柑橘采后品质变化及保鲜技术研究进展

柑橘Citrus spp.是中国南方重要的热带、亚热带果树,其果实具有较高营养价值。然而,柑橘果实采后容易发生腐烂、失水、营养损失和病害,导致果实品质劣变,商品价值降低。本文就柑橘果实采后外观色泽,果实水分,果肉糖、酸、维生素C含量变化,果实病害青霉病、褐斑病、枯水病、油斑病发生,以及低温贮藏、热处理、短波紫外线(UV-C)照射、化学保鲜剂、生物技术保鲜等保鲜技术的研究进展进行综述,为提高柑橘保鲜效果、保持柑橘果实采后品质、延长果实保鲜期提供科学依据与生产实践指导。     

野生紫果西番莲的开发利用

云南野杂果资源丰富,品种繁多。通过对野生紫果西番莲果实的营养成分分析和果实加工利用的研究,其营养丰富、味道鲜美,食疗效果显著,是高级天然饮料的理想原料,值得综合开发利用。     

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     

外源抗坏血酸处理对人工脱涩柿果的保鲜作用

该研究以广西中部地区的早熟品种‘牛心柿’(Diospyros kaki cv.Niuxin)的果实为材料,研究果实萼片施用5%抗坏血酸溶液处理对CO_2脱涩柿果采后贮藏期果实软化和细胞壁降解以及抗氧化体系等相关生理生化指标的影响。结果表明:抗坏血酸对人工脱涩后‘牛心柿’果实的保鲜效果明显,与空白和去离子水对照相比,外源抗坏血酸处理更好地延缓柿果实硬度的降低和总色差的升高。抗坏血酸处理后7~15 d,原果胶的下降速率和可溶性果胶的上升速率得以延缓,细胞壁降解酶PG和Cx活性均低于空白和对照。同时,外源抗坏血酸阻滞了整个贮藏期果实内源抗坏血酸的减少,并抑制了POD的活性和MDA的积累,果实自身抗氧化体系功能受到保护。此外,抗坏血酸处理还在一定程度上提高了果实还原糖的含量。因此,采后外源施用抗坏血酸不仅可以延长脱涩后鲜食柿果的货架期,而且还有助于提高果实的商品品质。     

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”品种杧果采后炭疽病和蒂腐病有显著控制效果,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 杧果,显著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,显著减少病害和腐烂损失,有利于提高采后杧果的商品率和远途运输及销售。     

紫果西番莲

紫果西番莲(Passiflora edulis Sims):属西番莲科西番莲属的多年生常绿藤本饮料植物,因果实卵圆形如鸡蛋,故又称鸡蛋果。原产巴西,现广植热带、亚热带地区。果实成熟时呈紫褐色。主要食用部分系为多汁的假种皮,具有独特的芳香气味,拌入砂糖和冰水,可制成芳香可口夏凉饮料。花美是庭园一种良好的观尝植物。     

采前果面喷施钙制剂对苹果果实品质的影响北大核心CSCD

以‘富士’、‘金冠’和‘粉红女士’3个苹果品种为试验材料,并用氯化钙、硝酸钙和氨基酸钙3种钙制剂在采前30 d对果实进行喷施处理,采用常规方法测定基本果实品质指标,应用顶空固相微萃取及气相色谱质谱联用技术等测定果实香气等13项品质指标,并结合主成分分析和线性加权求和等方法对钙制剂处理的果实品质进行综合评价,以探究比较钙制剂对不同品种苹果果实品质的改进效果,为提高苹果果实品质和品种改良提供理论依据。结果表明:(1)采前钙处理对‘富士’和‘金冠’的单果重影响不显著,但‘粉红女士’采用氯化钙和氨基酸钙处理后单果重显著上升。(2)采前用氯化钙处理显著提高了苹果果实的糖酸比和硬度等;硝酸钙处理能够显著提高果皮亮度和色泽饱和度等;氨基酸钙处理则显著提升了果实的各类香气物质含量。(3)主成分分析和综合评价结果显示,经氯化钙、硝酸钙和氨基酸钙处理后,各品种苹果果实品质的综合得分均高于对照,且以氨基酸钙处理后果实的品质综合得分最高。研究发现,采前30 d钙处理可有效提升苹果果实的色泽、糖酸比、硬度以及香气等品质,且以氨基酸钙的处理效果最佳,而且对‘粉红女士’苹果果实品质的提升效果最为明显。     

红富士苹果品质与生态气象因子关系的研究

通过对我国不同生态类型区红富士苹果果实品质的调查和实验室分析,应用多元统计分析,研究了不同生态类型区红富士果实品质差异及影响果实品质的主要气象因子．红富士苹果在我国陕西渭北、甘肃陇东和山东渤海湾地区呈现出果实大、果面光洁、果色鲜艳的特征;而在西南高地果色暗红;黄河故道地区果面粗糙、着色差、果肉松;宁夏地区果实偏小．经典范相关分析筛选出影响苹果品质因素的主要气象因子,不同品质因素受气象因子的影响各异,果实花青素含量主要受年总降雨量、１０月平均温度、７月平均最高气温、９月平均最低气温、９月日照时数等气象因子的影响     

两种微生物菌剂对西番莲果渣高温堆肥腐熟进程的影响

研究了在西番莲果渣堆肥体系中加入两种微生物菌剂（福贝和榕风）后的温度、C／N、NH4^＋ -N和NO3^- -N的动态变化及对西番莲果渣堆肥产品品质的影响．结果表明,在西番莲果渣中加入微生物菌剂能增加高温分解持续时间,加快物料C／N降低的速率,促进NH4^＋ -N向NO3^- -N转化,加快西番莲果渣堆肥腐熟化进程．添加福贝和榕风菌剂后,堆肥高温持续时间分别比对照（4d）增加7d和8d;腐熟后堆肥的NO3^- -N浓度分别比对照增加58．0％和64．2％．添加菌种显著增加了西番莲果渣堆肥的N、P、K养分含量,降低了堆肥容重,提高了堆肥总孔隙度和持水孔隙度,改善了堆肥产品的品质．两种菌剂间对西番莲果渣高温腐熟进程的影响没有显著差异,但福贝菌剂更有利于改善堆肥品质．     

果实热处理保鲜技术研究（综述）

应用热处理技术控制果实采后病虫害和延缓果实衰老是近年来果实保鲜领域的研究热点,本文概述热处理对果实形态、生理生化和品质的影响,以及热处理的应用现状与应用前景。     

O2和CO2配比对低温贮藏李品质及生理变化的影响

为了探索适宜‘黑宝石’李贮藏的气体参数,研究了不同气体成分(6.0%O2+5.0%CO2、6.0%O2+1.0%CO2、10.0%O2+5.0%CO2和10.0%O2+1.0%CO2)处理对贮藏及货架期‘黑宝石’李采后品质(硬度、总糖、可滴定酸和腐烂指数)、抗氧化酶(SOD、POD和CAT)活性及MDA含量的影响。结果显示:(1)在贮藏0~45 d期间,冷藏对照果实的腐烂指数在8%以下,其货架果实的硬度仍可下降;贮藏至75 d时,冷藏对照果实的腐烂指数达38%,而且其果实失去了软化能力。(2)气调处理可减缓低温贮藏李果实硬度的下降,降低果实的腐烂指数,维持货架果实的后熟能力,但6.0%O2+1.0%CO2处理对果实腐烂指数的影响不显著。(3)气调处理可提高低温贮藏李果实的SOD、POD和CAT活性,抑制这3种酶在货架模拟过程中的升高,且可降低低温贮藏及货架期果实的MDA含量。(4)气调贮藏中以6.0%O2+5.0%CO2处理的效果最佳,果实的贮藏期可达75 d。研究说明,常规冷藏(0~1.5℃)可满足‘黑宝石’李果实采后短期贮藏(<45 d)的需要,而适宜的气调贮藏可使其贮藏期限延长30 d左右。     

Impact of nitric oxide on shelf life and quality of nectarine (<Emphasis Type="Italic">Prunus persica</Emphasis> var. <Emphasis Type="Italic">nucipersica</Emphasis>)

Nectarine is an emerging fruit crop in India which has immense nutritional quality and fairly good amount of antioxidants. In India, peach orchards are being replaced by nectarine primarily because of fuzzless peel. However, shelf life of nectarine is lean due to its climacteric behaviour. Hence, we attempted to observe the effect of nitric oxide (NO), using its donor compound, namely sodium nitroprusside (SNP) on postharvest life and quality of ‘Silver Queen’ nectarine fruit. In this study, fruit of ‘Silver Queen’ nectarine were treated with various concentrations of SNP (0.25 mM, 0.5 mM, 1.0 mM, 1.5 mM) after harvesting at climacteric stage of maturity. Fruit were stored at ambient condition for further analysis on daily basis, after air drying at room temperature. Our results revealed that among the various concentrations of SNP, 0.5 mM was found to be best in reducing physiological loss in weight (PLW), maintaining firmness and retaining higher phenolics, antioxidant activity, exhibiting slower increase in lipoxygenase (LOX) and pectin methylesterase (PME) activity and better quality fruit up to 8 days than 4 days of untreated fruit. Hence, postharvest dip of ‘Silver Queen’ nectarine fruit in 0.5 mM solution of SNP could be recommended for enhancing the shelf life by 4 days.     

Variability of responses to 1-methylcyclopropene by banana: influence of time of year at harvest and fruit position in the bunch

To examine the effect of early‐climacteric (postripening) 1‐methylcyclopropene (1‐MCP) exposure on the shelf‐life and quality of green Cavendish bananas (Musa acuminata cv. Williams) from the middle section of the bunch, bananas were harvested bimonthly and treated with 100 μL L^?1 ethylene for 2 consecutive days prior to exposure to 0, 100, 300, 1000, 3000 or 10 000 nL L^?1 1‐MCP for 24 h prior to storage at 22°C. 1‐MCP treatment at a concentration of 300 nL L^?1 or above increased banana shelf‐life significantly compared with the control, regardless of the month in which fruit were harvested except March where a higher concentration was needed (3000 nL L^?1). Fruit harvested in May were the most responsive with a greater than twofold increase in shelf‐life. To examine the effect of fruit position in the bunch on 1‐MCP efficacy, green fruit from the top or bottom of bunches were treated with 100 μL L^?1 ethylene for 2 consecutive days prior to early‐climacteric 1‐MCP (300 nL L^?1) exposure for 24 h at 22°C. In spring and autumn but not in summer, application of 1‐MCP to early‐climacteric fruit was more effective in fruit from the top than in those treated from the bottom of the bunch, increasing shelf‐life. Firmness of 1‐MCP‐treated fruit was up to 19% greater than that of the control across the year, except in fruit from the bottom of the bunch. Given that 1‐MCP is less effective in extending the shelf‐life of summer‐harvested fruit (particularly those from the bottom of the bunch), we conclude that preharvest conditions and fruit position in the bunch affect their responsiveness to ethylene and their behaviour during the ripening process.     

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.     

Postharvest biology and technology of sapota: a concise review

Sapota is cultivated in many countries of tropical and subtropical climate. It is delicious, nutritive, and commercially grown mainly for fresh consumption. Postharvest life of sapota is very short due to its highly perishable nature and other many reasons such as quick ripening, faster senescence, rapid loss of moisture, microbial spoilage, and fruit sensitivity to cold storage. To maintain and/or increase the shelf life of sapota, proper postharvest management is required. Unfortunately, very little work has been done so far, with limited success, leaving scarce literature published on postharvest management technologies of sapota. Different pre and postharvest treatments to reduce metabolic activity and quality loss have been suggested. Moreover, proper storage temperature and packaging may be used to increase the shelf life of fruits. This review explores the postharvest technologies adopted to enhance the shelf life of sapota during storage and distribution channel.     

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.     

Postharvest temperature influences volatile lactone production via regulation of acyl-CoA oxidases in peach fruit

The biosynthesis of volatile compounds in plants is affected by environmental conditions. Lactones are considered to be peach‐like aroma volatiles; however, no enzymes or genes associated with their biosynthesis have been characterized. White‐fleshed (cv. Hujingmilu) and yellow‐fleshed (cv. Jinxiu) melting peach (Prunus persica L. Batsch) fruit were used as materials in two successive seasons and responses measured to four different temperature treatments. Five major lactones accumulated during postharvest peach fruit ripening at 20 °C. Peach fruit at 5 °C, which induces chilling injury (CI), had the lowest lactone content during subsequent shelf life after removal, while 0 °C and a low‐temperature conditioning (LTC) treatment alleviated development of CI and maintained significantly higher lactone contents. Expression of PpACX1 and activity of acyl‐CoA oxidase (ACX) with C16‐CoA tended to increase during postharvest ripening both at 20 °C and during shelf life after removal from cold storage when no CI was developed. There was a positive correlation between ACX and lactones in peach fruit postharvest. Changes in lactone production in response to temperatures are suggested to be a consequence of altered expression of PpACX1 and long‐chain ACX activity.