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The aim was to study the changes in flavor compounds hydrolyzed by different proteases in fish soup boiled with fish scraps The odor compounds were extracted by solid-phase microextraction (SPME) and analyzed by two-dimensional comprehensive gas chromatography-olfactometry-mass spectrometry (GC×GC-O-MS). The state of the distribution of free amino acids, 5'-nucleotides, peptides and equivalent umami concentration (EUC) were investigated. It was found that enzymatic hydrolysis significantly reduced off-flavor compounds, and the umami taste increased significantly. The synergistic effect between FlavourzymeTM and ProtamexTM (F-P) made the flavor of enzymatic hydrolysis better than that of other enzymes. [ABSTRACT FROM AUTHOR]

Umami taste is the most recent confirmed basic taste in addition to sour, sweet, bitter, and salty. It has been controversial because of its effects on human nutritional benefit. Based on the available literatures, this review categorized 13 positive and negative effects of umami taste on human health. On the positive side, umami taste can improve food flavor and consumption, improve nutrition intake of the elderly and patients, protect against duodenal cancer, reduce ingestion of sodium chloride, decrease consumption of fat, and improve oral functions. On the other hand, umami taste can also induce hepatotoxicity, cause asthma, induce migraine headaches, damage the nervous system, and promote obesity. Due to its novelty, there are many functions and effects of umami taste waiting to be discovered. With further investigation, more information regarding the effects of umami taste on human health will be discerned. [ABSTRACT FROM AUTHOR]

Proteolytic changes in Suanyu, a traditional fermented fish product of China, were determined during 6 weeks of fermentation. The gradual decrease of pH value and aw was detected, accompanied with an increasing trend detected in trichloroacetic acid-soluble C-1: peptides concentration. Protein composition changed throughout the fermentation. A decrease in sarcoplasmic and myofibrillar protein fractions was accompanied by an increase in the insoluble fraction. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed most bands of sarcoplasmic, myofibrillar, and insoluble proteins lightened or disappeared due to proteolysis or denaturation. New bands emerged especially in insoluble proteins. Fluctuation of molecular weight distribution of the water-soluble nitrogen in Suanyu was found during fermentation. The highest percentage in Suanyu end-products was observed in the fraction of <0.18 kDa, followed by 0.18-0.5 kDa, 66.02 ± 0.38% and 10.79 ± 0.27%, respectively. Free amino acids analysis showed that nearly all amino acids increased, especially for Asp, Glu, Met, Phe, Leu, Val, and Ile. Overall, intense proteolysis in Suanyu brought numerous of small peptides and free amino acids, which contribute to the taste and flavor of Suanyu. [ABSTRACT FROM AUTHOR]

Proteolytic changes in Suanyu, a traditional fermented fish product of China, were determined during 6 weeks of fermentation. The gradual decrease of pH value andawwas detected, accompanied with an increasing trend detected in trichloroacetic acid–soluble C-1: peptides concentration. Protein composition changed throughout the fermentation. A decrease in sarcoplasmic and myofibrillar protein fractions was accompanied by an increase in the insoluble fraction. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed most bands of sarcoplasmic, myofibrillar, and insoluble proteins lightened or disappeared due to proteolysis or denaturation. New bands emerged especially in insoluble proteins. Fluctuation of molecular weight distribution of the water-soluble nitrogen in Suanyu was found during fermentation. The highest percentage in Suanyu end-products was observed in the fraction of <0.18 kDa, followed by 0.18–0.5 kDa, 66.02 ± 0.38% and 10.79 ± 0.27%, respectively. Free amino acids analysis showed that nearly all amino acids increased, especially for Asp, Glu, Met, Phe, Leu, Val, and Ile. Overall, intense proteolysis in Suanyu brought numerous of small peptides and free amino acids, which contribute to the taste and flavor of Suanyu. [ABSTRACT FROM AUTHOR]