Improvement of the antioxidant and hypolipidaemic effects of cowpea flours (Vigna unguiculata) by fermentation: results of in vitro and in vivo experiments.

BACKGROUND

The antioxidant capacity and hypolipidaemic effects of Vigna unguiculata, as well as their potential improvement by different fermentation and thermal processes were studied using in vitro and in vivo methods.

RESULTS

Phenolic content and reducing capacity of legume acetone extract were significantly increased by different fermentation processes, and by the thermal treatment of fermented legume flours. TBARS inhibiting capacity was increased by fermentation but not by thermal treatment. A higher ability to decrease Cu(2+)/H2O2-induced electrophoretic mobility of LDL was found in fermented when compared to raw legume extracts, and a higher protective effect on short term metabolic status of HT-29 cells was found for raw and lactobacillus-fermented Vigna followed by naturally fermented Vigna extracts. Significant improvements in plasma antioxidant capacity and hepatic activity of antioxidant enzymes were observed in rats that consumed fermented legume flours when compared to the untreated legume or a casein-methionine control diet. In addition, liver weight and plasma levels of cholesterol and triglycerides were also positively affected by untreated or naturally fermented Vigna.

CONCLUSIONS

V. unguiculata has demonstrated its potential as a functional food with interesting antioxidant and lipid lowering properties, which can be further augmented by fermentation processes associated or not to thermal processing.