臭氧在鲜切果蔬加工中的应用

鲜切果蔬属于生鲜食品,加工造成的机械损伤会引发一系列不利的生理生化反应,导致鲜切果蔬货架期变短,限制了鲜切果蔬工业的发展。臭氧(水)处理是一种高效、环保、节能的杀菌保鲜技术,可用于鲜切果蔬的杀菌保鲜。文章对臭氧(水)在鲜切果蔬保鲜中的应用进行了综述,介绍了臭氧(水)在鲜切果蔬加工中的研究现状,并对其应用前景进行了展望,以期为臭氧在鲜切果蔬工业中的应用提供参考。     

臭氧在鲜切果蔬保鲜中的应用

对臭氧在鲜切果蔬保鲜中的应用进行了综述。详细介绍了臭氧保鲜的机理、臭氧保鲜的影响因素、臭氧与其他保鲜技术在鲜切果蔬保鲜中的协同作用,并分析了臭氧在鲜切果蔬保鲜应用中存在的问题及今后的发展方向。     

臭氧水处理对鲜切猕猴桃品质的影响

为了研究臭氧水对鲜切猕猴桃保鲜效果的影响,本实验以"海沃德"猕猴桃为试材,研究了不同浓度的臭氧水处理对鲜切猕猴桃可溶性固形物、可滴定酸、失重率、色差、抗坏血酸含量及细菌总数的影响。结果表明,0.7mg/L的臭氧水处理可以减缓鲜切猕猴桃贮藏期间可溶性固形物含量、色差值(L*值和a*值)和抗坏血酸含量的下降,并可以显著降低鲜切猕猴桃表面的细菌总数,在贮藏14d时细菌总数保持在106CFU/g以内,可以满足鲜切果蔬对微生物安全性的要求。然而,不同浓度臭氧水处理对鲜切猕猴桃的失重率和可滴定酸含量没有显著影响。实验结果表明,采用浓度为0.7mg/L的臭氧水浸渍鲜切猕猴桃5min,并于4℃条件贮藏,可使鲜切猕猴桃的货架期由10d(对照组)延长至14d。     

臭氧水溶液的ORP、pH与灭大肠菌的研究

检测了通臭氧于除氯水中过程的ORP、pH以及臭氧灭大肠茵率.实验结果表明:臭氧水溶液ORP大于500mV时在短时间内具有灭绝大肠茵能力;可以通过控制饮用水的ORP达到控制臭氧浓度,从而达到对水的消毒目的.     

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。     

化学保鲜在国外鲜切果蔬上的应用进展

近年来,随着收入水平提高和生活节奏加快,鲜切果蔬为越来越多的人所接受。在介绍鲜切果蔬定义的基础上,着重介绍了鲜切果蔬化学保鲜剂包括消毒清洗剂、生理调节剂、钙类保鲜剂、抗褐变剂和抗菌剂5种保鲜剂对鲜切果蔬的影响及作用机理,同时就保鲜剂的使用方法进行了阐述。最后,对鲜切果蔬的发展前景及注意事项提出了几点看法。     

鲜切苹果臭氧水杀菌工艺研究

以红富士苹果为试材,在鲜切加工过程中,采用臭氧水进行杀菌处理,确定了臭氧水的最佳杀菌浓度、杀菌时间和杀菌温度,并研究了臭氧水杀菌处理对鲜切苹果低温贮藏期间菌落总数和品质指标的影响。结果表明,1.00 mg/L 15℃臭氧水处理鲜切苹果5 min,对其表面微生物的杀灭作用效果明显,在贮藏9 d时,该处理鲜切苹果的菌落总数仅是对照的1.7%。同时,该处理抑制了鲜切苹果的褐变,延缓了果实硬度、可溶性固形物和抗坏血酸含量的下降,降低了失重率。总之,1.00 mg/L 15℃臭氧水处理鲜切苹果5 min,杀菌效果和保持果实品质的效果均较好。     

可食涂膜在鲜切果蔬包装上的研究进展

通过对国内外研究现状和研究成果的分析和总结,介绍常用的鲜切果蔬保鲜方法,可食涂膜的种类、特点及应用,概括了可食涂膜在包装鲜切果蔬上的研究进展,为进一步开发可食涂膜材料在鲜切果蔬上的应用提供科学的研究基础。分析表明,可食涂膜绿色、环保,与包装系统结合能够达到保鲜鲜切果蔬的效果,并且能延长产品的货架期。大量研究结果表明,通过在鲜切果蔬表面建立可食涂膜能够在一定程度上保鲜鲜切果蔬,并且可食涂膜与活性包装相结合运用在保鲜鲜切果蔬方面的发展潜力较大,但是,可食涂膜对于影响鲜切果蔬的性质比如风味、营养物质有待进一步研究。     

鲜切果蔬非热杀菌技术的研究与应用

鲜切果蔬因具有即食、即用的优点而有着广阔的发展前景.组织损伤导致鲜切果蔬存在营养物质外流、易受微生物污染、贮藏期短等问题.而非热杀菌技术较热处理技术更能有效的保证鲜切果蔬原有的色、香、味及营养成分,据此本文主要概述了臭氧、超高压、辐照、高压静电场、超声波、紫外线、脉冲电场等非热杀菌技术的机理以及目前在鲜切果蔬行业的应用状况.     

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。     

不同质量浓度臭氧化水对鲜切西兰花贮藏品质的影响

采用不同质量浓度臭氧化水处理鲜切西兰花。结果表明:质量浓度2.0mg/L的臭氧化水处理组保鲜效果最优,在贮藏12d时与对照组相比,质量损失率降低24.37%,VC含量提高40.7%,多酚氧化酶酶活降低23.5%,过氧化物酶酶活降低25.6%;在4℃的条件下,质量浓度2.0mg/L的臭氧化水处理组鲜切西兰花贮藏期可达到15d。     

大气压冷等离子体在鲜切果蔬保鲜中的应用研究进展

鲜切果蔬因具有新鲜方便、无添加剂和营养价值高等优点而广受消费者喜爱,但是鲜切果蔬在加工和贮藏过程中极易受微生物污染,导致食品品质劣变并缩短货架期。大气压冷等离子体（Atmospheric cold plasma,ACP）是一种新型非热加工技术,广泛应用于食品及生物医药领域。本文综述了ACP对鲜切果蔬表面微生物的灭活效果以及对鲜切果蔬中酶活的作用,同时探讨了ACP处理对鲜切果蔬品质的影响,旨在为ACP在鲜切果蔬保鲜中的应用提供参考。     

臭氧水处理鲜切生菜贮藏期间的品质变化

研究了臭氧水处理鲜切生菜在 4℃贮藏期间的细菌总数、大肠菌群、PPO活性、Vc含量、失重率和感官质量的变化。试验结果表明 ,与对照相比 ,采用 0 1 8μg/L臭氧水处理可使鲜切生菜中细菌总数下将 1 5个数量级、大肠菌群数低于 3 0× 1 0 - 2 /g ,PPO活性被抑制、Vc损失减少 ,失重率降低 ,同时 ,贮藏至 9天 ,感官质量明显优于对照组。     

Dietitians' attitudes, perceptions, and usage patterns for fresh-cut fruit and vegetables.

PURPOSE: New fresh-cut fruit and vegetable products are being developed worldwide. Nutrition educators' perceptions of these products were studied. METHODS: Professional dietitians in Nova Scotia were asked to complete a questionnaire on their use of fresh-cut produce. The questionnaire also elicited their attitudes and perceptions about the convenience, taste/quality, nutrition/health benefits, cost, and safety of fresh-cut fruit and vegetables. RESULTS: Sixty-three percent of respondents reported eating five to six servings of fruit and vegetables a day. This group most frequently consumed fresh-cut fruit as snacks or dessert, and vegetables in stir-fry dishes or salads or cooked with meals. In general, fresh-cut fruit and vegetables were perceived as convenient, safe, and nutritious. While approximately 50% of participants felt fresh-cut produce did not differ in taste from whole fresh produce, almost the same number considered whole fresh produce superior in taste. CONCLUSIONS: Dietitians have a generally positive perception of fresh-cut products; however, there is uncertainty about the nutritional value, cost/benefit, and use of the products. Dietitians require more information on the nutrient value of these products and on suggested alternative uses. Attention should be paid to developing fresh-cut products that have good sensory quality.     

Efficacy of neutral electrolyzed water (NEW) for reducing microbial contamination on minimally-processed vegetables

Consumption of minimally-processed, or fresh-cut, fruit and vegetables has rapidly increased in recent years, but there have also been several reported outbreaks associated with the consumption of these products. Sodium hypochlorite is currently the most widespread disinfectant used by fresh-cut industries. Neutral electrolyzed water (NEW) is a novel disinfection system that could represent an alternative to sodium hypochlorite. The aim of the study was to determine whether NEW could replace sodium hypochlorite in the fresh-cut produce industry. The effects of NEW, applied in different concentrations, at different treatment temperatures and for different times, in the reduction of the foodborne pathogens Salmonella, Listeria monocytogenes and Escherichia coli O157:H7 and against the spoilage bacterium Erwinia carotovora were tested in lettuce. Lettuce was artificially inoculated by dipping it in a suspension of the studied pathogens at 10(8), 10(7) or 10(5) cfu ml(-1), depending on the assay. The NEW treatment was always compared with washing with deionized water and with a standard hypochlorite treatment. The effect of inoculum size was also studied. Finally, the effect of NEW on the indigenous microbiota of different packaged fresh-cut products was also determined. The bactericidal activity of diluted NEW (containing approximately 50 ppm of free chlorine, pH 8.60) against E. coli O157:H7, Salmonella, L. innocua and E. carotovora on lettuce was similar to that of chlorinated water (120 ppm of free chlorine) with reductions of 1-2 log units. There were generally no significant differences when treating lettuce with NEW for 1 and 3 min. Neither inoculation dose (10(7) or 10(5) cfu ml(-1)) influenced the bacterial reduction achieved. Treating fresh-cut lettuce, carrot, endive, corn salad and 'Four seasons' salad with NEW 1:5 (containing about 50 ppm of free chlorine) was equally effective as applying chlorinated water at 120 ppm. Microbial reduction depended on the vegetable tested: NEW and sodium hypochlorite treatments were more effective on carrot and endive than on iceberg lettuce, 'Four seasons' salad and corn salad. The reductions of indigenous microbiota were smaller than those obtained with the artificially inoculated bacteria tested (0.5-1.2 log reduction). NEW seems to be a promising disinfection method as it would allow to reduce the amount of free chlorine used for the disinfection of fresh-cut produce by the food industry, as the same microbial reduction as sodium hypochlorite is obtained. This would constitute a safer, 'in situ', and easier to handle way of ensuring food safety.     

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。     

Heterogeneous photocatalytic disinfection of wash waters from the fresh-cut vegetable industry

The effectiveness of photocatalytic disinfection for control of natural and potentially pathogenic microflora in wash waters used for fresh-cut vegetables was evaluated. Wash waters for lettuce, escarole, chicory, carrot, onion, and spinach from a fresh-cut vegetable processing plant were treated with a titanium dioxide (TiO2) photocatalytic system. The vegetable wash waters were impelled out with a pump at a flow rate of 1,000 liters/h and conducted through a stainless steel circuit to the filtration system to reach the TiO2 photocatalyst fiber, which was illuminated with a 40-W UV-C lamp. The microbial and physicochemical qualities of the wash water were analyzed. Heterogeneous photocatalysis was an effective disinfection method, reducing counts of bacteria, molds, and yeasts. Most of the treated wash waters had total bacteria reductions of 4.1 +/- 1.3 to 4.8 +/- 0.4 log CFU/ml after 10 min of treatment when compared with untreated water. Higher decontamination efficacy was observed in carrot wash water (6.2 +/- 0.1-log reductions), where turbidity and organic matter were lower than those in the wash waters for other vegetables. The tested heterogeneous photocatalytic system also was effective for reducing water turbidity, although chemical oxygen demand was unaffected after the treatments. The efficacy of the photocatalytic system for reducing microbial load depended on the physicochemical characteristics of the wash water, which depended on the vegetable being washed. The conclusions derived from this study illustrate that implementation of a heterogeneous photocatalytic system in the fresh-cut vegetable washing processes could allow the reuse of wash water.     

应用于鲜切果蔬中的保鲜技术研究进展

鲜切果蔬因其方便、健康、新鲜等特点日益受到人们的青睐,销售量逐年增加。鲜切果蔬又称为切割果蔬、半加工果蔬、调理果蔬等,通常是指改变了蔬菜、水果物理形状、但仍然保持其新鲜状态的果蔬制品或果蔬混合产品。其生产过程一般要经过清洗、分级、修整、切分、洗涤、干燥、包装、贮存、配送等工序,可供消费者直接食用或餐饮业使用。鲜切果蔬保鲜技术对果蔬的色泽、气味、质地、营养成分、组织状态等感官方面得以最大的保留,减少果蔬因经过清洗、去皮、等机械处理过程导致的品质改变。本论文主要对现阶段鲜切果蔬的保鲜技术研究进展进行综述,其主要技术包括物理、化学和综合保鲜技术,以期为今后更深入的研究与探索提供参考与借鉴,并对未来发展方向进行了展望。     

真空预冷处理对鲜切猕猴桃品质的影响

为延长鲜切果蔬的货架期,选取浆果类——猕猴桃为研究对象,研究真空预冷处理对鲜切猕猴桃贮藏品质的影响。结果表明:与对照组相比,真空预冷能够很好地起到保鲜鲜切猕猴桃的作用;其中预冷终温为2℃的鲜切猕猴桃在贮藏末期(6 d)的综合品质优于其它处理,其失重率为11.08%;果肉、果心硬度下降率分别为45.19%和33.98%;VC含量和色差ΔEab值与对照组差异明显。