Characterization of Carnobacterium maltaromaticum LMA 28 for its positive technological role in soft cheese making

Carnobacterium maltaromaticum is a lactic acid bacterium isolated from soft cheese. The objective of this work was to study its potential positive impact when used in cheese technology. Phenotypic and genotypic characterization of six strains of C. maltaromaticum showed that they belong to different phylogenetic groups. Although these strains lacked the ability to coagulate milk quickly, they were acidotolerant. They did not affect the coagulation capacity of starter lactic acid bacteria, Lactococcus lactis and Streptococcus thermophilus, used in dairy industry. The impact of C. maltaromaticum LMA 28 on bacterial flora of cheese revealed a significant decrease of Psychrobacter sp. concentration, which might be responsible for cheese aging phenomena. An experimental plan was carried out to unravel the mechanism of inhibition of Psychrobacter sp. and Listeria monocytogenes and possible interaction between various factors (cell concentration, NaCl, pH and incubation time). Cellular concentration of C. maltaromaticum LMA 28 was found to be the main factor involved in the inhibition of Psychrobacter sp. and L. monocytogenes.     

离子对κ-卡拉胶/刺槐豆胶相互作用的影响研究

采用剪切黏度、动态黏弹模量、石英晶体微天平等技术研究了离子种类及混合条件对κ-卡拉胶/刺槐豆胶相互作用的影响。结果表明,K+可促进两者的相互作用,而Na+、Ca2+、Mg2+则对两者相互作用没有明显影响。K+对κ-卡拉胶/刺槐豆胶相互作用的促进存在阶段性,即0~25mmol/L时促进效果逐渐增加,达到30 mmol/L时促进效果减弱,继续增加K+浓度则会进一步促进κ-卡拉胶/刺槐豆胶的相互作用。在固定K+浓度时,卡拉胶和刺槐豆胶质量比为3:7、pH为4.0时有最佳协同效应。这种相互作用与卡拉胶螺旋结构数量变化有关。     

The influence of protein–flavonoid interactions on protein digestibility in vitro and the antioxidant quality of breads enriched with onion skin

Different types of breads enriched with onion skin were studied. The objectives were twofold: to show and examine protein–phenolic interactions and to discuss results concerning phenolic content, antioxidant activity and protein digestibility in the light of in vitro bioaccessibility. Phenolic contents and antiradical abilities were linked with the level of onion skin supplement however, the amounts determined were significantly lower than expected. Fortification influenced protein digestibility (a reduction from 78.4% for control breads to 55% for breads with a 4% supplement). Electrophoretic and chromatographic studies showed the presence of indigestible protein–flavonoid complexes – with molecular weights about 25 kDa and 14.5 kDa; however, the reduction of free amino group levels and the increase in chromatogram areas suggest that flavonoids also bind to other bread proteins. The interaction of phenolics with proteins affects antioxidant efficacy and protein digestibility; thus, they have multiple effects on food quality and pro-health properties.     

家具交互展示设计探讨

传统的家具展示设计主要是在展厅内通过模拟生活环境的形式陈列家具,加以一定的灯光效果烘托产品。本文通过探寻国内外各行业的交互设计,将交互展示设计运用到家具行业当中,分析在家具领域运用该技术的可行性和有可能出现的问题,探讨了在家具展示领域,短期、中期和长期运用交互设计的方案。旨在通过生动有趣的交互展示方式使用户与产品之间产生双向信息交流,不仅让产品得以展示,也让用户参与其中,进行感性体验和情景模拟,以推动消费者对产品的深度体验和营销效果。     

分散染料分子结构对涤氨织物染色性能的影响

讨论了分散染料分子结构对涤氨织物上染性能的影响。结果表明:与普通偶氮、蒽醌和羧酸酯结构分散染料相比,噻吩、吡啶酮、苯并二呋喃酮和苯并噻吩酮结构具有较高的始染温度和较低的移染度。将分子平面性好的杂环结构引入染料中,能大大提高染料与染料间π-π堆积作用能。pH值对噻吩、吡啶酮、苯并二呋喃酮和羧酸酯结构分散染料影响较大。苯并二呋喃酮和苯并噻吩酮结构分散染料对氨纶纤维的上染量低,羧酸酯和吡啶酮结构分散染料染色后进行碱性清洗能明显降低染料在氨纶纤维上的得色。     

贮藏期UHT奶中蛋白质组成结构及其糖基化的变化

通过测定UHT奶在贮藏过程中蛋白水解,蛋白在胶束相和乳清相的分布,乳蛋白糖基化位点变化,探究乳蛋白在贮藏过程中性质的变化.结果表明贮藏过程中UHT奶中菌落总数增大,纤溶酶含量增大.UHT奶在内外源酶的作用下乳蛋白发生不同程度的水解.热处理导致从胶束表面脱落的κ-CN和乳清蛋白以热诱导聚合物的形式,在贮藏过程中重新结合到...     

转基因食品安全监管的演化博弈分析

近年来,食品安全问题不断出现,公众对其的关注日趋广泛。食品安全问题,尤其是关于转基因食品安全性的议题在各国范围内争议日益剧烈。本文运用经济学演化博弈的方法,分析了转基因食品安全监管中食品生产商与政府监管部门行为的动态演化过程,并且用数值仿真展示了演化结果。研究结果表明,政府监管部门的监管力度、处罚力度以及对监管部门成功监管的奖励力度的大小等对于转基因食品市场的健康发展有着至关重要的影响。     

乳化剂和多糖对蛋白质乳浊液的稳定性的影响

低分子质量乳化剂和多糖在食品乳浊液体系中用来调节和改善乳浊液的乳化特性和体系的稳定性。文章介绍了蛋白质乳浊液的不稳定过程 ,乳化剂和多糖在蛋白质乳浊液体系中与蛋白质的相互作用及其对乳浊液体系稳定性的影响 ,并展望了这一领域的发展趋势     

阳离子疏水缔合聚丙烯酰胺的合成及性能

以环氧氯丙烷、丙烯酰胺(AM)及N,N-二甲基十八烷基叔胺为原料,制备了二甲基十八烷基(2-羟基-3-丙烯酰胺丙基)氯化铵(DMOHAC)阳离子表面活性单体,利用红外光谱及核磁共振氢谱方法对其结构进行了表征,并将DMOHAC与AM通过胶束共聚反应制备了阳离子疏水缔合聚丙烯酰胺P(DMOHAC/AM),通过红外光谱对聚合物的结构进行了表征,并利用表观黏度法考察了DMOHAC用量、疏水嵌段长度及疏水碳链长度不同的表面活性剂对P(DMOHAC/AM)溶液缔合性能的影响.结果表明,P(DMOHAC/AM)聚合物与阴离子表面活性剂在疏水缔合、静电吸引及氢键三重作用下能显著提高聚合物溶液的缔合性能,且阴离子表面活性剂与P(DMOHAC/AM)聚合物之间的缔合作用随表面活性剂烷基碳链长度的增加而增强.