热杀菌剂处理对“紫花”和“留香”杧果贮藏品质影响?

５２±１℃热杀菌剂苯来特或ＴＢＺ等溶液浸果处理,对“留香”和“紫花”品种Ｍａｎｇ果采后炭疽病和蒂腐病有显控制效果,改善果实外观,延长贮藏寿命,提高贮藏品质,减少病害的腐烂损失６０％,获得在常温下贮藏１８ｄ的采后寿命和１００％的商品率。在热杀菌剂处理后,贮藏于低温１３±１℃下的Ｍａｎｇ果,显减慢果皮转黄和后熟软化,降低呼吸速率,延长贮藏寿命２￣３周以上,并且,显减少病害和腐烂损失,有利于提高采     

杀菌剂与果蜡处理对“紫花”芒果后熟软化及采后病害的影响

采后利用ＳＦ果蜡处理,可以推迟“紫花”芒果果皮转黄和后熟软化,增加果面光泽,减少果实失重率和果皮皱缩,提高贮藏品质,增加杀菌剂ＴＢＺ或普克唑处理对炭疽病和蒂腐病的防治效果。在不同浓度的ＳＦ果蜡处理比较中,１：１（蜡：水）浓度的果蜡稀释液较适合于“紫花”芒果的采后处理。     

杀菌剂与果蜡处理对“紫花”芒果后熟软化及采后病害的影响

采后利用ＳＦ果蜡处理,可以推迟“紫花”芒果果皮转黄和后熟软化,增加果面光泽,减少果实失重率和果皮皱缩,提高贮藏品质,增加杀菌剂ＴＢＺ或普克唑处理对炭疽病和蒂腐病的防治效果。在不同浓度的ＳＦ果蜡处理比较中,１：１（蜡：水）浓度的果蜡稀释液较适合于“紫花”芒果的采后处理。     

温度、抗坏血酸、柠檬酸和氯化钠对采后红毛丹果实几种生理指标与品质的影响

采后红毛丹（品种‘粉红’）果实贮于10℃下时呼吸速率下降、细胞膜透性减小、多酚氧化酶活性（PPO）下降、病害少;4℃下贮藏至第4天时即发生冷害;采后用3％抗坏血酸溶液、2％柠檬酸溶液和1％NaCl处理的红毛丹果实中含糖量和果皮花色素苷含量均不减小,其中以10℃下用化学药品处理的效果最显著。     

高O2或高CO2浓度气调贮藏对“那翁”甜樱桃采后生理和贮藏性的影响

研究了甜樱桃品种“那翁”（Prunus avium L.cv.Napoleon)在1℃的高O2浓度气调（CA－1：70％ O2＋0％,CO2）,高CO2浓度气调（CA－II：5％ O2＋10％ CO2）,自发气调（modified atmosphere package,MAP)和普通冷藏条件下果实生理,品质,耐藏性的变化,结果表明：与其他处理相比,高O2浓度的气调可以抑制果实腐烂,减少果肉中乙醇含量,但果实的丙二醛（MDA）含量迅速上升,褐变严重,高CO2浓度的气调能有效抑制MDA含量上升的速率和多酚氧化酶（PPO）活性,保持果实硬度和维生素C含量,减少果实腐烂和褐变,延长贮藏寿命,不同处理对果实可溶性固形物含量的影响不大。“那翁”甜樱桃在5％ O2＋10％ CO2气调中贮藏80d能保持果实固有的风味品质。在MAP下,70％O2＋0％CO2和普通冷藏中的适宜贮藏期分别为40d,20d和30d。     

地衣芽孢杆菌W10菌液和抗菌蛋白对桃果实贮藏保鲜效果的影响

以桃‘沪油018’(Amygdalus persica ‘Huyou 018’)果实为试验材料,经地衣芽孢杆菌W10菌液及其抗菌蛋白浸果后常温条件下(25 ℃)贮藏,定期测量桃果各项保鲜指标。结果表明,与对照桃果实比较,地衣芽孢杆菌W10菌液和抗菌蛋白处理可提高桃果实色泽、硬度和可溶性固形物含量,显著降低桃果失重率和腐烂率。经菌液处理桃果腐烂率降低至20%,菌液抑制桃果腐烂效果与多菌灵类似。菌液和抗菌蛋白在提高贮藏期桃果品质方面差异不显著。地衣芽孢杆菌W10菌液和抗菌蛋白应用于采后桃果的贮藏保鲜效果较好,潜力较大。     

丁香精油对冷藏冬枣果实腐烂及诱导抗病相关酶活性的影响

对不同浓度丁香精油处理冬枣果实在0℃贮藏期间(60d)及藏后25℃货架期(5d)的果实腐烂率、诱导抗病相关酶活性和总酚含量的变化特征进行分析,以探索丁香精油抑制冬枣果实腐烂与抗病性诱导的关系。结果表明:丁香精油处理能有效抑制冬枣贮藏期果实腐烂的发生,提高其苯丙氨酸解氨酶、多酚氧化酶和过氧化物酶活性,诱导总酚含量的增加。经丁香精油处理冬枣果实在贮藏60d后25℃货架期5d时的腐烂指数得到明显下降,同时保持了较高的苯丙氨酸解氨酶、多酚氧化酶、过氧化物酶活性和总酚含量,并以0.50%丁香精油处理的效果最显著,其贮藏后货架期的果实腐烂指数较对照下降了45.5%。可见,丁香精油抑制贮藏冬枣果实的腐烂与抗病相关酶活性的升高密切相关,抗病性诱导是丁香精油处理抑制冬枣采后果实腐烂的重要原因之一。     

采后处理对菠萝营养成分的影响

贮藏期间,杀菌剂处理可以推迟采后菠萝可溶性糖含量的减少,而对可滴定酸含量没有明显的影响。采后贮前加热４０℃２４ｈ处理的菠萝,其可溶性糖、可滴定酸等营养成分的变化与对照果实没有明显差异。与对照果实相比较,ＧＡ３处理果实除可溶性糖含量下降明显减少之外,可滴定酸和抗坏血酸含量显著增加。     

采后预温处理对草莓果实贮藏保鲜效果的影响

研究了采后预温处理对草莓果实贮藏保鲜的影响,结果表明,冷藏(5℃)条件下,贮前50℃预热处理30m in的果实腐烂率最低;室温贮藏(19℃~21℃)条件下,50℃预热处理30m in、5℃预冷处理30m in的果实腐烂率最低;贮藏前期,果实中超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量不断上升,预热处理能明显提高果实的SOD活性;贮藏后期,果实SOD活性不断下降、MDA含量持续上升,预处理能显著抑制果实SOD活性的下降和MDA含量的增加。     

热空气处理对杧果果实若干生理特性和贮藏效果的影响

采用紫花杧果为试材,以果实成熟季节的平均气温(30±2℃)为对照,研究35℃、38℃热空气分别处理24 h和48 h对果实生理生化特性和贮藏效果的影响。结果表明,与对照相比,温度升高或处理时间延长显著提高果皮MDA含量,抑制果实可溶性固形物含量的上升、可滴定酸的下降和果皮转黄,延缓果实的后熟过程。经38℃热空气24h和48h处理,病斑面积>50%的果实在第14天分别为45.8%和54.2%,果实发病率显著高于对照。而35℃热空气24h处理对上述指标的影响不明显。     

Effect of hot water treatment on development of anthracnose (Colletotrichum gloeosporioides) and quality of mango fruit at Jimma southwest Ethiopia

Anthracnose is the major postharvest disease of mango and occurs throughout mango producing areas of the world including Ethiopia. Evaluating effect of hot water treatment on development of anthracnose and quality of mango fruit is imperative. A total of three hot water levels 48, 52 and 56 °C at two time interval (5 and 10 min) were tested with factorial arrangement in completely randomised design. The study indicated that hot water treatment at different temperatures and time interval significantly (p < 0.001) affects disease development and shelf life and postharvest quality of mango fruits. Hot water treatments reduced the incidence and severity of anthracnose disease significantly (p < 0.001) in mango fruits as compared to control. There was a highly significant difference (p < 0.0001) on weight loss, total soluble solids, titratable acidity and fruit firmness of mango fruits due to treatment. The present study reviled that hot water treatment has a potential in reducing the postharvest loss due to anthracnose and improving the shelf life and quality of mango fruits. However, the reduction of disease pressure on fruits was not at applicable level, which call ups future effort on developing on integrated disease management strategies for reduction of postharvest loss of mango fruits.     

Effects of hot water treatments and storage temperatures on the ripening and the use of electrical impedance as an index for assessing post-harvest changes in mango fruits

The effects of hot water treatment and storage temperature (4°C, 13°C or 22°C) on the quality and impedance of outer and inner mesocarp of mango were assessed in two experiments during storage, impedance being a potential non‐destructive measure of tissue damage following heat treatment. Fruits were subjected to equivalent heat units at 36.5°C for 60 min plus 46.5°C for 43 min or 46.5°C for 90 min by hot water treatments (hwt) on the assumption of cumulative heat effects and a base temperature of 12–13°C. Fruit reflectance decreased whereas chroma and hue angle increased over storage time and also with increase in storage temperature. The yellow colour increased with a rise in storage temperature in hot water treated mangoes. Soluble solids content of mangoes held at 22°C was highest at 5 days of storage but decreased subsequently over storage time. Impedance of all fruits decreased with increase in frequency, storage temperature and time in store. The impedance of hwt mangoes was lower than that of non‐hwt fruits 8 h after immersion, but recovered almost to control levels on day 5 at 4°C or 13°C, but decreased gradually after 5 days at 13°C. Impedance of all mangoes stored at 22°C decreased continuously during storage. Impedance was higher in the inner mesocarp than outer pulp. Impedance of hwt fruits was poorly correlated with soluble solid content and chroma but well correlated with reflectance of fruit pulp at 22°C. Changes in impedance of mangoes are discussed in relation to physiological and biochemical changes that occur during heat treatment and storage.     

Effect of eco-safe compounds on postharvest quality preservation of papaya (<Emphasis Type="Italic">Carica papaya</Emphasis> L.)

Early ripening and susceptibility to microbial infection are major postharvest problems in papaya fruits. Being a tropical climacteric fruit, low-temperature storage is not successful in papaya. In this study, we demonstrate the effect of aqueous salicylic acid (1 and 2 mM), nitric oxide (1 and 2 mM), and calcium chloride (1 and 2%) to enhance the papaya shelf life at the ambient conditions with reduced disease incidence. Calcium chloride 2% was the most effective for maintaining postharvest quality. The fruits had good firmness and maintained TSS, acidity, total chlorophyll, free radical scavenging activity and ascorbic acid on the 6th day during ambient storage. Moreover, the weight loss, yellow color development and disease incidence were minimum in calcium chloride 2%, followed by 1% solution of calcium chloride. The nitric oxide (2 mM) maintained higher antioxidant capacity and total phenol content in fruits that was followed by 1 mM salicylic acid during storage. The result suggests that application of calcium chloride 2% could be an easy and effective technique for extending the shelf life without impairing fruit quality during storage.     

Chitosan and hot water treatments reduce postharvest green mould in ‘Murcott’ tangor

This study aims to evaluate the efficacy of hot water and chitosan treatments to control green mould caused by Penicillium digitatum in 'Murcott' tangor. P. digitatum conidial germination and mycelial growth were evaluated in assays in vitro to verify whether chitosan (0.5, 1 and 2%) or hot water (45, 50, and 55°C, for 30 s, 1, 2, and 5 min) acts directly on fungus development. In vivo assays consisted of inoculating the fruit with P. digitatum (10⁵ conidia ml⁻¹) 4 hr before the chitosan and hot water treatments. Subsequently, green mould incidence and severity were evaluated in fruits stored at 25°C/80% RH for 4 days. Also, treatments combining chitosan and hot water were investigated for controlling green mould and the effect on postharvest quality of fruit stored at 5°C/90% RH. The results showed that P. digitatum conidia germination and mycelial growth were significantly reduced by the hot water treatments especially at 50°C/5 min and 55°C/2 or 5 min in the first case and 50 and 55°C/5 min in the second. These two treatments, when applied alone, 1 min dipping in 2% chitosan or hot water at 50°C/5 min, significantly reduced green mould development in fruit kept at 25°C/80% RH or refrigerated. However, the hot water dip combined with chitosan did not improve green mould control on ‘Murcott’ tangor at room temperature or under refrigeration. Besides, chitosan and hot water did not impair fruit quality. Thus, chitosan and hot water could be an alternative to synthetic fungicides to control green mould in citrus while also contributing to a decrease in the postharvest losses of ‘Murcott’ tangor.     

中国芒果输出蒸热杀虫处理研究

中国芒果输出蒸热杀虫处理研究,包括海南产金煌、爱文、象牙和台农1号4个品种芒果鲜果内橘小实蝇Bactrocera dorsalis(Hendel)的卵和不同龄期幼虫的耐热力试验;芒果小规模、大规模蒸热杀虫处理试验;以及蒸热处理对芒果品质的影响等。结果显示,当蒸热室温度逐步达到50℃,芒果果心温度上升至47℃(使用饱和热蒸汽)并保持这一温度时,在不同处理时间(0、5、10、15、20min)条件下,不同品种芒果内橘小实蝇的耐热力由强至弱的发育期依次为2龄幼虫→3龄幼虫→1龄幼虫→卵,其中以金煌芒果(海南产芒果品种中果体最大,平均重量856g)内2龄幼虫的耐热力最强。完全杀灭海南产金煌芒果内橘小实蝇的卵和幼虫的蒸热条件是果心温度保持在47℃和使用饱和热蒸汽处理20min。金煌芒果的小规模、大规模蒸热杀虫处理试验的结果进一步确认和验证,在上述的蒸热处理条件下,总计数量分别为14000头和35000头最具耐热力的供试橘小实蝇2龄幼虫全部被杀灭(死亡率100%),完全可确保其检疫安全。同时,经蒸热杀虫处理后第7d和第12d的金煌芒果鲜果与对照鲜果品质(包括色泽,以及还原糖、蔗糖、总糖、总酸、维生素C和可溶性固形物的含量)的比较测定数据表明,蒸热温度47℃和使用饱和热蒸汽处理20min,除维生素C的含量有微量损失外,基本可保持鲜果的品质不变。     

The combined effect of 1‐methylcyclopropene and citral suppressed postharvest grey mould of tomato fruit by inhibiting the growth of Botrytis cinerea

1‐Methylcyclopropene (1‐MCP, 1 μl/L) and 1 × minimum fungicidal concentration (MFC) citral alone and in combination were used to treat on postharvest tomato fruits to investigate their influence on disease incidence and postharvest quality during fruit storage, which were stored at 90%–95% relative humidity and 25 ± 2°C. Weight loss, pH, hue angle (Hue^°), total soluble solid (TSS), ascorbic acid content, firmness and antioxidant enzyme activities were evaluated after each storage period. 1 μl/L 1‐MCP or 1 × MFC citral reduced weight loss, retarded peel colour changes and retained postharvest fruit quality. 1 μl/L 1‐MCP + 1 × MFC citral could better maintain firmness and ascorbic acid content and increase antioxidant enzyme activities, compared to other treatments. Disease incidence of tomato fruit was significantly decreased, and spore germination and mycelia growth of Botrytis cinerea were suppressed by the combined treatment with 1 μl/L 1‐MCP and 1 × MFC citral. These results indicate that the combined treatment could effectively delay postharvest tomato fruits senescence and inhibit postharvest pathogens in vitro.     

Polyamine Changes and Chilling Injury in Cold-stored Loquat Fruits

Free polyamine levels (spermine (SPM), spermidine (SPD), and putrescine (PUT)) were determined using thin-layer chromatography and fluorometric method in loquat (Eriobotrya japonica Lindl. cv. Dahongpao) fruits stored at 1℃ and 12℃ and in postharvest SPM treated fruits stored at 1℃ respectively to investigate the relationship between changes in polyamines and chilling injury. In the loquat fruits stored at 1℃, SPM level decreased gradually in the first two weeks, then increased sharply and reached a peak value after three weeks, thereafter it decreased rapidly. SPD level decreased steadily during the first three weeks and increased significantly afterwards. PUT level evolved in a similar way as the SPM level did except that it increased slowly in the first two weeks. The fruit showed symptom of chilling injury manifested as flesh leatheriness after three weeks. However, no significant increase and decrease of these three polyamines was detected during storage at the nonchilling temperature (12℃). The SPM-treated fruits maintained high levels of SPM and SPD and remained low level of PUT during storage at 1℃, and no symptom of chilling injury was observed. These results suggested that the increase in SPM level in response to chilling exposure might serve as a defense mechanism against chilling injury while the accumulation of PUT could be a cause of the stress-induced injury and the increase in SPD level could be a consequence of this kind of stress.     

Mango - Postharvest Biology and Biotechnology

Mango is one of the choicest fruits in the world and popular due to its delicate taste, pleasant aroma and nutritional value. Mango is indigenous to north-east India and north Burma, but now grown in over 90 countries. In the past two decades, mango production has increased appreciably with international trade jumping approximately four-fold valued close to US$ 950 million. Mango belongs to the category of climacteric fruits and its ripening is initiated and proceeded by a burst in ethylene production and a dramatic rise in the rate of respiration. Although there are a few hundred mango cultivars grown in the Indian subcontinent and other parts of the world, the most popular cultivars are generally highly perishable and ripen within 7 to 9 days of harvest at ambient temperature. Currently, the export potential and international trade of mango is limited due to several factors such as its perishable nature, disease and pest infestation, and susceptibility of certain premium cultivars to chilling injury when stored at low temperatures. Efforts are ongoing to develop technologies for improved storage and packaging, and overcome limitations encountered during storage and transit. Controlled atmosphere (CA) and hypobaric storage of mango are powerful means to overcome its perishable nature. The composition of CA varies among cultivars to ensure its original taste, flavor and aroma. Edible coating on the fruit skin may further cut down the rate of deterioration. Recently, significant advances have been made in understanding ripening characteristics of mango at the molecular level. Candidate genes related to ethylene biosynthesis and signalling, cell wall modification, aroma production and stress response have been cloned and characterized for future use in mango improvement. Efforts are also being made to establish a suitable transformation and plant regeneration system so that transgenic mango with added value and increased shelf life for long distance transportation could be developed.     

Salicylic acid influences lenticel discolouration and physiological and biochemical attributes of mango (<Emphasis Type="Italic">Mangifera indica</Emphasis> L.) fruits

Lenticel discolouration (LD) has now emerged as a leading postharvest threat in mango, which interferes with the face value of fruits, thereby affecting the trade and causing huge monetary losses to our country. For its management, we designed an experiment using salicylic acid at 200, 400 and 600 ppm concentration along with control fruits, as a dip treatment for 5 min. Our results revealed that salicylic acid at 200 ppm was not only effective in reducing LD significantly but also reduced the activities of polyphenol oxidase (PPO) (0.397 ?A₄₁₀ O.D min^?1 g^?1 FW), peroxidase (POD) (0.050 ? A₄₇₀ O.D min^?1 g^?1 FW), and lipoxigenase (LOX) (3.227 µmol min^?1 g^?1 FW) enzymes and helped in increasing the total phenolics (15.46 mg gallic acid equivalent 100 g^?1). This treatment also suppressed the rates of ethylene evolution (0.521 µL kg^?1 h^?1) and respiration (34.46 mL CO₂ kg^?1 h^?1) over untreated mango fruits. With respect to quality parameters, the significant decrease in postharvest decay (23.3%) occurred without any adverse effect on soluble solids concentrates (16° B) and total carotenoids (4.1 mg 100 g^?1pulp). Thus, keeping all parameters (physical, physiological, biochemical and quality) in view, salicylic acid at 200 ppm was most effective as a postharvest dip treatment for reducing LD in mango during storage or marketing without adversely affecting the fruit quality.     

Exogenous Nitric Oxide Delays Ripening and Maintains Postharvest Quality of Pointed Gourd During Storage

This study was aimed to assess the effect of nitric oxide (NO; 1 and 2 mM) on shelf life and quality of pointed gourd. Fruits were stored at 12 °C for 14 days with simulated ambient storage for 3 days (7 + 3 and 14 + 3) to mimic the marketing period. NO treatment significantly improved the postharvest shelf life as compared to control samples. The fruits underwent to the application of NO (2 mM) effectively maintained the chlorophyll, phenolics, antioxidant activity and membrane integrity. It suppressed weight loss, yellow color development, lignin formation, and electrolytic leakage. Activity of enzymes (PAL and LOX) was also influenced positively by NO application. Postharvest treatment of NO (2 mM) could be suggested as an eco-safe and effective technique for enhancing the shelf life without hampering quality of pointed gourd.