Effect of skin addition on the technological properties of comminuted chicken meat emulsions

Possibility of using skin supplement as collagen raw material (substituting leg muscles) in highly comminuted sausages made from breast muscles was investigated. It was found that 5% skin added to the comminuted breast muscles resulted in the collagen content equal to that obtained with 40% leg muscles. Addition of 5% skin to the breast muscles decreases emulsifying capacity of protein extracts but increases thermal stability, and changes the flow curve of meat emulsions more than the addition of dark muscles. The skin used instead of leg muscles does not change sausage binding (shear force) and overall sensory value, but reduces water-holding capacity and palat-ability of sausages.     

鸭肉酶解液美拉德反应制备鸭肉香精基料的研究

为制备鸭肉香精基料,以鸭肉酶解液为原料,添加还原糖、盐、维生素以及蒜粉进行美拉德反应。通过单因素实验和正交实验,确定最佳美拉德反应条件:酶解液中加入10%葡萄糖,3%盐,0.7%VB1,0.15%VC和0.1%蒜粉,110℃,自然pH6.87条件下反应30min。在此条件下制得的香精基料液体澄清,淡黄色,具有浓郁的鸭肉香味,令人愉快的香甜气和轻微蒜味,咸鲜味明显、突出,无苦涩味。     

Volatile flavour profile of goat meat extracted by three widely used techniques

Three procedures for the isolation of volatiles from grilled goat meat were compared: dynamic headspace entrainment on Tenax TA, simultaneous steam distillation-extraction, and solid-phase microextraction. Headspace entrainment on Tenax TA extracted the highest number of Maillard-derived volatile compounds. Two hundred and three volatile components were identified; 159 are reported for the first time in goat meat. Most of the volatiles detected (155) were lipid oxidation products, such as hydrocarbons, aldehydes, alcohols, ketones, carboxylic acids and esters. Forty-eight Maillard-derived compounds were identified, comprising pyrazines, pyrroles, thiophenes, furanthiol derivatives, alkyl and alicyclic sulphides, pyridines, and thiazoles. Some reported character impact compounds of cooked meat, e.g., 12-methyltridecanal, (E,E)-2,4-decadienal, methional, and dimethyl trisulphide were identified in the volatile profile of goat meat, together with a series of C₂ to C₅ alkylformylcyclopentenes, which have been reported in cooked chicken, pork, beef and lamb, as being important for the characteristic flavour impression of different animal species.     

表面解吸常压化学电离质谱法用于猪肉新鲜度评价

猪肉是我国人民的主要肉食之一,监督原料肉的新鲜度具有重要的现实意义。采用自行研制的表面解吸常压化学电离质谱（DAPCI-MS）,在无需样品预处理的条件下,对放置1～8天的猪肉进行正离子模式检测,获得其化学指纹图谱。通过分析谱图中各分解产物的信号峰,可将冷藏保存的猪肉新鲜度划分为3个等级：第1等级为保存1～3天,是新鲜度变化的初期,谱图中主要以丝氨酸、甘氨酸的微弱信号峰为特征,表明新鲜猪肉样品中的蛋白质正在发生微弱的降解;第2等级为保存4～6天,是猪肉向腐败变化的过渡时期,谱图中主要以吲哚、2,3-丁二醇的信号峰为特征;第3等级为保存7～8天,是猪肉完全变质的时期,谱图中以三甲胺的信号峰为主要特征。丝氨酸、甘氨酸、吲哚、2,3-丁二醇、三甲胺,这些主要分解产物的信号峰强弱可作为评价猪肉新鲜度的关键依据。根据指纹图谱之间的差异,结合主成分分析（PCA）和聚类分析（CA）法,实现了对不同新鲜级别猪肉的分类识别及对本方法的重现性验证。该方法无需样品预处理、灵敏度高、分析速度快、无污染,有望应用于市场上猪肉新鲜度的快速鉴别,也可为高粘性复杂基体样品的分析提供方法参考。     

In Vitro Antioxidant Properties of Berry Leaves and Their Inhibitory Effect on Lipid Peroxidation of Thigh Meat from Broiler Chickens

The present study is designed to evaluate the antioxidant compounds from bilberry, cranberry, and raspberry leaves in connection with their radical scavenging activities, and their potential in inhibiting the lipid peroxidation of thigh meat from broiler chickens. For this purpose, plant extracts are analyzed regarding the content in bioactive compounds, antioxidant properties analysis including 1,1‐diphenyl‐2‐picrylhydrazyl, superoxide, hydrogen peroxide, and hydroxyl radical‐scavenging activities. Lipid peroxidation is induced by an Fe⁺³/ascorbic acid system and the inhibitory effects of plants extracts are assessed using thiobarbituric reactive substances (TBARS) as biomarkers for quantifying lipid oxidation in meat. The overview of the analyzed antioxidant compounds shows that cranberry leaves present the highest concentrations of vitamin E, β‐carotene, lutein and zeaxanthin, and polyphenols and a total antioxidant capacity with 52% higher than bilberry and 360% than raspberry. Bilberry leaves extract shows the strongest effect (p  < 0.0001) in inhibiting meat lipid peroxidation. Practical Applications: The results demonstrate the positive effect of the selected berry leaves in the oxidative stability of broiler chicken meat under in vitro conditions, and may be suggested as an alternative source of natural antioxidants for animal nutrition, with benefits in inhibiting and delaying oxidation, and also enhancing the nutritional value of meat.     

Dietary Oil Type and Late Feed Restriction Elicit Synergistic Effects on Growth,Caeca Bacteria,Carcass, Fat Accretion,and Muscle Lipids in Female Broilers

The influence of dietary oil type (OT) and late feed restriction (FR) on growth, caeca bacteria count, carcass, separable fat depots, serum and muscle lipids, and meat quality in broilers is examined. In total, 224, 21-day-old female Arbor acres broilers are randomly allotted to either PN, Unrestricted+50 g kg⁻¹ palm oil (PO); PR, 25%-FR+PO; SN, Unrestricted+50 g kg⁻¹ soybean oil (SO); or SR, 25%-FR+SO for 21 d. The SN and PR birds have the heaviest and lightest body weight gain (BWG), respectively. Feed conversion ratio (FCR) is poorer in the PN birds. Feed-restricted birds have more caeca Lactobacillus and lower Salmonella, serum cholesterol, and triglycerides. Carcass yield is higher in SR birds and lower in PN birds. The FR-OT interaction is significant for muscle lipids and weight of fat depots. The PN birds deposit more abdominal, intramuscular, sartorial, mesentery and neck fats, muscle saturated fatty acids, and C18:1n-9 and lower C18:3n-3 and C20:5n-3 than other birds. Neither OT nor FR affects the pH, color, water holding capacity, and oxidative stability of breast meat. The changes elicited by 25%-FR on BWG, FCR, carcass yield, depot fats, and muscle lipids in female broilers are dependent on dietary OT. Practical Application: Fast growth rate and unrestricted access to feed can predispose broiler chickens to excessive fat accretion, which is counterproductive. Producing high-quality carcasses that meet consumers’ expectation is crucial for sustainable and efficient broiler production. The possible interaction between dietary OT and late quantitative FR in mitigating excessive fat accretion and altering production indices in female broilers is explored. Late quantitative FR reduces BWG, FCR, serum lipids, caeca pH and Salmonella spp. and fat accretion in fat depots, and enhances carcass yield and caeca Lactobacillus spp. However, the impacts are more pronounced in the PO birds than the SO birds. Late FR improves the C18:3n-3 and C18:2n-6 contents in PO meat while reducing the C14:0 and C16:0 contents in SO meat. These findings explicate that dietary OT and late quantitative FR can be synergistically used to mitigate excessive fat accretion and alter growth, caeca microflora, and muscle lipids in broilers.     

反相高效液相色谱法测定肉制品中残留的盐酸克伦特罗

建立了快速简便测定肉类产品中盐酸克伦特罗含量的反相高效液相色谱法。简化了样品前处理方法,优化了色谱分析条件。结果表明,以Inertil/WondaSil C18(5μm,4.6 mm×150 mm)为分离柱,流动相V(0.1%磷酸)∶V(甲醇)=6∶4,流速1.0 mL/min,进样量10μL,柱温40℃,检测波长244 nm时,可以获得良好的色谱峰。绞碎的样品经饱和硼砂和硫酸锌处理除去脂肪和蛋白质,用水定容。样品加标回收率在95%¹03%之间,保留时间的相对标准偏差为0.14%,峰面积的相对标准偏差为6.73%。此方法前处理简单,分析时间短,测定结果准确可靠,适于肉类产品中盐酸克伦特罗的测定。     

Growth of Clostridium perfringens from spore inocula in cooked cured beef: development of a predictive model

The objective of this study was to develop a model to predict the growth of C. perfringens from spores at temperatures applicable to the cooling of cooked cured meat products. C. perfringens growth from spores was not observed at a temperature of 12 °C for up to 3 weeks. The two parameters: germination, outgrowth, and lag (GOL) time and exponential growth rate, EGR, were determined using a function derived from mechanistic and stochastic considerations and the observed relative growths at specified times. A general model to predict the amount of relative growth for arbitrary temperature was determined by fitting the exponential growth rates to a square root Ratkowsky function, and assuming a constant ratio of GOL and generation times. The predicted relative growth is sensitive to the value of this ratio. A closed form equation was developed that can be used to estimate the relative growth for a general cooling scenario and determine a standard error of the estimate. The equation depends upon microbiological assumptions of the effect of history of the GOL times for gradual changes in temperature. Applying multivariate statistical procedures, a confidence interval was computed on the prediction of the amount of growth for a given temperature. The model predicts, for example, a relative growth of 3.17 with an upper 95% confidence limit of 8.50 when cooling the product from 51 to 11 °C in 8 h, assuming a log linear decline in temperature with time.     

Nutritional Quality of Rabbit Meat as Affected by Cooking Procedure and Dietary Vitamin E

ABSTRACT: The effect of two dietary treatments (50 as opposed to 200 mg kg^-1 of α-tocopheryl acetate) on rabbit meat, cooked by different procedures (boiling, frying, roasting), was evaluated. Cooking caused an increase of pH, shear force, lightness, hue and chroma, and a decrease of water holding capacity. The change in nutritional value was slight but lipid oxidation was increased and the fat quality worsened. Boiled meat had the lowest nutrient retention and the highest TBARS values. Supplemental vitamin E was effective in reducing oxidative processes and increasing the amount of n-3 polyunsaturated fatty acids also during cooking.     

新型辅助加工技术提高肉制品消化特性的研究进展

随着国民生活质量的提高,人们对肉制品的需求也不再仅仅局限于感官质量和卫生质量等基本特性。肉制品中蛋白质含量高达10%-20%,是人体不可缺少的营养物质。近年来,如何提高肉制品的消化率这一问题受到了广泛的关注。目前,改善肉制品中蛋白质的结构和功能特性是提高消化率的主要可行性途径。在传统蒸煮、烘烤等加工方式的前提下,肉制品的制作过程中辅以新型加工技术(如超声波,超高压,脉冲电场,真空低温烹饪,酶解技术等),可以达到改变蛋白质结构、提高蛋白质分解酶活性的目的,从而提高肉制品的消化率。本文系统综述新型辅助加工技术在提高肉制品消化特性方面的研究进展,旨在探求更经济有效的加工方法,为改善提高肉制品的消化特性提供理论基础。