Efren Delgado-Licon

Influence of extrusion on the bioactive compounds and the antioxidant capacity of the bean/corn mixtures

The aim of this investigation was to examine the influence of extrusion on the bioactive compounds and the antioxidant capacity of bean/corn mixtures. Whole bean flour and nixtamalized corn were mixed in a 60:40 proportion and extrusion was performed in different moisture (14.5%, 15.4%, 17.1% and 18.0%) and temperature (150°C, 160°C, 170°C, 180°C and 190°C) conditions in order to find the optimal extrusion conditions. According to their functional properties and antioxidant status, the mixtures 142°C/16.3% H, 170°C/16.3% H and 198°C/16.3% H were defined as optimal, moderate and bad, respectively. Total polyphenols and flavonoids in the mixture of 142°C/16.3% H (15.09±1.7 mg gallic acid equivalent [GAE]/g dry weight [DW] and 1.57±0.2 mg catechin equivalent [CE]/g DW) were significantly higher (P<0.05) than in the sample 170°C/16.3% H (9.42±1.1 mg GAE/g DW and 1.4±0.1 mg CE/g DW) and the mixture 198°C/16.3% H (6.46±0.8 mg GAE/g DW and 0.78±0.1 mg CE/g DW). The antioxidant activity (37.02±3.8 and 25.01±2.5 µM Trolox equivalent [TE]/g DW) of mixture 142°C/16.3% H, determined by the cupric reducing antioxidant capacity with Trolox equivalent antioxidant capacity and β-carotene–linoleic acid (β-carotene,% of inhibition) assays, was significantly higher (P<0.05) than in 170°C/16.3% H (25.69±2.8 and 17.02±1.8 µM TE/g DW) and in mixture 198°C/16.3% H (13.93±1.5 and 8.94±0.9 µM TE/g DW), respectively. The free polyphenols, flavonoids and the antioxidant activities showed lower results than the hydrolyzed ones. The correlation coefficients between polyphenols, flavonoids, and cupric reducing antioxidant capacity capacities were between 0.93 and 0.99. In cereal proteins extracted and separated by electrophoresis, some differences were found in the sodium dodecyl sulfate–protein bands in the region from 36 to 45 kDa for 142°C/16.3% H, in comparison with other samples. Therefore, there is a need to find such conditions for the extrusion procedures that would take into consideration the contents of the bioactive compounds and the antioxidant capacity in the end product.

Seed oils improve lipid metabolism and increase antioxidant potential in rats fed diets containing cholesterol

Abstract The goal of this investigation was to find the most valuable among four often-used seed oils for atherosclerosis preventing diets. Fatty acids, sterols, antioxidant compounds, stability and total radical-trapping antoxidative potential (TRAP) in sunflower, sunflower high oleic, rapeseed and grapeseed oils were determined. The highest stability and the highest TRAP (3.8 Rancimat 120°C, hours and 324 nmol/ml) and the lowest stability and the lowest TRAP (2.4 Rancimat 120°C, hours and 201 nmol/ml) were in rapeseed and sunflower oils, respectively. The effect of these two seed oils on lipid metabolism and antioxidant activity was investigated on 60 (divided in six diet groups of 10) male Wistar rats adapted to cholesterol-free or 1% cholesterol diets. The control group (Control) consumed basal diet (BD) only. To the BD were added 10g/100g rapeseed (Rapeseed group) or sunflower (Sunflower group) oils, 1 g/100 g cholesterol (Chol group) or both (Chol/Rapeseed group) and (Chol/Sunflower group). The experiment lasted 4 weeks. In the Chol/Rapeseed and Chol/Sunflower vs. Chol group, the oil supplemented diets significantly ( P

Inter-relationship between electrophoretic characteristics of pseudocereal and cereal proteins and their microscopic structure for possible substitution based on nutritional evaluation

Amaranth, soybean and maize were screened for proteins and their nutritional value. Isopropanol-soluble protein and buffer-soluble protein fractions were extracted from seeds and separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The comparison of the identity and differences between investigated plants was carried out by the obtained SDS-PAGE electrophoretic patterns, and their microstructure was determined by scanning electron microscopy. Electrophoretic patterns of extracted proteins have shown that the main protein subunits were concentrated between 10 and 50 kDa. Variations were found in major fractions and minor bands as well as in the fine structure. The microstructure of pseudocereal and cereal protein fractions was inter-related with the results obtained by their electrophoretic separation. Pseudocereal amaranth can be used as a nutritive substitute of cereal maize in functional foods.