Corn grits were extruded then extrudates were expanded by microwave-heating.Effects of addition of xanthan gum (XG) (0%-1%), feed moisture content (37%-47%) and screw speed (100-300 rpm) level on physicochemical properties of snacks were evaluated with response surface methodology (RSM). All suspensions of expanded samples exhibited shear-thinning behavior. Apparent amylose content of samples ranged from 22.47% to 37.97%. Screw speed and feed moisture content had positive effect on apparent viscosity and amylose content but XG level had negative effect on them. Increasing screw speed increased expansion and luminosity but decreased browning index and total color difference. Increasing feed moisture content resulted in reduced expansion, luminosity but increased browning index. In contrast to the initial effect, expansion and browning index decreased when XG addition level was above 0.5%. Optimum conditions were determined to obtain the maximum values for expansion index and luminosity and minimum value for the total color difference by desirability function. They were found as 300-rpm screw speed, 47% feed moisture content and 0.34% XG level. How to cite this article: Gümüşay ÖA, Şeker M. Effects of extrusion parameters on physicochemical properties of third generation corn snacks expanded by microwave heating.
Dbjective of this study was to investigate the changes of oxidative stress parameters in Chinese hamster ovary (CHD) cells exposed to xanthene food dyes (erythrosine and phloxine), commonly-used azo dyes in the food industry. For this purpose, glutathione (GSH) and malondialdehyde (MDA) levels, glutathione peroxidase (GPx) and catalase (CAT) activity measurements of CHD cells treated with erythrosin (50 µM) and phloxine (40 µM) were compared with the control group. There was no significant difference between MDA levels in CHD cells exposed to both dyes and control group (p > 0.05), however GSH levels significantly decreased with dye addition (p ≤ 0.05). An increase in GPx activity of the CHD cells exposed to phloxin was observed (p ≤ 0.05). However, there was no change in GP X activity of erythrosin-exposed CHD cells (p > 0.05). On terms of CAT activity, difference between the dye-added cells and the control group was not observed. Consequently, decrease in level of GSH, which one of major antioxidant components in the cell, suggests that erythrosine and phloxine can have a toxic effect.
Freeze-drying is a trend method for the preservation of thermosensitive and nutritive food products. In this study, two different fruits, kiwi fruit with high ascorbic acid content and cherry laurel fruit with high phenolic content, were selected to study the freeze-drying effect on these compounds. Ascorbic acid content, total phenolic content and antioxidant capacity of kiwi and cherry laurel fruits were determined before and after freeze-drying process. Ascorbic acid content of kiwi and cherry laurel fruit were 205.14±21.33 and 3.00±1.02 mg/100 g dry matter, respectively. Total phenolic content of kiwi and cherry laurel fruits were 262.66±19.97 and 1056.78±90.73 mg GAE/100 g dry matter, respectively. Ascorbic acid contents did not change, while antioxidant capacities increased by freeze-drying process for both fruits. The total phenolic content of cherry laurel fruits increased significantly after freeze-drying in contrast to the total phenolic content of kiwi fruits. Color values changed with freeze-drying, the lightness and yellowness values increased significantly for both fruits (p<0.05). The rehydration ratios of freeze-dried kiwi and cherry laurel fruits were found similar at 25 and 40C. The rehydration ratio in water at 40C increased more quickly in the beginning of immersion than the ratio at 25C. The results of this study showed that freeze-drying method is highly recommended for the preservation of nutritive values of these fruits and off-season products.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.