猪骨素组分对鲜味及鸡汤模型香气鼻后感受强度的增强作用

该研究采用分子量截留法将猪骨素分为3个组分,并以感官分析法对猪骨素组分增鲜及增鼻后香气能力进行评价,进一步对猪骨素中蛋白组分的分子量分布、疏水性情况进行评价分析,探讨其蛋白质组分疏水性聚集与其增鲜、增香能力间关系。结果表明,变性剂处理后,猪骨素中>30 ku组分可由36.07%降至2.95%,说明其蛋白存在聚集现象;将3个组分分离冻干后感官分析发现,PBE（10~30 ku）组分在以NaCl为基底的溶液中评分分别为咸味7.6、浓厚度8.6、连续性7.6、口感丰富度8.0,高于另两种组分的感官评分,而其香气鼻后感受评分为7.5,也高于另两种组分。对3个组分进行分析发现,PBE（10~30 ku）的鲜味及甜味氨基酸含量分别为14.7%及44.19%,与PBE（>30 ku）差异不具显著性,但其增鲜效果显著高于该组分,而分析疏水性后发现,PBE（10~30 ku）组分的疏水性指数为60.00±1.33,与另两种组分差异存在显著性,据此推测呈味氨基酸（鲜味、甜味）含量高对PBE（10~30 ku）组分的增鲜增香效果起到一定提升作用,但只有蛋白质或肽的整体疏水性在一定范围内时,其鲜味及香气增强作用才最佳。最后,疏水性与增鲜、增鼻后香气感受方面关系由40及70 ℃加热处理实验所证明。     

Comparison of free amino acids and 5′-nucleotides between Tuber fermentation mycelia and natural fruiting bodies

The profiles of free amino acids and 5′-nucleotides were first compared between Tuber fermentation mycelia and natural fruiting bodies. A total of 20 free amino acids and five 5′-nucleotides were identified in the Tuber fermentation mycelia and natural fruiting bodies. Not only the total contents of the free amino acids and 5′-nucleotides, but also the contents of umami amino acids and flavour 5′-nucleotides in the fermentation mycelia were higher than those in the fruiting bodies. By the addition of soybean flour in the fermentation media, the flavour 5′-nucleotides content in the fermentation mycelia was significantly increased, and the equivalent umami concentration of the fermentation mycelia (i.e., 608.07 g/100 g) was approximately 38.1-93.4 times higher than those of the fruiting bodies. From the viewpoint of umami taste, this work confirms the potentiality of Tuber fermentation mycelia as the alternative resource for its fruiting bodies.     

Salt Reduction in Foods Using Naturally Brewed Soy Sauce

ABSTRACT:  In recent years, health concerns related to salt/sodium chloride consumption have caused an increased demand for salt-reduced foods. Consequently, sodium chloride (NaCl) reduction in foods has become an important challenge. The more so, since a decrease in NaCl content is often reported to be associated with a decrease in consumer acceptance. The objective of the present study was to investigate whether or not it would be possible to reduce the NaCl content in standard Western European foods by replacing it with naturally brewed soy sauce. Three types of foods were investigated: salad dressing ( n  = 56), soup ( n  = 52), and stir-fried pork ( n  = 57). In the 1st step, an exchange rate (ER) by which NaCl can be replaced with soy sauce without a significant change in the overall taste intensity was established per product type, by means of alternative forced choice tests. In the 2nd step, the same consumers evaluated 5 samples per product type with varying NaCl and/or soy sauce content on pleasantness and several sensory attributes. The results showed that it was possible to achieve a NaCl reduction in the tested foods of, respectively, 50%, 17%, and 29% without leading to significant losses in either overall taste intensity or product pleasantness. These results suggest that it is possible to replace NaCl in foods with naturally brewed soy sauce without lowering the overall taste intensity and to reduce the total NaCl content in these foods without decreasing their consumer acceptance.
PRACTICAL APPLICATION: Health concerns related to salt consumption cause an increased demand for salt-reduced foods. Consequently, the development of foods with reduced salt content without decreasing the consumer acceptance is an important challenge for the food industry. A new possible salt reduction approach is described in the present article: The replacement of salt with naturally brewed soy sauce.     

The importance of ATP-related compounds for the freshness and flavor of post-mortem fish and shellfish muscle: A review

ATP degradation is one of the most important biochemical changes in the post-mortem muscle of fish and shellfish. This process has long been recognized as an accurate way to evaluate freshness of fish and shellfish product. This review updates and condenses the overall history and recent advances in understanding the role of ATP-related compounds in post-mortem fish and shellfish muscle including a discussion of key analytical methods, their use as a freshness indicator, their roles in flavor enhancement, the factors affecting their transitions, and the possible mechanisms responsible for their impact on flavor and freshness. Moreover, some challenges and future directions for research regarding ATP-related compounds in fish and shellfish flavor and freshness are presented. With increasing consumer demands for fresh products with extended shelf life, understanding the relationships between ATP-related compounds and their involvement in the freshness and umami taste is a prerequisite for assuring the high quality of fish and shellfish.     

兰茂牛肝菌菌柄和菌盖中鲜味成分的分析及菌盖中鲜味肽的鉴定

采用反相高效液相色谱技术对兰茂牛肝菌（Lanmaoa asiatica）菌柄和菌盖中的游离氨基酸及5’-核苷酸的含量进行分析，结果显示菌盖中呈鲜氨基酸及呈鲜核苷酸的含量显著高于菌柄。结合凝胶过滤色谱、反相高效液相色谱和纳升级超高效液相色谱-串联质谱对鲜味成分含量多的菌盖进行鲜味肽的分离纯化及鉴定，共鉴定出3 条鲜味肽，分别为FKDLGEENFK（1 225.598 Da）、KMDDFAAFVEK（1 357.622 Da）和LVNEVTEFAK（1 148.608 Da）。通过滋味稀释分析实验，确定3 条肽的阈值分别为9.78、10.25 mmol/L和13.01 mmol/L。     

食用菌鲜味强度评价及鲜味氨基酸和核苷酸提取工艺优化

通过高效液相色谱对9种食用菌的鲜味氨基酸、核苷酸含量进行检测并计算等鲜浓度(EUC)值,再结合感官分析和电子舌技术评价9种食用菌的鲜味强度。结果表明:鹿茸菇在9种食用菌中的感官评分和电子舌的鲜味评分值最高,EUC值为160.56g/100g,因此选用鹿茸菇为原料进行酶解提取工艺研究,以EUC值为考察指标,选用纤维素酶和风味蛋白酶复合,通过单因素实验和响应面法对鹿茸菇中鲜味氨基酸和核苷酸提取工艺进行优化,得到食用菌的优化酶解条件为:料液比(g/mL)1∶44.78、纤维素酶添加量1607.52U/g、风味蛋白酶添加量3044U/g、酶解时间6.14h、pH值6.50。以优化条件进行3次平行实验,得到EUC实际值为406.74g/100g,与预测值相对误差为6.12%。     

A report of the proceedings of an MSG workshop held august 1991

This report of the proceedings of a workshop on monosodium glutamate (MSG) represents the output of an exchange of scientific information, discussed and debated, by a group of experts representing a variety of disciplines. Experts in the areas of food science, potential adverse reactions to foods, pharmacology, neuroscience, biochemistry, nutrition, pediatrics, and anatomy reviewed the current scientific literature relative to the safe use of MSG in foods. These proceedings supplement the extensive literature compiled by various prestigious international expert committees since the flavor‐enhancing properties of MSG were identified around the turn of the century.     

鲜味物质及其在水产调味品中的应用

阐述了氨基酸和核苷酸等一些鲜味物质的结构，产生鲜味的机理，列举了部分天然食品中鲜味物质的含量，介绍鲜味物质的呈味特性，生产现状及其应用情况。阐述了氨基酸和核苷酸之间的显著的相乘作用。详细的介绍了水产品中鲜味物质的研究，包括水产品中鲜味物质的种类，水产品中的味与鲜味的关系，鉴定水产品中特征风味成分的方法，为水产品鲜味调味品的开发利用提供了科学依据。