肉源微生物发酵重组牛肉干和传统牛肉干的品质比较

目的 比较发酵重组牛肉干和传统牛肉干的品质差异。方法 将原料牛肉绞碎后投入发酵剂(清酒乳杆菌7 log cfu/g, 肉糖葡萄球菌6 log cfu/g), 并在15 ℃发酵48 h使pH值达到5.0~5.3范围。然后成型(直径8 mm条状)干燥制得发酵重组牛肉干。比较发酵重组牛肉干和传统牛肉干在水分含量、水分活度、pH值、色泽、剪切力、感官评定等方面的差异。结果 发酵重组牛肉干的水分含量和水分活度(15.57%, 0.63)显著低于在同样的干燥条件下加工的传统牛肉干(18.15%, 0.67)(P＜0.05); 红度值(a*)和黄度值(b*)分别为12.41和4.27, 均显著高于传统工艺生产的牛肉干的红度值(9.65)和黄度值(2.68); 剪切力(34.16 N)比传统牛肉干(42.07N)降低18.8%。感官评定结果显示, 发酵重组牛肉干的色泽、风味和嫩度显著高于传统工艺生产的牛肉干(P＜0.05), 虽然嚼劲明显低于传统牛肉干, 但是83.3%的感官评定人员表示更喜欢发酵重组牛肉干。结论 达到同样的水分含量和水分活度, 发酵重组牛肉干的加工比传统牛肉干加工工艺可以缩短干燥时间, 添加发酵剂可以缓和制品颜色由红变褐色的过程, 发酵重组牛肉干有良好的可接受性。     

气相色谱-质谱法分析冷鲜滩羊肉微生物差异代谢物

以托盘密封包装的冷鲜滩羊肉为研究对象,基于气相色谱-质谱平台对其中微生物的代谢物组进行检测,区分不同贮藏时间生物样本之间的差异,寻找出造成上述差异的变量或分子,并将该差异物映射到滩羊肉主要腐败菌假单胞菌属(Pseudomonas)相应的代谢途径中,分析其代谢的相对强度。采用模式识别方式正交偏最小二乘法判别分析将不同贮藏时间组完全区分。结果表明:该差异代谢物所映射的代谢途径中三羧酸循环、精氨酸代谢、丙氨酸、天冬氨酸及谷氨酸代谢及磷酸戊糖途径的代谢强度相对较高。说明基于气相色谱-质谱技术对微生物的代谢物组进行检测,寻找并鉴定差异代谢物是可行的。     

痘克乳膏微生物检查方法验证

目的验证痘克乳膏微生物检验方法,保证检验方法的合理性和结果真实性。方法参照《中国药典》2010年版二部微生物限度检查法(附录ⅪJ),采用常规法和培养基稀释法验证。结果培养基稀释法可消除痘克乳膏的抑菌活性。结论化妆品微生物检验方法也需进行验证。     

食品微生物新型快速筛查技术研究进展

随着食品微生物安全事件的频发,食品微生物的检测方法要求具有快速、灵敏且准确的特点。目前,市场上的食品微生物快速筛查产品多种多样,但产品性能参差不齐。本文从食品微生物检测的前处理、增菌、富集、分离和检测等环节对国内外已被广泛认可且商业化的微生物快速筛查技术进行综述,为相关研究和产品的开发提供全面的信息。最后对国内外新型微生物快速筛查技术进行展望。     

计算机视觉技术对食品腐败检测的研究进展

食品腐败变质是食品安全问题中最主要的原因之一,据世界卫生组织(WHO)数据统计,每年全球食品工业仅因食品腐败变质带来的经济损失就多达数百亿美元。食品发生腐败变质不仅带来巨大的经济损失,而且给人们健康带来严重危害。食品在生产、加工、储存、运输和销售等各个环节中,当受到微生物、酶作用、机械损伤、病害、光照、氧气等不当的贮藏条件都有可能导致腐败变质。因此,加强对食品腐败变质的检测和监测显得尤为重要。然而,目前现有常用的检测方法存在过程操作繁琐、时效性差或灵敏度较低等缺点,难以满足现代快速准确检测的需要,成为制约食品质量安全的瓶颈。本文主要介绍了计算机视觉技术对微生物、病害引起的食品原料腐败变质的检测,来判断食品腐败变质的程度,并介绍最新进展及研究现状,最后展望了其应用前景。     

低温肉制品加工、储运和销售过程中的微生物控制技术

微生物控制技术是保证低温肉制品的食用安全性和产品质量的关键技术。这是一个系统工程,要求从原辅料的品质,生产加工过程的技术参数、人员、器具、环境和管理各个环节进行质量控制;同时还要考虑产品的水活度,采取保鲜技术和保鲜剂,选择合适的包装并进行二次杀菌以达到控制产品微生物水平的目标;并保证在产品的储运和销售过程中进行冷链控制,为消费者提供具有较长保质期、安全性高的肉制品。     

Isolation of antimicrobial agent from the marine algae Cystoseira hakodatensis

Cystoseira hakodatensis is an unutilised brown algae belonging to family Sargassaceae. A crude methanol extract from the algae showed inhibitory effects on the growths of Bacillus cereus and Bacillus licheniformis. To isolate the major antimicrobial agent, a sequential active‐guided isolation procedure was applied: liquid–liquid extraction, column chromatography and bio‐autography. A marked antimicrobial agent (active α) was isolated in hydrophobic fraction and was determined to phenolics without carbohydrates and proteins by phytochemical test. Regarding the antimicrobial potential, the isolated active α showed better inhibitory effects against B. cereus and B. licheniformis at 2 and 4 times of lower concentrations (62.5 and 31.3 μg mL^?1) in comparison with epigallocatechin gallate. These results showed that C. hakodatensis is a potential source of antimicrobial agent capable of preventing the growth of the two bacteria.     

Pulsed light for the inactivation of fungal biofilms of clinically important pathogenic Candida species

Microorganisms are naturally found as biofilm communities more than planktonic free‐floating cells; however, planktonic culture remains the current model for microbiological studies, such as disinfection techniques. The presence of fungal biofilms in the clinical setting has a negative impact on patient mortality, as Candida biofilms have proved to be resistant to biocides in numerous in vitro studies; however, there is limited information on the effect of pulsed light on sessile communities. Here we report on the use of pulsed UV light for the effective inactivation of clinically relevant Candida species. Fungal biofilms were grown by use of a CDC reactor on clinically relevant surfaces. Following a maximal 72 h formation period, the densely populated biofilms were exposed to pulsed light at varying fluences to determine biofilm sensitivity to pulsed‐light inactivation. The results were then compared to planktonic cell inactivation. High levels of inactivation of C. albicans and C. parapsilosis biofilms were achieved with pulsed light for both 48 and 72 h biofilm structures. The findings suggest that pulsed light has the potential to provide a means of surface decontamination, subsequently reducing the risk of infection to patients. The research described herein deals with an important aspect of disease prevention and public health.     

瘤胃内共轭亚油酸(CLA)的形成

对瘤胃内共轭亚油酸（CLA）的形成机制、参与氢化的微生物及影响氢化的因素进行了综述，并对如何提高牛乳中CLA含量进行简要概述。