叉烧肉软包装的加工研究

探讨了以传统叉烧肉工艺为基础,以鲜瘦肉为原料,经过多道工序生产的一种口味多样的即食产品的配方、工艺、包装,并探讨了生产工艺的几个关键问题.产品的特点是滋味鲜美、口感细腻,不油腻,肉香浓郁,风味独特,开袋即食.     

A modified VERI-FRY® quick test for measuring total polar compounds in deep-frying oils

The AOCS official method for the determination of total polar compounds in deep-frying oils is often used to estimate frying oil degradation. It can be accurate and reliable, but with sacrifices of time and expense. The TPM VERI-FRY® PRO (Libra Technologies, Inc., Metuchen, NJ) quick test provides a quick and easy way to measure polar compounds in frying oils. The modified quick test measured at 490 nm has a good correlation with the AOCS official method (r=0.975, P<0.001) and provides a good estimate of polar compound accumulation in oils over 80 h of deep-frying. Using the quick test to measure polar compounds is fast, convenient, economical and reliable.     

高效液相色谱-质谱串联法检测中餐常见肉类中杂环胺含量

本文通过优化液液萃取和固相萃取,结合高效液相色谱-质谱串联法对肉制品中的杂环胺进行分析测定。该方法对肉制品中六种杂环胺的检出限和定量限分别低至0.0006 ng/g和0.0021 ng/g。应用该方法研究了常见烹饪方式(烘烤和油炸)对大众餐桌上最常见肉品(鸡肉、猪肉、牛肉、草鱼)中杂环胺形成的影响。结果表明,相同烹饪方式处理的肉制品中杂环胺的生成量随烹饪温度的升高而增加;在相近加工温度下,油炸烹制的肉和鱼会产生较烘烤处理更多的杂环胺。烘烤和油炸烹制的肉制品中含量最高的杂环胺分别是2-氨基-1-甲基-6-苯基咪唑并[4,5-b]吡啶(Ph IP)和2-氨基-3,8-二甲基咪唑并[4,5-f]喹喔啉(Me IQx)。相同烘烤烹制条件下(275℃),烤鸡肉中产生的杂环胺总含量最高,其次是烤猪肉,草鱼和牛肉。275℃下烘烤烹制的鸡肉中检出最高含量的Ph IP(341.15ng/g)。在相同的实验用油炸烹制条件下,油炸肉类和鱼类中杂环胺含量处于相对较低的水平,相互之间略有差异;于200℃的油炸牛肉中检测出最高含量Me IQx (7.44 ng/g)。     

不同烹饪条件下食物中反式酸含量变化的研究

大量研究已经证明食物中的反式酸对人体健康有害,目前国外人们日常餐饮主要采用煎炸方式烹饪食物,而国内餐饮主要采用煎炒食物的烹饪操作,研究烹饪过程中反式酸含量的变化情况有着重要意义。采用煎炸鸡翅和薯条,煎炒土豆丝和肉丝的方法,来考察食物在烹饪过程中反式酸的变化情况。试验结果显示:煎炸完鸡翅后,鸡翅反式酸含量从起始的0.032 g/100 g变化到0.178 g/100 g(P<0.05)。煎炸完薯条后,薯条的反式酸含量从起始的0.019 g/100 g变化到0.269 g/100 g(P<0.05)。煎炒完土豆丝和肉丝后,食物反式酸含量由起始的0 g/100 g和0.017 g/100 g变化到0.037 g/100 g(P>0.05)和0.023 g/100 g(P>0.05)。上述试验结果说明煎炒后食物中反式酸的含量变化不显著,虽然煎炸后食物中反式酸的含量显著升高,但其反式酸的总量都小于0.30 g/100 g,均处于较低的水平。     

A review of factors affecting fat absorption in hot chips

Consumption of hot chips is a convenience food in most countries. Unfortunately, these are high in fat and contribute to fat-related diseases in societies with a high fat consumption. There is substantial scope through best-practice deep-frying techniques for producing lower fat, high-quality chips. From a review of the literature, the main factors associated with a lower-fat content of chips are thick (>12 mm), straight cut chips; cryogenic freezing methods; low moisture content of potatoes (specific gravity >1.1); frying fat: chip volume ratio of 6:1; frying at optimal temperature (180 to 185 degrees C) during cooking and turning the temperature down (approximately 140 degrees C) and covering the vats during slack periods; vigorously shaking the basket and hanging it over the deep fryer to drain after frying; maintaining the quality of the frying fat by regularly skimming the cracklings, filtering the fat, and topping up the fryer with fresh fat; keeping the fat turnover <5 days; regular cleaning of frying equipment. It is important that all deep frying operators are adequately trained in these techniques. It is also important that the frying medium is low in saturated and trans fatty acids (<20%) because of their effects on blood lipids and low in linolenic acid (<3%) because it is readily degraded. The widespread implementation of best-practice deep-frying would reduce fat content of hot chips and thus lower overall fat consumption.     

Formation of malondialdehyde, 4-hydroxy-hexenal and 4-hydroxy-nonenal during deep-frying of potato sticks and chicken breast meat in vegetable oils

The present work investigated the formation of three toxic aldehydes, malondialdehyde (MDA), 4-hydroxy-hexenal (HHE) and 4-hydroxy-nonenal (HNE), during deep-frying of different foods in corn oil (CO), rapeseed oil (RO) and linseed oil (LO). Besides, their contents in French fries (FF) and fried chicken breast meat (FCBM) were also explored. Results showed that the MDA/HHE/HNE levels in frying groups were all lower than those in control, indicating the incorporation into the fried foods. Apart from the different levels, MDA/HHE/HNE in FF and FCBM possessed similar variation tendencies, revealing the matrix-mediated distribution. The combined exposure assessment based on the threshold of toxicological concern (TTC) levels was conducted, and risks of exceeding the limitation values (1.5 μg kg bw⁻¹ day⁻¹) for HNE in CO and HHE in LO were exhibited. The consumption of both FF and FCBM should be regulated, considering the levels of MDA, HHE and HNE these fried foods may contain.     

不同高温烹饪方式加工过程中滩羊肉风味化合物的差异比较

探讨滩羊肉高温烹饪（炒制、煎制、炸制）加工过程中挥发性风味化合物形成、变化及差异。在整体气味感知上,利用电子鼻可以区分生肉与炒制、煎制、炸制样品之间的不同气味。采用顶空固相微萃取-气相色谱-质谱（gas chromatography-mass spectrometry,GC-MS）对挥发性化合物进行定性分析,通过偏最小二乘判别分析（partial least squares-discrimination analysis,PLS-DA）法,辨别3?种加工方式不同加工阶段可挥发性成分组成。结果表明：在整体气味感知上,采用电子鼻可以区分3?种加工方式各个加工阶段,在炒制煸炒脂肪出油阶段、煎制1?min阶段、炸制3?min阶段响应值最强。GC-MS鉴定滩羊高温烹饪肉制品挥发性化合物273?种,其中炒制174?种,炸制158?种,煎制134?种。煎制、炸制前期就产生了大量的挥发性风味物质,而炒制是在加工后期才产生大量的挥发性风味物质。PLS-DA评分散点图将原料肉、3?种加工方式的滩羊肉制品挥发性化合物区分开,且有各自清晰的气味特征。醛类是3?种滩羊肉制品主要的挥发性化合物,己醛的浓度含量最高。炒制煸炒脂肪出油阶段增加了滩羊肉的可挥发性风味化合物种类及相对含量,对风味的整体贡献最高,尤其是酸类、酯类、杂环类化合物的贡献。     

油炸食品风味的研究进展

油炸食品因其具有良好的风味特征而被消费者所喜爱。油炸食品的风味是原料在油脂中发生复杂理化反应的结果。本文简述了油炸过程与风味的关系, 介绍了油炸食品香气、质构和色泽的研究进展。油炸食品的香气主要是由两种香气按一定比例构成的特殊香气, 一是由低级的、不饱和的醇类和醛类构成的油脂香, 二是吡嗪、吡啶、呋喃酮等含氧、含氮的杂环化合物所构成的焦糖、烘烤香; 其主要受油脂本身的风味成分、炸油中脂肪酸组成、油炸方式、油炸工艺参数等因素影响。油炸食品的质构特征主要是在外部形成一层坚硬的外壳、在内部分布着微孔, 主要受油炸的工艺参数、炸油的品种、油炸的方式等的影响。油炸食品的特征色泽主要是红色和黄色, 主要是由焦糖化反应和美拉德反应以及其他反应共同生成, 主要受原料本身的性质、油炸中产生的物质、油炸工艺参数、加工处理方法等因素影响。     

Analysis of Dynamic Changes of Lipid Composition and Structure of Deep-Fried Pork Slices during Storage

To understand the reasons for the quality deterioration of traditional battered and deep-fried pork slices during storage, fried pork slices stored for 12 h at 0–40 °C are used as the research samples, and Fourier-transform infrared spectroscopy （FTIR） and gas chromatography-mass spectrometry （GC-MS） are used as analytical methods. The oil migration mode, fatty acid composition change, and functional group changes in the meat slices are analyzed. The experimental results show that the unsaturated fatty acid (USFA) in the starch paste enters the meat slice in a single diffusion mode during storage, and the migration direction of the fatty acid is reversed after 7 h. Oxidation mainly occurs after 4 h of storage. At this time, the absorption peak intensities of the C═C, OH, CH₂, and CH₃ groups began to increase significantly. After 8 h, the characteristic peak of C═O narrowed and disappeared after 12 h, indicating that the oxidation has entered a decline period. The content of USFA and linoleic acid (C_18:2) showed a downward trend in phospholipids. Therefore, the stability of phospholipids, especially linoleic acid, plays an important role in the edibility of meat slices during storage. Practical Applications: Many studies have demonstrated that the edible quality of fried meat products decreases gradually during storage and the change in lipid content is the main reason for this phenomenon. However, there is a lack of targeted studies on lipid migration and compositional and structural changes during the storage of deep-fried foods. In this study, dynamic mobility, dynamic modeling, and changes in fatty acid composition and structure of lipids before and after storage provide data support for the implementation of targeted improvement measures to reduce oil migration, oxidation, and decomposition, and thus effectively extend the consumption cycle.