两类蔬菜品种营养成分含量及碳氮素特征的研究

为了阐述有机蔬菜和普通蔬菜营养成分含量和稳定同位素的差异,本文以普通蔬菜为对照,采用化学分析和稳定同位素质谱方法,对有机蔬菜和普通蔬菜的营养成分含量及碳氮素特征进行了研究。结果表明:普通类蔬菜中水分含量高于有机类蔬菜。有机类蔬菜品种中Vc、可滴定酸、蛋白、多酚和总糖含量均高于普通类蔬菜,其中7种有机类蔬菜的维生素C含量是普通类蔬菜的1.11~2.90倍,有机蔬菜可滴定酸的含量是普通蔬菜的1.1~1.5倍,有机蔬菜总糖含量是普通蔬菜的1.09~1.34倍。碳氮素特征表明,7个品种的有机类和普通类蔬菜的δ13C、δ15N的值均不同,其中有机玉米和茄子的δ15N值分别高出普通类5.36和4.62。两类蔬菜品种中营养成分和碳氮素特征都区别于普通类蔬菜,这是由于蔬菜之间种植环境和施肥标准不同而造成的。     

发酵蔬菜中乳酸菌的功能性与安全性研究进展

乳酸菌是发酵蔬菜制作过程中发挥重要作用的一类优势微生物,可利用蔬菜中的可溶性成分进行乳酸发酵,还能抑制有害微生物并发挥多重功能。本文首先对其最新研究进展做了归纳。近年来食品发酵微生物出现可转移耐药性问题,成为国际关注热点。作者结合研究实践,综述了可转移耐药性及其在发酵蔬菜乳酸菌中的研究现状,以及发酵蔬菜中乳酸菌的控制策略。     

西南典型种植区蔬菜重金属健康风险评估

以玉溪市红塔区、通海县和元江县土壤-蔬菜系统为研究对象,分析土壤和蔬菜中Cd、As、Pb、Cr的积累特征,结合体外胃肠模拟法和肠道细胞Caco-2毒性评估蔬菜中重金属生物可给性与人体健康风险。结果表明:通海和红塔菜地土壤受As、Cd或Pb污染,其芸薹类蔬菜中Cd的含量分别超出标准限量值13.6倍和2.2倍。通海西兰花、白菜中Cd在胃阶段生物可给性分别为36.40%和9.84%,肠阶段分别下降到0.91%和0%,元江鱼腥草中As在胃、肠阶段的生物可给性分别为25.23%和6.69%。基于重金属总含量的评估,通海芸薹类蔬菜存在潜在健康风险,而基于生物可给性的评价,以上蔬菜均不存在健康风险。细胞毒性试验表明生物可给态重金属暴露后不会抑制细胞活性,验证了基于生物可给性健康风险评估更为准确。结论:重金属生物可给性分析结合肠道细胞毒性的风险评估方法,可更准确评价蔬菜中重金属健康风险。     

山东省可溯体系有机蔬菜购买意愿及影响因素研究

本研究以山东省内16个地级市定点调查获取的735份有效问卷为基础,运用描述性统计分析方法,结合Logistic回归模型,研究山东省可溯体系有机蔬菜消费、购买行为及山东省可溯体系有机蔬菜购买意愿影响因素,并根据研究结论提出相关建议。结果表明,虽然山东省消费者购买具有安全可追溯属性有机蔬菜的意愿较高,但对于可溯体系的认知度仍有待提高,需要相关部门加大宣传力度,强化监管,多措并举,以龙头企业带动有机蔬菜产业协同发展。     

“中药蔬菜”上桌要谨慎

正核心提示:即便中药蔬菜有一定的防病作用,也绝不等于就可以拿中药材随便作为日常蔬菜食用。近段时间以来,因不当食用"中药蔬菜"前来医院就诊的病人越来越多,归根结底,大多数人都是因为过分夸大或小看了中药蔬菜的药性才引起的脾胃问题。事实上,所谓"药用蔬菜",原意泛指那些具有某些治疗作用的蔬菜,如葱姜具有解表散寒的功效,临床可用于治疗和改善轻症感冒;大蒜有杀菌作用,可用于防治痢     

墨西哥培育出防腹泻转基因蔬菜

墨西哥科学家最近利用转基因技术成功培育出可防治腹泻的蔬菜。动物实验结果表明,老鼠服用这些蔬菜之后可增强免疫力,预防腹泻的有效率达95%以上。据该科研项目负责人塞尔希奥·罗萨莱斯介绍说,他们将大肠埃希氏菌基因植入菠菜、胡萝卜和苋菜等蔬菜后,这些蔬菜会在该基因编码控     

自动洗菜机

菲律宾一家公司制造了一种自动洗菜的机器。该机可洗各类蔬菜和水果。把蔬菜等放入机内后 ,机器自动灌水 ,水量随菜量而定位 ,机体作翻转运动 ,反复冲洗掉蔬菜上的泥沙、小虫及其它脏物。一般 3～ 5分钟便可洗净 1 2～ 1 6公斤的蔬菜。这种洗菜机用不锈钢制成 ,配有自动卸料的液压系统和电机控制系统 ,可自由选择洗菜时间、强洗或弱洗。该机使用时运转平稳 ,不会损伤蔬菜。自动洗菜机@李玲玲     

蔬菜与健康

我国是栽培蔬菜最古老的国家之一。蔬菜是供佐餐的植物,它不仅供食用,而且好多蔬菜还可起到保健的效果,本文就常食用的九种蔬菜的主要保健作用编成谚语的形式,可记可诵,朗朗上口,供人们在食用时,常常想起它的保健作用。1 大蒜 每天生食几瓣蒜,肠胃菌毒清一遍。 因大蒜含有丰富的大蒜素、蒜酶、大蒜油等,故有帮助消化和     

野生蔬菜成新宠

野生蔬菜生长于山区、森林、田野，无污染，味道鲜美，风味独特，营养丰富，且具有较高的医疗保健作用。据专家研究资料表明，许多野生蔬菜的营养价值远远超过人工栽培的蔬菜。野生蔬菜不仅可制成各种名贵佳馔，其中许多品种还是常用的中草药。 那么，哪些蔬菜属于野生蔬菜呢？从广义上来说，野生蔬菜指的是那些生长在野外的可食用植物。这些可食用植物按它们可供食用的部位，可分为以下几类； １ 茎类野生蔬菜指的是蔬菜嫩茎、幼芽嫩枝。如毛竹笋、蕨菜、土当归、虎杖、酸模、山芹菜、粟米笋、青芒麻等，共有３０多种。蕨菜在日本被称为“…     

蔬菜保鲜过程中营养成分的变化

研究了营养液培养的方法对延长蔬菜保鲜的作用,并对保鲜期间蔬菜的维生素C、可滴定酸、亚硝酸盐和微量元素镁和铁进行含量测定。结果发现本实验所使用的营养液对延长蔬菜保藏时间有明显作用,上海青保藏25 d之内仍可食用,菜花的保藏期为15 d。维生素C、可滴定酸、亚硝酸盐测定结果显示,使用营养液储存的蔬菜维生素C和可滴定酸含量均高于对照组,亚硝酸盐含量则低于对照组。微量元素测定结果显示,采摘后的上海青和菜花仍可吸收营养元素。     

Recent Advances on Edible Films Based on Fruits and Vegetables—A Review

Food packaging materials are traditionally expected to contain foodstuffs and protect them from deteriorating agents. Although petroleum‐derived polymers have been widely used for this purpose, the rising concern with their nonrenewable and/or nonbiodegradable nature paves the route for the development of greener alternatives, including polysaccharides and polypeptides. The use of these food‐grade biomacromolecules, in addition to fruits and vegetables, provides edible packaging with suitable physical‐mechanical properties as well as unique sensory and nutritional characteristics. This text reviews the chronological development pathway of films based on fruit and vegetable purees, pomaces, and extracts. Recent advances are extensively reviewed with an emphasis on the role that each film component plays in the resulting materials, whose production methods are examined from a technical standpoint and essential properties are compiled and contrasted to their conventional, synthetic counterparts. Finally, this comprehensive review discusses advantages and limitations of edible films based on fruits and vegetables.     

不同工艺制备植物油中金属元素迁移性的统计分析

为分析食用植物油原料及不同工艺制备的产品中金属元素迁移性规律,便于控制食用植物油品质,利用干法消解食用植物油原料及其产品,结合原子吸收光谱法测定植物油原料及其产品中7种微量金属元素。结果表明,有害金属铬元素在油中的迁移率最高,是影响食用植物油品质的关键控制元素。金属元素从原料中迁移到油中的迁移率均较低,主要残留于渣饼中。此外发现,整体上重金属元素含量与食用植物油的制备工艺之间的相关性不强。     

Antimicrobial edible films and coatings for fresh and minimally processed fruits and vegetables: a review

The use of edible films and coatings is an environmentally friendly technology that offers substantial advantages for shelf-life increase of many food products including fruits and vegetables. The development of new natural edible films and coatings with the addition of antimicrobial compounds to preserve fresh and minimally processed fruits and vegetables is a technological challenge for the industry and a very active research field worldwide. Antimicrobial agents have been successfully added to edible composite films and coatings based on polysaccharides or proteins such as starch, cellulose derivatives, chitosan, alginate, fruit puree, whey protein isolated, soy protein, egg albumen, wheat gluten, or sodium caseinate. This paper reviews the development of edible films and coatings with antimicrobial activity, typically through the incorporation of antimicrobial food additives as ingredients, the effect of these edible films on the control of target microorganisms, the influence of antimicrobial agents on mechanical and barrier properties of stand-alone edible films, and the effect of the application of antimicrobial edible coatings on the quality of fresh and fresh-cut fruits and vegetables.     

Physical and antibacterial properties of edible films formulated with apple skin polyphenols

Fruit and vegetable skins have polyphenolic compounds, terpenes, and phenols with antimicrobial and antioxidant activity. These flavoring plant essential oil components are generally regarded as safe. Edible films made from fruits or vegetables containing apple skin polyphenols have the potential to be used commercially to protect food against contamination by pathogenic bacteria. The main objective of this study was to evaluate physical properties as well as antimicrobial activities against Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella enterica of apple skin polyphenols at 0% to 10% (w/w) concentrations in apple puree film-forming solutions formulated into edible films. Commercial apple skin polyphenol powder had a water activity of 0.44 and high total soluble phenolic compounds and antioxidant capacity (995.3 mg chlorogenic acid/100 g and 14.4 mg Trolox/g, respectively). Antimicrobial activities of edible film containing apple skin polyphenols were determined by the overlay method. Apple edible film with apple skin polyphenols was highly effective against L. monocytogenes. The minimum concentration need to inactive L. monocytogenes was 1.5%. However, apple skin polyphenols did not show any antimicrobial effect against E. coli O157:H7 and S. enterica even at 10% level. The presence of apple skin polyphenols reduced water vapor permeability of films. Apple skin polyphenols increased elongation of films and darkened the color of films. The results of the present study show that apple skin polyphenols can be used to prepare apple-based antimicrobial edible films with good physical properties for food applications by direct contact.     

果蔬可食性涂膜剂结构组分与功能的研究进展

随着人们绿色消费和环保意识的增强,可食性涂膜剂成了国内外学者研究的热点,其添加剂成分也向天然、可食的方向发展。文中综述了果蔬可食性涂膜剂结构组分与功能的研究进展,包括多糖类膜、蛋白质膜和脂质膜,以及添加于可食性涂膜剂中的抗氧化剂、杀菌剂和其他助剂的研究情况。     

Innovative processes and technologies for modified atmosphere packaging of fresh and fresh-cut fruits and vegetables

Modified atmosphere packaging (MAP) technology has been commercially viable since the 1970s. Currently, MAP is extensively used worldwide to preserve the quality and extend the shelf-life of whole fresh fruits and vegetables, but is also increasingly used to extend the shelf-life of minimally processed fresh fruit and vegetables. This review discusses new processes and technologies that can be used to improve quality preservation and consumer acceptability of minimally processed produce where high respiration rates and challenging degradation processes operate. New packaging innovations are enabling producers and retailers to further maintain quality for longer. Innovative approaches to extend shelf-life include active MAP with differentially permeable films, films that incorporate antimicrobial properties, edible coatings that confer barriers properties, and the use of non-traditional gases to modify respiration. Intelligent packaging using integrated sensor technologies that can indicate maturity, ripeness, respiration rate and spoilage are also appearing. This review demonstrates that preservation technologies and associated packaging developments that can be combined with modified atmosphere are constantly evolving technology platforms. Adoption of combinations of technology improvements will be critical in responding to commercial trends towards more minimally processed fresh-cut and ready-to-eat fruit and vegetable products, which require specialized packaging solutions.     

A survey of nitrate and oxalate content in fresh vegetables

A survey of nitrate and oxalate ((COO⁻)₂) content in fresh vegetables was conducted in Bari (Italy) over 15 months (from March 1994 to May 1995). A total of 327 samples (edible portions and related sub-samples) were taken from 26 different vegetable types on the wholesale fruit and vegetable market. The data revealed that leaf vegetables (namely rocket, celery, parsley and spinach) contained higher levels of nitrate than bulb, root, shoot, inflorescence and tuber vegetables. Higher oxalate levels were found in spinach and Swiss chard. Based on consumption data for the whole population provided by the National Institute of Nutrition, daily nitrate intake from vegetables was calculated to be 71 mg. Over 30% of nitrate intake was derived from the consumption of lettuce and Swiss chard. © 1999 Society of Chemical Industry     

子午岭林区常见野生蔬菜硝酸盐、亚硝酸盐及维生素C含量的测定

测定了子午岭林区常见19种野生蔬菜中的硝酸盐、亚硝酸盐和维生素C的含量,比较蔬菜中硝酸盐分级评价标准和我国制定的无公害蔬菜亚硝酸盐限量标准及维生素C的含量发现,香椿硝酸盐含量处于安全水平,但亚硝酸盐含量高于我国制定的无公害蔬菜亚硝酸盐的限量标准,且维生素C含量小于50 mg/100g,不属于无公害蔬菜的范畴,建议少量食用或经过特殊处理后再食用;其余17种野生蔬菜均属于安全无公害蔬菜,且维生素C的含量高,可放心食用.     

可食性果蔬膜包装材料研究进展

目的:为了研究双酶复合酶解大豆分离蛋白制备大豆肽的相对分子量分布及活性片段对实验性高血压大鼠的降压效果。方法:通过单因素实验优选,采取正交实验优化复合酶的酶解工艺,以酶解液对血管紧张素转换酶(ACE)抑制率为指标优选最佳工艺;通过超滤、纳滤后得到最佳分子量片段,应用左硝基精氨酸(L-NNA)诱导大鼠高血压模型,分别给予不同剂量的活性片段进行实验。结果:双酶复合酶解的最佳条件为:在料液比为1:20 g/mL的情况下,酶解温度50℃,酶底比3.0%,酶解pH7.0条件下先用菠萝蛋白酶酶解2 h后,再以酶底比4.0%加入胰蛋白酶,控制温度为40℃、酶解pH为8.0条件下酶解4 h,大豆分离蛋白的水解度35.31%。经过高效液相对酶解液的相对分子量分布得出,大豆分离蛋白原液含有的蛋白质及多肽的相对分子质量主要区间在5000~1.0×105 Da,在双酶复合酶解下,酶解液的蛋白质及多肽的相对分子质量主要区间均在500~4000 Da;通过超滤得出最佳活性片段为1000~3000 Da,药理实验表明,与模型对照组相比各组血压均有降低,且大豆肽剂量组有显著性差异(p<0.05);其中大豆肽高剂量组和卡托普利组相当。结论:双酶复合酶解制备的大豆肽相对分子量较小,活性片段对高血压大鼠模型降压作用显著。     

可食性膜保鲜技术的发展与展望

可食性膜是一种由天然可食性材料制成的选择透过性薄膜,常被应用于保鲜新鲜果蔬,通过控制果蔬的内部气体交换、延缓水分损失、提高机械性能,阻止空气中氧气与食品发生氧化反应,防止微生物细菌的滋生,最终起到降低腐败速率、延长其货架期和提升商品价值的作用。随着这种绿色型保鲜技术的不断发展,可食性膜也被作为抗菌剂、防腐剂、调味剂和增塑剂等功能性成分的载体,由两种或者两种以上材料组成的复合配方涂膜互相丰富并改善了不同类型涂膜之间的保鲜作用,从而得到更加优质有效的可食性涂膜配方。本文主要概述了可食性膜的保鲜原理与成分组成、应用历史及发展演变,综述了可食性膜的类型、特点及其制作工艺,进一步展望了可食性膜的发展方向。