Comparative Effects of Electron Beam Irradiation and Ultra-high Pressure Treatment on the Flavor of Jujube pulp

Abstract

This study investigated the effects of pasteurization (80 ℃ for 30 min), electron beam irradiation (3, 5 and 7 kGy) and ultra-high pressure treatment (400, 500 and 600 MPa for 6 min) on the flavor of jujube pulp. Untreated samples were used as control. The content of taste compounds such as free amino acids and reducing sugar was determined, and flavor quality was evaluated by electronic nose and electronic tongue and sensory evaluation. The results showed that compared with the control sample, free amino acid contents were significantly reduced by pasteurization and electron beam irradiation, and the contents of bitter amino acids such as arginine, valine and leucine were significantly increased by pasteurization. Electron beam irradiation and ultra-high pressure treatment could significantly increase the content of fructose in jujube pulp. Significant differences in electronic nose sensor responses were found among the eight groups. The electron tongue results showed significant differences in taste characteristics between the electron beam irradiated, ultra-high pressure treated and the control samples, while the taste characteristics of the pasteurized samples were closer to those of the control group. In addition, the samples treated with electron beam irradiation had higher sensory values for taste, color and reconstitutability than the other treatments. In conclusion, both electron beam irradiation and ultra-high pressure treatment could effectively improve the flavor quality of jujube pulp.

Keywords

• electron beam irradiation; ultra-high pressure treatment; jujube pulp; quality; flavor