Nutritional composition and bioactive profiles of green rice and its milling fractions: Potential ingredients for functional food development

This study investigated the bioactive and nutritional profiles of green rice, harvested before full maturity (30 days after flowering), and its milling fractions including whole grain green rice (GR), broken green rice (BGR), white broken green rice (WBGR), and green rice bran (GRB), using white rice (WR) as a control. GRB was the most nutrient-rich fraction, exhibiting the highest levels of phenolic acids, flavonoids, antioxidant activity, essential amino acids, and key nutrients including ash, protein, fat, and fiber. GR and BGR demonstrated favorable profiles, with GR rich in phenolic acids and BGR in flavonoids. Both showed the most diverse phenolic acid profiles, with gentisic acid uniquely abundant, while GRB was rich in gallic acid and protocatechuic acid. GRB also contained the highest essential amino acid content, with tryptophan predominating, while arginine and histidine were abundant across all samples. Interestingly, phenylalanine levels were significantly higher in all green rice samples than in WR, with GRB exhibiting the highest. Principal component analysis clearly separated GRB from other samples based on its elevated bioactive and nutritional profiles. These results highlight GRB as a promising functional ingredient with superior nutritional and bioactive composition, while GR and BGR also possess potential for functional food applications. • Green rice bran (GRB) was rich in in gallic acid and protocatechuic acid. • GRB was richest in phenolics, flavonoids, amino acids, ash, protein, fat, and fiber. • Gentisic acid uniquely abundant in green rice (GR) and broken green rice (BGR). • GR had the highest gentisic and sinapic acids; BGR showed highest chlorogenic acid. • Phenylalanine levels were higher in all green rice samples than white rice.