Maturity‐related chilling tolerance in mango fruit and the antioxidant capacity involved

BACKGROUND: In order to evaluate how effect of mature stage on the chilling tolerance of mangoes (Mangifera indica L. cv. ‘Zihua’) and the mechanism involved, the fruit were categorized into three stages of ripeness: Green (100% green fruit), Preyellow (10–20% yellow fruit) and Yellow (45–55% yellow fruit) after harvest and stored at 2 °C for 12 days and then incubated at 25 °C for 2 days for chilling injury (CI) development. RESULTS: CI index in Preyellow and Yellow fruit was significantly lower than that of the Green fruit, as a rapid increase in ion leakage was observed in the Green fruit. Activities of superoxide dismutase, catalase, ascorbate peroxidase and polyphenoloxidase of Preyellow and Yellow fruit were higher than those of the Green from day 6 to day 12 during cold storage. A lower content of malondialdehyde but higher levels of glutathione and ascorbic acid were maintained in Preyellow and Yellow fruit than that in Green fruit. CONCLUSION: These results suggested that stronger resistance of Preyellow and Yellow mangoes to CI compared to Green fruit was due to their higher antioxidant capacity involved in the tolerance to chilling temperature. Alleviating CI in mangoes during storage may be achieved by storing the fruit when skin colour is beginning to change to yellow from green. Copyright © 2008 Society of Chemical Industry     

不同贮藏温度对采后86-1哈密瓜果实冷害及品质的影响

为了研究不同贮藏温度对采后哈密瓜果实冷害及品质的影响,分别对1、3、5℃贮藏条件下86-1哈密瓜果实的冷害症状、冷害指数、冷害率、细胞膜相对透性、硬度、可溶性固形物含量、可滴定酸及维生素C含量进行了系统观察、统计与测定。结果表明:86-1哈密瓜冷害的发生与贮藏温度及持续时间有关,1℃贮藏条件下,86-1哈密瓜果实冷害出现的时间较早,果实的冷害指数、冷害率及细胞膜相对透性较高;硬度、可溶性固形物及维生素C含量下降较快,可滴定酸出现先上升后下降的趋势。3℃贮藏有利于维持86-1哈密瓜果实的品质,5℃贮藏果实虽未发生冷害,但后期品质劣变较快,腐烂较重。      

Structural changes,chemical composition and antioxidant activity of cherry tomato fruits (cv. Micro‐Tom) stored under optimal and chilling conditions

BACKGROUND: Cherry tomato fruits cv. Micro‐Tom, a model plant for tomato genetics, were analysed in order to determine the main structural and chemical changes under optimal and chilling storage conditions. The comparison of Micro‐Tom to standard tomato cultivars will give an insight into suitability of this dwarf cultivar as a model for studying the influence of low‐temperature conditions on tomato fruits. RESULTS: During chilling, fruit tissue was progressively destroyed due to the collapse of the deep layers of the pericarp. Chilling lowered the typical tomato kinetics of ripening in sugars (glucose, fructose, sucrose), organic acids (tartaric, malic, citric, ascorbic and succinic) and the antioxidants phenol and lycopene, while carotenoid synthesis seemed to be blocked. Glutathione level was elevated and the activity of ROS scavenging enzymes was altered. Essentially, Micro‐Tom fruits showed a quality evolution that was similar to that described for standard tomato cultivars. CONCLUSION: The cherry tomato cultivar Micro‐Tom could be used as a model for studying the influence of low temperature on biochemical and structural changes taking place during chilling injury conditions. Copyright © 2009 Society of Chemical Industry     

Effect of cold‐shock treatment on chilling injury in mango (Mangifera indica L. cv. ‘Wacheng’) fruit

To investigate how cold shock may affect chilling injury in mango fruit (Mangifera indica L. cv. ‘Wacheng’), the fruit were treated for 3, 4 or 5 h at 0 °C, or treated for 8, 10 or 12 h at 4 °C, respectively, then transferred to 20 °C for 20 h prior to being stored at 2 °C, 85–95% RH. The chilling injury index of mango treated at 0 °C for 4 h was 59.7% lower than that of the control fruit directly stored at 2 °C, 85–95% RH. Some attributes were assayed in the fruit treated at 0 °C for 4 h. Ion leakage of the cold‐shock fruit at 0 °C for 4 h was 16% or 10% lower than that of the control on day 9 or day 12 of storage, respectively. Malondialdehyde content of the cold‐shocked fruit was 70% or 50% lower than that of the control on day 6 or day 12 of storage at 2 °C, respectively. Activities of catalase, ascorbate peroxidase, and contents of glutathione and phenolic compounds in the fruit during storage were all markedly enhanced by the cold‐shock treatment, whereas activities of superoxide dismutase, glutathione reductase and content of ascorbic acid in the mango were slightly influenced by the cold‐shock treatment. These results suggest that cold‐shock treatment may hold promise as an alternative approach to reduce chilling injury in mango fruit during cold storage. Copyright © 2006 Society of Chemical Industry     

Physiological age at harvest regulates the variability in postharvest ripening, sensory and nutritional characteristics of mango (Mangifera indica L.) cv. Coghshall due to growing conditions

BACKGROUND: Climacteric fruits are harvested at the green‐mature stage and ripen during their marketing cycle. However, growing conditions induce variability into the maturity stage of mangoes at harvest, with an impact on their final quality. Assuming that the physiological age can be correctly evaluated by a criterion based on the variable chlorophyll fluorescence of the skin (F_v) and that differences in physiological age depend on growing conditions, controlled stress experiments were carried out on mango fruit by manipulating either the leaf/fruit ratio or the light environment. RESULTS: Delays from 9 to 30 days were observed, depending on stress level and harvest stage, to obtain the same F_v value. For moderate stress, fruit composition after ripening was partially compensated for, with little or no difference in sugar, dry matter, carotenoid and aroma contents. For more pronounced stress, the major metabolites were not particularly affected, but the synthesis capacity of carotenoids and aromas was lower after maturity. CONCLUSION: The ripening ability of a fruit is acquired on the tree and defines its postharvest changes. Control of the physiological age at harvest can minimise the variability observed under natural conditions and guarantee fruit batches whose postharvest changes will be relatively homogeneous. Copyright © 2011 Society of Chemical Industry     

Effect of storage in controlled atmosphere on post‐harvest infections of Phytophthora brassicae and chilling injury in Chinese cabbage (Brassica rapa L pekinensis (Lour) Hanelt)

Heads of Chinese cabbage (Brassica rapa L pekinensis (Lour) Hanelt) were inoculated with Phytophthora brassicae De Cock and Man in't Veld and stored at 1.5 °C in the following concentrations of CO₂/O₂: 0.5%/20.5% (control), 0.5%/1.5% or 3.0%/3.0%. In experiments with cv ‘Nerva’, stored for 94–97 days, the infection caused by P brassicae was significantly higher (p < 0.05) in the controlled atmosphere (CA) treatments than in the control. However, in vitro growth of P brassicae on agar was slower (p < 0.001) in the CA treatments than in the control. Chilling injury (brown midribs) found in cv ‘Parkin’ was highest in heads from the control. Storage in 0.5% CO₂/1.5% O₂ significantly (p < 0.001) reduced this disorder, and the lowest percentage of brown midribs was found in 3.0% CO₂/3.0% O₂. No chilling injury was found in cv ‘Nerva’. Copyright © 2005 Society of Chemical Industry     

Modulation of salt (NaCl)‐induced effects on oil composition and fatty acid profile of sunflower (Helianthus annuus L.) by exogenous application of salicylic acid

BACKGROUND: Salicylic acid (SA) is a potential endogenous plant hormone that plays an important role in plant growth and development. Since sunflower yield and its seed oil yield are adversely affected by salinity, in this study the role of SA in modulating salt (NaCl)‐induced effects on various yield and oil characteristics of sunflower was investigated. For this purpose a greenhouse experiment comprising two sunflower hybrid lines (Hysun‐33 and SF‐187), two NaCl levels (0 and 120 mmol L^?1) and four SA levels (0, 100, 200 and 300 mg L^?1) was conducted. RESULTS: Salt stress markedly reduced yield, oil content, linoleic acid and δ‐tocopherol in both sunflower lines, while it increased linolenic acid, palmitic acid, stearic acid and α‐ and γ‐tocopherols. However, increasing levels of foliar‐applied SA resulted in improved achene yield and hundred‐achene weight in both lines. Foliar‐applied SA caused a significant decrease in oil stearic acid and α‐ and γ‐tocopherols in both lines under non‐saline and saline conditions. CONCLUSION: Salt‐induced harmful effects on achene yield and oil characteristics of sunflower could be alleviated by exogenous application of SA. High doses of SA caused a marked increase in sunflower achene oil content as well as some key fatty acids. Copyright © 2010 Society of Chemical Industry     

Biological evaluation and quantitative analysis of antioxidant compounds in pulps of the Amazonian fruits bacuri (Platonia insignis Mart.), ingá (Inga edulis Mart.), and uchi (Sacoglottis uchi Huber) by UHPLC‐ESI‐MS/MS

Bacuri, ingá, and uchi are Amazon fruits consumed specially in the North region of Brazil. Due to their large consumption and the lack of knowledge regarding its chemical composition, these fruits were studied in relation to their Antioxidant chemical constitution. The total phenolic content ranged from 3.86 ± 0.47 to 33.38 ± 1.51 mg GAE/100 g, and the total flavonoid content ranged from 1.75 ± 0.22 to 19.44 ± 0.87 mg QUERE/100 g, where the contents showed a significant correlation with DPPH and ABTS antioxidant assays. Thus, UHPLC‐MS/MS was applied do quantify selected compounds, been citric acid the most abundant for all fruits. Furthermore, samples were screened for their α‐glycosidase and lipase inhibitory effects, in addition to their antimicrobial potentials. Bacuri showed the highest antioxidant and α‐glycosidase inhibitory capacity (IC₅₀ 15.20 μg/mL), whereas uchi and its main metabolite bergenin displayed moderate antimicrobial activities. The results shed light into the potentials of Amazonian fruit sources.

Practical applications

Plant phenolics are essential components of functional foods, due to their antioxidant and enzyme inhibition activities, which are directly linked to several diseases prevention. This is the first study about the quantification of antioxidant compounds in the Amazonian fruits: bacuri, ingá, and uchi. Although they are quite consumed in the North region of Brazil, there are no bio‐products made from them. This study aimed to elucidate the knowledge about the chemical composition and potentialities within these fruits with the practical purpose of highlighting them to future commercial applications. In addition, once we indicate their capabilities, we contribute with local populations in respect to the production of such fruits, which still is a family activity.