Analysis of Taste Components in Different Varieties of Fresh Lotus Seeds Based on Electronic Tongue

To determine the characteristic taste substances of different varieties of fresh lotus seeds, the taste substances of 'Guolian 1', 'Guolian 2', 'Guolian 3' and 'Mantianxing' were measured and electronic tongue was applied. Dynamic factor analysis (DFA) was used to distinguish the taste of different varieties of lotus seeds and partial least squares-discriminant analysis (PLS-DA) was adopted to find out the characteristic taste substances. The correlation between amylose and other taste substances were determined by grey correlation analysis. Results showed that taste difference existed in different varieties of lotus seeds and the distinction about umami taste was the most obvious. The umami intensity of 'Guolian 2', 'Guolian 3' and 'Mantianxing' was greater than that of 'Guolian 1', which was equivalent to the umami intensity of 0.55 mg/mL sodium glutamate solution. Amylose, free amino acids and flavonoids were the characteristic taste substances that distinguish different varieties of lotus seeds. The VIP score of amylose was close to 2.0, so it was the most critical characteristic taste substance. Amylose content had a greater correlation with soluble sugar and water content (over 0.8). In summary, the characteristic taste of different varieties of lotus seeds was umami, and the characteristic taste substance was amylose.