Effect of Different Cooking Methods on Color, Phytochemical Concentration, and Antioxidant Capacity of Raw and Frozen Brassica Vegetables

Abstract

This study evaluated the effect of common cooking practices (i.e., boiling, microwaving, and basket and oven steaming) on the phytochemical content (carotenoids, chlorophylls, glucosinolates, polyphenols, and ascorbic acid), total antioxidant capacity (TAC), and color changes of three generally consumed Brassica vegetables analyzed fresh and frozen. Among cooking procedures, boiling determined an increase of fresh broccoli carotenoids and fresh Brussels sprout polyphenols, whereas a decrease of almost all other phytochemicals in fresh and frozen samples was observed. Steaming procedures determined a release of polyphenols in both fresh and frozen samples. Microwaving was the best cooking method for maintaining the color of both fresh and frozen vegetables and obtaining a good retention of glucosinolates. During all cooking procedures, ascorbic acid was lost in great amount from all vegetables. Chlorophylls were more stable in frozen samples than in fresh ones, even though steaming methods were able to better preserve these compounds in fresh samples than others cooking methods applied. The overall results of this study demonstrate that fresh Brassica vegetables retain phytochemicals and TAC better than frozen samples.

The effects of plant density and irrigation on phenolic content in cauliflower

“…In the present study, the most abundant phenolic acid in cauliflower curds was caffeic acid, followed by p-coumaric acid, sinapic acid, gallic acid and ferulic acid (Table 4). These results are in agreement with studies conducted by Pellegrini et al (2010) and Mazzeo et al (2011), but not with the study of Sikora et al (2012). These authors reported p-coumaric acid to be most abundant, followed by sinapic acid, caffeic acid and ferulic acid.…”

“…These data are in agreement with Sikora et al (2012). In the studies conducted by Mazzeo et al (2011) and Pellegrini et al (2010) caffeic acid content was almost 4-fold higher. On the other hand, Ahmed and Ali (2013) found 8-fold lower caffeic acid content.…”

Effect of cooking on glycemic index, antioxidant activities, α‐amylase, and α‐glucosidase inhibitory properties of two rice varieties

“…It has been reported that cooking caused a significant alteration in chemical compositions as well as antioxidant activities of grains and cereals (Pellegrini et al., 2010). Alpha‐amylase and alpha‐glucosidase play crucial role in sudden rise in blood glucose level observed in diabetic patients after taking carbohydrate‐rich foods due to hydrolysis of carbohydrate by these enzymes into simpler monomeric unit (glucose) (Kim, Jeong, Wang, Lee, & Rhee, 2005; Kwon, Vattem, & Shetty, 2006).…”

“…before consumption and these processing techniques have effect on the concentration and bioavailability of some vital nutrients and compounds. Previous studies showed that cooking significantly reduced total phenolic contents of some grains (Pellegrini et al., 2010; Towo, Svanberg, & Ndossi, 2003). Having in mind the lack of scientific literatures on the effect of cooking on in vitro GI, α‐amylase, and α‐glucosidase inhibitory properties of grains, therefore, present study was designed to assess the effect of cooking on amylose and amylopectin contents, sugar and starch contents, GI, and antioxidant properties of two rice varieties, as well as their effects on starch hydrolyzing enzymes (α‐amylase and α‐glucosidase).…”

Impact of High Hydrostatic Pressure Processing on Fruit Flesh Quality of Fruit Containing Carrot Juice

“…At present, carrot juice products adopt the traditional way of thermal processing. It is known that thermal processing induces significant changes in chemical composition, affecting the bioaccessibility and the concentration of nutrients and health-promoting compounds such as vitamin C, carotenoids, and polyphenols [1].…”