Effects of ultra-high temperature treatment and packages on baked purple sweet potato nectar

The effects of ultra-high temperature (UHT) (140 degrees C, 10 s) and packages on quality and shelf life of baked purple sweet potato nectar (BPSPN) were evaluated in this study. UHT did not change pH, titratable acidity (TA), centrifugal sediment ratio, viscosity, lightness, redness, particle size distribution (PSD) character of D-(4,D-3), reducing sugar, total phenols and antioxidant capacity, but lightly reduced browning degree, ascorbic acid and total anthocyanins while increased PSD character of D-(3,D-2). UHT treatment succeed in assuring the microbial safety at 4 degrees C for 28 days, total aerobic bacteria in different packing materials did not shown statistical tendency (P < 0.05) at same condition storage. All three packages had no or less effect on total soluble solid, pH and TA, but glass-bottled BPSPN performed the comprehensive retention of color parameters, nutritional and critical volatiles during the whole storage. This study developed a purple sweet potato nectar with backed flavor, which was a pioneer in the market. This study provided technical support for commercialization of purple sweet potato products.