Hydrothermal effects on physicochemical, sensory attributes, vitamin C, and antioxidant activity of frozen immature Dolichos lablab.

Immature Dolichos bean is popular in the Asian region, which is a potent source of vitamin C, antioxidants as well as other macro and micronutrients. Extending shelf life with retaining maximum quality parameters through hydrothermal treatments (HTT) followed by freezing of immature Dolichos bean were carried out. In particular, samples were undergone HTT (n = 9), cooled at room temperature, packed in HDPE packs and stored in a freezer (-18 °C±2), whereas samples without HTT considered as control. The samples were analyzed for physicochemical, sensory attributes, vitamin C and antioxidant activity after three months of freeze storage. In the case of vitamin C, antioxidant activity and color retention, significant differences (p < 0.05) were observed among HTT samples. HTT resulted in improving the cooking quality, sensory characteristics and retaining fresh like traits especially antioxidant activity and vitamin C in Dolichos bean. The study revealed that higher temperature (85 °C-98 °C) HTT for a shorter period of time (3 min) could be suitable for immature Dolichos bean to retain quality parameters without great loss during storage.