Effect of Thermosonication on Amino Acids, Phenolic Compounds, Sensory Properties and Microbial Quality in Freshly Squeezed Verjuice

Abstract

Thermosonication is a process that can be used as an alternative to thermal pasteurization by combining mild temperature and ultrasound treatments. This study evaluated the effects of verjuice on the thermosonication process and its bioactive values modeled with the RSM (response surface method). The bioactive components of verjuice were found to increase with high predictive values. Additionally, the presence and amounts of 20 free amino acids in C-VJ (untreated verjuice), P-VJ (thermally pasteurized verjuice) and TS-VJ (thermosonicated verjuice) samples were investigated. Significant (p < 0.05) differences were detected among C-VJ, P-VJ and TS-VJ samples in all free amino acid values except methionine. Although 17 free amino acids were detected at various concentrations, glycine, taurine and cystine were not found in any samples. Thirteen phenolic filters in C-VJ, P-VJ and TS-VJ samples were also examined in this study. Eight phenolic donors with various abilities were detected in the C-VJ sample, along with nine phenolic acceptors in the P-VJ sample and eleven phenolic contents in the TS-VJ sample. The content of phenolic products in the TS-VJ sample increased by 37.5% compared to the C-VJ techniques and by 22.22% compared to the P-VJ techniques. Thermosonication did not significantly affect color and physiochemical values. Panelists generally appreciated the effects of thermosonication. It is concluded that the thermosonication process is a good alternative to thermal pasteurization. The results of this study provide essential data for future in vivo studies and show that the bioactive values of verjuice can be increased by using the thermosonication process.

Keywords

• thermosonication
• verjuice
• amino acids
• phenolic compounds
• RSM
• antioxidant