Young cereal grains as a new source of healthy and hypoallergenic foods: a review.

Abstract

Young cereals contain higher quantities of nutrients such as sterols, γ-oryzanols, tocols and phenolic compounds than mature grains. They are more easily digested with low allergenic potential. Applications of young cereals include plant-based milk substitutes, substitution of wheat flour, malting, fructose and pigments production. Research on young cereals is scarce and mainly focused on botanical studies. This review focused on major young cereals (wheat, rice and corn) compositions, bioactive compounds and applications that will benefit future research in plant-based food and functional ingredients. During grain maturity, amylose content increased, whereas amylopectin content and its structure varied depending largely on grain type. In rice, non-significant differences in average chain length of amylopectin during grain maturity were reported, with protein contents of young rice and wheat higher than at their mature stages. High digestibility of the flowery-to-milky stage rice protein indicated lower allergen levels. Immune-reactive gluten was not found in young wheat. Young wheat contained high essential amino acids with a more balanced profile, particularly for lysine. The angiotensin-converting enzyme inhibitory effect of milky stage protein hydrolysate was higher than mature protein. Young grains contained less starch with more fiber and sugar. Antioxidant activity in young rice was high as it contained gamma-oryzanol, ascorbate, glutathione tocopherols and phenolic compounds. This review of the available information concerning the composition, properties and functional ingredients of immature cereals will assist future research in plant-based food and functional ingredients.