Ultrahigh pressure treatment of Actinidia arguta turbid juice: Kinetics of microbial inactivation and assessment of bioactive ingredient availability

Abstract

Mathematical models can be used to predict the kinetics of microbial inactivation in Actinidia arguta juice (AAJ) during ultra-high pressure (UHP) treatment. The inactivation of E. coli, S. aureus and S. cerevisiae by UHP was investigated. The pressure levels ranged from 100 to 500 MPa and the treatment time was 0–10 min. Cell morphology, intracellular protein content and cell membrane structure of UHP-treated microorganisms were evaluated. In addition, the effect of UHP treatment on the bioacceptability of AAJ was explored by an in vitro simulated gastrointestinal test. The maximum reduction of E. coli (5.14 lg), S. aureus (3.12 lg) and S. cerevisiae (3.94 lg) was achieved at 500 MPa/10 min. The coefficient of determination (0.957–0.999), root mean square error (0.010–0.343), coefficient of precision (1.033–1.213), and coefficient of deviation (0.876–1.068) indicated the satisfactory performance of the Weibull and Log-logistic model. The correlation coefficients of the predicted values of the Weibull model with the measured values (0.9938–0.9967) was higher than that of the Log-logistic model (0.9795–0.9909) and was considered to be the appropriate model. The UHP treatment increased (p < 0.05) the content of total phenols, total flavonoids, total sugars, and ascorbic acid in the juice. At the end of the simulated digestion, UHP-treated AAJ retained a higher content of bioactive compounds and antioxidant capacity (p < 0.05). The potential application of UHP in improving the nutritional value and health functions of different foods can be further explored in the future.