Addressing anti-nutritional factors of barley and exploring different processing conditions to enhance nutritional value and digestibility: A review

Barley (Hordeum vulgare) is a nutritionally rich cereal containing proteins, carbohydrates, β-glucans, vitamins, minerals, and bioactive compounds that promote health through cholesterol reduction, glycemic control, and antioxidant effects. However, its utilization is limited by anti-nutritional factors (ANFs) such as phytic acid, tannins, protease and amylase inhibitors, lectins, saponins, and alkaloids, which reduce mineral bioavailability, protein digestibility, and overall nutritional quality. This review synthesizes current knowledge on these ANFs and highlights both conventional and advanced processing methods aimed at their reduction. Traditional techniques (soaking, germination, fermentation, roasting, and dehulling) are effectively decrease water-soluble and heat-labile ANFs, improving digestibility and sensory quality. Recent innovations such as enzymatic treatment, high hydrostatic pressure (HHP), ultrasound-assisted soaking, pulsed electric fields (PEF), and cold plasma (CP) offers targeted, energy-efficient alternatives that maintain functional components like β-glucans and phenolic. Integrated multi-step processing (ultrasound pretreatment combined with enzymatic or microbial fermentation) demonstrates synergistic effects in reducing multiple ANFs simultaneously while enhancing nutrient bioaccessibility. Collectively, evidence indicates that optimizing these technologies can significantly improve the nutritional quality and digestibility of barley-based foods. The review concludes that adopting integrated and scalable processing strategies can help transform barley into a sustainable, functional food source supporting efforts to alleviate malnutrition and meet the growing demand for health-promoting cereal product.