Influence of Cooking Methods on Phenolic Compounds and their Activities in Pea Shoots (Pisum sativum)

Pea shoots (Pisum sativum) are well known to have nutritional benefits when consumed raw; however, the effects of home cooking on their bioactive compounds remain unclear. Therefore, we investigated how different cooking methods affect the antioxidant activity and stability of antioxidants. Our evaluation revealed that antioxidant activity is preserved by steaming but significantly reduced by microwaving and boiling, which also causes weight loss during cooking. Quantitative analysis of four flavonoid glycosides, with quercetin or kaempferol as aglycones bound to sophorotrioside and p-coumaric acid, showed decreases after microwaving, boiling, and high temperature and pressure treatments, with minimal antioxidant losses after steaming. Model experiments using purified antioxidants revealed that compounds conjugated with p-coumaric acid are important for thermal and pressure stability. The findings of this study suggest that steaming is the most effective cooking method for preserving the antioxidant properties of pea shoots.