Influence of Hot Water Treatment Combined with Sodium Chlorite on Microbial Counts and Antioxidant Quality of Fresh-Cut Broccoli Florets

摘要

The effects of combined treatments with hot water (HW) and sodium chlorite (SC) solution on microbial reduction, quality and antioxidant properties of fresh-cut broccoli florets were determined during storage at low temperature. Broccoli heads were cut into individual florets using sterile knives. Fresh-cut broccoli florets were then pre-washed with cold tap water (8-10°C) for 2 min, dipped in HW at 45°C for 1 min, cooled with tap water, and then dipped in 300 ppm of SC solution for 1 min at ambient temperature (25±2°C). The samples were packed in clamshell plastic boxes and stored at 4±1°C for 12 days. Results revealed that washing with either HW combined SC solution or pre-washing with tap water reduced microbial loads. The combined treatments had a powerful effect by decreasing the total aerobic bacteria, coliforms. and yeasts and molds during storage within the ranges of 1.31-1.97, 1.06-1.33 and 1.08-1.96 log CFU.g~(-1), respectively, which are lower than in non-treated samples. The combined treatment had no negative effects on color quality (lightness and hue angle), ascorbic acid, and total chlorophyll content throughout the storage period, while the antioxidant capacity (DPPH) was maintained. These results indicate that the combined treatment may have potential to reduce microbial contamination and preserve the antioxidant capacity of fresh-cut broccoli.