Effects of fermentation, boiling, and drying methods on bioactive properties, phenolic and nutrient profiles of aerial parts of purslane (Portulaca oleracea L.) plants

Summary Total carotenoid results of fresh and processed purslane samples were recorded between 4.21 (fermented) and 107.40 μg/g) (microwave). Total phenol and flavonoid amounts of purslane were reported to be between 25.21 (fermented) and 143.02 mg GAE/100 g (microwave) to 44.14 (fermented) and 810.48 mg/100 g (microwave), respectively. Antioxidant activity results of fresh and purslane plants were reported between 1.18 (fermented) and 1.54 mmol/kg (DPPH) (fresh and boiled) to 1.43 (fermented) and 13.25 mg/g (FRAP) (oven), respectively. Catechin and rutin results of purslane samples were recorded to be between 0.81 (boiled) and 35.33 mg/100 g (microwave) to 0.14 (fermented) and 21.45 mg/100 g (air dried), respectively. The most abundant element in the purslane samples was K, followed in descending order by Ca, Mg, P and S. Calcium (Ca) and magnesium (Mg) results of purslane samples were detected to be between 2460.92 (boiled) and 17153.18 mg/kg (air dried) to 1159.25 (boiled) and 13428.23 mg/kg (air dried), respectively. A decrease in the protein and mineral contents of purslane was observed by fermentation and boiling. In general, flavour, colour and texture values of fermented purslane sample has reached an acceptable value by consumers. In this study, the effect of fermentation, boiling, oven and microwave drying on the bioactive compounds, antioxidant activity, phenolic compounds and mineral compositions of purslane leaves was investigated. The highest results of phenolic and flavonoid compounds were observed in sample dried conventional oven (CO) and microwave oven (MO) in comparison with other processes. The most abundant element in the Purlane samples was K, followed in descending order by Ca, Mg, P and S.