Nutritional composition, fatty acid, amino acid and phenolic profiles of popped pseudocereal grains

Póster presentado al VI Congreso Mundial de la Quinua y III Simposio Internacional de Granos Andinos, celebrado en Universidad Nacional del Altiplano de Puno (Perú) del 21 al 24 de julio de 2017.

Puffed cereals are widely used as ready-to-eat products or as ingredients in snack formulations, and their demand is currently increasing because of changing life styles. They are generally obtained from rice, wheat, maize, oat and barley most often from whole kernels. Increasing attention to the nutritional quality of foods has fostered the interest in Andean pseudocereal grains such as kiwicha (Amaranthus caudatus L.) and quinoa (Chenopodium quinoa Willd). Few studies are available in literature about oil-free puffing of Peruvian varieties of kiwicha and quinoa and its effects on amino acid, fatty acid and phenolic profile. The objective was to characterize the impact of puffing on nutritional composition, fatty acid, amino acid and phenolic profiles of kiwicha and quinoa. Popping of kiwicha slightly increased protein and lipid contents and reduced carbohydrates while popped quinoa showed slightly higher lipid, ash and carbohydrates contents and a minor decrease in protein content. Kiwicha fatty acid composition was not affected by dry heat puffing while a minor degradation of cetoleic acid was observed in popped quinoa. Popping did not change ω-6/ω-3 ratio of both pseudocereal oils, although it was observed a healthier ω-6/ω-3 ratio (7:1) in popped quinoa compared to popped kiwicha (65:1). Thermal treatment reduced essential amino acids content and protein quality indexes of both grains, although amino acid content remained adequate to fulfil FAO/WHO requirements for adults. Popping cause a general decrease in hydroxybenzoic and hydroxycinnamic acids in both pseudocereal grains. Flavonoids were negatively affected by heat treatment in kiwicha. Interestingly, it was found that puffed quinoa had improved flavonoid contents compared to raw seeds. Given the increasing demand for natural and healthy foods and the scientific evidence on health promoting properties of flavonoids this nutritional aspect of puffed quinoa grains is of great interest. In summary, puffing of kiwicha and quinoa grains is an alternative processing method to obtain expanded products or precooked flours of high nutritional value.

This research was cofunded by the Ministry of Economy and Competitiveness (Spain) and the European Union (project number AGL2013-43247-R). E. Peñas thanks to Ramón y Cajal Programme and Professor L. Paucar-Menacho to Consejo Nacional de Ciencia y Tecnologia (Peru) for financial support (Grant number 118-2013-CONCYTEC-FONDECYT).

Peer Reviewed