Effect of Thermal Processing on Key Phytochemical Compounds in Green Leafy Vegetables: A Review

Green leafy vegetables are widely cultivated and consumed in South East Asia. These vegetables are rich in phytochemicals, which have been associated to particular health benefits. Preparation/processing, particularly those involving heat, prior to consumption can change the level of phytochemicals in the vegetables following various mechanisms, including thermal breakdown, oxidation, leaching, and matrix degradation. Appropriate processing should minimize degradation of phytochemicals so that the optimum intake toward health promotion be achieved. Better understanding of how processing influence the retention of phytochemical compounds is therefore crucial to provide guidelines on the processing of green leafy vegetables while maximizing their nutritional values.