生物防腐剂及其在食品中的应用

主要介绍了来源于植物、微生物及动物的天然生物防腐剂抗菌特性及其在食品加工中的应用。     

微波萃取在食品工业中的应用

微波萃取技术是一种快速、高效的提取新技术,目前已广泛应用于多种领域。文章对近年来微波萃取在食品安全及理化分析、食品营养成分及添加剂萃取和保健食品功效成分萃取等方面的应用研究作了综述,同时对微波萃取方式及微波萃取设备的发展前景进行了展望。     

食品添加剂暴露量评估方法

为给我国的食品添加剂的暴露量评估提供借鉴,介绍了目前国际常用的5种食品添加剂暴露量评估方法,每种方法分别介绍了评估所用的资料、计算方法、结果表示方法及优缺点等.     

Control of Listeriamonocytogenes on commercially-produced frankfurters prepared with and without potassium lactate and sodium diacetate and surface treated with lauric arginate using the Sprayed Lethality in Container (SLIC®) delivery method

Viability of Listeriamonocytogenes was monitored on frankfurters formulated with or without potassium lactate and sodium diacetate at a ratio of ca. 7:1 and treated with lauric arginate (LAE; 22 or 44 ppm) using the Sprayed Lethality in Container (SLIC®) delivery method. Without antimicrobials, pathogen numbers remained relatively constant at ca. 3.3 log CFU/package for ca. 30 d, but then increased to ca. 8.4 log CFU/package over 120 d. Regardless of whether or not lactate and diacetate were included, when treated with LAE, pathogen numbers decreased from ca. 3.3 log CFU/package to ca. 1.5 log CFU/package within 2 h, but then increased to 7.3 and 6.7 log CFU/package, respectively, after 120 d. When frankfurters were formulated with lactate and diacetate and treated with LAE, pathogen numbers decreased by ca. 2.0 log CFU/package within 2 h and remained relatively unchanged over the 120 d. These data confirm that LAE provides an initial lethality towards L. monocytogenes and when used in combination with reduced levels/ratio of lactate and diacetate as an ingredient for frankfurters provides inhibition throughout shelf life.     

Tracing the geographical origin of honeys based on volatile compounds profiles assessment using pattern recognition techniques

The goal of this study was to examine the possibility of verifying the geographical origin of honeys based on the profiles of volatile compounds. A head-space solid phase microextraction (SPME) combined with comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (GC × GC–TOFMS) was used to analyze the volatiles in honeys with various geographical and floral origins. Once the analytical data were collected, supervised pattern recognition techniques were applied to construct classification/discrimination rules to predict the origin of samples on the basis of their profiles of volatile compounds. Specifically, linear discriminant analysis (LDA), soft independent modeling of class analogies (SIMCA), discriminant partial least squares (DPLS) and support vector machines (SVM) with the recently proposed Pearson VII universal kernel (PUK) were used in our study to discriminate between Corsican and non-Corsican honeys. Although DPLS and LDA provided models with high sensitivities and specificities, the best performance was achieved by the SVM using PUK. The results of this study demonstrated that GC × GC–TOFMS combined with methods like LDA, DPLS and SVM can be successfully applied to detect mislabeling of Corsican honeys.     

基于拉曼光谱分析配送食物中的脂质氧化

针对以往长距离配送过程中食物易氧化变质等问题,对变质原因进行分析,采用改变pH值、运输温度、摇晃速度及时间方法解决长距离配送中油脂易氧化变质问题。本文采用间接碘量法测定不同pH值、配送温度、晃动速度以及运输时间下油脂的过氧化值。基于拉曼光谱分析藻油、棕榈仁油和橄榄油氧化过程。实验结果表明,当pH值达到10时,食物油脂的过氧化值仅为3 meq/kg。长距离配送温度超过40 ℃,摇晃速度3 周/s,食物油脂的过氧化值超过10 meq/kg。食物油脂的过氧化值仅在4 d时达到最大15 meq/kg。食物油脂氧化过程中,拉曼峰强先升高再降低,说明食物油脂分子基团在一定程度上产生变化,发生变质,说明长距离配送食物应该在pH值较大、温度偏低、运输时间较短、减少摇晃等条件下进行,为防止食物变质提供可靠分析依据。     

Determination of pesticide residues in food matrices using the QuEChERS methodology

The determination of pesticide residues in food matrices is a formidable challenge mainly because of the small quantities of analytes and large amounts of interfering substances which can be co-extracted with analytes and, in most cases, adversely affect the results of an analysis. However, safety concerns require that pesticides of the wide range of chemical properties (including acidic, basic and neutral) should be monitored. Because of the wide variety of food matrices, the sample must initially be cleaned up before final analysis. That is why the analytical chemist is faced with the need to devise new methodologies for determining such residues to be determined in a single analytical run. To accomplish the goal, QuEChERS methodology has been developed. It is a streamlined and effective extraction and cleanup approach for the analysis of diverse analyte residues in food matrices. So far, there have been achieved promising results by liquid or gas chromatography analysis, including pesticides, but also acrylamide, pharmaceuticals and veterinary drugs.     

Sensitive and specific detection of almond (Prunus dulcis) in commercial food products by real-time PCR

Almond has been widely used in all sorts of food products, mostly due to its pleasant flavor and health benefits. However almonds can become an important health problem since they are responsible for triggering adverse immune responses in allergic individuals, and since they are present in many processed foods they are considered as a potential hidden allergen. Consequently, it's important for food processors and regulatory agencies to be able to ensure accurate labeling of foods to protect the safety of the public and to avoid expensive recalls. We propose a simple and highly sensitive approach to detect almond in a wide range of processed foods. The method consists of a real-time PCR assay targeting the gene encoding for the ITS1 in almond, using a nuclease (TaqMan) probe labeled with FAM and BBQ. Sensitivity of real time PCR was determined by analysis of raw and heat treated almond-wheat flour mixtures with a range of detection of 0.1–100,000 mg/kg. The assay was successfully trialed on a total of 214 commercial foodstuffs allowing the detection of trace amounts of almond down to the level of 0.1 mg/kg, and is therefore proposed as a ready-to-use analytical tool to trace almond allergens in foods.     

Recent advances in biotechnological valorization of brewers' spent grain

Brewers'' spent grain (BSG) is the most abundant by-product of beer-brewing. BSG is rich in nutrients such as protein, fiber, minerals, and vitamins, and therefore it is conventionally used as low-cost animal feed. On the other hand, alternative utilization of BSG has gained increased attention during recent years due to technological progress in its processing and the emergence of the concept of circular economy. The valorization of BSG through biotechnological approaches is environmentally friendly and sustainable. This review was focused on recent advancements in the conversion of BSG into value-added products, including bioenergy (ethanol, butanol, hydrogen, biodiesel, and biogas), organic acids, enzymes, xylitol, oligosaccharides, and single cell protein, via biotechnological approaches. In addition, the potential applications of BSG as immobilization matrices in bioprocesses have been reviewed.     

食品中氯丙醇脂肪酸酯风险及应对措施概述

氯丙醇酯作为食品中的一类新型污染物,得到世界各国和地区的广泛关注和研究。氯丙醇酯类物质种类繁多,其反应机制、毒理学和代谢转化研究尚不成系统,目前研究表明氯丙醇酯类物质具有一定的肾脏、生殖毒性及潜在的致癌性。国内外对氯丙醇酯的检测方法、污染水平和暴露评估等研究主要集中在3-氯-1,2-丙二醇酯和2-氯-1,3-丙二醇酯,且主要集中在婴儿配方奶粉、油炸和烘焙食品等脂肪含量较高的食品上。通过研究发现,普通消费者从日常饮食中摄入氯丙醇酯类物质一般是无风险的,但对于一些年轻群体和仅食用配方奶粉的婴幼儿来说风险较高。国内外已相继开展了对氯丙醇酯的研究和监控,以减少食品中氯丙醇酯类物质污染水平。目前只有欧盟制定了3-氯-1,2-丙二醇酯在部分食用油和婴幼儿配方食品中的限量要求,仅国际食品法典委员会制定了植物油中3-氯-1,2-丙二醇酯的控制规范,来降低氯丙醇酯的风险。鉴于此,本文主要对氯丙醇酯形成机制、代谢、毒性、国内外食品中氯丙醇酯的污染水平、风险评估研究进展及其管理控制措施等方面进行了简要概述,以期为食品安全监管提供参考。