鲜切水果加工工艺及保鲜技术的研究

近年来鲜切水果加工产业在国内快速发展。由于其具有营养、食用方便快捷等特点,具有较为广阔的市场前景。现就鲜切水果的发展现状、生理生化变化特点和后期的加工工艺技术展开探讨,提出物理保鲜、低温冷链储藏等多种新型的保鲜技术,希望能为鲜切水果的发展提供技术支持。     

茶多酚对鲜切水果保鲜的影响——以对苹果的作用为例

茶多酚是茶中的多酚类物质,有着良好的抗氧化功效,是一种绿色无毒害的保鲜剂,目前在食品加工中有着广泛应用,本文用实验探索茶多酚对于鲜切水果中的苹果的保鲜与抑菌效果,最终得出1g/L的茶多酚溶液在这两方面均表现最出色。     

鲜切水果品质控制研究进展

鲜切水果具有较大的市场前景,综述了鲜切水果品质控制的研究进展,介绍了水果加工与保鲜技术的研究进展,分析不同保鲜方法的利弊,对其发展趋势和商业前景进行了展望。     

天然防腐剂在鲜切水果和果汁保鲜中的研究进展

随着国民生活水平的提高,人们对低热量食品的需求不断增大,即食鲜切水果和果汁的消费也逐渐增加,它们的安全性越来越受到人们的重视。鲜切水果和果汁由于组织和形态被破坏极易受到病原微生物和腐败微生物的污染,如果加工或储存条件不当,极易造成微生物致病和腐败。微生物学、酶学、化学或物理学变化均能引起鲜切水果与未高温消毒果汁的质量损失。其中,微生物造成的损失非常重要,有两方面原因:一是微生物毒素或病原微生物对消费者的健康构成威胁,二是微生物腐败给消费者造成经济损失。使用防腐剂可以有效减少微生物污染增强安全性。天然防腐剂既能保证食品安全又能保持品质特征,近年来,将其用于鲜切水果与未高温消毒果汁以防止微生物腐败方面的研究备受关注。本文综述了来自动物、植物和微生物的天然防腐剂对鲜切水果和果汁中病原微生物及腐败微生物的抑菌作用。     

臭氧联合植酸处理对鲜切水果甘蓝品质的影响

为了提高鲜切水果甘蓝的品质、延长其货架期,本实验采用臭氧处理（30?mg/L,10?min）、植酸浸泡处理（0.5?mmol/L,15?min）、臭氧联合植酸处理（先0.5?mmol/L植酸浸泡15?min,然后30?mg/L臭氧处理10?min）对鲜切水果甘蓝进行保鲜研究,以未经任何处理的样品为对照组。将水果甘蓝切分成2?cm×5?cm的小块,分别经上述处理后装入聚乙烯保鲜袋中,置于4?℃冷库中贮藏,分别测定第0、2、4、6、8天的生理生化指标和菌落总数。结果表明：贮藏第8天时,臭氧联合植酸处理组的可溶性糖、可溶性蛋白含量最高,分别是对照组的1.21、1.28?倍;同时保持了较高的抗坏血酸、硫代葡萄糖苷和异硫氰酸盐的含量;并提高了总酚含量、苯丙氨酸解氨酶、超氧化物歧化酶活力,抑制了过氧化物酶、过氧化氢酶的活力;菌落总数相比对照组低2.10（lg（CFU/g））。综上所述,臭氧联合植酸处理能较好地保持鲜切水果甘蓝的品质,延长其货架期。     

螺旋藻多糖对鲜切苹果的保鲜效果

以红富士苹果为材料,研究螺旋藻多糖对鲜切苹果酶促褐变中关键酶及相关生理生化指标的影响。结果表明,螺旋藻多糖可显著抑制PPO活性、增强SOD和POD活性,从而减缓鲜切苹果的褐变程度;螺旋藻多糖可使鲜切苹果中总蛋白质、蔗糖、抗坏血酸、谷胱甘肽含量维持在较高能量水平,为延长贮藏期提供物质基础;螺旋藻多糖还有助于鲜切苹果中总酚的保持,提升鲜切水果抗逆性物质浓度,整体表现出显著综合保鲜效果。试验为螺旋藻多糖在鲜切水果保鲜中的应用提供研究思路和理论基础。     

纸和纸板制的生,鲜物保护材料

纸和纸板制的生、鲜物保护材料Ｔｈｅｂｉｏｌｏｇｉｃａｌｐｒｏｔｅｃｔｉｖｅｍａｔｅｒｉａｌｍａｄｅｂｙｐａｐｅｒａｎｄｐａｐｅｒｂａａｒｄ一、前言本文以生物体作为主要对象，对“生物、鲜物”的保护，即对纸、纸板的性能和用途以现代的观点进行了调研。作为典...     

微酸性电解水对鲜切云南红梨贮藏品质影响研究

目的研究微酸性电解水(slightly acidic electrolyzed water,SAEW)处理对鲜切云南红梨贮藏过程中品质的影响。方法以SAEW中有效氯质量浓度、料液比和处理时间为自变量,样品表面菌落总数的死亡数量级为响应值,应用响应面法优化其最佳处理条件。按该优化条件对红梨鲜切品进行处理并置于4℃环境中贮藏,定期测定菌落总数、维生素C含量、总糖含量、多酚氧化酶活性、质量损失率及p H值,探讨SAEW处理对鲜切云南红梨贮藏品质的影响。用无菌水处理做空白对照。结果 SAEW的最佳处理条件为:有效氯质量浓度30.00 mg/L、料液比1:15(m:V)、处理时间3.69 min。在此条件下,SAEW处理能够有效控制云南红梨鲜切品表面微生物数量,并延缓其贮藏过程中维生素C含量和总糖含量的衰减,抑制多酚氧化酶活性,而对质量损失率与p H均无显著影响。结论 SAEW在控制鲜切水果表面微生物危害和延缓品质衰减方面均有一定潜力,相关结果将为SAEW在鲜切水果加工中的应用提供理论依据。     

壳聚糖处理对鲜切菠萝防腐保鲜效果初探

对0．5％、1．0％、1．5％壳聚糖溶液处理鲜切菠萝的保鲜效果的影响进行了试验。结果表明，经壳聚糖溶液处理样品，鲜切菠萝的微生物生长、多酚氧化酶（PPO）活性被有效抑制；能有效减少VC、总糖的损耗；有一定的量效关系；鲜切菠萝的感官品质得到改善，延长贮藏期。     

鲜切莴苣生理生化变化及其保鲜技术的研究进展

该文基于近几年国内外有关鲜切莴苣的研究,分析莴苣加工后的品质变化,并总结了鲜切莴苣物理、化学和生物保鲜技术的研究现状,旨在为鲜切莴苣尤其是鲜切蔬菜保鲜技术的研究提供理论参考。     

几种主要产地猕猴桃的果籽营养成分比较

对湘西野生猕猴桃、湘西米良1号猕猴桃、陕西秦美猕猴桃、贵州中华猕猴桃的果籽含量及其营养成分进行分析对比。结果表明：湘西米良1号猕猴桃果籽含量及其粗脂肪、亚麻酸、微量元素硒含量均高于其它产地，但亚油酸含量低于其它产地；不同产地猕猴桃果籽Vc与氨基酸含量差别不大，贵州中华猕猴桃果籽VE最高。     

Pre-processed fruits as raw materials: part II—process conditions,demand and safety aspects

The demand for pre-processed fruits has grown rapidly in recent years as a result of consumer attention towards fresh, healthy and convenient foods. Most of the fruits are available seasonally and they are perishable, so it is necessary to have a continuous supply of the fruits to avoid the blockages in the fruit processing industry. The review is written in the purview of this issue, and it presents pre-processed fruits as a sustainable solution. The present review is part II of the series of articles on pre-processed fruits as the raw material for various food industries. The fruits covered here are mango, pineapple, pear, olive and papaya. The article continues to emphasise the critical processing and storage condition for these fruits ranked higher in terms of their production quantity and economic value. The fruits are critically reviewed for their processing, storage and safety aspects along with key research findings of different processing techniques. The important safety aspects associated with such processed commodities are also discussed.     

果汁中单宁脱除方法的研究进展

单宁是广泛存在于蔬菜和水果中的植物多酚,果汁生产中单宁会影响其口感、色泽和澄清度,因此,果汁生产中单宁的脱除对果汁产品质量的提高具有重要的作用。本文综述了果汁生产中单宁脱除方法(物理脱除法、化学脱除法、生物脱除法和其他方法) 的机理、优缺点、应用研究现状及前景。     

Dietary Bioactive Compounds and Their Health Implications

There is strong scientific evidence suggesting that regular consumption of fruits and vegetables is negatively associated with risk of developing chronic diseases. The 2010 Dietary Guidelines for Americans recommend at least 9 servings of fruits and vegetables a day based on a 2000 kcal diet. However, the average person in the United States consumes 3.6 servings of fruits and vegetables per day. In order to achieve the goal of at least 9 servings, we should continue educating Americans about the health benefits of fruits and vegetables and recommend consumers to eat a wide variety of fruits and vegetables. The key is to increase the amount up to 9 to 13 servings of fruits and vegetables a day in all forms. Fresh, cooked, and processed fruits and vegetables including frozen and canned, 100% fruit juices, 100% vegetable juices, and dried fruits are all considered as servings of fruits and vegetables. A wide variety of fruits and vegetables provide a range of nutrients and different bioactive compounds including phytochemicals (phenolics, flavonoids, and carotenoids), vitamins (vitamin C, folate, and provitamin A), minerals (potassium, calcium, and magnesium), and fibers. More and more evidence suggests that the health benefits of fruits and vegetables are attributed to the additive and synergistic interactions of the phytochemicals present in whole foods by targeting multiple signal transduction pathways. Therefore, consumers should obtain nutrients and bioactive compounds from a wide variety of whole foods for optimal nutrition and health well‐being, not from expensive dietary supplements.     

Sugar Composition and lnvertase Activity in Prickly Pear Fruit

Sucrose was the predominant sugar in peel samples and present in lesser amounts in pulp and juice samples of prickly pear fruit. The relative total content of glucose and fructose differed among species and within fruit tissues. Acid invertase activity was found in all fruits examined while neutral invertase activity was found in two of the three species. Red-skinned fruits had no neutral invertase activity and yellow-skinned fruits had relatively high neutral invertase activity. When both invertase activities were added, a pattern of distribution of invertase activity that corresponded with sucrose levels within fruits was observed. The overall total invertase activity levels in red-skinned fruits were about twofold that of the yellow-skinned fruits and fourfold that of purple-skinned fruits.     

柠檬酸处理对采后芒果保鲜效果的影响

为探索芒果采后果实保鲜新方法,“台农一号”芒果采后分别经0(对照)、5、10mmol/L 柠檬酸浸果10min后,常温贮藏,定期检测果实的常规品质、成熟进程和病情发展的变化。结果表明：柠檬酸处理使果实软化、果肉可溶性固形物增加及可滴定酸含量降低的速率减缓,果实的转黄指数和病情指数降低,说明适当水平的柠檬酸处理能有效延缓芒果采后果实的成熟进程,并且抑制果实腐烂发生。柠檬酸处理是芒果采后贮藏保鲜的一种可选新方法。     

凉果半成品的加工方式和存在的问题

凉果是热带亚热带地区比较流行的一种休闲食品。凉果半成品的加工是凉果生产中比较重要的一个环节。本文将凉果半成品的加工归类为食盐处理、亚硫酸盐处理、普通干燥处理和蒸煮打浆处理四种方式，并对每种加工方式的加工原理和工艺进行了综述，同时对其存在的问题进行了初步的分析。     

The Effects of Genetic Transformation of Tomato with Antisense Phospholipase D cDNA on the Quality Characteristics of Fruits and Their Processed Products

The physico-chemical characteristics of tomato juice and sauce, prepared from transgenic tomato fruits (Lycopersicon esculentum Mill, var. Celebrity) transformed with an antisense phospholipase D (PLD) cDNA construct, were evaluated. The antisense transformation resulted in a 30-40% reduction of PLD activity in ripe fruits. The transgenic fruits were firmer, possessed better red color, and flavor. The juice and sauce preparations from transgenic fruits showed improved red color, lycopene content, Brookfield viscosity, and increased levels of major flavor volatiles such as hexenal. The dry matter and ash contents, as well as the precipitate weight ratio (PPT) of the transgenic fruit products were significantly higher when compared to the products from control fruits. The vitamin C content of the transgenic fruits was also higher as compared to the control fruits. The results suggest that a reduction in PLD activity may lead to increased membrane stability and preservation of membrane compartmentalization that can have positive quality impacts in transgenic fruits and their products.     

短波紫外线处理对鲜切果蔬品质及抗氧化活性的影响研究进展

鲜切果蔬因具有营养、便利、新鲜、可食率达100%等特点,越来越受到人们的关注。但鲜切果蔬由于受到机械损伤,其品质下降、易被微生物污染。短波紫外线作为一种非热力杀菌技术,近年来被研究者们用于鲜切果蔬保鲜,得到了良好的效果。本文介绍了鲜切果蔬及短波紫外线技术的特点,综述了短波紫外线处理对鲜切果蔬安全品质、营养品质及感官品质的影响及短波紫外线处理对鲜切果蔬抗氧化物质及抗氧化活性的作用,并讨论短波紫外线技术在鲜切果蔬中的应用前景,为短波紫外线处理鲜切果蔬的深入研究和推广应用提供重要的理论依据和参考。     

茉莉酸甲酯对果蔬抗性、抗氧化活性及品质影响的研究进展

茉莉酸甲酯作为与抗损伤相关的植物激素和信号分子,外源应用可激发植物防御基因的表达,诱导其产生与机械伤害相似的防御效果。采后果蔬在贮藏和运输期间总酚、抗坏血酸以及谷胱甘肽等抗氧化物质含量下降,致使其抗氧化活性降低,且品质和抗性受到了不良影响,大大缩短了果蔬的货架期,造成了一定的经济损失。研究发现茉莉酸甲酯可通过提高果蔬抗性物质合成酶和抗氧化相关酶的活性增强果蔬抗性,有效维持果蔬的抗氧化活性、降低品质损失、延长货架期。本文对近些年国内外茉莉酸甲酯在果蔬应用上的研究进展进行了综述,聚焦于其对果蔬抗性、抗氧化活性及品质等方面的影响及作用机理,为今后茉莉酸甲酯在果蔬保鲜上的研究及应用提供参考。