Recrystallization in Model Ice Cream Solutions as Affected by Stabilizer Concentration

Ice recrystallization rates in simple aqueous solutions comprising fructose and a hydrocolloid stabilizer were measured. The stabilizers were an enzyme-modified guar and a non-gelling high methoxy pectin. The stabilizer concentration dependence of the recrystallization rates for both materials was similar in that increasing the concentration resulted in decreasing rates until a point is reached where further addition had no additional effect. That recrystallization rates were reduced by both gelling and non-gelling stabilizers was strongly suggestive that gelation was not a requirement for recrystallization inhibition and another more specific mechanism applies, for example a weak interfacial effect such as adsorption or blocking. This behavior was also seen with locust bean gum and guar and provided further empirical evidence to support the hypothesis that stabilizers adsorb to ice crystal surfaces.     

一款含鲜奶面霜缓解皮肤红斑反应的功效评价研究

采用客观仪器评价方法对含鲜奶面霜单次使用后的缓解皮肤红斑反应的功效进行研究。选择30名18~55周岁有效受试者为研究对象,使用胶带粘贴及组胺刺激构建皮肤红斑反应模型,并采用无创仪器的方式检测并记录实验组、安慰剂组、阴性组及空白组受试者在组胺造模前、造模后、涂抹产品后30 min和60 min时的皮肤红斑指数EI值、皮肤敏感度值,采集皮肤图像,通过SPSS数据统计软件对实验结果进行统计分析。结果显示,含鲜奶面霜可以持续改善皮肤红斑指数EI值和皮肤敏感度,缓解由组胺导致的皮肤红晕反应,说明其具有一定的缓解皮肤红斑反应,改善皮肤敏感状态的功能。     

原子荧光光谱法测定祛斑霜中的汞

采用盐酸处理祛斑霜样品，用还原气化-原子荧光光谱法测定其中的汞，研究了仪器测定条件和不同样品处理方法对测定的影响。结果表明样品处理方法对测定结果影响不大；此方法的加标回收率在96％以上，相对标准偏差为2．5％；此方法具有快速、简便和灵敏的特点。     

氟化铝生产废水处理工艺的研究

对氟化铝生产废水的处理方法进行了研究。结果表明，一级中和沉淀法和二级中和二级沉淀法均不宜用于氟化铝生产废水的结果，理想的处理方法是碱过量中和酸回调法，辅加氯化钙的石灰乳中和法也可考虑采用。     

护肤品新剂型的研究

介绍了中药护肤品－成团型涂抹膏新产品研究的相关实验，主要包括基质实验，药物选择实验等。     

解读纳西民族文化的密码--女性羊皮披肩

纳西族女性羊皮披肩是纳西族传统服饰中的精华.文章除了对羊皮披肩从材质、色彩、造型、装饰要素在形式美感和实用功能层面的阐述之外,还深入到服饰文化内涵的层面进行分析,提出了在面对现代文明的撞击和多种文化交融的情形下,承载着纳西族服饰文化传统的羊皮披肩仍然焕发着特有的魅力和强大的生命力,但我们必须要树立保护传统服饰文化精粹的意识,通过研究与挖掘,让其延续的同时将其发扬光大.     

Enumeration and characterization of Listeria monocytogenes in novelty ice cream samples manufactured on a specific production line linked to a listeriosis outbreak

Listeriosis is an invasive illness typically caused by the ingestion of foods contaminated with Listeria monocytogenes. In 2015, an outbreak of listeriosis was linked to ice cream products produced on a specific production line at Facility X. The United States Food and Drug Administration (FDA) obtained samples representing several lots of three products manufactured on that line from May 2014 through January 2015. Two of these products, A and B, while not linked to any reported illnesses, were analyzed to determine the frequency of contamination and the contamination level for risk assessment and dose-response analyses. These enumerations were performed utilizing a Most Probable Number (MPN) method, with a lower detection limit of 0.03 MPN/g, on 344 samples of Product A and 95 samples of Product B. Ten lots of Product A were analyzed and 77% of the samples tested were found to be positive for L. monocytogenes. Five lots of Product B were analyzed and 46% of the tested samples were found to be positive. Additionally, the level of contamination of positive Product B samples was always less than 1 MPN/g. The contamination levels of both products, overall, were low with median values of 0.1 MPN/g and 0.02 MPN/g for Products A and B, respectively. A majority of Product A samples (52%) were contaminated at levels of less than 1 MPN/g and only one sample was above 100 MPN/g. Whole genome sequencing (WGS) of L. monocytogenes isolated from ice cream samples produced in the line suggested minor strain differences related to product type, possibly due to differences in the food matrices and/or differences in the manufacturing equipment. Overall, the data showed a consistent low level of contamination in products produced from a single production line over a nine month period.     

Innovative Ingredients and Emerging Technologies for Controlling Ice Recrystallization,Texture, and Structure Stability in Frozen Dairy Desserts: A Review

Over the past decade, ice cream manufacturers have developed a strong understanding of the functionality of key ingredients and processing, developing effective explanations for the link between structure forming agents, stability mechanisms, and perceived quality. Increasing demand for products perceived as healthier/more natural with minimal processing has identified a number of new tools to improve quality and storage stability of frozen dairy desserts. Ingredients such as dietary fiber, polysaccharides, prebiotics, alternate sweeteners, fat sources rich in unsaturated fatty acids and ice strucsturing proteins (ISP) have been successfully applied as cryoprotective, texturizing, and structuring agents. Emerging minimal processing technologies including hydrostatic pressure processing, ultrasonic or high pressure assisted freezing, low temperature extrusion and enzymatically induced biopolymers crosslinking have been evaluated for their ability to improve colloidal stability, texture and sensory quality. It is therefore timely for a comprehensive review.     

Fermentation of table cream by Lactobacillus plantarum strains: effect on fungal growth,aflatoxin M1 and ochratoxin A

Aflatoxin M1 (AFM₁) and ochratoxin A (OTA) are two main mycotoxins in milk and dairy products. In the present work, the ability of four Lactobacillus strains (L. plantarum PTCC 1058, L. plantarum LP3, L. plantarum AF1 and L. plantarum LU5) to remove AFM1 and OTA in fermented cream was studied during 24 h fermentation. The antifungal activity of the mentioned lactobacilli against the defined fungi (Aspergillus flavus PTCC 5004, Aspergillus parasiticus PTCC 5018, Aspergillus nidulans PTCC 5014, Aspergillus ochraceus PTCC 5060) was also evaluated. The results showed that the cell counts of all strains were increased by 64–70% during fermentation. All Lactobacillus strains decreased the amount of AFM₁ significantly (P ≤ 0.05) in the range of 26–52%, which the highest AFM₁-reducing effect was related to L. plantarum LU5 (from 0.5 to 0.24 μg kg⁻¹). The mean OTA removal by Lactobacillus strains in fermented cream also ranged from 32 to 58%. Amongst Lactobacillus strains, the cell-free culture supernatants of L. plantarum LU5 showed the highest (inhibition zone of 26.7 ± 1.2 mm) and L. plantarum LP3 and L. plantarum PTCC 1058 the lowest antifungal activities. The fermented creams contained Lactobacillus strains exhibited the highest and lowest antifungal activities against A. ochraceus and A. parasiticus, respectively. L. plantarum LU5, with the inhibition zone of 27.6 ± 0.9 mm, was the most effective fungal inhibitor, while L. plantarum PTCC 1058 had the lowest antifungal activity.