Quality assurance in pepper and orange juice blend treated by high pressure processing and high temperature short time

Abstract

Abstract The impact of mixing ratio of pepper juice/orange juice ( v / v ) at 1:5, 1:2, 1:1, 1:0.5 and 1:0.2 on sensory attributes of pepper and orange juice blend (POJB) was studied, and the ratio of 1:0.5 achieved the highest ratings in mouthfeel and overall acceptability and was chosen for the following study. Effects of high pressure processing (HPP, 550 MPa, 5 min, ambient temperature) and high temperature short time (HTST, 110 °C, 8.6 s) on quality attributes of the POJBs were compared. Reduction of total aerobic bacteria (TAB) and molds and yeasts (M&Y) in the POJBs was > 4 log cycles after HPP and HTST, and the two POJBs were microbiologically safe during the whole refrigerated storage. The color, flavor, appearance, mouthfeel and overall acceptability of HPP-treated POJB were closer to untreated POJB than the HTST-treated one. After 25 days, 77.3% and 75.3% of total phenols content, 90.8% and 90.7% of ascorbic acid, and more than 80% of antioxidant capacity in two POJBs were retained, respectively. Particle size distribution (PSD) of HPP-treated POJB was consistent with untreated POJB (1 ~ 76 μm, 3 peaks at 4.2, 17, 52 μm), while HTST changed the PSD (1 to 33 μm, 2 peaks at 2.4 and 17 μm). Higher level of sedimentation in HPP-treated POJB during storage was interpreted by higher residual PME activity (67.0%) and larger and more unstable pulp particles. The POJBs behaved as Newtonian fluids, their viscosity right after processing were ranked as HPP > untreated > HTST, and the values were slightly reduced during storage. Industrial Relevance This study was intended to develop yellow sweet pepper and orange juice blend (POJB), which are not available on the market. Further this study was also intended to explore the application of high pressure processing (HPP) and high temperature short time (HTST) on quality assurance of the POJB. This study would provide technical support for commercialization of juice blend products treated by high pressure.