Quality of Fungicide Treated and Individually Shrink-Wrapped Tomatoes

Fungicide-treated mature green and pink tomatoes were individually shrink-wrapped with plastic films and stored at 13°C and 18°C. Shrink-wrapped pink tomatoes lost less water than unwrapped tomatoes, but there were no significant shelf-life or quality differences. The shelf-life of mature green tomatoes at 18°C, however, was increased 10 days by shrink-wrapping. Color development of wrapped mature green tomatoes at 18°C was delayed. Wrapped fruit at both temperatures were firmer than the controls. Titratable acidities and soluble solids of wrapped fruit were lower than those of the unwrapped fruit at 13°C, while no significant changes were observed in citric acid or monosaccharide concentrations. The differences in titratable acidities and soluble solids in the wrapped and unwrapped fruit stored at 18°C were not significant.     

The effects of ethanol treatment on the metabolism,shelf life and quality of stored tomatoes at different maturities and temperatures

Two maturity stages of commercially grown tomatoes (breaker and mature green) were exposed to ethanol vapour (2 ml ethanol kg⁻¹ fruit) for 6 h at 20 °C prior to storage at 5 °C and 20 °C. During storage the colour, firmness and composition changes were examined every 3 and 7 days. The results showed that ethanol vapour treatment could significantly slow down the colour changes and softening of both mature green and breaker tomatoes with greater effects when stored at 5 °C. There was no difference between the two maturity stages in retardation of softening during storage; in contrast the maturity stage had a highly significant effect in the colour development of stored tomatoes. When the fruit stored at 5 °C was then held at 20 °C for 7 days the ripening process was accelerated but the fruit did not reach the same level of colour development as the fruit stored at 20 °C continuously. The results suggest that ethanol vapour pretreatment could be used as a cheap and easy method to extend the storage life of tomatoes. © 1999 Society of Chemical Industry     

Shelf Life of Mature Green Tomatoes Stored in Controlled Atmosphere and High Humidity

Freshly harvested mature green tomatoes were washed, sorted and treated with 125 ppm chlorine water. The treated tomatoes were stored at 85% or 98% RH under controlled atmosphere (CA) storage for periods up to 8 wk. The controlled atmosphere was 2.5% O₂, 5.0% CO₂, and N₂ as the balance gas at 12°C. After storing 40 days, the tomatoes were allowed to ripen in air at 23°C. Samples of tomatoes were tested every 3 days to examine changes in quality as determined by visual observation, weight loss, titratable acidity, pH, color and firmness. Weight loss was reduced significantly by CA storage of tomatoes at 98% RH. Tomatoes remained green up to 40 days of storage and changed in color gradually during consecutive storage in atmospheric conditions. Appearance of the tomatoes was acceptable after ripening.     

Effect of high-voltage electrostatic field pretreatment on the antioxidant system in stored green mature tomatoes

BACKGROUND: High‐voltage electrostatic field (HVEF), as a feasible and non‐chemical technique, applied to food preservation is a new area of study. Our previous research suggested HVEF could maintain the quality of tomato in storage. The present article intensively investigated the effect of HVEF pretreatment on antioxidant system of green mature tomato in storage. RESULTS: Green mature tomatoes were exposed to negative (or positive) HVEF for 2 h at 20 °C and then stored for 24 days at 13 ± 1 °C, 85–90% relative humidity. The results indicated HVEF significantly reduced contents of O₂^? and H₂O₂ of tomato fruits during storage compared to the control. HVEF treatment also enhanced the activities of antioxidant enzymes including catalase, superoxide dismutase, ascorbate peroxidase and peroxidase. The contents of non‐enzyme antioxidant components including reduced glutathione, phenols and ascorbic acid also were increased by HVEF treatment. However, HVEF treatment did not increase the content of lycopene in tomato fruit. CONCLUSION: HVEF treatment could promote the antioxidant capacity of tomato fruits in storage. Further research is be highly recommended to understand the mechanisms improving the antioxidant capacity of tomato fruits by HVEF. Copyright © 2011 Society of Chemical Industry     

Protection of vessel permeability by genistein against lipopolysaccharide induced acute inflammation in a chick embryo chorioallantoic membrane model

Effects of dip treatments on nutritional quality preservation during the shelf life of fresh-cut tomato (Licopersicum esculentum Mill.) cv. Eufrates were investigated. Fresh-cut tomatoes were dipped in solutions of 2% ascorbic acid, citric acid, and calcium lactate for 2 min, then stored at 4°C for 20 days. Color (L*, a*, and b*), firmness, °Brix, phenolics, ascorbic acid content, antioxidant activity (DPPH), and sugars were measured during storage. Pathogen development was monitored, and a sensory evaluation was performed. Ascorbic acid was better in maintaining firmness. No treatments significantly affected °Brix, color, or sugars. Ascorbic acid maintained a higher antioxidant capacity, phenolics, and ascorbic acid content, and was better at reducing bacterial growth, while citric acid treatment was better at prevention of yeast and molds proliferation. Fresh-cut tomatoes showed good quality after 10 days of shelf life, except for flavor with the calcium lactate treatment. Ascorbic acid treatment better preserved the general and nutritional quality parameters.     

Superoxide dismutase from hen’s egg yolk can protect fatty acids from peroxidative damage

Superoxide dismutase (SOD, EC1.15.1.1) is a family of enzymes, which remove superoxide anion (O ₂ ^·? ) from the cells of living organisms. The aim of this study was to describe antioxidative properties of SOD with regard to the protection of unsaturated fatty acids (UFA) from peroxidative damage and to compare this effect with butylated hydroxytoluene (BHT). In this experiment, Cu, Zn-SOD from hen’s egg yolk with a mass of 15.59 ± 0.38 kDa and pI 6.58 ± 0.10, 6.41 ± 0.08 and 6.30 ± 0.15 was used to protect fatty acids from peroxidative damage in vegetable oil (sunflower oil and olive oil) during 200 days of storage at different temperatures—4, 20 and 35 °C. Antioxidative properties of SOD and BHT were expressed as the ratio of unsaturated to saturated fatty acids (SFA) in samples after 50, 100 and 200 days of storage as well as the percentage content of selected fatty acids in the examined oils. SOD from egg yolk showed the same or better antioxidant properties with regard to the concentration of linoleic acid (C18:2) contained in sunflower oil and olive oil than the corresponding concentrations of BHT during 200-day storage at 4, 20 and 35 °C. The concentration of linoleic acid (C18:2) in the sample with SOD was significantly higher during storage at 35 °C on day 200. At all storage temperatures, the ratio of SFA to UFA in samples with the addition of SOD was statistically higher than in oils stored without the antioxidant. With regard to linoleic acid (C18:2), SOD proved to be a better antioxidant than BHT. The results demonstrated better antioxidant properties of SOD from hen’s eggs compared with the same concentrations of BHT at elevated temperatures (at 20 and 35 °C) in oil with a high content of UFA. No negative antioxidative effect (worse than that of BHT at a corresponding concentration) of the addition of SOD from egg yolk on fatty acid composition of the tested samples was observed. Though further research is necessary, SOD from hen’s egg yolk seems to be a promising natural antioxidant of vegetable oils.     

Effect of 1-methylcyclopropene on tomato flavour components, shelf life and decay as influenced by harvest maturity and storage temperature

BACKGROUND: In Florida, tomatoes are harvested green (GR), which includes mature green (MG) and immature green (IG) fruits, and stored at low temperature (13 °C), resulting in poor flavour. Flavour improvement might be achieved if fruits were harvested with some colour (to eliminate IG fruits) and/or stored at higher temperature with the ripening inhibitor 1‐methylcyclopropene (1‐MCP). RESULTS: ‘Florida 47’ tomatoes were harvested at GR (MG + IG), breaker (BR), turning (TR) and pink (PK) stages, treated (+) or not (?) with 1‐MCP and stored at 13 and/or 18 °C. 1‐MCP treatment resulted in a gain of up to 6 days of shelf life depending on harvest maturity and storage temperature. Storage at 18 °C rather than 13 °C resulted in an increase in internal red colour, soluble solids (SS)/titratable acidity (TA) ratio and levels of many volatiles studied. The shelf life of BR (+) MCP fruits stored at 13 °C was similar to that of MG fruits. IG fruits exhibited lowest levels of SS, TA and ten volatiles compared with BR fruits. CONCLUSION: Harvesting tomatoes with colour (BR), thereby eliminating IG fruits, and treating with 1‐MCP resulted in better quality with adequate shelf life. Published 2011 by John Wiley & Sons, Ltd.     

Processing of green tea pastes by micro wet milling system: Influences on physicochemical and functional properties

This study aimed to develop green tea paste using a new micro wet milling (MWM) system. The influence of milling conditions on the particle size, morphology, solubility, and antioxidant properties of Matcha, shaded Yabukita, unshaded Yabukita, and Hojicha pastes were studied. MWM green tea paste retained smaller particles, better color, higher solubility, and antioxidant properties than the dry milled Matcha paste. Storage temperature and time affected the stability of ascorbic acid and visual green color at 20, 4, −18, and −60 °C for four weeks. Kinetic analysis demonstrated that first-order kinetic models could predict the degradation of ascorbic acid and the reduction in visual green color of green tea pastes during storage. Temperature-dependent rate constants of ascorbic acid and color of green tea pastes obeyed the Arrhenius relationship. The total viable count revealed that green tea paste could be stored for 7 days at 20 °C and 21 days at 4 °C within the permissible limit.     

Antioxidant properties and shelf‐life extension of fresh‐cut tomatoes stored at different temperatures

BACKGROUND: The feasibility of using modified atmosphere packaging (5 kPa O₂ + 5 kPa CO₂) to maintain the antioxidant properties of fresh‐cut tomatoes during shelf‐life was assessed through storage at different temperatures (5, 10, 15 and 20 °C). Health‐related compounds, antioxidant capacity, microbiological counts, physicochemical parameters and in‐package atmosphere of tomato slices were determined. RESULTS: Initial lycopene, vitamin C and phenolic contents and physicochemical parameters of tomato slices were well maintained for 14 days at 5 °C. Lycopene and total phenolic contents were enhanced over time in tomato slices stored at 15 and 20 °C. However, this increase in antioxidant compounds of fresh‐cut tomatoes during storage may be associated with excessive amounts of CO₂ (R² = 0.5679–0.7328) in the packages due to microbial growth. Although keeping tomato slices at temperatures above 10 °C increased their antioxidant content, the shelf‐life of the product was reduced by up 4 days. CONCLUSIONS: A storage temperature of 5 °C is appropriate for maintaining the microbiological shelf‐life of fresh‐cut tomatoes for up to 14 days and also allows the antioxidant properties of tomato slices to be retained over this period, thus reducing wounding stress and deteriorative changes. Copyright © 2008 Society of Chemical Industry     

Influence of Postharvest UV-C Hormesis on the Bioactive Components of Tomato during Post-treatment Handling

Mature green tomato fruit exposed to a pre-determined hormetic dose of UV-C (3.7 kJ/m²) and untreated fruit (control) were stored at 13 °C and 95% relative humidity. After 10, 20, and 30 days of storage, fruits were randomly sampled and transferred to room temperature (23 °C) for 7 and 14 days to allow ripening. Edible pericarp was excised from the equatorial region for subsequent analyses of the antioxidant components. Ascorbic acid and total phenolic contents were higher in the UV-treated tomatoes, but UV treatment significantly reduced the lycopene content of the tomatoes. The UV treatment did not affect significantly the antioxidant activity of the hydrophilic extract, expressed as Trolox equivalent. Both storage and ripening period were found to affect positively all the bioactive components of tomato evaluated in this study. The results suggest the possible existence of a window of opportunity for the development of practices based on storage temperature and duration to preserve the beneficial effects expected from UV-C hormesis and to circumvent its negative impact on lycopene synthesis.     

Comparing the Effects of High Hydrostatic Pressure and Ultrahigh Temperature on Quality and Shelf Life of Cloudy Ginger Juice

The effects of high hydrostatic pressure (HHP) at 500 MPa for 10 min and ultrahigh temperature (UHT) at 110 °C for 8.6 s on the quality of cloudy ginger juice (CGJ) were investigated during storage for 91 days at 4 and 25 °C. The quality aspects studied were microbial stability and selected properties, including pH, total soluble solids (TSS), titratable acidity (TA), total phenols, gingerols, antioxidant capacity, color, and aroma composition. The results showed that HHP treatment led to a 3.0 log cycle reduction of microbial load but did not influence pH, TSS, TA, antioxidant capacity, and color (day 0). Total phenol content increased by 5.31 % after HHP treatment but decreased significantly by 14.74 % after UHT treatment (day 0). Gingerols increased by 14.43 and 14.18 % after HHP and UHT treatments (day 0), respectively. Monoterpenoids, which are the main volatile aroma compounds, did not change significantly after HHP treatment but decreased significantly by 2.27 % after UHT treatment (day 0). During storage, the decreases in total phenols, gingerols, and antioxidant capacity in the UHT-treated GCJ were more noticeable than those in the HHP-treated GCJ. Kinetic data of changes in total phenols, gingerols, and antioxidant capacity fitted into the combined model well. The changes in antioxidant capacity were positively and significantly correlated to total phenols and gingerols. Color darkened and aroma faded in both HHP-treated and UHT-treated CGJs during storage. The quality changes in samples stored at 25 °C were also more noticeable than those stored at 4 °C.     

Control of Postharvest Quality in Blueberry Fruit by Combined 1-Methylcyclopropene (1-MCP) and UV-C Irradiation

The objective of this study was to investigate the effects of 1-methylcyclopropene (1-MCP) combined with UV-C irradiation on postharvest quality of blueberry fruit (Vaccinium spp. Berkeley) stored at 4 ± 1 °C for 8 days. Respiration rate, ethylene production, decay incidence, softness, color, total anthocyanin content, malondialdehyde (MDA) content, titratable acid content, soluble solid content, peroxidase (POD), phenylalanine ammonia lyase (PAL), and catalase (CAT) of treated blueberry fruit were examined. The results indicated that treatment with 1-MCP plus UV-C irradiation inhibited respiration rate, ethylene production, decay incidence, and MDA content. The combined treatment also delayed softness, color, titratable acid, and soluble solid content and improved total anthocyanin content of blueberries throughout the storage period at 4 ± 1 °C compared to the untreated samples. The efficiency of the combined treatment (1-MCP + UV-C irradiation) was better than that of 1-MCP or UV-C irradiation alone. Furthermore, combination of 1-MCP and UV-C irradiation effectively enhanced PAL and CAT activities and inhibited the increasing of POD activity in blueberries. Therefore, our results shows that 1-MCP plus UV-C irradiation treatments may be a useful method in maintaining commercial quality and extending shelf life of blueberries.     

EFFECT OF EVAPORATIVE COOLING STORAGE ON RIPENING AND QUALITY OF TOMATO

Tomatoes (Lycopersicon esculentum Mill cv. Rupali) ripened in evaporative cooling (EC) storage conditions (20°C–25°C, 92–95% RH) were compared with control fruits stored under room conditions (28°C–33°C, 45–65% RH) during summer in Mysore. EC ripened tomatoes on the 15th day reached 100% ripening index (RI) with a value of 2.48 for the ratio of redness to yellowishness (a/b) and hue angle (θ) of 22.1° whereas the control tomatoes on the same day reached a maximum 83.3% RI with a/b ratio of 1.59 and a hue angle of 32.9°. Higher development of chroma and total color difference were exhibited by EC stored tomatoes than control samples. The lycopene content of EC ripened fruits double that of the control. EC stored fruits showed lower values for rupture and shear stresses. The rate of moisture loss for control fruits was 6.5 times as great as for EC stored tomatoes.     

Effect of Chilling Exposure of Tomatoes During Subsequent Ripening

Mature green tomatoes were stored at 4°C, ≥ 90% RH, for up to 39 days and transferred to 21°C, ≥ 90% RH, for further ripening. After 15 days of chilling exposure, stimulation of C₂H₂ production and increased susceptibility to decay were observed when the fruit was ripened at ambient temperatures. As chilling exposure increased, C₂H₄, production upon removal to 21°C returned to the level of the control. Irreversible inhibition of color development was observed in fruit exposed to 4°C for 34 days and an increase in CO₂ production was noted upon warming of tomatoes chilled for 39 days.     

腐胺对机械伤青椒果实生理品质和抗氧化能力的影响

目的:研究腐胺处理对机械伤青椒生理品质和抗氧化能力的影响。方法:将青椒从1 m高处跌落来模拟运输过程中所受的机械损伤,然后将受损青椒浸泡在2 mmol/L的腐胺溶液和去离子水中20 min,在20 ℃下贮藏,测定青椒贮藏过程中生理品质和抗氧化酶活性的变化。结果:腐胺处理抑制了青椒转红,维持较高的维生素C和叶绿素含量,抑制丙二醛(MDA)的积累,提高了过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性。结论:腐胺处理可以减缓青椒在20 ℃贮藏时机械损伤引起的生理品质下降。     

Effects of high oxygen concentration on pro- and anti-oxidant enzymes in peach fruits during postharvest periods

Peach fruits (Amygdalus persica cv. Okubao) were stored in air, controlled atmospheres (CA) of 5% O₂ plus 5% CO₂, or CA with high O₂ concentration (70% O₂ plus 0% CO₂ for 15 days, then in CA with 5% O₂ plus 5% CO₂) at 0 °C, to determine the effects of different O₂ and CO₂ atmospheres on the activities of lipoxygenase (LOX), peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT), as well as malondialdehyde (MDA) content and membrane integrity during storage periods with or without 3 days of post-storage ripening at 20 °C. SOD, CAT and POD activities of the fruits stored in air markedly decreased during the first 30 days of storage, while LOX activity increased after 15 days. CA (5% O₂ plus 5% CO₂) reduced chilling injury, and delayed the reduction of SOD, CAT and POD activities compared to the control. CA with high O₂ treatment induced SOD and CAT activities and maintained membrane integrity, but no significant effect on alleviating chilling injury was found compared to CA storage. The results indicated that the decrease of SOD and CAT might contribute to the development of chilling injury in peach fruits.     

Quality and Nutritional Status of Fresh-Cut Tomato as Affected by Spraying of Delactosed Whey Permeate Compared to Industrial Washing Treatment

The aim of this study was to examine the applicability of delactosed whey permeate (DWP) treatment on preserving the quality and antioxidant attributes of fresh-cut tomato. Tomatoes were treated with 3% DWP by dipping, spraying and a combination of both, stored at 4?°C for 10?days and compared with the industrial standard, chlorine. The combination of dipping and spraying of DWP showed the best results for all the markers tested. The combined treatment of dipping and spraying of DWP significantly lowered total counts (??1.0 log cfu/g), yeast and moulds (??1.2 log cfu/g), inhibited the loss of firmness (25%) and reduced POD activity (15%) of the tomato slices after 10?days compared to the chlorine treatment. Moreover, DWP-treated tomatoes maintained significantly (p?<?0.05) higher levels of vitamin C, total phenols and antioxidant activity (DPPH) than the chlorine-treated samples during storage. Sensory scores confirmed that DWP-treated tomatoes retained better aroma and texture. Also, the appearance and overall acceptability were higher than chlorine-treated tomatoes. Thus DWP treatment has potential to extend the shelf life of fresh-cut tomatoes.     

Cutting Shape and Storage Temperature Affect Overall Quality of Fresh-cut Papaya cv. 'Maradol'

: The effect of cutting shape (cubes or slices) and storage temperature (5 °C, 10 °C, and 20 °C) on overall quality of fresh‐cut papaya were investigated. CO₂ production, color, firmness, total soluble solids (TSS), weight loss, overall quality, ascorbic acid, β‐carotene, and antioxidant capacity were evaluated as a function of shelf life. CO₂ production was high on day 0 for cubes and slices with an average of 150 and 100 mL/ kg/h, respectively. Storage temperature did not affect color changes; however, lower temperatures prevented loss of firmness. Fresh‐cut papaya stored at 20 °C showed the lowest TSS value and the highest weight losses. Shelf life based on visual quality ended before significant losses of total ascorbic acid, b‐carotene, and antioxidant capacity occurred. In general, quality parameters were not affected by shape. However, slices stored at 10 °C and 5 °C had a shelf life of 1 d and 2 d longer than cubes, respectively.     

纤维素可食性膜对番茄保鲜贮藏中硬度和色泽的影响

用于食品包装的绿色包装材料之一的可食性包装已逐渐地取代容易产生“白色污染”的不可降解性塑料薄膜。本研究采用羟丙基甲基纤维素 (HPMC)可食性膜 ,将之涂于番茄上 ,然后贮藏于 2 0℃下达 18d ,研究其对番茄硬度和色泽的影响。在贮藏期间 ,所有处理组的番茄的硬度都随着贮放时间的延长而下降。但是 ,施用HPMC可食性膜可以延缓番茄变软。在贮藏日的第 7、13和 18d ,观察到以HPMC涂膜的番茄的硬度都显著性地 (P≤ 0 0 5 )比未涂膜的番茄的硬度大。本研究还证实了HPMC可食性膜可以显著性地 (P≤ 0 0 5 )延缓番茄在 2 0℃贮藏时色泽的变化 ,延迟了番茄从粉红色到红色阶段的后熟。因此 ,HPMC可食性膜可以有效地减慢番茄后熟 ,延长番茄的保存期。同时番茄硬度损失率的减慢 ,可以减少番茄果实运输时因机械损伤导致果实腐败而造成的经济损失。     

预冷对气调荷兰豆货架期品质和生理的影响

为研究不同预冷方式和气调处理对模拟货架后荷兰豆品质和生理特性的影响。分别于0、6h 和12h 三种不同放置时间后对荷兰豆进行预冷并立即建立气调(体积配比为3% O2+5% CO2+92% N2)条件1℃贮藏,荷兰豆贮藏0、10、20d 和30d 后进行2d 常温模拟货架实验。结果表明：与6h 或12h 后预冷比较,立即预冷的荷兰豆在模拟货架后呼吸作用弱,纤维素增加量小,超氧阴离子自由基和丙二醛含量保持在较低水平,抗氧化酶——过氧化物酶和超氧化物歧化酶具有较高的活力。立即预冷可有效抑制货架期荷兰豆的生理活动和更好地保持其品质。