Oil and protein concentration and fatty acid composition of chia (Salvia hispanica L.) as affected by environmental conditions

Abstract

Chia (Salvia hispanica L.) has increased its consumption because its grains have the highest content of omega-3 acid among grain crops. The objective was to determine the effect of environmental conditions on oil and protein concentrations and the fatty acid profile of chia grains. Two field experiments were conducted in Salta (24°53′32″S, 65°82′26″W, Argentina) including two chia populations (white-seeds and mixed-seeds) and 3–4 sowing dates (depending on the season) that generated variations in temperature and radiation during grain filling. With the delay in sowing date, oil concentration decreased and protein concentration increased. There were significant and positive associations of oil concentration with day and night temperatures and accumulated intercepted radiation, whereas protein concentration showed, in general, significant and negative associations with those environmental variables. This behavior led to a negative association between these two quality components. As day and night temperatures increased, palmitic and linoleic acid concentrations decreased, whereas stearic and linolenic acid concentrations increased. In addition, there was a decrease in palmitic acid concentration and an increase in oleic acid concentration as accumulated intercepted radiation increased. An increase in oleic acid concentration was associated with an increase in stearic acid concentration and decreases in palmitic and linoleic acid concentrations; the concentration of linoleic acid was negatively associated with the concentration of linolenic acid. Although both chia populations responded similarly to environmental conditions, the white-seed population showed a higher concentration of palmitic and linolenic acids, whereas the mixed-seed population showed a higher linoleic acid concentration. During grain filling of chia, increased temperature and accumulated intercepted radiation increased the main quality attributes of this crop: oil concentration and linolenic acid concentration.