Abstract:The aim of this study was to evaluate the taste characteristics of Porphyra yezoensis during different harvest periods. Electronic tongue (INSENT taste analysis system) was applied to characterize the taste of lavers. The contents of free amino acids and flavor nucleotides in the first, second, fourth, and sixth harvest of lavers were measured. The electronic tongue data showed that the taste of lavers mainly consisted of umami, aftertaste of umami, saltiness, and bitterness. The umami value decreased successively in the first, second, fourth, and sixth harvest of lavers. The intensity of aftertaste of umami was the greatest in the second harvest of lavers, followed by the first and fourth harvest, and was significantly decreased in the sixth harvest (P<0.05). The saltiness intensity was higher in the first and second harvest of lavers. The intensity of bitterness was similar between the first and second harvest of lavers. The bitterness value was significantly lower in the sixth harvest of lavers (P<0.05). The astringency value was small, and there was no significant difference among the four samples (P>0.05). The contents of taste compounds and their contributions to the flavor were significantly different among the four laver samples. The contents of total free amino acids in the first, second, fourth, and sixth harvest of lavers were 4291.54 mg/100 g, 3485.29 mg/100 g, 3277.98 mg/100 g, and 1148.12 mg/100 g, respectively. Alanine and glutamic acid made the biggest contribution to the flavor. The content of inosine monophosphate (IMP) was relatively high in all flavor nucleotides. The taste active values (TAV) of IMP in the first, second, fourth, and sixth harvest of lavers were 4.13, 4.56, 2.19, and 2.33, respectively. The equivalent umami concentrations (EUC) of the first, second, fourth, and sixth harvest of lavers were 223.89 g MSG/100 g, 222.13 g MSG/100 g, 118.54 g MSG/100 g, and 47.19 g MSG/100 g, respectively, which means the umami of the earlier harvest of lavers was more intense. The electronic tongue analysis results are consistent with the experimental data of the flavor substances measurements. Electronic tongue technology could be used as a quick method to evaluate the taste of lavers and other aquatic products.
