Effect of water from various sources on bioactive contents, antioxidant activities, and physical characteristics of cooked broccoli

The present work aimed to determine the influence of various water sources on the bioactive contents, antioxidant activities, and physical characteristics of cooked broccoli. The boiling process was conducted with eight water sources at 0, 4, and 6 min. The water used included bottled water (BW), non-reverse osmosis (RO) refilled water, RO refilled water, municipal waterworks of Bogor city, municipal waterworks of Jakarta city, groundwater of Jakarta city, dense population groundwater of Bogor city, and less dense population groundwater of Bogor city. The water samples were tested following the Indonesian standards for drinking water released by the Ministry of Health. Four water samples did not meet the standard: dense population groundwater of Bogor city for pH and nitrate value, groundwater of Jakarta city for total dissolved solid, and less dense population groundwater of Bogor city and RO water for pH only. The broccoli samples were boiled using the water samples, and showed different physical and chemical properties. The broccoli samples cooked using the water samples with high pH (> 7.00) exhibited softer texture. Two best DPPH IC50 antioxidant activities were obtained from the broccoli samples cooked for 4 min in the RO (93 mg solid part/mL) and BW (117 mg solid part/mL) samples. The broccoli samples cooked in BW for 4 min contained the highest vitamin C content, whereas the vitamin C contents of the broccoli samples cooked in the municipal waterworks and the groundwater of Jakarta city were fully degraded. The vitamin C contents in the cooked broccoli samples exhibited higher contribution as antioxidants compared with phenolics.