ENVIRONMENTALLY EFFICIENT UTILIZATION OF SORGHUM AGRICULTURAL WASTE IN THE CONTEXT OF CIRCULAR ECONOMY

The article addresses the issue of organic waste management in the agro-industrial complex of Kazakhstan. Approximately 8.2 million tons of agricultural biomass are generated annually in the country. The implementation of circular economy principles is essential for its effective disposal. This study aims to develop a technology for the valorization of sorghum husks by extracting biologically active phenolic compounds. Sorghum is a drought-resistant crop promising for cultivation in arid zones. The study examined five sorghum varieties grown in South Kazakhstan: Daulet, Massino, Vakhsh, Sugar Sorghum, and Karabash. It was experimentally established that the average husk yield is 11.7% of the grain mass. This corresponds to the generation of 117 kg of secondary raw materials per ton of processed products. The extraction methodology was refined using the "Karabash" variety. The process was conducted using a 70% aqueous ethanol solution at a temperature of 50°C. The resulting extract has an intense burgundy color. Spectrophotometric analysis revealed a maximum absorption in the range of 500 –550 nm. An absorbance value above 3.0 confirms a high concentration of unique pigments – 3-deoxyanthocyanidins. Antioxidant activity analysis showed the presence of water-soluble and fat-soluble components. According to the perfomaned calculations, the base theoritical yield of the liquid exstract during technology scaling amounts to 788.6 kg, and considering technological scaling coefficients, it reaches up to 906.9 kg from the volume of husks generated during the processing of 1 ton of sorghum grain. The research results prove the efficiency of using sorghum husks as a source of natural colorants and antioxidants. The proposed approach allows for the transformation of agricultural waste into a valuable resource. This reduces the environmental burden on ecosystems and provides a safe "green" alternative to synthetic dyes. The implemented technology increases the environmental and economic efficiency of agro-industrial waste recycling, contributes to the formation of sustainable production systems at the regional level, and ensures the rational use of bioresources.

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