Characterisation of pore properties of deep‐fat‐fried chicken nuggets breading coating using mercury intrusion porosimetry technique

The objective of this study was to characterise the pore properties of deep‐fat‐fried chicken nuggets coating under different processing conditions namely frying temperatures (170, 180 and 190 °C) and time (0–240 s) using porosimetry technique. Porosity range obtained was between 39.93 and 68.99%. Porosity of the freeze‐dried samples decreased with frying time. The main effect of temperature on porosity was significant (P < 0.05). Porosity showed a high positive and negative correlation with moisture and fat contents, and the correlation coefficients ranged between 0.88 and 0.96 and 0.78 and 0.8, respectively. Bulk density increased with frying time, while apparent density was relatively the same. Pore distribution showed bimodality. There was no significant effect of temperature on pore size distribution. Over 70% of the pore volume is made up of pores greater than 1 μm. Pore volume ranged between 0.54 and 1.5 cm³ g^?1, and it decreased with frying time. Mean pore diameter was between 0.006 and 389 μm, while with frying time, it ranged between 0.25 and 8.32 μm. Total pore area was between 2.53 and 16.53 m² g^?1. Hysteresis phenomenon showed that some of the pores were not perfectly cylindrical in shape.     

Chemical and Physical Characteristics of Chicken Livers Following Adrenocorticotropic Hormone-induced Stress

Commercial chickens were implanted with a micro-osmotic pump which released 1 IU/kg BW/day of adrenocorticotropic hormone (ACTH) and were sacrificed after 24 and 48h. The weight of liver increased from 3.36% for the untreated controls to 4.56 and 5.40% of ready-to-cook carcass weight for 24 and 48h after implantation, respectively. The fat content increased from 4.44% for the untreated group to 9.97 and 12.17% for 24 and 48h treated group, respectively. However, the pH and moisture content of liver decreased with the ACTH treatment and the livers were more pale. The ATCH treatment decreased the percentages of 14:0 and 18:2 fatty acids and increased that of 18:1 fatty acid in the liver.     

Pre-Chill Spray of Chicken Carcasses to Reduce Salmonella typhimurium

A test chamber was designed and constructed and prechill chicken carcasses inoculated with Salmonella typhimurium were treated in it. They were sprayed with tap water, 0.85% sodium chloride (NaCl), 5% or 10% trisodium phosphate (TSP), 5% or 10% sodium bisulfate (SBS), 0.1% cetylpyridinium chloride (CPC), or 1% lactic acids (LAC) at 207, 345 or 827 kPa pressure for either 30 or 90 sec exposure time. Samples were taken from carcass wash water to determine the most probable number of Salmonella. Compared to tap water spraying, 0.85% NaCl spraying did not significantly reduce Salmonella. The greatest reductions of S. typhimurium, by 10% TSP, 10% SBS, 0.1% CPC or 1% LAC spraying, were 3.7, 2.4, 1.6 or 1.6 log in 90 sec treatments, respectively.     

Validation of a Combi Oven Cooking Method for Preparation of Chicken Breast Meat for Quality Assessment

ABSTRACT: Quality assessment results of cooked meat can be significantly affected by sample preparation with different cooking techniques. A combi oven is a relatively new cooking technique in the U.S. market. However, there was a lack of published data about its effect on quality measurements of chicken meat. Broiler breast fillets deboned at 24‐h postmortem were cooked with one of the 3 methods to the core temperature of 80 °C. Cooking methods were evaluated based on cooking operation requirements, sensory profiles, Warner–Bratzler (WB) shear and cooking loss. Our results show that the average cooking time for the combi oven was 17 min compared with 31 min for the commercial oven method and 16 min for the hot water method. The combi oven did not result in a significant difference in the WB shear force values, although the cooking loss of the combi oven samples was significantly lower than the commercial oven and hot water samples. Sensory profiles of the combi oven samples did not significantly differ from those of the commercial oven and hot water samples. These results demonstrate that combi oven cooking did not significantly affect sensory profiles and WB shear force measurements of chicken breast muscle compared to the other 2 cooking methods. The combi oven method appears to be an acceptable alternative for preparing chicken breast fillets in a quality assessment.     

醛化鸡红细胞吸附释放结合NP-40法纯化新城疫病毒蛋白

采用醛化鸡红细胞吸附释放结合NP-40法纯化鸡胚尿囊液中的新城疫病毒蛋白.通过收集纯化的新城疫病毒,并测定新城疫病毒血凝效价和进行9%SDS-PAGE电泳,以测定新城疫病毒蛋白的纯度.用该方法纯化的新城疫病毒血凝效价为1∶256,进行9%SDS-PAGE电泳后,发现得到的新城疫病毒蛋白不含鸡胚尿囊液蛋白,是纯度较高的新城疫病毒蛋白.以上结果表明,醛化鸡红细胞吸附释放法结合NP-40法是一种经济实用、操作简便,并有较高纯化效率的方法.     

Microporous carbon–nitrogen fibers from keratin fibers by pyrolysis

A two‐step pyrolysis method was developed for poultry keratin fibers to convert them into high temperature resistant and adsorbent fibers while retaining their original physical appearance and affine dimensions. Nearly all accessible pores in the microporous pyrolyzed chicken feather fibers (PCFF) have a diameter less than 1 nm and could be used in applications, such as adsorption, hydrogen storage, and separation of small gas molecules. An intermolecular crosslinking mechanism in the first step of pyrolysis at 215°C for 24 h provided an intact fibrous structure with no subsequent melting. The second step of the pyrolysis at 400–450°C for 1 h resulted in a microporous material with a narrower pore size distribution than commercial activated carbons. Surface and bulk characterization techniques including XPS, total carbon–nitrogen, and FTIR were utilized to examine property changes occurring during the two pyrolysis steps. A partially cyclic carbon–nitrogen framework (carbon/nitrogen ratio = 2.38) supported by double and triple bonds, and oxygen functionalities is the suggested structural model for the PCFF. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

The Antimicrobial Effect of Spice‐Based Marinades against Campylobacter jejuni on Contaminated Fresh Broiler Wings

The antimicrobial effect of spice‐based marinades against Campylobacter jejuni on inoculated fresh broiler wings was investigated. Experiments were carried out with 1 strain of C. jejuni and 6 marinades. Four experimental marinades were composed for the study and contained spices (thyme, rosemary, basil, marjoram, and so on) and different combination of bioactive compounds. Two marinades were commercial and contained spices (black pepper, sweet red pepper, and so on) and chemical additives (monosodium glutamate, sodium diacetate, calcium lactate), 1 commercial marinade was also enriched with bioactive compounds (linalool, cinnamaldehyde, lactic acid). Total aerobic bacterial count was examined to estimate the possible effect of tested marinades on the shelf‐life of marinated broiler wings. Study revealed that thyme‐based marinade was the most effective against C. jejuni on broiler wings and reduced the numbers of campylobacters by 1.04 log colony forming unit (CFU)/g (P ≤ 0.05) during storage for 168 h at 4 °C temperature. Moreover, it was more effective against C. jejuni than commercial marinade with 0.47 log CFU/g (P ≤ 0.05) reduction effect. Both experimental and commercial marinades had very similar effect on the total aerobic bacterial count. Although experimental and commercial marinades had different effect on pH of broiler wings, this parameter did not show a major impact on the antimicrobial effect of tested marinades (P ≥ 0.05). Our study shows that experimental natural thyme‐based marinade can reduce numbers of C. jejuni more effectively than tested commercial marinades.     

3种淀粉对鸡肉糜盐溶蛋白特性影响及其配方研究

为获得鸡肉蛋白较好的凝胶特性,从而改善其肉糜的加工品质,探讨玉米淀粉、马铃薯淀粉和磷酸酯淀粉3种常用淀粉与鸡肉盐溶蛋白相互作用对鸡肉糜加工基本特性的影响。以盐溶蛋白析出质量浓度、活性自由巯基含量和相对疏水性为指标,分别研究单因素条件下3种淀粉对鸡肉盐溶蛋白特性的影响,并通过二次通用旋转试验筛选出在5%淀粉添加总量条件下3种淀粉在鸡肉糜中的最佳组合配方。单因素试验表明:所选3种淀粉均对鸡肉盐溶蛋白特性有着复杂影响。3种淀粉最佳配方为:玉米淀粉1.6%、马铃薯1.6%、磷酸酯淀粉1.8%,此时鸡肉糜中盐溶蛋白基本特性参量指标预计为:盐溶蛋白质量浓度24.3mg/mL,活性自由巯基含量0.004μmol/mg,相对疏水性值22.86。     

安徽凌家滩出土古玉器软玉的化学成分特征

将安徽凌家滩出土鸡骨白古玉器碎片的全岩化学成分与新疆和田软玉、辽宁岫岩软玉等进行比较分析, 确定该鸡骨白古玉器的玉质成分为软玉, 其化学成分特征与和田白玉和青白玉相当. 据此推测, 该鸡骨白古玉器的原石可能为白玉和淡绿灰色玉. 该软玉的成因类型属镁质大理岩型, 为研究凌家滩出土古玉器玉材的来源提供了依据.     

超声波辅助酸/碱溶解等电点沉淀法提取鸡架分离蛋白的组成及其凝胶特性

利用高强度超声（high intensity ultrasound,HIU）辅助酸/碱溶解等电点沉淀（isoelectric solubilization/precipitation,ISP）法提取鸡架分离蛋白（protein isolate,PI）,采用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳研究PI组成,并分析PI凝胶特性。结果表明：PI主要由肌原纤维蛋白组成;酸溶解会导致肌球蛋白重链降解,HIU可减弱降解程度;碱溶PI凝胶的硬度、蒸煮损失率、离心损失率与对照（鸡胸肉糜凝胶,后同）无显著差异,显著高于酸溶PI凝胶（P＜0.05）;HIU显著提高了酸溶PI凝胶的硬度和弹性（P＜0.05）,降低了蒸煮损失率及离心损失率（P＜0.05）;PI凝胶白度均显著低于对照（P＜0.05）。碱溶PI凝胶对水分子的结合力和束缚力均优于酸溶PI凝胶;碱溶PI凝胶与对照凝胶均具有均匀致密微观结构,而酸溶PI凝胶微观结构明显粗糙、不均匀。结论：HIU辅助碱溶ISP法可高效提取鸡架中肌原纤维蛋白并保持其凝胶特性,有助于鸡架增值利用。