主成分分析法综合评价速冻菜用大豆籽粒的品质

为研究同一地域不同品种速冻菜用大豆籽粒的品质,本文选取13种菜用大豆为试验材料,测定硬度、色泽、叶绿素、Vc、可溶性蛋白、可溶性糖等影响速冻菜用大豆籽粒品质的10项主要理化指标,并对各指标进行主成分分析（PCA）。结果表明,提取的4个主成分累计贡献率达89.33%,其中第1、2主成分对速冻菜用大豆籽粒品质的贡献率相近,分别为28.13%、26.55%,可溶性蛋白、色泽、叶绿素、硬度等为影响速冻菜用大豆籽粒品质的主要因子。筛选出的新大粒1号在可溶性蛋白、色泽、叶绿素、硬度等理化指标综合表现出较优品质,其次为通豆6号、徐豆17号和通豆5号,主成分综合评价模型与感官评价结果具有高度一致性。这为速冻菜用大豆品种的筛选与品质评价提供了一定理论依据。     

速冻果蔬的生产工艺及产品品质控制

介绍了速冻果蔬的生产工艺及产品质量控制措施。用优质的原料，科学的加工处理和贮藏，良好的包装材料，才能获得优质的速冻果蔬产品。速冻果疏产品的质量是否良好，与加工过程的各个环节有直接关系，任何一个环节出现问题，都不会得到高质量的产品。     

Freezing Rate and Frozen Storage Effects on Color and Sensory Characteristics of Pineapple Fruit Slices

This study was carried out to evaluate the influence of freezing process (cold room –18°C and air-blast freezer –50°C) and frozen storage (–18°C for 0 to 12 mo) on color and sensory quality of pineapple fruit slices (Smooth Cayenne and Red Spanish cultivars). L, –a and +b color parameters showed differences (P ≦ 0.05) with cultivar, but not with freezing rate. No differences (P ≥ 0.05) were found in sensory analysis (color and appearance) between the cultivars, frozen at different rates, compared to fresh product, or after 1 yr frozen storage. The two cultivars are suitable for freezing.     

一种蔬果胶囊食用安全性评价

采用我国《食品安全性毒理学评价程序》中所规定的标准方法和实验模型，对一种蔬果胶囊的食用安全性进行了评价。结果显示该产品小鼠经口LD50值大于15．0g/kgbw，属实际无毒级；对基因、体细胞及生殖细胞无明显致突变作用；SD大鼠30d喂养未显示任何毒副作用。因此，该产品具有良好的食用安全性。     

Evaluation of an Extraction Method for the Detection of GI and GII Noroviruses in Fruit and Vegetable Salads

Human norovirus (HuNoV) is a major foodborne virus causing gastroenteritis outbreaks in humans. Salad products can be vectors of transmission for foodborne viruses such as HuNoV when these products are contaminated naturally or through unsanitary food handling. Therefore, development of simple, reliable and sensitive techniques for the detection of HuNoV in salad products is needed to ensure food safety. The purpose of our study was to optimize a method for the detection of HuNoV in artificially contaminated salad products. To this end, 2 different kinds of salads (fruit salads and vegetable salads) were experimentally inoculated with HuNoV GI, HuNoV GII, and MS2 suspensions. The selected method was based on treatment with pectinase followed by Trizol‐chloroform purification, and the recovery efficiencies were 6.07% to 26.52% for HuNoV GI and 5.54% to 37.36% for HuNoV GII. MS2 was used as the process control, and the recovery efficiencies for fruit salad and vegetable salad samples were 38.57% and 41.13%, respectively. The optimized method could be applied in diagnostic laboratories to identify NoV contamination in composite foods, such as salad products, should an event of foodborne outbreak occur.     

Fermented Frozen Dough: Impact of Pre-fermentation Time and of Freezing Rate for a Pre-fermented Frozen Dough on Final Volume of the Bread

This paper proposes an original study on the impact of the process condition using pre-fermented frozen dough on the final bread volume. The impact of the degree of pre-fermentation before freezing and the impact of the freezing conditions have been considered with an experimental design procedure. The first fermentation step (pre-fermentation) was between 60 and 120 min and the corresponding second (or final) fermentation was between 60 and 0 min, respectively, resulting in a total fermentation time of 120 min. Freezing was performed between the first and the second fermentation at −20°C, −30°C or −40°C in blast air tunnel. The results show that the faster the freezing rate, the higher the final bread volume. Further work is needed to fully optimise this process, which is minimally present at the industrial bread market, whereas the technology is now adopted by many viennoiseries such as croissant and laminated puffing pastries.     

果蔬汁等液态食品之冻结点的经验计算

冻结点是果蔬汁等液态食品冷冻加工与保藏中的重要参数，冻结点和冻结点的下降与果蔬汁等液态食品的组成分及浓度有关。本文介绍了几种通过计算冻结点下降值求得冻结点的经验公式。     

Effects of Freezing Rate, Frozen Storage Temperature and Storage Time on Tenderness Values of Beef Patties

All-beef and soy-extended patties were frozen to ?18°C in either 24, 48, 72 or 96 hr and stored at ?23°, ?18° or ?7°C for 6, 9, 12, 18 or 24 months. Freezing produced considerable reductions in both sensory and instrumental measures of tenderness with the effects being greater for the slower freezing rates. Thus, just after freezing, and prior to storage, tenderness was found to be higher in patties subjected to faster freezing compared to slower rates of freezing. Storage at ?7°C reduced sensory scores for tenderness and increased stress in relation to strain during shearing. Extending patties with soy reduced the effects of freezing rate, storage temperature and storage time on tenderness.     

果蔬中功能因子的高值化开发与安全性评价

功能因子是果蔬食品中重要的营养成分.果蔬功能因子的高值化开发是目前果蔬食品研究的热点和重点.本文对目前我国果蔬功能因子研究现状、存在的问题及未来发展方向进行了论述.     

Development and Characterization of Edible Films Based on Fruit and Vegetable Residues

Edible films were developed from the solid residue of the processing of whole fruits and vegetables. The solid residue, processed into flour (FVR flour) was chemically and structurally characterized by microstructure, elemental composition, structural links, and moisture sorption isotherm. Films were prepared by casting using aqueous extracts of 8% and 10% of flour (w/w) and characterized in terms of thickness, water solubility, mechanical properties, water vapor permeability, and Fourier transform infrared (FTIR). The analysis of microstructure and elemental composition, performed on flour (mean particle size 350 μm), showed an essentially granular aspect, with the presence of fibrous particles having potassium as one of the most abundant elements. FTIR results showed similarity between the characteristic bands of other raw materials used in edible films. The sorption isotherm of FVR flour showed a typical profile of foods rich in soluble components, such as sugars. Dried films presented an average thickness of 0.263 ± 0.003 mm, a homogenous aspect, bright yellow color, pronounced fruit flavor, and high water solubility. The FTIR spectra of the edible films revealed that addition of potato skin flour did not change the molecular conformation. Moreover, the films presented low tensile strength at break when compared with fruit starch‐based films.     

总黄酮含量分析法快速评价蜂胶原料质量

采用亚硝酸钠—硝酸铝分光光度法测定蜂胶原料中的总黄酮,检测结果(Y)与重量法测得的蜂胶含量(X)之间存在显著的相关关系,相关系数r=0.9134,回归方程:Y=1.2109X 5.0418蜂胶的检出限为0.762μg/mL,在黄酮含量30％及6％的加标水平下,回收率分别为97.7％及99.6％。从而为蜂胶原料的质量评定建立了一种快速、灵敏、准确的检验方法。     

A Rapid Method for Separation and Quantitation of D-Malic Acid in Fruit Juice

A HPLC method using an aqueous mobile phase containing the chiral ligand-exchanger Cu II-L-valine complex at pH 5.5 with a polystyrene divinyl-benzene copolymer column was used to resolve D-malic acid in apple, pear, and Concord grape juices. D-malic acid was detected and quantitated at 330 nm in less than 15 min per sample. The detection limit appeared to be 2 mg/100 mL D-malic acid in 12 Brix juice, or 0.33% total malic acid in a typical apple juice containing 0.6 g/100 mL using the described procedure.     

蔬菜中砷、铅、汞、镉快速检测的方法研究

本实验探讨了蔬菜样品经一次消解后,对其中砷、铅、汞、镉进行分次测量的快速检测方法,同时对消化温度和消化液残存量对测定结果的影响进行了研究.结果表明: 120.O℃是四种元素均无消化损失的最高温度;消化液残存量在0.50～1.50ml之间时(定容10.00ml)四种元素均能得到较好地回收(96.7%～103.3%);该方法最小检出限分别为砷0.002mg/L、铅0.005mg/L、汞0.0002mg/L、镉0.0002mg/L,RSD均小于5.4%.     

果蔬汁非热加工技术及其安全性评析

食品非热加工技术作为一种新型杀菌技术,具有减少营养损失和保持新鲜度等优点,正逐渐在食品工业中得到应用。本文在对果蔬汁产品的微生物危害性进行分析的基础上,论述了超高压、脉冲电场、电离辐射等非热加工技术对果蔬汁中病原微生物和腐败微生物的杀灭作用。     

质构仪在果蔬品质评定中应用的研究进展

质构是衡量果蔬产品品质的重要指标,果蔬在采后加工、运输、贮藏和销售等环节中其品质不可避免会受到不利因素的影响。运用质构仪可以较为客观准确的反映果蔬产品的质地特性,为果蔬品质评价提供一种快速便捷的研究方式。简述质构仪的构造及工作原理,对果蔬质构检测中常用的质构剖面分析和穿刺模式进行综述,并详细阐述其研究内容和应用现状,最后分析质构仪应用于果蔬质构检测中可能出现的问题,并对果蔬品质检测的研究方法做出展望。     

果蔬食品中有机磷类农药不确定度的测定

论述果蔬食品中有机磷类农药不确定度的测定方法,方法以实例形式确定不确定度计算的方法.在置信度为95%时,相对标准不确定度计算为U=u×k=u×2.     

果蔬及其制品中可溶性总糖和还原糖的测定方法评价

果蔬及其制品中可溶性总糖和还原糖是其质量指标的重要参数之一。综述了可溶性总糖和还原糖的不同测定方法的适用性及特点。由于不同果蔬的可溶性总糖和还原糖的含量有较大差异,综述的测定方法为果蔬可溶性总糖和还原糖的测定提供意义及借鉴。     

果蔬加工学课程立体教学模式的构建与实践

果蔬加工学是食品科学与工程专业的一门重要专业必修课。探索新的教学模式,对于该专业培养目标的实现具有重要意义。研究构建了基于"微视频+翻转课堂+网络学习平台"的立体教学模式,将其实施于果蔬加工学课程教学过程,并通过定性定量相结合的方式对其学习效果进行评价;进一步分析该教学模式现阶段存在的问题,并提出改进措施。该教学模式促进了果蔬加工学课堂教学从传统教学模式向现代化教学模式的转变,符合新工科背景下教学改革的必然趋势。     

应用脂肪酸甲酯快速筛选植物油中掺假地沟油

根据植物油和地沟油中脂肪酸酯存在方式的不同,建立植物油中地沟油掺假的快速筛选方法。植物油中脂肪酸是以甘油三酯的形式存在,地沟油中脂肪酸以脂肪酸甲酯的形式存在,利用气相色谱-质谱的全扫描模式,结合NIST 05标准谱库检索功能,对37 种脂肪酸甲酯进行测定。样品采用直接稀释-气相色谱-质谱全扫描分析脂肪酸甲酯,100 个植物油样品中均未检出脂肪酸甲酯;20 个地沟油样品中13 个检出肉豆蔻酸甲酯（C14∶0）、棕榈酸甲酯（C16∶0）和硬脂酸甲酯（C18∶0）等14 种脂肪酸甲酯,检出率为65%,且70%的检出脂肪酸甲酯的地沟油样品中脂肪酸甲酯种类多、含量较高。因此,若植物油样品脂肪酸甲酯种类多、含量高,则可判定为有地沟油掺假;若脂肪酸甲酯含量低或没有脂肪酸甲酯,则可以进一步用其他指标和方法进行检测,脂肪酸甲酯的检测方法可以作为地沟油掺假的快速粗筛方法。