Caracterização de plantas alimentares não convencionais Guizotia abyssinica (L.f.) Cass., Panicum miliaceum L. e Phalaris canariensis L. para aplicação na indústria da panificação

Abstract

Consumers have given preference to food products that, in addition to the nutritional properties, also present bioactive characteristics with beneficial effects on their health. The use of unconventional food plants (PANC) has been an asset for the food industry, not only due to its abundance, but also because it does not compete with other vegetable matrices used for human consumption, and for its nutritional properties, chemical and bioactive potentiality. Considering the growing increase in this demand by the consumer, the study of new food sources is urgent, as well as the study of its application for the development of new products with high added value. The present work aimed to study three seeds of unconventional food plants, namely Guizotia abyssinica (Lf) Cass., Panicum miliaceum L. and Phalaris canariensis L., commonly known as niger, millet and birdseed, respectively, starting with the study of its granulometry and water absorption index. It was also proposed to characterize its nutritional value by AOAC methods, determination, by chromatographic methods, of the levels of free sugars (HPLC-RI), fatty acids (GC-FID), organic acids (UPLC-DAD), tocopherols (HPLC - fluorescence) and phenolic compounds (HPLC-DAD / ESI (MS) and, the study of their antioxidant, hepatotoxic and antimicrobial potential. Finally, bakery products were developed with partial replacement of the wheat flour (20% of the PANC’s flour). An experimental statistical design using the centroid simplex method was applied to understand the effect of applying PANC flours on the final physical-chemical characteristics of the breads obtained. The three seeds under study showed high granulometry, associated with high water absorption index, which in the case of birdseed and niger indicates that their use would have to be complemented with other flours for application in bakery products. All seeds showed low values of humidity and ash, but with regard to nutritional and chemical value, it was the niger seed that stood out the most, with a higher content of total fat, PUFA (linoleic acid), sugars, tocopherols (α-tocopherol) and phenolic compounds (derivatives of caffeic acid). All seeds showed relatively low IC50 and MIC values for inhibition of lipid peroxidation and for antimicrobial activity, respectively. It should be noted that the results obtained for antifungal activity in the hydroethanolic extracts of niger and millet were lower when compared with the positive controls used (E211 and E224). The three samples did not show hepatotoxicity, assessing their safety and potentiality to be introduced into new food matrices. Breads made with partial replacement of 20% wheat flour by millet and birdseed flour, were the ones that showed the greatest similarity to control bread (100% wheat flour), in terms of texture, specific volume and color. Breads with partial replacement for niger flour were the ones that had the greatest difference in relation to the control, especially in parameter L * (luminosity). This study allowed to present innovative results in relation to the nutritional, chemical and bioactive properties of seeds that have been little studied and consumed, but with great potential to be applied in the food industry. Considering their composition in bioactive compounds, the use of these seeds is highly advisable in the context of a fortified diet, being sources of compounds of high nutritional value and with beneficial effects for the health of the consumer.