| The fermentation process of low-salt semi-dry grass carp by GIM3.439 Monascus was evaluated under specific conditions.The optimal production processing technology of the Monascus fermentation on carps were determined.The flavor and volatile component in the carp fermented by Monascus were analyzed.The effect of Monascus fermentation on the taste of carps was studied.(1)The single factor analysis and orthogonal experiment analysis were carried out to find the optimal production processing technology of fermented carps.The effects of Monascus inoculant amount,the fermentation temperature and the fermentation time were analyzed based on the quality of carps.To determine the optimal process of Monascus fermentation of carps.The grass carp as raw material was used,nitrogen content and the sensory evaluation as the index have been analyzed.The results showed that the best fermentation results can be achieved when the inoculant amount of Monascus fermentation agent was 9%,the fermentation temperature was 30℃ and the fermentation time was 18 hours.Under the optimal conditions,rich flavor and strong fragrance carps in red color can be reached.(2)The aim of the present study is to investigate the effects of Monascus fermentation on the aroma pattern of semi-dried grass carp.Semi-dried fish was fermented using Monascus purpureus.The volatile flavor substances present in fresh fish,semi-dry fish and Monascus fermented semi-dried fish were compared by simultaneous distillation and extraction combined with gas chromatograph-mass spectrometer(GC-MS).The results showed that alcohols,aldehydes and ketones were the main components of the flavor of the unfermented and fermented semi-dried grass crap.Monascus fermentation could significantly affect the volatile flavor substances of semi-dried grass carp.Moreover,the processing of semi-dried fish fermented by Monascus could not only effectively improve the fishy smell of fresh fish,but also make up for the defect of the pickled flavor of semi-dried fish.Eighteen of the main volatile components in semi-dried fish fermented by Monascus were identified by relative odor activity value(ROAV).(3)Fermentation by Monascus purpureus was applied to conventional low-saltsemi-dry grass carp to increase umami taste.grass carps and inactivated Monascus purpureus added carps were served as control groups.Water soluble nitrogen content(WSN),tricholoracetate acid soluble nitrogen content(TCA-SN)were used to determine protein hydrolysis.Umami taste was evaluated by the taste activity value(TAV)and equivalent umami concentration(EUC)which were calculated by free amino acids(FFA)and 5’-nucleotides content.Fermented carps product was reddish in color,richer in umami taste.More amino acids and peptides were released.The EDU of the fermented fish reached 7.34 g MSG/100 g,which was 4.38 times of that of the unfermented carps.The content of umami amino acids i.e.glutamic acid(Glu)and aspartic acid(Asp),and umami necleotides,i.e.,guanosine 5’-monophosphate(5’-GMP)and Inosine 5’-monophosphate(5’-IMP),was significantly increased.The both TAV of 5’-GMP and Glu were more than 1,indicating that these two components were the major contributers to the umami taste.Monascus fermentation of low-salt semi-dried carps was proved effective to enhance umami taste. |
