Pre‐ or post‐harvest applications of putrescine and low temperature storage affect fruit ripening and quality of ‘Angelino’ plum

BACKGROUND: Plum has a very short storage life. The role of pre‐ or post‐harvest applications of putrescine (PUT) and low temperature storage on fruit ripening and quality was investigated in plum fruit (Prunus salicina Lindl. cv. Angelino). RESULTS: Pre‐ or post‐harvest PUT treatments [(0.1, 1.0 or 2.0 mmol L^?1) + 0.01% Tween‐20 as a surfactant] delayed and suppressed the climacteric ethylene production and respiration rate irrespective of the method used to apply PUT. PUT‐treated fruit following low temperature storage (0 ± 1 °C; 90 ± 5% RH), at the ripe stage exhibited higher fruit firmness and titratable acidity (TA), while soluble solids content (SSC), levels of ascorbic acid, total carotenoids and total antioxidants were lower than in untreated fruit. Fruit both sprayed with PUT and stored in low temperature for 6 weeks, at the ripe stage showed reduced respiration rate, delayed changes in the SSC:TA ratio and levels of total carotenoids compared to post‐harvest PUT application. CONCLUSION: Pre‐harvest application of 2.0 mmol L^?1 PUT 1 week before the anticipated commercial harvest was more effective in delaying plum fruit ripening and can be used to extend the storage (0 ± 1 °C) life of plums for up to 6 weeks with minimum losses in fruit quality. Copyright © 2008 Society of Chemical Industry     

不同方式贮藏对拉萨刺梨品质的影响

本研究以拉萨地区刺梨果实为试材,分别采用室温、室温＋气调袋、低温（（1.0±0.5）℃）和低温 （（1.0±0.5）℃）＋气调袋4 种方式贮藏,测定贮藏过程中硬度、可溶性固形物质量分数、可滴定酸质量分数、 VC含量、超氧化物歧化酶（superoxide dismutase,SOD）活力、质量损失率、腐烂率的变化,研究不同方式贮藏对 刺梨品质的影响。结果表明：在贮藏6 d时,室温、室温＋气调袋、低温和低温＋气调袋贮藏的刺梨VC含量分别下 降了69.55%、25.91%、41.93%和14.47%,SOD活力分别下降了47.99%、24.96%、33.98%和14.32%,在贮藏6 d时仅 室温＋气调袋处理的刺梨有腐烂现象出现,腐烂率为1.78%;与其他贮藏方式相比,低温＋气调袋贮藏组果实的硬 度、可溶性固形物质量分数、可滴定酸质量分数、质量损失率等下降明显变缓,贮藏综合品质最好。     

1-MCP 与植酸处理对草莓果实采后生理品质的影响

采用1-甲基环丙烯(1-MCP)和植酸对草莓进行不同处理,通过追踪测定其贮藏期间的质量损失率、硬度、可溶性固形物(soluble solids content,SSC)、呼吸强度、维生素C(VC)、可滴定酸(titratable acidity,TA)和相对电导率等指标来研究不同处理对草莓的保鲜效果。结果表明：1-MCP和植酸处理可有效降低草莓的质量损失率和呼吸强度,推迟SSC出现峰值的时间,延缓其后熟衰老过程,抑制其硬度、TA和VC含量的下降;同时,1-MCP 和植酸复合处理比两者各自的单独处理都具有更好的效果,能显著改善草莓在贮藏期间的果实品质。     

Influences of preharvest spraying Cryptococcus laurentii combined with postharvest chitosan coating on postharvest diseases and quality of table grapes in storage

The effects of preharvest spray with Cryptococcus laurentii combined with chitosan coating after harvest on decay and quality of table grapes during storage periods were evaluated in the present study. Preharvest spray with C. laurentii (PreA) significantly decreased decay index (DI), and postharvest chitosan coating (PCC) enhanced the effectiveness of the pre-harvest spray when fruits were stored at 0 °C. PreA combination with PCC increased the activities of polyphenol oxidase (PPO) and phenylalanine ammonia-lyase (PAL) of fruit in storage. PreA + PCC treatment was effective in reducing weight loss of fruits by 85% at 17 d storage and 38% at 42 d storage as compared to PreA alone at the same stage. In addition, PreA enhanced the ratio of soluble solids content (SSC) to titratable acid (TA) by 12% at harvest time, 7% at 17 d storage and 25% at 42 d storage, mainly by increasing SSC and decreasing TA in fruit stored at 0 °C. These results suggested that integration of preharvest spray with C. laurentii and postharvest chitosan coating treatment may be a promising management strategy for decay control and quality maintenance of table grapes.     

Effects of stage II and postharvest deficit irrigation on peach quality during maturation and after cold storage

Effects of regulated deficit irrigation (RDI) on the quality of a mid–late maturing peach (Prunus persica L Batsch cv Andross) were determined at commercial harvest as well as 1 week before (early pick‐up) and after 1 week of cold storage. Respiration and ethylene evolution were measured during 96 h on fruits sampled at early pick‐up and at harvest. Fruits from a well‐watered irrigation treatment (Control) were compared with a treatment of RDI during stage II of fruit growth (RDI‐SII) and with RDI applied postharvest (RDI‐PH). A fourth treatment received a combination of deficit irrigation applied during stage II and postharvest (RDI‐SII‐PH). Higher soluble solids content (SSC) amd SSC/titratable acidity (TA) ratio for RDI‐SII were already noted at early pick‐up and these differences were enhanced after cold storage (RDI fruits having higher SSC, lower TA and higher SSC/TA ratio than Control fruits). This improvement in quality (high SSC/TA ratio) was also correlated with a more reddish colouration in the fruit skin. Moreover, ethylene production indicated different behaviour of the physiological evolution for fruits from the different treatments. Copyright © 2004 Society of Chemical Industry     

Effects of 1-methylcyclopropene(1-MCP) on ripening and resistance of jujube (Zizyphus jujuba cv. Huping) fruit against postharvest disease

The effects of 1-methylcyclopropene (1-MCP) on senescence and induction of resistance against postharvest decay in jujube (Zizyphus jujuba cv. Huping) fruit were investigated in this study. The results indicated that, compared to control, 1-MCP at 1 μL L^?l depressed ethylene production by 28% and respiration rate by 30% at 24 h after treatment, resulting in effective delay in fruit senescence. 1-MCP treatment was beneficial for maintaining quality of jujube fruit stored both at 25 and 0 °C, retarding decline of firmness, vitamin C, titratable acidity (TA) and soluble solids content (SSC) which are important parameters for fruit quality evaluation during the storage periods. Moreover, 1-MCP effectively limited the development of lesion diameter of blue mold rot and significantly reduced the incidence of natural decay. The activities of phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), catalase (CAT) and superoxide dismutase (SOD) were significantly induced after 1-MCP treatment. These findings indicate that the induced resistance in jujube fruit by 1-MCP is related with the increase of enzymes involved in scavenging of reactive oxygen species and enzymes associated with phenolics metabolism which produces highly toxic products against pathogen invasion. Our results suggest that 1-MCP has potential effect on maintaining the quality and extending postharvest life of jujube fruit.     

采前喷洒赤霉素对‘红贵妃’芒果贮藏品质和采后生理的影响

研究采前喷施不同质量浓度(0.1、0.5、1.0、2.0 g/L)的赤霉素(gibberellin,GA)处理对采后‘红贵妃’芒果贮藏品质和采后生理的影响。结果表明:与对照相比,0.5、1.0 g/L GA处理的果实具有较低的病情指数、果皮相对电导率和丙二醛含量,较慢的可溶性固形物含量、VC含量和可滴定酸含量变化速率和较高的果实硬度。采前高质量浓度的GA处理(2.0 g/L)的果实在整个贮藏期内色度a*值变化平稳,且一直维持在最低水平,至贮藏末期(30 d),其色度a*值分别比对照、0.1、0.5 g/L和1.0 g/L处理的芒果果实的a*值低18.7、17.5、12.5、5.1,各处理间差异极显著(P0.01)。说明采前0.5 g/L和1.0 g/L GA处理‘红贵妃’果实有利于延缓果实采后生理的变化,保持贮藏品质;而2.0 g/L GA处理的果实至完熟时也不能完全转色,对外观品质具有不利的影响。     

Quality Measurement of Intact and Fresh-cut Slices of Fuji, Granny Smith, Pink Lady, and GoldRush Apples

ABSTRACT: Development of fresh-cut apple products requires consideration of cultivars that store well as both intact and fresh-cut fruit. We compared the instrumental and sensory quality of 2 apple cultivars, Granny Smith and Fuji, that are used for fresh cutting with 2 new cultivars, Pink Lady and GoldRush, which were considered to have quality characteristics suitable for fresh cutting. Firmness, titratable acidity (TA), soluble solids content (SSC), and aromatic volatile concentration were measured in intact fruit of the 4 cultivars during 12 mo storage in air at 0 °C and during 3 wk storage at 5 °C as fresh-cut slices. After 1 wk storage as fresh-cut slices, sensory evaluations for acceptability of flesh and peel appearance, flavor, texture, and overall eating quality were performed. During storage, GoldRush apples maintained > 80 N firmness, approximately 17% SSC, > 0.5% TA, and had high aromatic volatile production, that is, maintained quality better than the other cultivars. The quality and shelf stability of GoldRush slices were also as good as or better than slices from the other cultivars, whereas Granny Smith slices generally rated lower than the other cultivars. The acceptability of flavor, texture, and overall eating quality of GoldRush slices was as good as that for Pink Lady and Fuji. The quality of GoldRush apples can be maintained throughout the year in refrigerated air storage and still remain suitable for fresh-cut processing. The results indicate that GoldRush and Pink Lady are 2 promising new, high-quality apple cultivars for fresh cutting. Keywords: fresh-cut fruit, Malus × domestica , postharvest quality, respiration rate, shelf life     

Effect of hot air treatment on quality and ripening of Chinese bayberry fruit

BACKGROUND: Postharvest decay and softening are the major factors limiting the extension of storage life of Chinese bayberry fruit. To evaluate the effects of hot air treatment (HAT) on Chinese bayberry fruit, fruits were stored at 2 °C after exposure to 20 °C (control), 40 °C (HAT₄₀), 45 °C (HAT₄₅) or 50 °C (HAT₅₀) hot air for 3 h. The effects of HAT on firmness, disease incidence, soluble solid content (SSC), titratable acidity (TA), respiration, ethylene production, pectic substances and activities of pectinmethylesterase (PME) and polygalacturonase (PG) were examined. RESULTS: HAT inhibited decrease in firmness, SSC and TA and retarded increase in disease incidence, while it promoted decrease in respiration rate and ethylene production. HAT suppressed the activities of PME and PG, which resulted in delaying the depolymerisation of chelator‐soluble and alkali‐soluble pectic substances and reducing the increase in water‐soluble pectic substances compared with control fruits. CONCLUSION: The present findings show that HAT can maintain postharvest quality and delay ripening of Chinese bayberry fruit and suggest that HAT could be considered for commercial use to extend the postharvest life of Chinese bayberry fruit. Copyright © 2008 Society of Chemical Industry     

The influence of light and maturity on fruit quality and flavonoid content of red raspberries

The effects of various fruit maturities and different light intensities on berry fruit quality, antioxidant capacity and phytonutrient levels in red raspberries (Rubus ideaus L.) were determined. At harvest, immature berries contained significantly lower levels of sugars and acids than ripe berries. When berries were harvested at 5% or 20% maturity, they never developed the levels of soluble solids content (SSC) and titratable acid (TA) values observed in ripe berries at harvest. However, fruit harvested at 50% or more advanced maturity had the capacity of attaining comparable levels of SSC, TA and sugars as those harvested at 100% maturity. When 5% and 20% berries were stored under light, higher level of SSC and lower levels of TA values were observed than those kept in the dark. However, light condition showed little effect in 50% and 80% maturity fruit after 4 days at 24/16 °C (day/night). Ripe raspberries (100%) had stronger antioxidant activities and higher total anthocyanin content when compared with the pink stage (50% maturity). Fruit harvested at greener stages (5% and 20%) also consistently showed higher antioxidant activities and total phenolics than those harvested at 50%. Cyanindin-based anthocyanins increased during postharvest period. On the other hand, other polyphenols such as ellagic acid, quercetin 3-glucoside, quercetin derivative, and kaempferol 3-glucuronide were initially present at high levels but decreased drastically during storage. Red raspberries harvested at different developmental stages continued their development during storage even under the dark conditions. The antioxidant activity of red raspberries was directly related to the total amount of phenolics and flavonoids. Results of this study indicate that red raspberries harvested at 50% or more advanced maturity could develop comparable quality and antioxidant levels as those harvested at full maturity.     

Extending shelf-life of persimmon (<Emphasis Type="Italic">Diospyros kaki</Emphasis> L.) fruit by hot air treatment

‘Qiandaowuhe’ persimmon fruits (Diospyros kaki L.) were stored at 20 °C after exposed to 20 °C (control), 44 °C (T ₄₄), 48 °C (T ₄₈) or 52 °C (T ₅₂) hot air for 3 h, respectively. Firmness, weight loss, peel color, total carotenoids content, soluble solids content (SSC), titratable acidity (TA), respiration, and ethylene production and cell wall hydrolysis enzymes activities were monitored to determine the efficacy of hot air treatment in delaying persimmon fruit ripening. Results showed that ‘Qiandaowuhe’ persimmon fruit displayed a typical climacteric pattern of respiration and ethylene production. Peak of CO₂ and ethylene production was observed after 4 days. Fruit softening was accompanied by a progressive increase in weight loss, total carotenoids content and decrease in h°. The activities of pectinmethylesterase (PME) and polygalacturonase (PG) sharply increased and reached maximal values after 4 and 6 days, respectively. Hot air treatment significantly delayed the onset of climacteric ethylene production, respiration, PME and PG activities in persimmon fruit. Moreover, it also significantly retarded the increase in carotenoids content and SSC, while decreased the firmness, h°, and TA. The hot air treatment promoted fruit weight loss. The shelf-life of persimmon ripening increased 4 days by T ₄₄, and 6 days by T ₄₈ or T ₅₂. Results suggest that hot air treatments can greatly extend the postharvest life of ‘Qiandaowuhe’ persimmon fruit.     

Comparative shelf life study of blackberry fruit in bio-based and petroleum-based containers under retail storage conditions

The shelf life of blackberries is relatively short, 2–3 days at 0 °C. Different marketing strategies like packaging can be used to retain blackberry quality during postharvest. This study compares the blackberry retail shelf life performance of different packaging materials, bio-based versus petroleum-based using the same packaging design. ‘Cancaska’ and ‘Chester’ blackberries were packaged in snap-fit closed packages made from oriented poly(lactic acid), OPLA, and oriented poly(styrene), OPS, and stored at 3 °C and 85% RH for three weeks. Both cultivars exhibited an increase in pH, weight loss, SSC to TA ratio, and fungal count, and a reduction in firmness, anthocyanin content, TA, and SSC during storage. The changes in TA, SSC, SSC to TA ratio, and weight loss significantly depended on the packaging material while no such effect was observed on firmness, anthocyanin content, pH and fungal growth. Both cultivars demonstrated better quality in the OPS container with less weight loss, and decrease in SSC and TA. Blackberries in both OPS and OPLA containers met the “US standard No 1” grade for commercialisation for more than 12 days at 3 °C.     

1-MCP对切分哈密瓜保鲜效果的研究

以新疆哈密瓜(8601)为材料,在5℃贮藏温度下,研究了1-MCP 对切分哈密瓜生理、品质和食用安全性的影响。结果表明：1.0μl/L 1-MCP 处理可显著抑制贮藏期间果实乙烯释放量,保持果实的感官,硬度、糖度和高VC 的含量,抑制切分哈密瓜透明化,降低了切分哈密瓜的细胞膜脂质过氧化水平,抑制微生物的数目,延长了切分哈密瓜的货架期。     

Effect of fruit load on maturity and carotenoid content of clementine (Citrus clementina Hort. ex Tan.) fruits

BACKGROUND: Citrus fruits contain many secondary metabolites displaying valuable health properties. There is a lot of interest in enhancing citrus quality traits, especially carotenoid contents, by agronomic approaches. In this study the influence of carbohydrate availability on maturity and quality criteria was investigated in clementine fruits during ripening. Fruiting branches were girdled and defoliated after fruit set to obtain three levels of fruit load: high (five leaves per fruit), medium (15) and low (30). RESULTS: Considering the soluble solid content/titratable acidity (SSC/TA) ratio, it was found that fruits of the high and medium fruit load treatments reached maturity 1.5 months later than fruits of the control. At the time of maturity the SSC/TA ratio of fruits of all treatments was about 13.6. At harvest, fruits were 23% smaller and total sugar concentration of the endocarp was 12.6% lower in the high fruit load treatment than in the control. In contrast, the concentrations of organic acids and total carotenoids were 55.4 and 93.0% higher respectively. Total carotenoids were not positively correlated with either soluble sugars or total carbohydrates. CONCLUSION: Taken together, the results do not support the common view that carbohydrate availability directly determines carotenoid synthesis by influencing precursor availability. Copyright © 2012 Society of Chemical Industry     

Biocontrol of Postharvest Anthracnose of Mango Fruit with Debaryomyces Nepalensis and Effects on Storage Quality and Postharvest Physiology

Anthracnose is presently recognized as one of the most important postharvest disease of mango worldwide. To control the disease, chemical fungicides for a long time was widely used among fruit farmers, but recently found that pathogen had developed increasingly resistance to it. With people's growing desire of healthy and green food, finding new and environmentally friendly biological control approach was very necessary. In this paper, we provided a kind of new antagonistic yeast which enriched the strain resources and the efficacy of Debaryomyces nepalensis against postharvest anthracnose of mango fruit and the influence on quality parameters were investigated. The results showed that the decay incidence and lesion diameter of postharvest anthracnose of mango treated by D. nepalensis were significantly reduced compared with the control fruit stored at 25 °C for 30 d or at 15 °C for 40 d, and the higher concentration of D. nepalensis was, the better the efficacy of the biocontrol was. Study also found that 1 h was the best treatment duration and antagonistic yeast inoculated earlier had good biocontrol effect on anthracnose. Meanwhile, treatment by D. nepalensis could significantly reduce postharvest anthracnose of mango, delay the decrease in firmness, TSS, TA, and ascorbic acid value, and do not impair surface color during postharvest storage. Moreover, the increase in MDA (malondialdehyde) content and increase in cell membrane permeability of fruit treated by D. nepalensis was highly inhibited. The results suggested D. nepalensis treatment could not only maintain storage quality of mango fruit, but also decrease the decay incidence to anthracnose disease. All these results indicated that D. nepalensis has great potential for development of commercial formulations to control postharvest pathogens of mango fruit.     

邻苯基苯酚结合果蜡涂膜处理对采后贡柑贮藏品质的影响

为延长贡柑贮藏期,探究邻苯基苯酚结合果蜡涂膜处理对采后贡柑果实的保鲜效果,本研究以采后德庆贡柑果实为实验材料,研究了0.2％浓度邻苯基苯酚结合果蜡涂膜处理对采后贡柑在常温贮藏期间果实品质的影响,观察和测定了贮藏期间果实的腐烂率、硬度、可滴定酸(TA)、可溶性固形物(TSS)、维生素C(VC)、细胞膜的通透性、丙二醛(M...     

不同贮藏温度对黄桃采后品质和抗氧化能力的影响

本文主要研究了低温贮藏对黄桃果实贮藏品质和抗氧化能力的影响。黄桃采后预冷12 h,在0、4和10℃三个不同低温条件下进行贮藏。结果表明,0℃贮藏的黄桃采后腐烂率和褐变率均为0,显著低于4和10℃(P<0.05)。与4和10℃相比,0℃贮藏还可以明显抑制膜透率的升高,且贮藏期品质、抗氧化酶活性以及总抗氧化能力均保持在较高水平。在0℃下贮藏,果实能够维持较好的硬度、总糖、可溶性固形物、可滴定酸、维生素C、总酚和总黄酮的含量;同时0℃贮藏抑制了多酚氧化酶和过氧化物酶活力,而且有利于抗氧化酶维持较高的活性,缓解果实冷害。4和10℃下,硬度和维生素C含量显著下降(P<0.05),丙二醛含量显著上升(P<0.05)。采用聚类分析和主成分分析进行数据分析,聚类分析可以将19种生理和品质指标分为两个明显的独立簇,与主成分分析的结果大体一致,即14～21 d是不同温度贮藏的品质劣变点,且第一主成分可以很好地将硬度、维生素含量、可滴定酸含量与其他指标分开,这体现出黄桃果实品质指标和生理指标间的相似性与差异性。因此,0℃贮藏可以显著保持黄桃采后品质和抗氧化能力。     

1-MCP结合冰温贮藏对葡萄采后品质及相关生理代谢的调控

以“乍娜”葡萄为试材,研究0.5μL/L和1.5μL/L 2个用量的1-MCP处理结合冰温贮藏(温度－0.3℃±0.3℃)对葡萄采后主要品质及相关生理指标的作用效果。结果表明：冰温贮藏结合2个浓度的1-MCP处理均可在不同程度上提高葡萄贮藏好果率并降低质量损失率和果梗褐变指数,抑制葡萄果穗呼吸强度和乙烯生成速率的增加,并能够有效抑制果实丙二醛(malondialdehyde,MDA)、超氧阴离子自由基(O2－ ·)、过氧化氢(H2O2)含量和脂氧合酶(lipoxygenase,LOX)活性的增加,保持或增大超氧化物歧化酶(superoxide dismutase,SOD)和过氧化物酶(peroxidase,POD)的活性;1μL/L 1-MCP处理结合冰温贮藏作用效果较好,使葡萄贮期较普通冷库对照延长20d。综上所述,适宜浓度的1-MCP处理结合冰温贮藏有利于提高葡萄采后贮藏品质和果实抗性、延缓果实衰老,在鲜食葡萄无硫保鲜方面具有非常好的应用前景。     

A combination of marine yeast and food additive enhances preventive effects on postharvest decay of jujubes (Zizyphus jujuba)

We investigated the effects of marine yeast Rhodosporidium paludigenum in combination with a food additive, carboxymethylcellulose sodium (CMC-Na), on prevention of postharvest decay and food quality of Chinese winter jujubes. R. paludigenum (1 × 10⁸ cells/ml) combined with CMC-Na (0.3%) significantly increased the inhibition of black rot on jujubes at 25 °C when compared with R. paludigenum-alone treatment (5.8% vs. 20%, p < 0.05). The combination also reduced natural rot from 86% (control) to 56%. The combination caused transient changes in enzyme activities or contents of some oxidation reactive markers such as peroxidase (POD), superoxide dismutase (SOD), and malondialdehyde (MDA) of jujubes. The combination had no significant effect on the food qualities such as colour (chroma and hue angle), total soluble solid (TSS) and titratable acidity (TA) of the fruit. While enhancing these effects, CMC-Na did not affect the survival of R. paludigenum in nutrient yeast dextrose agar (NYDA) culture. Thus, we conclude that the combination of R. paludigenum and CMC-Na is a promising formulation to control postharvest decay of Chinese winter jujubes.     

低温贮藏对晚熟龙眼“立冬本”果实采后生理和品质的影响

研究了龙眼"立冬本"果实在采后(25±0.5)℃和(3±0.5)℃温度下的呼吸强度、细胞膜透性和品质的变化。结果表明:龙眼果实属于非呼吸跃变型果实;在(25±0.5)℃下贮藏4天,果实呼吸强度下降,之后明显上升;果实采后果皮细胞膜透性快速增加,果实易失重、衰老、腐烂和果皮褐变,贮藏后期果肉自溶;果肉可滴定酸和维生素C含量快速下降,总糖和蔗糖含量下降,还原糖含量先升后降,可溶性固形物含量在贮藏前期下降而后期上升,可溶性固形物和可滴定酸比值先升后降;贮藏后期果肉可滴定酸含量增加。而(3±0.5)℃低温贮藏可显著降低果实呼吸强度,抑制病原菌生长,延缓果实衰老和果皮细胞膜透性增加,延迟果皮褐变,减少果实失重和果肉营养成分变化,抑制果肉自溶,保持果实较高的品质,延长果实贮藏期。