Effect of microwave steamable bag design on the preservation of ascorbic acid and antioxidant capacity and on the physical properties of cooked frozen vegetables: A case study on broccoli (Brassica oleracea)

Published data on new cooking methods such as steamable bag microwaving is minimal. This study investigated the effect of steamable bag design, including shape and surface area, on the changes in ascorbic acid, antioxidant capacity, and physical quality of frozen broccoli during microwaving. The results showed that most of the studied parameters were more affected by the shape of steamable bags than by surface area. Broccoli cooked in more square-shaped steamable bags retained significantly higher vitamin C content, was less green and more yellow, and firmer than broccoli cooked in more rectangular-shaped steamable bags. The smaller the surface area, the softer the broccoli became after cooking; however, vitamin C content and color did not follow this trend. Neither the shape nor surface area of steamable bags had an effect on lightness and antioxidant content. These results demonstrated the importance of controlling the surface area and shape of steamable bags to optimize frozen vegetables' qualities.