炒籽温度对茶油关键香气成分及感官品质的影响

为分析炒籽温度对茶油关键香气成分及感官品质的影响,并比较海南和湖南两地产热榨茶油的香气成分与感官品质间的相关性和差异,通过HS-SPME-GC-MS分析海南茶油及不同炒籽温度处理的湖南茶油的香气成分组成,计算ROAV值确定其关键香气成分,并进行感官分析,建立PLS模型。结果表明,海南茶油和湖南炒籽茶油中最主要的香气成分为(E)-2-癸烯醛、壬醛、苯乙醛、2,5-二甲基吡嗪和3-乙基-2,5-二甲基吡嗪;随着炒籽温度升高,炒籽茶油的黄色评分降低,红色、褐色显著升高,茶油清香味逐渐减少,烤香味逐渐增加;海南茶油均具有较强的茶油清香味和烤香味,湖南炒籽茶油在较高温度处理下会产生相似的烤香味,但茶油清香味普遍低于海南茶油,因此湖南产茶籽通过海南传统高温炒籽方法制得的茶油,其香气与海南茶油仍有一定的区别。此外,对关键香气成分与感官属性建立PLS模型,交叉验证相关系数Q2为0.901,说明该模型具有较好的预测热榨茶油香气品质的能力。     

肉桂添加量对卤鸡腿肉挥发性风味成分的影响

比较不同肉桂添加量对卤鸡腿肉挥发性风味成分的影响。设置5个梯度的肉桂添加量(0%,0.05%,0.1%,0.2%,0.3%),采用电子鼻(EN)、顶空固相微萃取(HS-SPME)和气质联用(GC-MS)的方法对不同肉桂添加量的卤鸡肉样品进行检测分析。结果显示:不同肉桂添加量鸡肉样品的电子鼻信号表现出较强的聚类特性;按肉桂添加量由低到高的顺序经GC-MS依次检出54、60、63、65、80种挥发性风味物质;与空白组相比,添加肉桂的鸡肉样品中新增了肉桂醛、桉叶油醇、香叶基丙酮、香豆素、对异丙基甲苯、石竹烯等40种挥发性风味物质,以0.3%肉桂组增加的萜烯类物质最多。表明添加肉桂后鸡肉样品中新增的挥发性风味物质多属于肉桂添加的直接引入。肉桂添加浓度达到0.3%时,样品中萜烯类物质急剧增加,风味成分变化较大。     

栗子鸡罐头的研制

介绍了以栗子和鸡为原料,研究了制成具有独特风味的栗子鸡罐头的工艺和配方。该产品是一种很具市场前景的产品。     

滚揉腌制液中添加Nisin对川香鸡柳的保鲜效果

在川香鸡柳滚揉腌制液中添加不同含量的Nisin(0.1、0.2、0.3、0.4g/kg,按鸡小胸质量计),结合托盘包装技术对其进行保鲜研究。通过测定其在(4.0±0.5)℃条件下贮藏期间的菌落总数、水分活度、pH值、色差值、贮藏损失各项指标,分析Nisin对川香鸡柳的保鲜效果。结果表明:滚揉腌制液中添加Nisin能显著抑制川香鸡柳中菌落总数的增长(P<0.05),贮藏第8天时最明显,与对照组相比,处理组菌落总数可降低3.32 lg(CFU/g);Nisin可显著提高川香鸡柳贮藏后期色泽亮度和黄度;显著延缓第8天后pH值的升高(P<0.05);但对水分活度影响不显著。综合各因素,添加0.3g/kg Nisin保鲜效果最佳。在滚揉腌制液中添加Nisin对川香鸡柳具有良好的保鲜效果。     

鸡的品种和蒸煮次数对白切鸡卤水的营养成分和风味影响研究

为了使白切鸡卤水标准化,推进其高值化利用,本文以黄油鸡和土二鸡为制作白切鸡的原料,研究了两种原料鸡在不同蒸煮次数（2、4、6、8次）下产生的卤水中营养成分的变化。此外,采用顶空固相微萃取-气相色谱-质谱联用法,测定了两种原料鸡在不同蒸煮次数卤水中的风味物质。结果表明:随着蒸煮次数的增加,白切鸡卤水中的蛋白质、脂肪、碳水化合物等营养成分均显著增加（P<0.05）。在蒸煮第2、4、6、8次的卤水中检测出醛类、醇类、酮类三类主要挥发性风味物质,其中黄油鸡卤水挥发性物质有52种,土二鸡有41种;醛类物质是鸡汤的主要物质,黄油鸡有31种,土二鸡有24种。综合分析,土二鸡卤水比黄油鸡卤水的利用价值高,与理化测定和风味测定结果相吻合。本文的研究结果可为白切鸡加工原料的选择提供一定的参考,同时,对白切鸡卤水的标准化生产提供数据支撑。     

A note on the incidence and antibiotic resistance of Staphylococcus aureus isolated from meat and chicken samples

One hundred and fifty samples of raw calf/lamb meat samples (mince and chunks) and chicken parts (giblets, carcass) were analysed for the presence of Staphylococcus aureus. Eighty S. aureus strains were isolated and identified. Resistance of the strains to methicillin and other antibiotics was determined by the Kirby-Bauer disc diffusion test. The overall methicillin resistance rate for S. aureus was 67.5%. Of S. aureus strains, 87.5% were resistant to bacitracin. A high prevalence of penicillin G resistance was detected for S. aureus (53.8%). Few of the strains were resistant to erythromycin (7.5%). All strains were susceptible to vancomycin, sulbactam–ampicillin, ciprofloxacin and cefaperazone–sulbactam. This study confirmed the presence of S. aureus, especially antibiotic-resistant strains, in the foods examined, indicating poor sanitary conditions during processing which may create a health risk for consumers.     

酱鸡腿加工工艺参数优化

以鸡腿为材料,采用二次通用旋转组合试验设计优化酱鸡腿的加工工艺参数。结果表明：酱鸡腿最优加工工艺参数为油炸温度170 ℃、油炸时间70 s、煮制温度100 ℃、煮制时间2 h。在此条件下,加工酱鸡腿的综合评分预测值为0.47,验证实验综合评分值实测值为0.451,实验值和预测值吻合良好。该工艺得到的成品色泽金黄、肉丝粉白、可口,其中感官评分为78.678,嫩度为7.517 N,a*值为15.51。     

冰鲜鸡肉品质及其货架期的研究进展与展望

相对于热鲜鸡肉和冷冻鸡肉,冰鲜鸡肉在口感、风味、新鲜度以及营养等方面具有很大优势,具有很好的市场发展前景。但冰鲜鸡肉的品质在生产加工和流通过程中容易发生腐败变质。随着消费者食品安全意识的日益提高,冰鲜鸡肉的品质及其货架期受到越来越多的关注。本文总结了冰鲜鸡肉的品质表征指标;阐述了微生物因素、物理因素以及化学因素对冰鲜鸡肉品质的影响;比较了化学、超高压和辐照等6种保鲜技术对冰鲜鸡肉保鲜的效果及特点;结合食品货架期预测模型,梳理了已有预测冰鲜鸡肉货架期的相关研究;最后分析了冰鲜鸡肉品质及其货架期的研究现状,并对其未来的研究趋势进行了展望,指出随着研究技术、手段和保鲜技术的不断发展,冰鲜鸡肉货架期的研究也将不断向实用和智能化的方向发展。     

Deep Sequencing Analysis of miRNA Expression in Breast Muscle of Fast-Growing and Slow-Growing Broilers

Growth performance is an important economic trait in chicken. MicroRNAs (miRNAs) have been shown to play important roles in various biological processes, but their functions in chicken growth are not yet clear. To investigate the function of miRNAs in chicken growth, breast muscle tissues of the two-tail samples (highest and lowest body weight) from Recessive White Rock (WRR) and Xinghua Chickens (XH) were performed on high throughput small RNA deep sequencing. In this study, a total of 921 miRNAs were identified, including 733 known mature miRNAs and 188 novel miRNAs. There were 200, 279, 257 and 297 differentially expressed miRNAs in the comparisons of WRRh vs. WRRl, WRRh vs. XHh, WRRl vs. XHl, and XHh vs. XHl group, respectively. A total of 22 highly differentially expressed miRNAs (fold change > 2 or < 0.5; p-value < 0.05; q-value < 0.01), which also have abundant expression (read counts > 1000) were found in our comparisons. As far as two analyses (WRRh vs. WRRl, and XHh vs. XHl) are concerned, we found 80 common differentially expressed miRNAs, while 110 miRNAs were found in WRRh vs. XHh and WRRl vs. XHl. Furthermore, 26 common miRNAs were identified among all four comparisons. Four differentially expressed miRNAs (miR-223, miR-16, miR-205a and miR-222b-5p) were validated by quantitative real-time RT-PCR (qRT-PCR). Regulatory networks of interactions among miRNAs and their targets were constructed using integrative miRNA target-prediction and network-analysis. Growth hormone receptor (GHR) was confirmed as a target of miR-146b-3p by dual-luciferase assay and qPCR, indicating that miR-34c, miR-223, miR-146b-3p, miR-21 and miR-205a are key growth-related target genes in the network. These miRNAs are proposed as candidate miRNAs for future studies concerning miRNA-target function on regulation of chicken growth.     

Molecular Characterization and Expression Pattern of Tripartite Motif Protein 39 in Gallus gallus with a Complete PRY/SPRY Domain

Members of tripartite motif (TRIM) proteins in mammals play important roles in multiple cellular processes in the immune system. In the present study we have obtained the chicken TRIM39 with the insertion of a base A at position 1006 bp, compared to the sequence in the NCBI database (Accession No: NM 001006196), which made TRIM39 fulfill the TRIM rule of domain composition with both PRY, and SPRY domains. The open reading frame consisted of 1392 bp encoding 463 amino acid residues. The amino acid sequences of TRIM39 protein in mammals were highly similar (from 91.48% to 99.61%), while chicken TRIM39 had relatively low homology with mammals (from 29.2% to 39.59%). Real time RT-PCR indicated that the mRNA expression level of TRIM39 was the highest in spleen, with a lower expression in liver, brain, and lung, suggesting it might be an important protein participating in the immune system.