storage of green peppers to 2-3 weeks at 7.2-10 °C. Chilling damage occurs below 7 °C (Hardenburg et al., 1986), and sometimes at less than 11.1-12.8 °C (Pushka and Srivastava, 1963). Chilling damage occurred at 7 °C in LP, but only became apparent 1-2 days after peppers were removed (Burge, 1976a). WATER LOSS MECHANISM Stomata of red hot chilli were monitored under scanning electron microscopy. Stomata apertures were observed only at the pedicel surface and were absolutely absent on the fruit surface. Hydro-cooled chilli at 0 and 2 oC resulted in significantly closing stomata while the same process at 4 oC was only partially closing them. The darkening was significantly reduced by hydro-cooling whereas slightly decreased by forced-air cooling. These results suggest that hydro-cooling is a suitable technique for keeping the quality of red hot chili after harvest (Taksinamanee at el., 2006)[a]. Exporting of fresh chilli faces a big problem especially the darkening at pedicel. The darkening disorder at pedicel of hot chili mainly causes by a water loss from stomata apertures. From this problem, hydro-cooling in combination with package for extending the fresh quality of red hot chili was investigated. The chili fruit were selected for uniformity of size and color then hydro-cooled at 0 ºC. Pre-cooled chillies were packed in plastic tray wrapped with 15 μm polyvinylchloride (PVC) film, 70 µm polyethylene (PE) bag and shell clam PE box then stored at 5 ºC. Non pre-cooled and unpacked chili fruit was set as a control treatment. Weight loss of hydro-cooled chilli and packed in all kind of packages significantly decreased as compared to control fruit. There was only slightly difference in water loss among packaging treatments. Hydro-cooled chilli and packed in plastic packaging maintained the fruit firmness higher than control. However, there were no consistency patterns of changes in ascorbate peroxidase activity during storage of red hot chilli in each treatment. The overall quality of red hot chilli was highest in hydrocooled chilli kept in shall clam PE box (Taksinamanee at el., 2006)[b]. Physical (weight, firmness) and compositional (sugars, organic acids, ascorbic acid, phenolic compounds and carotenoids) changes of red sweet peppers (Capsicum annuum L.) were monitored during 21 days of cold storage (at 7.5 °C); fruits were stored without packaging, packaged in low density polyethylene bags, after hot water dipping (53 °C for 4 min) and then packaging. Packaging prevented water loss, and preserved the firmness of the fresh product. Sugars (fructose and glucose) content was practically constant throughout the whole storage time, for all treatments. A moderate accumulation of citric acid was observed during storage, but no marked effects of packaging and hot water dipping on citric and malic acid content. Ascorbic acid content slightly increased in unpackaged and packaged fruits, but not in treated+packaged peppers. Hydroxycinnamics total content seemed not to be affected by cold storage, packaging or hot water treatment, whereas glycosylated flavonoids showed somewhat lowered levels during storage, particularly in the case of unpackaged and packaged+treated fruits. Regarding carotenoids content, the effect of the considered storage conditions seemed to be much

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smaller than that due to ripening stage. Provitamin A content showed an increasing trend in unpackaged and packaged fruits; packaged+treated peppers were characterized by a lower retention of provitamin A and a higher level of capsanthin and cucurbitaxanthin A with respect to not treated fruits. On the whole, packaging and hot water treatment did not produce noticeable adverse effects on the majority of the examined compositional quality parameters (Raffo et al., 2006). Quantitative variations in total solids, ascorbic acid and total pigment content of fifteen capsicum cultivars grown under field conditions were assessed. A progressive increase of total solids was found in all cultivars at all stages of fruit maturation and ripening. A direct relationship was found between ascorbic acid content and capsicum maturity. Total pigment contents increased between two and seventy fold as the result of transition from the immature to the fully ripe condition (Rahman et al.,1978). Bell pepper (C. annuum cv. Mazurka and cv. Evident), at three maturation stages, were evaluated sensorily on flavor attributes. Green bell peppers scored mainly on the attributes bitterness, grassy, cucumber, and green bell pepper aroma. Sugars and organic acids were determined by high performance liquid chromatography (HPLC), and concentrations of different ions of the acids were calculated from their dissociation equilibria. Principal Component Analysis (PCA) demonstrated that HPLC data of fructose, glucose, total sugar, and dry matter content were related to the attribute sweetness in the red maturation stage. HPLC concentrations of citric and ascorbic acid, as well as calculated concentrations of undissociated ascorbic and dissociated citric 1 and citric 2, showed close relationships with the attribute sourness. Moreover, pH and HPLC concentrations of malic, oxalic, fumaric, and pyroglutamic acid and calculated contents of dissociated malic 2, pyroglutamic 1, and oxalic 2 appeared to be negatively related with sourness (Luning et al., 1994).

PHENOLIC COMPOUNDS Peppers also contain various phenolics and flavonoids (Materska & Perucka 2005). These compounds served as antioxidants (Harborne & Williams 2000) as well as performed plant defense mechanism against any extraneous agents (Delgado-Vargas & Paredes-Lopez 2003) and can reduce harmful oxidation reactions in human body; thus consumption of peppers may prevent various diseases associated with free radical oxidation, such as cardiovascular disease, cancer, and neurological disorders (Shetty 2004). A wide variety of phenolic substances derived from spice possess potent antimutagenic and anticarcinogenic activities. Curcumin, a yellow colouring agent, contained in turmeric (Curcuma longa L., Zingiberaceae), [6]-gingerol, a pungent ingredient present in ginger (Zingiber officinale Roscoe, Zingiberaceae) and capsaicin, a principal pungent principle of hot chilli pepper (Capsicum annuum L. Solanaceae). The chemopreventive effects exerted by these phytochemicals are often associated with their antioxidative and anti-inflammatory activities. Cyclo-oxygenase-2 (COX-2) has been recognized as a molecular target of many chemopreventive as well as anti-inflammatory agents (Surh, 2002).

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(Capsicum annuum L., Solanaceae)

(Cucurma longa L., Zingiberaceae)

(Zingibel officinale Roscoe, Zingiberaceae)

COLOR Green, yellow, orange, and red bell peppers are commonly available in markets and green bell pepper is the most produced and consumed one (Frank et al., 2001). The color of sweet bell peppers is the major factor associated with the consumer purchasing decisions. Besides color, differences in common nutrient compositions of different colored peppers have been reported, such as the content of vitamin C (Simonne et al., 1997; Frank et al., 2001). The yellow-orange color of peppers is formed by α-and β-carotene, zeaxanthin, lutein, and β-cryptoxanthin (Howard, 2001). The red color of peppers is due to the presence of carotenoid pigments of capsanthin, capsorubin and capsanthin 5, 6-epoxide. The different colors of peppers may be due to different levels of those compounds. As those compounds have antioxidant function, the different colors of bell peppers may have different antioxidant activity.

ABIOTIC STRESS TOLERANCE Abiotic stresses, including drought, high salinity and extreme temperatures, greatly impair the growth and development of soil plants. Among these abiotic stresses, drought or water deficit is the most severe environmental factor responsible for the reduction of crop yield in many parts of the world. A number of genetic and cellular events that occur under such stress have been widely documented (Zhu, 2002; Bray, 1997).

STRUCTURE OF CAPSAICIN PRESENT IN CHILLIES

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Chemical structure of Capsaicin (trans-8-methyl-N-vanillyl-6-nonenamide).

GENERAL USES Peppers are eaten raw in salads and salsa, processed by canning, freezing, pickling, and dehydrated and powdered to produce paprika and chili powder. Unlike the U.S., most European paprika is mildly pungent. Chili powder prepared at different levels of pungency is usually comprised of ground, dried, pungent peppers mixed with other spices, such as oregano, cumin, and garlic. Various pepper forms, usually chili types, are extensively used in combination with other spices such as turmeric, cumin, and coriander to produce curry powder, the pungency of which depends on the pepper cultivars used. For instance, Cayenne powder is a high-pungency condiment produced from dried mature fruit of cayenne-type cultivars

QUALITY CHARACTERISTICS AND CRITERIA Good quality sweet bell peppers should be of uniform shape, size and color typical of the variety. The flesh (pericarp) should be firm, relatively thick with a bright skin color and sweet flavor, and free from defects such as cracks, decay, and sunburn. Peppers that are shriveled and dull-looking or pitted should be avoided. The same quality criteria apply to fresh chili peppers. Dry lines or striations across the skin indicate a hotter pepper. These lines are not an indication of poor quality.

HORTICULTURAL MATURITY INDICES Criteria for the maturity of green peppers include fruit size, firmness, and color. For colored peppers the additional criteria of having a minimum of 50% coloration is important. Chilli peppers are harvested by hand. They are generally picked when ripe and then dried and allowed to equilibrate in moisture content in covered piles. The major peppers dried are hot red peppers for cayenne and occasionally pimientos for paprika. The pods may be sliced before drying. This shortens drying time and improves color and flavor. Seeds may be removed by screening and water sprays. Whole peppers are also dried until brittle and the seeds/pulp are completely dry. The dried product is used in flavoring and improving the appearance of various products, included canned products. Some sliced peppers are partially dried and mixed with salt for preservation for ultimate use in various processed products. The growth and harvest index of 472 accessions (selected for adaptability and productivity) belonging to 4 types of chilli pepper were evaluated in Colombia. Recently set fruits with ovaries that still had not passed the apex of the calyx were identified and harvested twice a week. The physiological and chemical variables of these fruits were evaluated during unripe, physiological maturity and maturity stages. Fruits from CS-032 (Capsicum annuum) required 46 days to reach maturity, which was higher compared to other accessions (35-38 days). Most accessions showed non-climatic behaviour, except fruits from CS-170 (C. baccatum). (Méndez et al., 2004).

GRADES, SIZES AND PACKAGING Grades for fresh sweet bell peppers include U.S. Fancy, U.S. No.1 and U.S. No. 2. 17

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Not all sweet peppers are graded; ungraded peppers are “unclassified.” Differences between grades are based primarily on external appearance. Sizes include Small, Medium, Large, and Extra Large/Jumbo. Cardboard boxes commonly hold 6.8 to 15.9 kg (15 to 35 lb) of randomly packed peppers. Very high quality peppers are often marketed in 5 kg (11 lb) flat cartons with one or two layers of fruit. There are no U.S. grades for chili peppers.

OPTIMUM STORAGE CONDITIONS Fresh peppers can be kept for 2 to 3 weeks at 7 °C with 90 to 95% RH. Storagelife can be extended another week by packaging in moisture-retentive films at 7 to 10 °C. Peppers are subject to chilling injury when stored below 7 °C and to accelerated ripening and bacterial soft rot when stored above 13 °C. Storage at 5 °C reduces water loss and ripening, but after 2 weeks chilling injury will appear. Some pepper cultivars can be sensitive to chilling if stored at 7 °C, so a good storage temperature range should be 7 °C to 13 °C.

CURRENT TREND IN FOOD During the past decade, it has been reported that the consumption of certain foods may have a positive effect on an individual’s health. Foodstuffs supply not only energy, essential amino acids, fiber, vitamins, and minerals but also some active compounds such as antioxidants (tocopherols, carotenoids, vitamin C, phenolic compounds, etc.) that may have different beneficial functions in the body. Dietary components, which are capable of acting as antioxidants, are likely to be beneficial by augmenting cellular defenses and protecting the cell against damage caused by free radicals, by acting as radical scavengers, reducing agents, potential complexes of prooxidant metals, and quenchers of singlet oxygen formation (Doblado et al., 2005; Oboh, 2005, 2006). Genotoxicity studies evaluating capsaicin effects are sparse and contradictory. While some studies demonstrated a marked mutagenic and genotoxic activity of the compound in the presence or absence of an external metabolic activation system, others failed to provide evidence for its genotoxic potential (Surh & Lee, 1996). Carcinogenicity studies in mice demonstrated that capsaicin can induce duodenal adenocarcinomas (Toth, Rogan & Walker, 1994; Toth, Rogan, Walker, 2002) and act as a promoter of stomach and liver tumors (Agrawal et al., 1986). Conversely, other studies pointed out for antimutagenic, antigenotoxic and anticarcinogenic proprieties of capsaicin (reviewed in (Surh & Lee, 1996; Surah, 1999). Epidemiological studies have yielded contradictory results for the association of chilli pepper consumption and cancer. A Mexican case-control study from found that chilli pepper is a strong risk factor for gastric cancer. Chilli pepper consumers were at 5.5-fold greater risk for gastric cancer than non-consumers and persons who rated themselves as heavy consumers of chilli were at 17-fold greater risk (López-Carrillo et al. 1994). An earlier study carried out in Italy, however, revealed a protective effect of chilli on the relative risk of gastric cancer (Buiatti et al., 1989).

CURRENT STUATUS IN PAKSITAN In Pakistan its cultivation is on an area of 38.4 thousand hectares with 90.4 thousand 18

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tones of production (Govt. of Pakistan, 2005), mainly grown in Sindh as a major kharif crop. Its production not only fulfils 88 percent of the country’s requirement but also helps in earning foreign exchange. Pakistan earned 3.2 million dollar during 2004-05 by exporting red chillies to Middle East, USA and other European countries (Govt. of Pakistan, 2004-05). The Pakistan export of chillies had been due to detection of aflatoxin in red powder by the Portuguese food authorities (Russel and Peterson, 2007). Due to this threat hot pepper international trade market for Pakistan is badly vectored and even the price of hot pepper due to rejection of consignments of Pakistani hot pepper price is very much contradictory. Chillies production in Pakistan has been decreased 49.6% (Govt. of Pakistan, 2006) due to several types of biotic and abiotic stresses. Controlled Atmosphere Storage (CA-Storage) CA atmospheres containing 2-5% [O2] + 2-10% [CO2] slightly extend storage life. Less than 2% [O2] causes low [O2] damage, and more than 2-10% [CO2] eventually causes calyx discoloration (Hatton el al., 1975; Dilley, 1978; Leshuk and Saltveit, 1990). Behavior of Pepper in Different Packaging Materials The storage of peppers is improving by treatments that restrict water loss, including pre-packaging in perforated polyethylene, MA packaging and waxing (Hughes el al., 1981; Hardenburg et al., 1986). Ali and Keith (1998) performed an experiment on packaging system was used to compare the atmospheric composition within sealed packs containing tomato fruits. The films used were 20 micron (PE20) and 50 micron (PE50) polyethylene, 10 micron polyvinylcholoride (PVC) or 25 micron polypropylene (PP) compared with unwrapped fruit as a control. Sealed packaging, especially using with PE50 and PP films, delayed the development of the red color of tomatoes until 30 days of storage and those tomatoes were also still very firm even after 60 days of storage. Tomatoes sealed within PE50 and PP films had also the lowest weight loss and the highest soluble solids after 60 days of storage. Waxing on Fresh Peppers Non-waxed peppers were stored at 7.2 °C either in NA or in LP at pressure at 6.7, 10.7or 16.0 kPa 50, 80 or 120 mm Hg (Burg, 1970). Peppers began to deteriorate after 16 days in NA were in poor condition by 21 days. Those kept at a pressure of 12.7 kPa (80 mm Hg) were still in excellent conditions after 28 days, while at 6.7 and 16.0 kPa (50 and 120 mm Hg) they were only in fair condition. Peppers were marketable with excellent taste and quality after 46 days’ LP storage at 12.7 kPa (80 mm Hg), except for a trace of mould, which appeared on stem ends. Storage was limited by decay. A chlorine rinse prior to storage reduced the incidence of decay, and a Benlate dip was effective for up to 7 weeks during LP storage. Low Pressure Storage (LP-Storage) Storage of peppers in NA and in LP at a pressure of 10 kPa (75 mm Hg) was compared during a 23 days test at 10-12 °C. The peppers remained firmer and greener in

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LP with slightly higher ascorbic acid contents and significantly lower ethylene production (Bangerth, 1973).LP storage was limited by decay. Respiration was reduced by as much as 67-75% at a low pressure (Bangerth, 1974). NA storage was compared to LP at lower pressure, 2.0, 5.3 and 10.7 Kpa (20, 40 and 80 mm Hg), in laboratory tests run by Grumman Allied Industries. Some of the peppers stored in NA were pre-treated with chlorine and/ or Benlate; the remainder and all peppers stored in LP were untreated and unwaxed. After 50 days, the percentage of saleable peppers was 80-87% at 5.3-10.7 kPa (40-80 mm Hg), respectively; 47% at 2 kPa (15 mm Hg); and none in NA regardless of the pre-treatment (Jamieson, 1980). The storage temperature was not specified. Excellent results with peppers stored at 10.13 kPa (76 mm Hg) were reported by Staby (1976a). Hughes et al. (1981) reported that no benefit resulted when pepper cultivar ‘Bellboy’ was stored at 8.8 °C in CA at 2% [O2] supplemented with 0, 3, 6 or 9% [CO2], or in LP at 20.3, 10.1 and 5.1 kPa 9152, 76 and 38 mm Hg). Normal Atmosphere Storage (NA-Storage) At atmospheric pressure, film wrapping reduced wastage, mainly due to less water loss, while storage in 2% [O2] + 6% [CO2] resulted in a significant increase in decay during subsequent shelf life at 20 °C. Weight loss in LP was at least five times higher per day compared to NA, and 7-10 times greater than that needed to remove respiratory heat by evaporative cooling indicated that the humidity was not properly maintained in this LP study. Ramandeep and Geoffrey, (2006) studied that nutritional implication of storage on tomatoes. The harvested tomatoes were stored at 7, 15 and 25 °C for a period of 10 days. The soluble phenolics and ascorbic acid contents of tomatoes showed slight increases during storage, regardless of temperature. The mean lycopene content of tomatoes stored at 15 and 25 °C on the 10th day of storage was, approximately, 2-fold (7.5 mg/ 100 g) than of the tomatoes stored at 7 °C (3.2 mg/100 g). The soluble antioxidant activity increased from 17–27 % during the storage period of tomatoes. Storage Diseases of Peppers The main storage disease of peppers are alternaria rot (A. tenuis), anthracnose (C. gloeosporioides), bacterial soft rot (E. carotovora), Cladosporium rot (C. herbarum), grey mould rot (B. cinerea), bacterial spot (X. versicatoria), phoma rot (Phoma destructor), sunken spot (Vermicularia capsici) and rhizopus rot (Rhizopus stolonifer) (McColloch et al., 1966; Ryall and Lipton, 1972; Eckert et al., 1975; Hardenburg et al., 1986). There are no data for X. vesicatoria and V. capsici, but provided that CO 2 is absent, the growth of other organism is suppressed by the [O 2] present in 7-13 °C watersaturated air at pressure of 2.0-2.7 kPa (15-20 mm Hg). This low pressure range should be tested at non-chilling temperature as high as 12-13 0C to determine if decay in peppers can be controlled without causing low-[O2] or low-temperature injury. Peppers tolerated a 2-day exposure to a pressure of 2.67 kPa (20 mm Hg) at 10 0C with no adverse effects (S.P. Burg, 2004), but longer exposure periods and higher temperatures have not yet been tested.

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Physiological Disorders of Peppers Maturity Indices Harvesting Grading and Sorting Blanching Surface Sterilization Packing Transportation Storing Ethylene Biosynthesis Ethylene controlling Scientific Name and Introduction: Pepper (Capsicum Annul, L), also called bell pepper, chili, chilies, aji, pimiento, paprika, and capsicum is a warm-season crop that is a member of the Solanaceae family. Sweet bell peppers are green at the immature stage (when most are sold) and turn red, gold, purple, orange, and/or brown as they ripen. Because sugar content increases as they ripen, colored peppers tend to be sweeter than green peppers. The most notable feature of peppers is flavor, which can be sweet, mild or strongly pungent. Sweet bell peppers are available year-round, with California Wonder being the most common cultivar. Chili peppers occur in a number of varieties that vary greatly from mild to very hot, which is determined by capsaicin content. These include: Ancho, anaheim, cayenne, cherry hot pepper, cheese, fresno (red and green), habanero (red, green and orange), jalapeno, poblano, serrano (green and red), yellow, chiltepin, cuban, long wax, new mexican, tabasco, thai, etc. Some chili peppers are dried and sold individually or tied together in ornamental arrangements. Peppers are eaten raw in salads and salsa, processed by canning, freezing, pickling, and dehydrated and powdered to produce paprika and chili powder. Unlike the U.S., most European paprika is mildly pungent. Chili powder prepared at different levels of pungency is usually comprised of ground, dried, pungent peppers mixed with other spices, such as oregano, cumin, and garlic. Various pepper forms, usually chili types, are extensively used in combination with other spices such as turmeric, cumin, and coriander to produce curry powder, the pungency of which depends on the pepper cultivars used. For instance, Cayenne powder is a high-pungency condiment produced from dried mature fruit of cayenne-type cultivars Quality Characteristics and Criteria: Good quality sweet bell peppers should be of uniform shape, size and color typical of the variety. The flesh (pericarp) should be firm, relatively thick with a bright skin color and sweet flavor, and free from defects such as cracks, decay, and sunburn. Peppers that are shriveled and dull-looking or pitted should be avoided. The same quality criteria apply to fresh chili peppers. Dry lines or striations across the skin indicate a hotter pepper. These lines are not an indication of poor quality. Horticultural Maturity Indices: Criteria for the maturity of green peppers include fruit size, firmness, and color. For colored peppers the additional criteria of having a minimum of 50% coloration is important. Chili peppers are harvested by hand. They are generally picked when ripe and then dried and allowed to equilibrate in moisture content in covered piles. The major peppers

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dried are hot red peppers for cayenne and occasionally pimientos for paprika. The pods may be sliced before drying. This shortens drying time and improves color and flavor. Seeds may be removed by screening and water sprays. Whole peppers are also dried until brittle and the seeds/pulp are completely dry. The dried product is used in flavoring and improving the appearance of various products, included canned products. Some sliced peppers are partially dried and mixed with salt for preservation for ultimate use in various processed products. Grades, Sizes and Packaging: Grades for fresh peppers include U.S. Fancy, U.S. No.1 and U.S. No. 2. Not all sweet peppers are graded; ungraded peppers are “unclassified.” Differences between grades are based primarily on external appearance. Sizes include Small, Medium, Large, and Extra Large/Jumbo. Cardboard boxes commonly hold 6.8 to 15.9 kg (15 to 35 lb) of randomly packed peppers. Very high quality peppers are often marketed in 5 kg (11 lb) flat cartons with one or two layers of fruit. There are no U.S. grades for chili peppers. Pre-cooling Conditions: After harvest, fresh market peppers should be rapidly cooled to no lower than 7 °C (45 °F) at high RH to reduce water loss and shrivel. Pre-cooling can be done using forced-air, hydro-cooling or vacuum-cooling. Properly vented cartons are required to facilitate forced-air cooling. If hydro-cooling is used, care should be taken to prevent development of decay. High RH is necessary to avoid desiccation. Waxing has been used to reduce desiccation, but it tends to increase bacterial soft rot. Shelf-life varies among different pod types. Deterioration is often due to moisture loss, with some pod types more prone to desiccation than others. Optimum Storage Conditions: Fresh peppers can be kept for 2 to 3 weeks at 7 °C (45 °F) with 90 to 95% RH. Storage-life can be extended another week by packaging in moisture-retentive films at 7 to 10 °C (45 to 50 °F). Peppers are subject to chilling injury when stored below 7 °C (45 °F) and to accelerated ripening and bacterial soft rot when stored above 13 °C (55 °F). Storage at 5 °C (41 °F) reduces water loss and ripening, but after 2 weeks chilling injury will appear. Some pepper cultivars can be sensitive to chilling if stored at 7 °C (45 °F), so a good storage temperature range should be 7 °C (45 °F) to 13 °C (55 °F). Controlled Atmospheres (CA) Considerations: Peppers derive a slight benefit from CA storage (Saltveit, 1997). Low O2 atmospheres (2 to 5% for bell and 3 to 5% for chili) retard ripening and respiration during transit and storage, and have a slight benefit on quality. At 10 °C (50 °F), high CO2 (> 5%) can cause calyx discoloration, skin pitting, discoloration and softening in both bell and chili peppers. A 3% O 2 + 5% CO2 atmosphere is more beneficial for red than green peppers stored at 5 to 10 °C (41 to 50 °F) for 3 to 4 weeks. Before processing, chili peppers can be stored under 3 to 5% O2 + 15 to 20% CO2 for up to 3 weeks at 5 °C (41 °F) without appreciable chilling injury or quality loss. Freshly harvested chili or other hot peppers should be stored under the same temperature and RH conditions as sweet peppers. Chilling Sensitivity: Peppers are sensitive to chilling injury when stored below 7 °C (45 °F). Symptoms include surface pitting, water-soaked areas, decay (especially Alternaria) and discoloration of the seed cavity. Symptoms can appear after a few days at 0 °C (32 °F) or a few weeks at 5 °C (34 °F). Sensitivity varies with cultivar; ripe or colored peppers are less chilling sensitive than green peppers.

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References: Agrawal, R.C., M. Wiessler, E. Hecker, S.V. Bhide. 1986. Tumourpromoting effect of chilli extract in BALB/c mice, Int. J. Cancer 38: 689–695. Ali B. and A.K. Thompson. 1998. Effects of Modified Atmosphere Packaging on Post Harvest Qualities of Pink Tomatoes. Turkish Journal of Agriculture and Forestry. 22: 365-372 Amakura, Y., Umino Y., Tsuji S., Ito H., Hatano T., Yoshida T. and Tonogai Y. 2002. Constituents and their antioxidative effects in eucalyptus leaf extract used as a natural food additive. Journal of Food Chemistry. 77:47–56. B. Toth, E. Rogan, B. Walker. 2002. Tumorigenicity and mutagenicity studies with capsaicin of hot peppers. S. Marques et al. / Mutation Research 517 (2002) 39–46 Bengerth F. (1974) Hypobaric storage of vegetables. Acta Horticulturae 1: 23-32 Bengerth, F. (1973). The effect of hypobaic storage on quality, physiology and storage life of fruits, vegetables and cut flowers. Gartenbauwissenschaft 38: 479-508 Ben-Yehoshua, S., B. Shapiro, J. Chen and S. Lurie. 1983. Mode of action of plastic film in extending life of lemon and bell pepper fruits by alleviation of water stress. Journal of Plant Physiology. 73:87-93. Brackett, R.E. 1990. Influence of modified atmosphere packaging on the microflora and quality of fresh bell peppers. Journal of Food Protection. 53:255-257. Bray, E.A. 1997. Plant responses to water deficit. Trends in Plant Sciences. 2: 48-54. Buiatti, E., D. Palli, A. Decarli, D. Amadori, C. Avellini, S. Bianchi, R. Biserni, F. Cipriani, P. Cocco, A. Giacosa, E. Marubini, R. Puntoni, C. Vindigni, J. Fraumeni, W. Blot. 1989. A Case-Control Study of Gastric Cancer and Diet in Italy, Int. J. Cancer 44: 611–616. Burg, S.P (2004). Postharvest Physiology and Hypobaric Storage of Fresh Produce. (ed.) CABI Publishing, Wallingford, UK. pp. 413-415 Burg, S.P. (1970) Progress Reports for United Fruits Co. Burg, S.P. (1976a). Extending the storage life of green sweet corn by means of hypobaric technology. Low Pressure Storage Systems Laboratory Research Report Cantwell, M. 1998. Bell peppers. Fresh Produce Facts website at http://postharvest.ucdavis.edu. Collins, M.D. and P.W. Bosland. (1994). Rare and novel capsaicinoid profile in Capsicum. Capsicum and Eggplant Newsletters, No. 13: 48-51 Daood, H.G., M. Vinkler, F. Markus, E.A. Hebshi & P.A. Biacs. 1996. Antioxidant vitamin content of spice red pepper (paprika) as affected by technological and varietal factors. Journal of Food Chemistry. 55: 365–372. Delgado-Vargas, F., Paredes-Lopez O. 2003. Natural colorants for food and nutraceutical Dilley, D.R. 1978. Approaches to maintenance of post harvest integrity. Journal of Food Biochemistry. 2: 235-242. Doblado, R., H. Zielinski, M. Piskula, H. Kozlowska, R. MunOz, J. Friaas. 2005. Effect of processing on the antioxidant vitamins and antioxidant capacity of Vigna sinensis Var. Carilla. Journal of Agriculture and Food Chemistry. 53(4): 1215– 1222. Doll, R. 1990. An overview of the epidemiologic evidence linking diet and cancer. Proc

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Du J., M. Fu, M. Li and W. Xia. 2007. Effects of chlorine dioxide gas on postharvest physiology and storage quality of green bell pepper (Capsicum frutescens L. var. Longrum). Journal of Agricultural Sciences in China. 6(2): 214-219 Eckert, J.W. (1975) Postharvest pathology. Part 1. General principles. In: Pantastico, E.B. (ed.) Postharvest Physiology, Handling and Utilization of Tropical and Subtropical Fruits and Vegetables. AVI, Westport, Connecticut, pp, 393-414 Frank, C.A., Nelson R.G., Simonne E.H., Behe B.K., Simonne A.H. 2001. Consumer preferences for color, price, and vitamin C content of bell peppers. Journal of Horticulture Sciences. 36: 795–800. González, M., A. Centurión, E. Sauri, and L. Latournerie. (2005). Influence of refrigerated storage on the quality and shelf life of ´habanero´ chilli peppers (Capsicum chinense Jacq.). Acta Horticulturae. (ISHS) 682:1297-1302 Gonzalez-Aguilar, G.A. and M. Tiznado. 1993. Postharvest physiology of bell peppers stored in low density polyethylene bags. Lebensm-Wiss. U-Thechnol. 26(5):450455. Govt. of Pakistan. (2006). Ministry of Food, Agriculture and Livestock. Economic Wing. pp. 12-16)[b] Govt. of Pakistan. (2007). Ministry of Food, Agriculture and Livestock, Economic Wing. pp. 25-26)[a] Greenleaf, W.H. 1986. Pepper breeding. In: Basselt, M.J. (ed.). Breeding vegetable crops. Avi Publishing, Westport, Connecticut. pp. 67-134 Gutteridge, J. M. 1993. Free radicals in disease processes: A compilation of cause and consequence. Free Radical Research Communication. 19: 141–158. Harborne, J.B., Williams C.A. 2000. Advances in flavonoid research since 1992. Journal of Phytochemistry. 55: 481–504. Hardenburg, R.E., A.E. Watada, and C.L.Wang. 1986. The Commercial Storage of Fruits, Vegetables and Florist and Nursery Stocks. USDA Agricultural Handbook No. 66 (revised). Hatton, T.T., E.B. Panstastico and E.K. Akamine. (1975) Individual commodity requirements. In: Harrd, N.F. and Salunkhe, D.K. (eds) Symposium: Postharvest Biology and Handling of Fruits and Vegetables. AVI, Westport, Connecticut, pp. 201-218 Hollman, P.C.H., Katan M.B. 1999. Dietary flavonoids: intake, health effects and bioavailability. Journal of Food Chemistry and Toxicology. 37:937–42. Hughes, P.A., Thompson, A.K., Plumbley, R.A. and Seymour, G.B. (1981) Storage of Capsicums (Capsicum annum cultivar Bellboy) under controlled atmosphere, modified atomosphere and hypobaric conditions. Journal of Horticulture Sciences. 56: 261-266 Krinsky, N.I. 2001. Carotenoids as antioxidants. Journal of Nutrition. 17: 815–817. Lee, Y., Howard L.R., and Villalon B. 1995. Flavonoids and antioxidant activity of fresh pepper (Capsicum annuum) cultivars. J. Food Sci. 60:473–6. Leshuk, J.A. and M.E. Saltveit. (1990) Controlled atmosphere storage requirements and recommendations for vegetables. In: Calderon, M. and Barkai-Golden, R. (eds) Food Preservation by Modified Atmospheres. CRC Press, Boca Raton, Florida, pp. 315-352. López-Carrillo, L., M.H. Avila, R. Dubrow. 1994. Chilli pepper consumption and gastric

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cancer in Mexico; A Case-Control Study. American Journal of Epidemiology. 139: 263–271. Luning, P.A., Harry J.W. and J.P. Roozed. (1994). Combined instrumental and sensory evaluation of flavor of fresh bell peppers (Capsicum annuum) harvested at three maturation stages. Journal of Agriculture and Food Chemistry. 42: 2855-2861 Lutz, J.M. and Hardenburg, R.E. 1986. The Commercial Storage of Fruits, Vegetables and Florist and Nursery Stocks. USDA Agricultural Handbook No. 66. Marin, A., F. Ferreres, F.A. Tomas-Barberan & M.I. Gil. 2004. Characterization and quantitation of antioxidant constituents of Sweet pepper (Capsicum annuum L.). Journal of Agriculture and Food Chemistry. 52: 3861–3869. Markus, F., H.G. Daood, J. Kapitany, & P.A. Biacs. 1999. Change in the carotenoid and antioxidant content of spice red pepper (paprika) as a function of ripening and some technological factors. Journal of Agriculture and Food Chemistry. 47, 100– 107. Materska, M. and Perucka I. 2005. Antioxidant activity of the main phenolic compounds isolated from hot pepper fruit (Capsicum annuum L.). Journal of Agriculture and Food Chemistry. 53:1750–6 Matsufuji, H., H. Nakamura, M. Chino & M. Takeda. 1998. Antioxidant activity of capsantin and the fatty acid esters in paprika (Capsicum annuum). Journal of Agriculture and Food Chemistry. 46: 3468–3472. McColloch, L.P., H.T. Cook and W.R. Wright. (1966) Market Diseases of Tomatoes, Peppers and Eggplant. USDA Agr. Handbook 28. Meir, S., Y. Rosenberger, Z. Aharon, S. Grinberg and E. Fallik. 1995. Improvement of the postharvest keeping quality and color development of bell pepper (cv. ‘Maor’) by packaging with polyethylene bags at reduced temperature. Journal of Postharvest Biology and Technology. 5:303-309. Méndez, M.A., M.S. Hernández, G.A. Ligarreto. 2004. Evaluating growth and determining harvesting index in four types of hot chilli pepper (Capsicum sp.) grown in the Colombian Amazonian Region. Agronomía Colombiana. 22(1): 7-17 Mercado, J.A., M.A. Quesada, V. Valpuerta, M. Reid and M. Cantwell. 1995. Storage of bell peppers in CA at chilling and non-chilling temperatures. Acta Horticulturae. 412:134-142. Miller, W.R. and L.A. Risse. 1986. Film wrapping to alleviate chilling injury of bell peppers during cold storage. Journal of Horticulture Sciences. 21:467-468. Miller, W.R., L.A. Risse and R.E. McDonald. 1986. Deterioration of individually wrapped and non-wrapped bell peppers during long term storage. Journal of Tropical Sciences. 26:1-8. Oboh, G. 2005. Effect of blanching on the antioxidant properties of some tropical green leafy vegetables. Lebensmittel-Wissenschaft Und-Technologie, 38(5): 513–517. Oboh, G. 2006. Nutritive value, antioxidant and antimicrobial properties of Struchium sparganophora leaves. Journal of Medicinal Food. 9(2): 276–280. of plant phenolics for functional food and environmental applications: A Review. Proceeding of Biochemistry. 39:789–803. Palevitch, D. & L.E. Craker. 1995. Nutritional and medicinal importance of red pepper (Capsicum spp). Journal of Herbs, Spices and Medicinal Plants. 3: 55–83.

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