Influence of heating on chemical composition, antioxidant activity and protein quality of an advanced line Amaranthus cruentus L. seed flour

Özet

Amaranth is a pseudocereal of Andean origin, and compared to other crops, its seeds have a higher content of proteins, lipids and bioactive compounds of nutraceutical relevance. The goal of the present work is to study the chemical composition, antioxidant activity and biological value of the protein of an advance line Amaranthus cruentus L. seed flour (ACRU), compared with the same flour subjected to thermal treatment (90 ºC, 1 h). Regarding the proximal chemical composition, the protein and lipid contents stand out, reaching values of 19.59 g % and 7.47 g %, reflecting an increase of 17% and 50% in the treated sample, respectively. A significant increase (p<0.05) is observed in the ash content, as well as in the content of the main elements of nutritional interest, of the treated samples. The anti-nutrients values are within the acceptable limits in all samples, and present an adequate content of total phenols, with an antioxidant activity highlighted by its free-radical scavenging capacity. In the biological tests, the Net Protein Utilization (NPU) presents lower values for the treated samples, the True Digestibility (tD) does not show significant differences, and the Biological Value (BV) turns out to be lower in the treated sample (p<0.05). A significant hypotriglyceridemic effect is observed. The applied thermal treatment, even though increases the nutrients concentration and the total phenols, according to the biological tests, it decreases the protein quality. These are aspects that should be contemplated in the food technology to optimize the nutritional quality of this amaranth.