Productive and Qualitative Traits of Amaranthus Cruentus L.: An Unconventional Healthy Ingredient in Animal Feed

SIMPLE SUMMARY: Amaranthus cruentus (red amaranth) can be considered a very interesting crop for its high nutritional and functional value. In this study, agronomic traits, oil content, fatty acid composition, quality indices, antioxidant activity, and total phenolic compounds were studied on eight A. cruentus accessions grown in Southern Italy. Data showed a valuable seed yield (0.27 kg/m(2), on average) comparable to the main cereals used for animal feeding, a higher oil content compared to that of conventional cereals such as maize with a fatty acid profile composed approximately for the 60% of unsaturated fatty acids, and a valuable antioxidant potential and phenolic compounds that are far superior to corn and wheat. The studied seed-oil composition revealed a high content of essential fatty acid n-6 (linoleic acid) and n-9 (oleic acid). Therefore, this species can be used as pseudo-cereals to balance the animal diet according to animal species requirements and to the different metabolic pathways of unsaturated fatty acids in ruminants and monogastrics. In conclusion, A. cruentus may be of potential value as an oilseed crop of importance to areas of the Mediterranean and a high-quality alternative feed ingredient to traditional cereal grains. ABSTRACT: Agronomic traits, oil content, fatty acid composition, antioxidant activity, and total phenolic content were studied on eight A. cruentus accessions cultivated in Southern Italy. A one-way ANOVA model was performed to compare accessions and the Principal Components Analysis was applied to identify patterns in our dataset and highlight similarities and differences. A. cruentus showed valuable seed yield (0.27 kg/m(2), on average) comparable to the main tradition cereals used for animal feeding. Seed-oil composition showed significant differences among the accessions. Data showed a higher lipid content than most cereal grains (from 5.6 to 7.3%). Approximately 60% of fatty acids were unsaturated; linoleic fatty acid ranged from 19 to 34%, oleic acid from 29 to 36%, and alfa-linolenic fatty acid from 0.3 to 0.5%, respectively. The saturated/unsaturated fatty acid ratio ranged from 0.5 to 0.8, the hypocholesterolemic:hypercholesterolaemic ratio from 1.7 to 2.7, the Atherogenic Index from 0.38 to 0.66, the Thrombogenic Index from 0.85 to 1.48, the total phenolic content from 0.14 to 0.36 mg/g seeds, and the antioxidant activity (DPPH(•)) from 0.30 to 0.50. The studied seed-oil composition evidenced A. cruentus as a healthy ingredient for animal feed and consequently, as a possible substitute for traditional cereals. Accessions from Mexico and Arizona emerged for their high qualitative traits.