丁香、艾叶提取物与长角豆胶复合涂膜保鲜剂对杨梅耐藏性的影响

以长角豆胶、黄原胶复配胶为涂膜基质,配以丁香、艾叶等具有抗菌作用的中草药制剂,配制成中草药复合涂膜保鲜剂,以杨梅为保鲜目标,常温下对其进行保鲜实验,研究该保鲜剂对杨梅品质变化的影响。结果表明：经该保鲜剂涂膜处理的杨梅与对照组相比,果实的腐烂率、呼吸强度明显被抑制,有机酸、可溶性固形物等营养成分能较好地保存,贮藏到第5 天时,好果率为80%。     

Yield and biosynthesis of nitrogenous compounds in fruits of green bean (Phaseolus vulgaris L cv Strike) in response to increasing N fertilisation

The objective of the present work was to determine the effect of different dosages of N on the biosynthesis of organic N compounds in fruits and their influence on yield in green bean (Phaseolus vulgaris L cv Strike) plants. The nitrogen was applied to the nutrient solution as NH₄NO₃ at 1.5 (N1), 3 (N2), 6 (N3), 12 (N4), 18 (N5) and 24 mM (N6). Treatment N3 was considered optimal for efficient yield in green bean plants and also for the null presence of NO₃^?. Highest N dosages (18 and 24 mM ) resulted in the accumulation of NO₃^? in pods and seeds. This accumulation encouraged nitrate reductase (NR) and nitrite reductase (NiR) activity in both tissues and treatments, and therefore NR activity might be considered as a good bioindicator of the presence of NO₃^? in edible fruits. The greater NH₄⁺ assimilation by glutamine synthetase (GS) and glutamate synthase (GOGAT) occurred primarily in the pods of the N6 treatment, while the seeds acted as physiological sinks, these latter tissues presenting the highest concentrations of amino acids, proteins and organic N. The high accumulation of NO₃^? and NH₄⁺ in both seeds and pods could be the direct cause of the reduction in fruit production, indicating that green bean plants are very sensitive to high N levels. Copyright © 2004 Society of Chemical Industry     

五种柑橘属水果膳食纤维功能特性及微观结构研究

以脐橙、葡萄柚、柠檬、贡柑和椪柑五种柑橘属水果的果皮为试材,比较了果皮中膳食纤维（DF）功能特性和微观结构的差异。结果表明：五种膳食纤维成分的功能特性和微观结构存在显著差异。葡萄柚DF具有最高的胆酸钠吸附量（877.69±13.32mg/g）,胆固醇吸附量（10.88±0.32mg/g [pH2.0],17.90±0.17mg/g [pH7.0]）,α-淀粉酶活力抑制率（56.73%）和胰脂肪酶活力抑制率（32.5%）。在胃的酸性环境下,椪柑DF具有最高的NO2-清除率（36.40%）。脐橙DF中主要单糖是葡萄糖（33.87%）,而其他四种柑橘属DF中主要单糖是阿拉伯糖,其中葡萄柚DF中阿拉伯糖最高（44.83%）。通过扫描电镜观察,葡萄柚和椪柑DF表面更加不规则、粗糙,并且蜂窝状结构更致密伴随大量裂缝和孔隙。     

胶体金免疫层析法快速检测果蔬中的三唑酮及其代谢物残留

目的 建立胶体金免疫层析法快速检测蔬菜水果中三唑酮及其代谢物农药残留的分析方法。方法 采用胶体金标记三唑酮单克隆抗体, 利用胶体金的可视化及抗体与抗原的特异性结合, 实现对果蔬中三唑酮农药残留的定性和半定量检测。结果 本方法对黄瓜和香蕉中三唑酮及其代谢物的总残留量检出限分别为0.05和0.85 mg/kg, 均低于国家标准食品中三唑酮农药最大残留限量(0.1~1 mg/kg), 该试纸条对其他农药无交叉反应, 重复性良好。结论 该方法具有高灵敏度、高特异性, 可快速准确的检测大批量样品中的三唑酮及其代谢物农药残留, 能够满足应急超标事件的现场检测需求。     

Recent advances in the improvement of freezing time and physicochemical quality of frozen fruits and vegetables by ultrasound application

Freezing is widely used for the preservation of fruits and vegetables (FVs). Whereas, the conventional freezing method presents low process efficiency in frozen FVs. Ultrasound application is used as a supplementary technology to improve the freezing process of FVs. This reviewed paper shows the cavitation effect of ultrasound and the effect of ultrasound application on freezing time and the physicochemical quality of frozen FVs. The cavitation effect of ultrasound in the freezing process was described in detail. Compared with conventional freezing, ultrasound application in freezing of FVs can shorten the freezing time, and improve physicochemical quality including drip loss, colour, firmness, chemical compositions (ascorbic acid, total phenolic and anthocyanin), as well as microstructure. Therefore, the results of these studies illustrated that ultrasound is a potential technology to enhance freezing efficiency and retain the quality of FVs during freezing.     

果蔬压缩破坏特性的试验研究

为探索不同种类果蔬的破坏特性,选取白萝卜、土豆和苹果为研究对象进行压缩试验,分别得到了3种试样的破坏力、破坏极限、破坏能和弹性模量值,方差分析结果表明:不同种类果蔬力学特性指标差异显著,白萝卜的特性参数值均显著高于土豆、苹果参数值。     

鲜切果蔬中生物保鲜剂的研究进展

随着人们对食品质量与安全的要求日益提高,鲜切果蔬保鲜技术迅速发展,生物保鲜剂因具有安全、高效等特点成为鲜切果蔬保鲜的研究热点。鲜切果蔬经分级、清洗、修整、去皮、切分、保鲜、包装等过程处理后,机械损伤、生理代谢、病原微生物污染等问题会引起鲜切果蔬腐烂、品质下降,给鲜活农产品的经济贸易带来了巨大损失,并对人类生命安全造成了重大威胁,因此本文综述了温度、气体环境、生理生化反应、微生物等几项能够导致鲜切果蔬褐变腐烂、品质下降的重要影响因素;总结了3种生物保鲜剂在鲜切果蔬保鲜中的应用,包括植物类天然保鲜剂、动物类天然保鲜剂和微生物保鲜剂;讨论了生物保鲜剂的不足,并对今后生物保鲜剂的发展进行了展望。     

常见果蔬的抗氧化方法研究进展

综述了常见果蔬的抗氧化机理以及果蔬中抗氧化物质的测定方法,通过研究果蔬的抗氧化能力找到优良的抗氧化物质。     

即食鲜切蔬果货架期保存环境对微生物指标的影响

目的 即食鲜切蔬果行业目前没有统一的行业规范,其中一个重要的原因是没有相对应的检测指标。蔬果本身就相比其它食品更难以保存,易产生食品安全问题,即食鲜切蔬果的这一特点就更为明显,所以需要展开相关研究为制定行业规范提供依据。通过开展保存环境的温度与湿度的协同研究,以获得适宜的保存条件,并确定经济安全的保存期限。方法 选取市面常见即食鲜切蔬果样品(黄瓜、梨、生菜、西红柿、火龙果)五种,经洗净、切制、分装等操作,且未经特殊消毒处理,检测微生物指标(检验菌落总数和致病菌)初始值后,在温度2℃、4℃、6℃与相对湿度50%、70%下保存,每隔24小时(至生产后4天)取样检测,并绘制微生物生长曲线。结果 对比实验中采取温度条件,保存在2℃环境下,微生物污染程度较低;对比实验中采取湿度条件,保存在相对湿度70%环境下,保存效果更好。结论 温度2℃与湿度70%以上是即食鲜切蔬果的适宜保存条件,存放一天的货架期是较为经济安全的保存期限。     

《果蔬贮藏与加工》课程多媒体双语教学改革的研究

文章阐述了在《果蔬贮藏与加工》课程中实施双语教学的具体方法及要求,重点讨论了课堂气氛与教学组织、教材的选用以及多媒体的有效使用,并对该课程的考核方法进行了分析,同时也指出了双语教学面临的问题及改进思路。