Keratin-based peptide: biological evaluation and strengthening properties on relaxed hair

A peptide based on a fragment of hair keratin type II cuticular protein, keratin peptide (KP), was studied as a possible strengthening agent for weakened relaxed hair. The peptide was prepared both in aqueous water formulation (WF) and organic solvent formulations (OF), to determine the effect of organic solvents on peptide interaction with hair and the differences in hair recovery. Both peptide formulations were shown to improve mechanical and thermal properties of weakened hair with peptide in OF showing the stronger effect. As a potential new hair care product, and so would necessitate contact with skin, the cytotoxicity and genotoxicity of the peptide were also evaluated through different methodologies (Alamar Blue assay, 2'-7'-dichlorofluorescein probe, cell morphology and growth and evaluation of DNA damage by an alkaline version of the comet assay) in skin fibroblasts. These tests are indicators of the potential of peptide to cause irritation on skin or to be carcinogenic, respectively. The peptide in WF did not cause cytotoxicity or genotoxicity in any of the concentrations tested. The presence of OF, however, induced a 20% decrease in cell viability in all of the range of concentrations used after 72-h incubation. Moreover, OF inhibited cell growth and was considered genotoxic at first contact with cells. The peptide was therefore considered a promising strengthening agent for hair and was shown to be innocuous when applied in WF.     

基于 Monte Carlo 的淡水产品中硫丹及其代谢物的风险评估

目的 开展淡水产品中硫丹及其代谢物的定量风险评估研究, 量化居民通过食用淡水产品途径摄入硫丹及其代谢物的风险水平。方法 应用基于Monte Carlo模拟的@risk5.7软件, 选择风险商表征, 描述食用淡水产品途径摄入硫丹及其代谢物的膳食风险。结果 普通居民通过食用淡水产品途径摄入硫丹及其代谢物的风险商平均值以及各百分位数风险商均小于1, 且特殊人群高于普通人群, 其中婴幼儿、儿童、青少年通过食用淡水产品途径摄入硫丹及其代谢物的风险商平均值以及各百分位数风险商是普通居民的2倍。结论 居民仅通过食用淡水产品途径摄入硫丹及其代谢物的膳食暴露并不存在健康风险, 但仍需要加强对环境中硫丹及其代谢物的监控, 从而进一步降低居民通过食用淡水产品途径摄入硫丹及其代谢物的膳食风险水平。     

PVA纤维伴纺牦牛绒纺纱工艺研究及产品开发

根据牦牛绒和水溶性PVA纤维的性能特点,采用PVA纤维伴纺牦牛绒纤维,从而改善牦牛绒纤维的可纺性能.通过控制牦牛绒/PVA混纺纱的各道生产工艺参数和生产条件,开发出了较低线密度的纯纺牦牛绒纱线.     

迷你萨拉米香肠加工及其产品特性分析

以高原牦牛肉为主要原料,肉馅制作灌装后采用西式发酵肠缓慢发酵法发酵和干燥,以每小节1袋的迷你式小包装后再巴氏热处理、熟化并避免再污染,开发出具备发酵香肠和中式腊肠双重风味特色,质地口感适中, 风味柔和, 宜于儿童食用的方便、休闲食品迷你萨拉米肠。产品特性分析得出其主要指标为:aw0.84~0.86,pH5.4,糖2.2%,食盐3.1%,蛋白质33.4%,脂肪26.3%。     

拉伸细化牦牛毛的表面性能与染色性

拉伸细化后牦牛毛表观形态及内部结构均发生变化,必将影响细化后纤维的表面性能与染色性.实验结果表明:纤维拉伸细化后接触角减小,吸湿性增加.细化后纤维的染色性能更加优异,细化毛平衡上染率明显高于原毛,随拉伸率增加,纤维上染速率加快,平衡上染率提高,且拉伸细化处理可以降低牦牛毛的染色温度.     

Effect of inulin on the textural and sensory properties of mortadella, a Spanish cooked meat product

Inulin is a fructooligosaccharide with demonstrable beneficial effects on health. Its effect on the textural and sensory properties of mortadella, a Spanish cooked meat product, was studied. Conventional (23% fat) and reduced‐fat sausages (10% fat) were prepared. Fat reduction yields an energy value reduction close to 33%. In both cases, inulin was incorporated, in powder and as gel form, in sufficient amounts to constitute the 2.5%, 5% and 7.5% of the final product. To evaluate the effect of inulin, instrumental measures of texture and sensory analysis (hedonic test) were performed. Textural analysis indicated that powdered inulin increases hardness and this fact was more evident in reduced‐fat sausages which showed that this changes even at concentrations of 2.5%. However, when inulin was incorporated as a gel, textural parameter changed only when the high levels were assayed (7.5%) showing softer sausages independent of the fat content. Sensory analysis was highly favourable and the overall acceptability was good in all batches in spite of the changes observed in texture. It can be established that this product can be enriched with inulin to a maximum level of 7.5% and preferably as gel with a good sensory quality.     

不同处理对猪毛角蛋白提取效果及功能特性的影响

目的 探究不同处理方式对猪毛角蛋白提取效果及功能特性的影响。方法 采取碱解法、酶解法、蒸汽爆破法、还原法4种处理提取猪毛角蛋白,研究不同处理对猪毛溶解率和可溶性蛋白含量以及角蛋白功能特性的影响。结果 碱解和蒸汽爆破处理下猪毛溶解率较高,均为65%左右,而还原法处理的可溶性蛋白含量较高,为165mg/g左右;不同处理对猪毛角蛋白的功能特性影响差异较大,溶解性和持水性较好的分别是碱解和蒸汽爆破处理得到的角蛋白,而还原法提取出的猪毛角蛋白持油性、冻融稳定性、乳化性及乳化稳定性较好。结论 各处理方法均有利弊,需要根据角蛋白的用途选择合适的提取方法。本研究为猪毛角蛋白的提取及猪毛的充分利用提供了一定理论参考。     

农产品质量安全风险评估研究进展

农产品质量安全问题不仅关系到消费者的身体健康,也成为我国加入WTO后保护国内产业、扩大农产品出口的巨大障碍。风险评估是解决当前农产品质量安全问题,确立农产品质量安全政策和指南的科学依据,对保护消费者健康和促进国际贸易至关重要。本文分析了影响农产品质量安全的危害因素及来源,并针对农产品化学性污染和生物性污染两种不同危害因素风险评估的4个方面:危害识别、危害描述、暴露评估、风险描述进行研究,总结了我国农产品质量安全风险评估研究现状。     

谷氨酰胺转胺酶的功能特性及其在面粉制品加工中的应用

谷氨酰胺转胺酶是一种催化酰基转移反应的转移酶，它可使蛋白分子间和分子内产生共价交联反应，是一种良好的面筋改良剂。主要论述了谷氨酰胺转胺酶的功能特性、作用机理、改良面筋的流变学特性以及它在面粉制品加工中的应用。     

河南省居民肉及肉制品中铜摄入水平及其风险评估

目的以河南省肉及肉制品中铜为例,演示采用简单分布评估方法,评价河南省居民肉及肉制品饮食中铜摄入情况及其潜在的健康风险。方法 2014—2015年在河南省16个省辖市随机采集肉及肉制品309份,按照食品中铜测定的原子吸收光谱法标准操作程序进行检测,结合河南省2010—2012年开展的居民营养与健康状况监测中肉及肉制品的消费量数据,采用简单分布模型(确定性评估)方法,借鉴文献发表的肉及肉制品对膳食中铜的贡献率,计算河南省不同年龄组人群全膳食中铜摄入水平及其潜在的健康风险。结果肉及肉制品中铜的平均含量为0.556 mg/100 g,中位数为0.060 mg/100 g,不同肉及肉制品中铜平均含量最高为内脏(1.561 mg/100 g),铜平均含量最低的为猪肉(0.068 mg/100 g)。河南省居民每天通过进食肉及肉制品的铜平均摄入量为0.046 mg/d,高端(P95)摄入量为0.144 mg/d。利用文献报道的肉及肉制品贡献率外推全膳食中铜摄入量后发现,河南省居民全膳食中铜的平均和P95摄入量分别为0.638和1.977 mg/d。个体评估结果显示,全人群铜摄入量处于推荐摄入量(RNI)与可耐受最高摄入量(UL)之间的个体比例为21.12%(801/3 792),处于EAR和RNI之间的个体比例为8.10%(307/3 792),而低于平均需要量(EAR)、大于UL的人群比例分别为69.75%(2 645/3 792)和1.03%(39/3 792)。结论河南省全人群膳食中铜摄入量缺乏的风险较高,铜过量的风险较低。     

不同品种籼米生产的鲜湿米粉理化特性与感官品质

采用湖南省各地区广泛种植的50种籼米原料来生产鲜湿米粉,对鲜湿米粉的理化特性及其感官品质进行研究.通过二者相关性和回归分析,为生产鲜湿米粉的品质评价和专用稻种的选择提供理论依据.研究结果发现,理化性质中的透射比、熟断条率、碘蓝值、吐浆值与鲜湿米粉的组织形态、口感、色泽等重要感官品质呈极显著或显著相关,当碘蓝值中等(0.1～0.3)、透射比高(＞0.85)、熟断条率低(＜10%)以及吐浆值低(＜5%)时,鲜湿米粉的感官评分相对最高.碘蓝值、透射比、熟断条率和吐浆值这些理化特性指标能够较好地反映出鲜湿米粉的感官特性,可以用来评价鲜湿米粉的品质.同时,稻米品种对鲜湿米粉的品质有极显著影响,其中T优167、早熟213和中嘉早17品种的籼米制作的鲜湿米粉的品质最好.     

调味品感官品评及新产品开发与食品流变的相关性探讨

调味品的感官特性与食品流变之间有着一定的关系.利用质构仪等仪器设备可以测定小调味品的某些特性,但是其不能像感官品评那样将调味品的特性综合的表达或描述出来;将调味品感官评价和食品流变学的原理相结合的方法综合起来,应用到新产品开发、工艺设计、设备选择等方面对调味品工业的发展可起到积极的促进作用.     

蒸汽闪爆处理对山羊毛及鸡毛吸附染色废水的影响

以山羊毛、鸡毛为原料,采用蒸汽闪爆、冷冻粉碎处理方法制备得到闪爆粉碎山羊毛、鸡毛,并应用于吸附染色废水中活性蓝19染料(RB19)。对比研究了蒸汽闪爆、冷冻粉碎处理前后山羊毛、鸡毛吸附性能的变化。结果表明:原鸡毛(175 mg/g)吸附能力高于山羊毛(55.24 mg/g)的吸附能力。经过蒸汽闪爆、冷冻粉碎处理后,山羊毛、鸡毛的吸附量分别达到426.7、440.0 mg/g,闪爆粉碎山羊毛表面鳞片被破坏,闪爆粉碎山羊毛、鸡毛的结晶指数均下降,分别为8.6%、13.1%,闪爆粉碎山羊毛比表面积、BJH吸附孔累积比表面积、孔径体积是闪爆粉碎鸡毛的1.64、2.74、2.65倍。蒸汽闪爆、冷冻粉碎联合处理提高了山羊毛、鸡毛等废弃角蛋白对活性蓝19染料的吸附性能。     

Effect of different ozone treatments on aflatoxin degradation and physicochemical properties of pistachios

This study evaluated the efficiency of ozone for the degradation of aflatoxins in pistachio kernels and ground pistachios. Pistachios were contaminated with known concentrations of aflatoxin (AF) B₁, B₂, G₁ and G₂. Pistachio samples were exposed to gaseous ozone in a chamber at 5.0, 7.0 and 9.0 mg L^?1 ozone concentrations for 140 and 420 min at 20 °C and 70% RH. Aflatoxin degradation was determined by high performance liquid chromatography (HPLC). The efficiency of ozone for aflatoxin degradation in pistachios increased with increasing exposure time and ozone concentration. The results indicated that AFB₁ and total aflatoxins could be reduced by 23 and 24%, respectively, when pistachio kernels were ozonated at 9.0 mg L^?1 ozone concentration for 420 min. Only a 5% reduction in AFB₁ and total aflatoxin levels could be achieved for ground pistachios under the same conditions. No significant changes occurred in pH, color, moisture content and free fatty acid values of pistachio kernels and ground pistachios. Fatty acid compositions of pistachios did not change significantly after the ozonation treatments. No significant changes were found between sweetness, rancidity, flavor, appearance and overall palatability of ozonated and non‐ozonated pistachio kernels. Significant changes were observed in the organoleptic properties of ground pistachios, except rancidity, after 5.0 mg L^?1 ozone treatment for 140 min. Ozonation was found to be more effective for degrading aflatoxins in pistachio kernels than ground pistachios. Copyright © 2006 Society of Chemical Industry     

三种马铃薯复合变性淀粉对马铃薯面条的物性及品质的影响

将马铃薯全粉与面粉按不同比例配成混合粉以制作面条,并用马铃薯复合变性淀粉提升面条的品质;通过对不同比例混合粉糊化特性,面条断条率、烹调损耗、物性、烹调特性和感官评定的研究,得出制作面条的最优马铃薯全粉:面粉质量比和预糊化交联淀粉、氧化交联淀粉、酯化交联淀粉的添加量。结果表明,最优的质量比为20:80 (w/w);添加马铃薯复合变性淀粉对马铃薯面条的弹性、黏着性等都有显著影响(p<0.05);在烹调实验中,随着预糊化交联淀粉、氧化交联淀粉、酯化交联淀粉的增加,吸水率升高,当三者的添加量分别为5%、4%、5%时,浊度最低;感官评定实验中,当添加5%预糊化交联淀粉、4%氧化交联淀粉、6%酯化交联淀粉时,马铃薯面条的各指标评分之和最高,且分别为:31.2、33.1、34.6。从质构,烹调特性,感官特性等方面综合对比三种马铃薯复合变性淀粉对马铃薯面条的影响,得出6%酯化交联淀粉最适宜。