Effect of different cooking methods ofHibiscus surratensisL. leaf vegetable on nutritional, anti-nutritional composition, and antioxidant activities

Modern and traditional cooking methods affect the antioxidant activity and phenolic compounds content of Trachystemon Orientalis (L.) G. Don

“…CUPRAC and FRAP values of raw and cooked Trachystemon orientalis (L.) G. Don plants are provided in Table 1, and DPPH values are presented in Fig 2 . When the antioxidant activity of Trachystemon orientalis (L.) G. Don was evaluated, and it was observed that the CUPRAC value was 138.86±5.17 mmol trolox/g DW, the FRAP value was 44.74±0.59 μmol Fe (II)/g DW, and DPPH value was 0.43±0.33 mg/mL. When CUPRAC, FRAP and DPPH values were examined in many studies, it was found that the antioxidant activity of raw Trachystemon orientalis (L.) G. Don plant was higher than many plants in nature [32][33][34][35][36][37]. The average CUPRAC values of Hypericum montbretii, Paliurus spina-christi Mil and Hypericum bupleuroides were determined to be 1.07±0.14-0.19±0.05 mmol trolox/g DW [32].…”

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

“…Frying also decreased phenolic compounds in spinach by 17%, bush sorrel by 29-39%, and tatsoi by 4% likely due to decomposition and liberation of phenolic compounds. [69,73,74] On the contrary, frying has been found to increase considerably the total polyphenol and flavonoid contents in drumstick leaves, spinach, water spinach, and Chinese mustard and, to a lesser degree, increased ascorbic acid availability. Previous studies suggested that the apparent increase of these phytochemical compounds can be related to the breakdown of the cell wall and softening vegetable tissues, thus liberating the phytochemical compounds and making it more accessible.…”

“…[78] Similar to blanching, the increase of phytochemical compounds is likely an artifact due to the softening of the vegetable matrix due to heat, which subsequently increases extractability. [71,74] An in vitro study reported that boiling could enhance the extractability of polyphenols in Bidens pilosa leaf matrix. Although bioaccessibility of polyphenols reduced after duodenal digestion, polyphenols still have sufficient antioxidant activity to protect cells from oxidative damage.…”

“…Microwave cooking reduced phenolic compounds in water spinach, [67] drumstick leaves, [113] sweet potato leaves, [17] Chinese mustard [72] , tatsoi, [39] and bush sorrel. [74] Microwave cooking also reduced a significant amount of flavonoid, [72] carotenoid, [31] and ascorbic acid [31] in Chinese mustard, and chlorophyll and ascorbic acid in tatsoi. [39] Thermal breakdown, leaching (when water is added during cooking), and oxidation are the responsible mechanisms of phytochemical degradation during microwave cooking.…”

“…[80] Breakdown of cell walls and complex phenolic compounds during heating may increase the availability of these phytochemical compounds. [71,74,80,114]…”