The Mechanisms Of Tastants Produce And Release During The Storage And Processing Of Fish

With the progress of the society,consumers' demand for food is not only to meet the nutritional needs,but also to have fun through eating.Taste is one of the sensory qualities of food and an important factor in purchasing decisions of consumers.People's taste perception of food not only depends on the characteristics of food,but also related to the release of tastants in the chewing process.Therefore,the comprehensive evaluation of food taste should be evaluated from the aspects of food properties and chewing process.The fish was widely loved by consumers with the characteristics of delicious taste,tender meat,and rich nutrition.At the same time,it is inevitable to undergo storage and transportation due to the regional distribution of fish.This study preliminarily explored the formation and release process of flavoring substances in fish storage and chewing process,and revealed the changes of flavoring substances in the whole process from fish fishing to slaughter to consumer consumption,which is of great significance to the selection of fish storage conditions and the improvement of consumer satisfaction.The study of tastants produce and release in fish is divided into two parts: during storage and chewing process.Turbot(Scophthalmus maximus)was used as material for the release of nucleotide during storage.In this study,a strategy was developed for quantification of 28 nucleobases,nucleosides,and nucleotides using hydrophilic interaction chromatography coupled with tandem mass spectrometry.This method showed good precision,repeatability,and recovery.Furthermore,the developed strategy was successfully applied to monitor the changes in the contents of nucleobases,nucleosides,and nucleotides in turbot mince during chilled and partial freezing storage.The results indicated that the content of nucleobases,nucleosides and nucleotides significant changed during the storage,and the rates and patterns of the changes of analytes differed considerably depending on the storage temperature.During partial freezing storage,the contents of IMP and GMP reached the height level at first day,and lasted until the end of storage.Inosine slightly increased during early storage,and decreased after 12 h.The content of hypoxanthine gradually increased and reached 4 times of the initial content at the end of storage.Therefore,a large amount of umami compounds released on the first day of storage,which increased the edibility of the fish,and a high quality of fish was maintained during the storage for 168 h.During the chilled storage,high IMP and GMP levels lasted until the fourth day.The content of IMP was significantly lower in chilled samples.The nucleotide was rapidly degraded at the end of storage,metabolites were increased,and significant deterioration occurred.In this study,a strategy for the simultaneous analysis of 20 free amino acids(FAAs)and six nucleotides,using stable-isotope-labeling-liquid chromatography coupled with tandem mass spectrometry is proposed.The method showed good precision,resolution and repeatability.This method provides an effective tool for studying the release of tastants during different processing.The chewing process was studied in chilled and baked salmon(Salmo salar).The results indicated that there were significant differences in FAAs and nucleotides between chilled and baked salmon and there were no significant differences between salmon with different baking time.The food bolus and saliva which produced during the chewing process of salmon were analyzed.In the process of chewing,the particles of bolus gradually reduced,the smallest particles were generated before swallowing.Sensory evaluation of salmon showed that complex taste perception was occurred during chewing process.Fresh salmon is fishy and umami at the early stage of chewing,and gradually changed to salty taste.The sweet taste is the main dominant taste at the end stage of chewing.There were differences in the dominant taste of salmon with various baking time.With the baking time increasing,the fishy taste decreased.The fishy taste could not be perceived in salmon which baked for 20 min.Baked salmon presented strong fried and smoked flavor at the early stage.At the end of chewing process,the tastants released and a variety of flavor appeared.The main dominant flavor in samples is umami and sweet respectively which baked for 10 and 20 min.