切分及烹调对叶类蔬菜品质的影响

随着我国经济的发展,人们对生活质量的追求也越来越高,其中叶类蔬菜的品质也越来越受到人们的重视。本文主要研究切分与烹调对生菜、芥菜、菜心等多种叶类蔬菜原材料的影响,研究内容分为对叶绿素含量的影响,对亚硝酸盐含量的影响和对维生素C含量的影响三个方面,从而探寻影响叶类蔬菜品质的加工条件。相关研究结果显示,切分后经过烫漂,会使叶类蔬菜中的叶绿素、亚硝酸盐和维生素C的含量都呈下降趋势。而对于汽蒸、油炒和烫漂三种烹调方式来说,汽蒸对叶类蔬菜含量的损失相对较小,是比较值得推广的一种烹调方式~([1])。     

切分及烹调对叶类蔬菜品质的影响

以芥菜、菜心、生菜等为主要原材料,研究切分方式与烹调方式对叶类蔬菜中维生素C、叶绿素和亚硝酸盐含量的影响,以明确加工条件对叶类蔬菜品质的影响。结果表明,切分后烫漂,叶类蔬菜中维生素C较新鲜蔬菜下降超过40%,亚硝酸盐含量下降超过45%,叶绿素下降不明显,且随细胞液的流失有明显上升趋势;油炒、烫漂和汽蒸三种烹饪方式对叶类蔬菜中叶绿素、维生素C、亚硝酸盐影响的研究表明,汽蒸加工可以保留叶类蔬菜中60~67%的维生素C,可降低40~70%的亚硝酸盐含量,而对叶绿素含量影响不大,是一种较理想的营养烹饪方式。本论文的研究成果具备良好的理论与实践意义,对减少叶类蔬菜烹饪加工过程中营养成分的损失、有害物质的产生、提高叶类蔬菜烹饪品质起到良好的方法借鉴。     

臭氧水在鲜切蔬菜贮藏保鲜中应用的研究进展

鲜切蔬菜属于生鲜食品,是一种新兴的蔬菜加工产品,而去皮、切分会破坏蔬菜结构,给鲜切蔬菜带来不利的物理影响,还会导致引发一系列不利的生理生化反应,导致鲜切蔬菜货架期降低,阻碍鲜切蔬菜的加工与销售。臭氧及臭氧水在食品冷杀菌应用方面极具潜力,也是有效的绿色灭菌新方法,非常适合鲜切蔬菜的杀菌保鲜。本文综述臭氧水处理对鲜切蔬菜品质的影响,以期为臭氧水在鲜切蔬菜工业中的应用提供一些依据。     

速冻调理蔬菜的研究进展

速冻调理蔬菜的前处理工艺包括新鲜蔬菜的清洗、切分漂烫以及成型等工艺,处理之后的调理蔬菜为了在贮存、运输和销售环节上保持其良好的口感与风味,选取适宜的速冻技术就显得极为重要。为此详细概括了速冻调理蔬菜的前处理工艺,并论述了目前国内外速冻技术的发展现状,同时综合分析了我国速冻调理蔬菜技术的发展方向与趋势。     

适宜的护色处理对切分杏热风干燥过程中颜色的影响

为了提高切分杏干制品的品质,对切分后鲜杏进行护色工艺的研究。以赛买提切分杏为研究对象,采用热风烘干工艺,研究护色过程中不同的护色工艺对烘干后的切分杏颜色的影响。以柠檬酸、D-异抗坏血酸钠、氯化钠、亚硫酸钠、热烫等工艺对切分、去核后的的果肉进行护色,并用正交实验法优化护色处理的工艺条件。结果表明:采用热烫和复合护色剂协同作用,最终得到最佳的护色工艺为热烫时间为4 min,亚硫酸钠为0.06%,D-异抗坏血酸钠0.2%。经验证这种复合护色技术处理切分杏△E值为22.09,能很好地保持杏子原有的色泽,为改善切分杏的品质提供技术依据。     

切割蔬菜加工通用良好操作规范（一）

1范围本规范规定了切割蔬菜在分级、清洗、去皮、切分、修整、包装、检验、贮藏、运输等过程中有关机构与人员、工厂建筑和设施、设备以及卫生、加工工艺及产品卫生与质量管理等遵循的良好操作条件,以确 保产品安全卫生符合我国食品卫生法的要求。本规范内容适用于切割蔬菜的生产加工。     

1-MCP对切分哈密瓜保鲜效果的研究

以新疆哈密瓜(8601)为材料,在5℃贮藏温度下,研究了1-MCP 对切分哈密瓜生理、品质和食用安全性的影响。结果表明：1.0μl/L 1-MCP 处理可显著抑制贮藏期间果实乙烯释放量,保持果实的感官,硬度、糖度和高VC 的含量,抑制切分哈密瓜透明化,降低了切分哈密瓜的细胞膜脂质过氧化水平,抑制微生物的数目,延长了切分哈密瓜的货架期。     

鲜切蔬菜加工技术对产品品质的影响

鲜切蔬菜因其新鲜、营养、方便等特点,成为健康饮食的主要组成部分,越来越受到消费者的关注与喜爱。我国鲜切蔬菜起步较发达国家晚,产业向原料产区、重点销区和重要交通物流节点集聚,其他小规模的城市分布较少,产业发展有着巨大的市场空间。然而切分导致细胞损伤,致使产品的生理及理化性质有很大改变,影响其货架期。从国内外鲜切蔬菜处理方式、加工装备及关键技术等方面综述了主要加工程序切分、清洗、脱水、包装技术对产品品质的影响,并提出今后发展的主要方向,为鲜切蔬菜加工产业的发展提供理论及技术支撑。     

国内外蔬菜粉加工研究进展

蔬菜粉营养丰富,易于保藏、运输而备受关注。综述了国内外蔬菜粉的干燥技术、加工过程中助干剂对蔬菜粉品质的影响以及贮藏条件对蔬菜粉品质的影响情况,并对蔬菜粉加工及研究中存在的主要问题、发展方向进行了总结与展望。     

蔬菜保鲜包装技术的研究进展

蔬菜属于易腐农产品,在贮、运、销过程中,由于受到周围环境以及机械伤的影响,容易衰老变质乃至腐 烂,品质降低,较难贮运保鲜。蔬菜适宜的保鲜包装不仅能够保持蔬菜的品质,而且为贮藏流通提供了便利,研究蔬菜 保鲜包装对延长蔬菜的贮藏保鲜期具有很重要的意义。本文从控制气体、控湿、抗菌、控温保鲜包装以及减损包装和智 能包装6 个方面介绍了蔬菜保鲜包装技术,并报道其研究进展及概况,指出其存在的问题以及展望未来的发展趋势。     

Predictive modelling for packaging design: equilibrium modified atmosphere packages of fresh-cut vegetables subjected to a simulated distribution chain

The impact of temperature fluctuations in a simulated cold distribution chain, typical of commercial practice, was investigated on both the microbial and sensorial quality of equilibrium modified atmosphere (EMA) packaged minimally processed vegetables. The internal O2 concentration of the designed packages could be predicted for the different steps of the simulated distribution chain by applying an integrated mathematical system. The internal atmosphere in the packages remained in its aerobic range during storage in the chain due to the application of high permeable packaging films for O2 and CO2. Spoilage microorganisms were proliferating fast on minimally processed bell peppers and lettuce. Yeasts showed to be the shelf-life limiting group. Visual properties limited the sensorial shelf-life. Listeria monocytogenes was able to multiply on cucumber slices, survived on minimally processed lettuce and decreased in number on bell peppers due to the combination of low pH and refrigeration. Aeromonas caviae was multiplying on both cucumber slices and mixed lettuce, but was as well inhibited by the low pH of bell peppers. Storage temperature control was found to be of paramount importance for the microbial (spoilage and safety) and sensorial quality evaluation of EMA-packaged minimally processed vegetables.     

NUTRITIONAL CONSEQUENCES OF MINIMAL PROCESSING OF FRUITS AND VEGETABLES

Consumption of fresh or minimally processed fruits and vegetables is increasing due to consumer concern about the effects of processing on nutrients in foods. Relatively little information is available in the literature regarding specific storage and handling techniques that have an impact on nutritional value for fruits and vegetables. Commonly used technologies such as low temperature and controlled atmosphere storage affect vitamin content. The information about other operations such as preparation for the table and irradiation on vitamin losses is fragmentary and may not reflect current practices. It appears that conditions that preserve sensory quality of fruits and vegetables also maintain nutritional value.     

果蔬的“最少加工处理”及研究现状

食品最少加工处理（ＭＰ）是近年来食品工业发展的新趋势。本文详细介绍了果蔬最少加工的生产现状和贮藏加工技术在ＭＰ果蔬上应用研究情况。     

Storage behaviour of minimally processed pumpkin (Cucurbita maxima) under modified atmosphere packaging conditions

 Minimally processed vegetables in fresh, ready-to-cook form are gaining the confidence of both the trader and the consumer. This has led to a need to develop technology for increasing shelf life while maintaining the microbial, nutritional and sensory quality of minimally processed vegetables. This investigation was carried out on pumpkin in minimally processed form, packed in different polymeric film bags of varying permeabilities, creating an active equilibrium modified atmosphere within the package for the extention of storage life. It was observed that minimally processed pumpkin, which has a high respiratory rate at room temperature (155.7 mg CO₂/kg/h) could be stored for a period of 25 days at 5±2  °C under modified atmosphere packaging conditions with a minimum physiological loss in weight of 0.06% and marginally low changes in biochemical constituents, such as vitamin C, total soluble solids, moisture, carotenoids and titrable acidity, enabling the retention of near-fresh quality. The microbial loads of mesophilic aerobes and coliforms, which were log 5.5 and log 4.3 were less than threshold level. There was no growth of yeasts and moulds or mesophilic spore formers at the end of the storage period. Received: 24 January 2000 / Revised version: 4 April 2000     

The microbiological safety of minimally processed vegetables

Summary Demand for fresh, convenient, minimally processed vegetables has led to an increase in the quantity and variety of products available to the consumer. Modified atmosphere packaging, in combination with refrigeration, is increasingly being employed as a mild preservation technique to ensure quality and storage-life. The fresh nature of these products, together with the mild processing techniques and subsequent storage conditions, have presented indigenous and pathogenic microorganisms with new ecosystems and potential infection vehicles; a number of outbreaks of foodborne disease being attributed to their consumption. Psychrotrophic pathogens and pathogens which are capable of maintaining an infectious potential under mild preservation regimes are of particular concern; Listeria monocytogenes , Aeromonas hydrophila and Clostridium botulinum being amongst the most notable. This review describes the processing, packaging and storage procedures involved in the production of minimally processed vegetables, and details their impact upon the survival and growth of associated pathogens. Gaps in our current understanding of the consequences of this novel technology for microbiological safety are highlighted.     

Susceptibility of minimally processed green pepper and cucumber to chilling injury as observed by apparent respiration rate

Apparent respiration rate and total microbial count were measured for intact and cut vegetables of green chilli pepper and cucumber stored at 5 and 10 °C. The minimally processed vegetables were more sensitive to chilling injury at 5 °C compared to the intact produce. Their response of increased respiration to chilling injury at 5 °C was noticed earlier than spoilage due to microbial growth, and determined the limit of shelf-life (4 days) in storage. Due to increased susceptibility to chilling injury when these products were stored at 5 °C, they had shelf-lives shorter than or equal to those at 10 °C.     

Effect of processing and storage conditions on the microbiological quality of minimally processed vegetables

The microbiological contamination of minimally processed vegetables was measured before and after processing and at different times and storage temperatures (5 and 10 days at 4 and 20 °C). To evaluate the efficacy of the overall process the water used for washing and rinsing the vegetables during the various phases of the operation were also examined. Thanks to the high quality of the vegetables at origin, simple chlorine treatment was sufficient to achieve a satisfactory reduction in coliforms, Escherichia coli, coliphages and saprophytic flora, thus ensuring that all of the freshly packed samples conformed to reference standards and guidelines. This conformity was maintained when the storage instructions indicated on the package (4 °C for 5 days) were followed. However, the persistence of faecal indicators after treatment suggested a potential risk of infection that could increase if the original contamination was higher. Microbiological examination of the water used for preliminary washing and for rinsing was seen to be useful in the assessment of the safety of the vegetables, at origin and after processing. The advantage of choosing coliphages for such monitoring is that they are indicators of viral contamination that can be measured rapidly. Critical points to be checked during the process are the levels of residual chlorine remaining in the washing tanks and the storage temperatures.     

Preliminary characterization of bacteriocin-like substances from lactic acid bacteria isolated from organic leafy vegetables

This study presents the characterization of new strains of lactic acid bacteria (LAB) from organic vegetables. Forty-five strains of LAB isolated from vegetables were investigated by its antimicrobial activity against taxonomically related microorganisms. Genetic identification of selected LAB was performed by means of PCR method. These strains were Enterococcus faecium, Lactococcus lactis, Enterococcus hirae and Enterococcus canis. Bacteriocin-like substances were active against Gram-positive bacteria and Gram-negative foodborne pathogens (Listeria monocytogenes and Escherichia coli, respectively). The antimicrobial activity of LAB strains was inactivated by the addition of proteases, thus confirming the proteinaceous nature of the inhibition. In all four strains the bacteriocin activity was stable after extended refrigerated storage and freezing-thawing cycles. This fact suggests that bacteriocin produced by the four LAB strains may find application as biopreservatives in minimally processed vegetables.     

非热加工在鲜切果蔬安全品质控制中的应用进展

鲜切果蔬由于其食用方便、营养丰富、清洁卫生等特点,近年来倍受人们关注。但由于鲜切果蔬在实际生产中极易发生微生物污染、营养成分和食用品质降低等不良变化,严重阻碍了鲜切果蔬加工业的进一步发展。非热加工技术是目前鲜切果蔬加工研究的热点,基于此探讨臭氧、电解水、辐照、紫外、脉冲物理场、超声波、高静压及高压二氧化碳等非热加工技术,在鲜切果蔬安全性与品质控制中的应用研究进展。     

加工和贮藏对果蔬营养成分变化及抗氧化活性影响的研究进展

水果和蔬菜是维生素、非维生素植物化学物质和抗氧化活性的重要来源,因此膳食指南推荐人们摄入足够多的水果和蔬菜,但是这里并没有区分是新鲜果蔬还是加工过的果蔬。然而,人们消费的大部分果蔬都是加工过的,与同样的新鲜果蔬相比,它们的营养物质、功能性成分和抗氧化活性或许不同。讨论了不同罐装、烹调、常温和低温贮藏以及冻藏等贮藏和加工方式对果蔬中维生素、非维生素植物化学物质和抗氧化活性的影响。大量研究表明,加工和贮藏造成了大多数种类果蔬植物化学物质和抗氧化活性的损失。这些信息将有助于指导人们使用贮藏和加工过的水果和蔬菜。