不同真空包装净菜菌相组成及生长趋势比较

主要以真空包装山药段、南瓜、红薯块、土豆块、芋艿、香芋块、紫薯块为原料,比较不同种类的鲜切净菜的初始和腐败时的菌相组成和生长趋势。实验结果表明:净菜中的主要微生物包括酵母菌属、乳酸菌属、肠杆菌科、假单胞菌属和微球菌属。山药段、南瓜、红薯块、土豆块、芋艿、紫薯中酵母菌初始数量较多,在培养一段时间后,均呈现增长趋势;净菜中的乳酸菌数量初始都超过了2.0lgcfu/g,并且都呈现了显著的增长;净菜初始的肠杆菌科含量都超过了3.0lgcfu/g;但山药段、土豆块、芋艿、紫薯块中的肠杆菌科呈增长趋势,而香芋块、南瓜和红薯块中的肠杆菌科出现了下降趋势;香芋、芋艿的假单胞菌属、微球菌属生长迅速,山药段、南瓜、红薯、土豆块、紫薯块中的微球菌属都呈现下降的趋势。      

不同真空包装净菜菌相组成及生长趋势比较

主要以真空包装山药段、南瓜、红薯块、土豆块、芋艿、香芋块、紫薯块为原料,比较不同种类的鲜切净菜的初始和腐败时的菌相组成和生长趋势 实验结果表明:净菜中的主要微生物包括酵母菌属、乳酸菌属、肠杆菌科、假单胞菌属和微球菌属 山药段、南瓜、红薯块、土豆块、芋艿、紫薯中酵母菌初始数量较多,在培养一段时间后,均呈现增长趋势;净菜中的乳酸菌数量初始都超过了2.0lg cfu/g,并且都呈现了显著的增长;净菜初始的肠杆菌科含量都超过了3.01g cfu/g;但山药段、土豆块、芋艿、紫薯块中的肠杆菌科呈增长趋势,而香芋块、南瓜和红薯块中的肠杆菌科出现了下降趋势;香芋、芋艿的假单胞菌属、微球菌属生长迅速,山药段、南瓜、红薯、土豆块、紫薯块中的微球菌属都呈现下降的趋势.     

鲜切果蔬包装的研究现状与进展

包装在维持鲜切果蔬品质、延长货架寿命等方面发挥着重要的作用.本文综述了近年来国内外包装材料在鲜切果蔬保鲜方面的研究进展与应用.介绍了鲜切果蔬的包装技术,包括气调包装、涂膜包装和智能包装等,总结了其优缺点及应用现状,并且讨论了鲜切果蔬包装未来的发展趋势.     

鲜切果蔬包装的研究现状与进展

包装在维持鲜切果蔬品质、延长货架寿命等方面发挥着重要的作用。本文综述了近年来国内外包装材料在鲜切果蔬保鲜方面的研究进展与应用。介绍了鲜切果蔬的包装技术,包括气调包装、涂膜包装和智能包装等,总结了其优缺点及应用现状,并且讨论了鲜切果蔬包装未来的发展趋势。      

气调包装对混合鲜切果蔬保鲜效果的影响

以包装盒中充入空气为对照组,设置3组不同浓度的气调包装气氛比例,对预处理后的杨桃、砀山梨、黄瓜、小麦草4种混合鲜切果蔬进行包装,于4℃贮藏,通过测定并分析其理化指标,判断混合鲜切果蔬品质。结果表明,5%O₂+5%CO₂+90%N₂处理的混合鲜切果蔬贮藏8d后的感官品质较高,失重率较低,色泽和硬度保持良好,可溶性固形物含量降低较缓,微生物滋长得到抑制。说明气调包装对杨桃、砀山梨、黄瓜、小麦草4种混合鲜切果蔬有良好的保鲜效果,其中5%O₂+5%CO₂+90%N₂气氛比例下的保鲜效果最好。     

Effect of gamma irradiation on microbial growth and sensory quality of fresh-cut lettuce

Fresh-cut lettuce was irradiated and microbiological and sensory quality was examined during storage at 4 degrees C. Experimental results showed that the number of aerobic mesophilic bacteria on fresh-cut lettuce irradiated with 1.0 kGy was reduced by 2.35 logs and sensory quality was maintained best during storage for 8 days at 4 degrees C. It was indicated that Gompertz model could predict the bacterial number on fresh-cut lettuce if the initial level was known.     

鲜切果蔬包装技术研究进展

鲜切果蔬因失去外层组织保护,再加上微生物侵害,品质不易保持。适当的包装可以从改善鲜切果蔬周围环境、减少微生物数量、延长货架期和维持鲜切果蔬品质等方面起重要作用。本文结合鲜切果蔬保鲜过程中的品质变化特点,对国内外鲜切果蔬包装技术的发展动态进行了研究,系统总结和分析了气调包装、涂膜包装、真空包装等不同包装技术的保鲜原理与研究进展,归纳了适合鲜切果蔬的包装技术参数;同时,结合鲜切果蔬包装的技术要求,提出了鲜切果蔬包装的研究趋势。该文为鲜切果蔬包装技术与装备的研究提供参考。      

鲜切果蔬精准保鲜包装技术的研究进展

鲜切果蔬因具有即食即用、方便营养及新鲜安全等特点受到广大消费者的青睐。但最小加工处理造成的机械损伤不利于鲜切果蔬品质的保持,限制了果蔬加工业的发展。因此,如何有效地保持品质、延长货架期是鲜切果蔬加工过程中需要解决的关键问题。而适当的精准包装可以改善鲜切果蔬周围环境、减少微生物数量,达到延长货架期和维持品质的作用。但不同种类的鲜切果蔬通常因其自身特点需要采用不同的包装技术。该文综述了鲜切果蔬分类及其适用包装技术的研究进展,系统分析了低温贮藏、气调包装、臭氧水处理、真空包装、超高压包装、可食性涂膜、纳米包装及微胶囊包装技术的保鲜原理及其在鲜切果蔬中的应用,旨在为今后鲜切果蔬包装技术的研究提供参考。     

Effect of high oxygen modified atmosphere packaging on microbial growth and sensorial qualities of fresh-cut produce.

The application of High Oxygen Atmospheres (HOA) (i.e. > 70% O2) for packaging ready-to-eat vegetables was evaluated as an alternative technique for low O2 Equilibrium Modified Atmosphere (EMA) packaging (3% O2-5% CO2-balance N2) for respiring products. Comparative experiments between both techniques were performed in-vitro and in-vivo. Typical spoilage causing microorganisms (Pseudomonas fluorescens, Candida lambica), the moulds Botrytis cinerea, Aspergillus flavus and the opportunistic psychrotrophic human pathogenic microorganism associated with refrigerated minimally processed vegetables. Aeromonas caviae (HG4), showed a retarded growth during the conducted in-vitro studies at 4 degrees C in 70%, 80% and 95% O2 as examples of HOA compared to the in-vitro experiments in 5% O2 (as example of EMA packaging) and the effect was more pronounced in 95% O2. The effect of the high O2-concentrations on the human pathogen Listeria monocytogenes resulted in an extended lag phase (95% O2). The plant pathogen Erwinia carotovora was increasingly stimulated by increasing high O2-concentrations. During a storage experiment of three types of ready-to-eat vegetables (mushroom slices, grated celeriac and shredded chicory endive), which are sensitive to enzymatic browning and microbial spoilage, the effect of EMA and HOA (95% O2-5% N2) on their quality and shelf life was compared. High O2 atmospheres were found to be particularly effective in inhibiting enzymatic browning of the tested vegetables. Also, the microbial quality was better as a reduction in yeast growth was observed. The HOA can be applied as an alternative for low O2 modified atmospheres for some specific types of ready-to-eat vegetables, sensitive to enzymatic browning and spoilage by yeasts.     

鲜切果蔬抗菌物质与抗菌包装应用研究进展

针对鲜切果蔬易出现腐败微生物和食源性致病菌生长繁殖的问题,文章综述了鲜切果蔬抗菌包装应用研究进展,分析了果蔬中存在的腐败微生物和致病菌,介绍了3大类用于鲜切果蔬包装中的抗菌物质(有机抗菌剂、无机抗菌剂和天然抗菌剂),并详细总结了3种抗菌包装的形式(抗菌涂层包装、抗菌薄膜包装和抗菌小袋包装)及其释放机制。鲜切果蔬抗菌包装与其他保鲜手段联用,将产生巨大的应用价值,抗菌包装也将朝着更加绿色、安全的方向发展。     

国内鲜切果蔬包装的研究现状

包装是保持鲜切果蔬外观品质、质地品质、营养品质和风味品质的重要生产环节。本文简述了鲜切果蔬品质的变化,概述了适用于鲜切果蔬的包装材料,并对抑制鲜切果蔬不良生理变化的包装方法进行了介绍。      

Effect of packaging under vacuum or under nitrogen on the keeping quality of Danedar khoa

A khoa variety popularly known as Danedar khoa, which has a very short life under ambient conditions, was studied for its shelf life at room and refrigerated temperatures under controlled conditions after packaging in a flexible material (poster paper/aluminium foil/low-density polyethylene [LDPE]). The samples were observed periodically for characteristics such as moisture content, peroxide value, titratable acidity and overall acceptability. Samples packed under nitrogen and stored under refrigeration were found to be distinctly superior in all respects.     

净菜商品化处理中品质变化及其控制的研究

净菜的生产和消费已成为现代社会发展的趋势,但其具有特殊的加工特点,品质维护难度很大,对净菜商品化处理过程中品质变化及其控制措施进行了论述。     

高氧气调包装对鲜切胡萝卜的保鲜效果

研究了不同氧分压条件对鲜切胡萝卜保鲜效果的影响,评定其在贮藏过程中感官品质、呼吸强度、PPO、POD、PAL活性的变化。结果表明,40%氧气包装不适合鲜切胡萝卜贮藏保鲜。100%氧气包装的保鲜效果最好,可有效抑制鲜切胡萝卜呼吸强度以及PPO、POD、PAL的活性。60%、80%氧气包装的保鲜效果次之,但均可起到保鲜的作用。      

Recent advances in modified atmosphere packaging and edible coatings to maintain quality of fresh-cut fruits and vegetables

Processing of fruits and vegetables generates physiological stresses in the still living cut tissue, leading to quality deterioration and shorter shelf life as compared with fresh intact produces. Several strategies can be implemented with the aim to reduce the rate of deterioration of fresh-cut commodities. Such strategies include low temperature maintenance from harvest to retail and the application of physical and chemical treatments such as modified atmosphere packaging (MAP) with low O₂ and high CO₂ levels and antioxidant dips. Other technologies such as edible coatings with natural additives, new generation of coatings using nanotechnological solutions such as nanoparticles, nanoencapsulation, and multilayered systems, and nonconventional atmospheres such as the use of pressurized inert/noble gases and high levels of O₂ have gained a lot of interest as a possibility to extend the shelf life of minimally processed fruits and vegetables. However, the high perishability of these products challenges in many cases their marketability by not achieving sufficient shelf life to survive the distribution system, requiring the combination of treatments to assure safety and quality. This review reports the recent advances in the use of MAP, edible coatings, and the combined effect of both technologies to extend the shelf life of fresh-cut fruits and vegetables.     

Effects of plasma-activated water on microbial growth and storage quality of fresh-cut apple

Fresh-cut ‘Fuji’ apples were immersed for 5 min in plasma-activated water (PAW) generated, by plasma generated with sinusoidal voltages at 7.0 kHz with amplitudes of 6 kV, 8 kV, and 10 kV, designated PAW-6, PAW-8, and PAW-10, respectively. The control group was soaked in distilled water for 5 min instead of PAW. The results indicated that the growth of bacteria, molds, and yeasts was inhibited by PAW treatments during storage at 4 ± 1 °C, especially the microbial inactivation with PAW-8, which was the most efficient. PAW-8 reduced the microbial counts by 1.05 log₁₀CFU g⁻¹, 0.64 log₁₀CFU g⁻¹, 1.04 log₁₀CFU g⁻¹ and 0.86 log₁₀CFU g⁻¹ for aerobic bacteria (aerobic plate counts), molds, yeasts and coliforms on day 12, respectively. In addition, the bacterial counts of fresh-cut apples treated with PAW were <5 log₁₀CFU g⁻¹, which did not exceed to the existing China Shanghai local standard (DB 31/2012–2013) during 12 days of storage. PAW treatments reduced superficial browning of fresh-cut apples without affecting their firmness and titratable acidity. In addition, no significant change was observed in antioxidant content and radical scavenging activity between the PAW-treated and control groups. It is suggested that PAW is a promising method for preservation of fresh-cut fruits and vegetables, which is usually beneficial to the quality maintenance of fresh-cut fruits and vegetables during storage.     

Effect of vacuum-steam-vacuum treatment on microbial quality of whole and fresh-cut cantaloupe

Minimally processed fruits and vegetables have a limited shelf life because of deterioration caused by spoilage microflora and physiological processes. Cutting may increase microbial spoilage of fruits through transfer of microflora on the outer surfaces to the interior tissue. The objectives of this study were to use the vacuum-steam-vacuum (VSV) process to reduce indigenous spoilage microflora on the surface of cantaloupes and to investigate the effects of such treatments on transfer of spoilage microflora from the cantaloupe surface to the fresh-cut melon during rind removal and cutting. Whole cantaloupes were treated in the VSV processor, and fresh-cut pieces prepared from treated and control samples were stored at 5 and 10 degrees C for up to 9 days. Presence and growth of mesophilic bacteria, yeasts and molds, and Pseudomonas spp. were determined in fresh-cut samples during storage. Texture and color (CIE L*, a*, and b*) also were measured during storage. VSV treatment resulted in a 1.0-log reduction of aerobic mesophilic bacteria, a 2.0-log reduction of yeasts and molds, and a 1.5-log reduction of Pseudomonas spp. on cantaloupe surfaces. VSV treatment significantly reduced transfer of yeasts and molds and Pseudomonas spp. from whole cantaloupe surface to fresh-cut pieces during preparation (P < 0.05). Texture and color of the fresh-cut pieces prepared from the VSV-treated whole melons were similar to those of the controls. The results of this study indicate that the use of the VSV process to reduce the surface populations of yeasts and molds and Pseudomonas spp. on whole cantaloupes will reduce subsequent transfer of these microbes to fresh-cut pieces and enhance the microbial quality of the fresh-cut product.     

Prediction of microbial growth in fresh-cut vegetables treated with acidic electrolyzed water during storage under various temperature conditions.

Effects of storage temperature (1, 5, and 10 degrees C) on growth of microbial populations (total aerobic bacteria, coliform bacteria, Bacillus cereus, and psychrotrophic bacteria) on acidic electrolyzed water (AcEW)-treated fresh-cut lettuce and cabbage were determined. A modified Gompertz function was used to describe the kinetics of microbial growth. Growth data were analyzed using regression analysis to generate "best-fit" modified Gompertz equations, which were subsequently used to calculate lag time, exponential growth rate, and generation time. The data indicated that the growth kinetics of each bacterium were dependent on storage temperature, except at 1 degrees C storage. At 1 degrees C storage, no increases were observed in bacterial populations. Treatment of vegetables with AcEW produced a decrease in initial microbial populations. However, subsequent growth rates were higher than on nontreated vegetables. The recovery time required by the reduced microbial population to reach the initial (treated with tap water [TW]) population was also determined in this study, with the recovery time of the microbial population at 10 degrees C being <3 days. The benefits of reducing the initial microbial populations on fresh-cut vegetables were greatly affected by storage temperature. Results from this study could be used to predict microbial quality of fresh-cut lettuce and cabbage throughout their distribution.     

低温结合气调包装处理对鲜切胡萝卜品质的影响

该研究以鲜切胡萝卜为对象,采用低温结合气调包装对鲜切胡萝卜进行处理,研究不同保鲜方式对鲜切胡萝卜品质的影响。鲜切胡萝卜经气调(气体组成分别为5%O₂+5%CO₂+90%N₂、5%O₂+10%CO₂+85%N₂、10%O₂+5%CO₂+85%N₂)包装后,(4±1)℃下在保鲜盒中贮藏,每3 d测定感官品质、失重率、可溶性固形物含量、抗坏血酸含量、胡萝卜素含量、菌落总数、丙二醛(malondialdehyde,MDA)含量和以及超氧化物歧化酶(superoxide dismutase,SOD)和过氧化氢酶(catalase,CAT)活性等指标。结果表明,低温结合5%O₂+10%CO₂+85%N₂气调包装处理组有效地保持了鲜切胡萝卜的品质,减少了水分的流失,延缓了营养物质可溶性固形物、胡萝卜素以及抗坏血酸含量的下降,抑制了MDA含量...