Influence of common household processing methods on retention of bioactive components of selected plant foods

The influence of household processing methods (open cooking and pressure cooking) on the retention of bioactive components of selected plant foods viz., Oryza sativa (rice), Eleusine coracana (ragi), Cajanus cajan L. (red gram), Vigna radiata (green gram), Vigna mungo (black gram), Moringa oleifera (drumstick), Amaranthus polygonoides (sirukeerai), Alternanthera sessilis (ponnanganni), Solanum lycopersicum (tomato), Solanum melongena (brinjal), Momordica charantia (bitter gourd), Solanum tuberosum (potato), Raphanus sativus (radish), Daucus carota subsp. sativus (carrot) and Allium cepa (small onion) were evaluated. The highest loss of bioactive components was observed in all plant foods after boiling (open cooking) and pressure cooking except carrot and tomato. Cooking carrot and tomato by pressure and open cooking methods had maximum retention for total antioxidant capacity (14.21 and 26.38%), total phenols (45.97 and 78.99%) and flavonoids (56.54 and 95.20%) contents respectively. The present study revealed pressure cooking method as the most effective cooking method in terms of better retention of antioxidant capacity and phytochemicals, which was more than 70% of the bioactive components in the selected plant foods. Therefore, application of thermal processing had both positive and negative impact on the bioactive components of the plant foods depending on the cooking methods and type of foods.