Sorghum has been studied for its physiological benefits, including its antioxidant, anti-cancer, anti-bacterial, and anti-diabetic properties. It is commonly consumed after undergoing heat treatment. However, this may lead to the loss of some nutritional and functional components. Microwave treatment presents a way to efficiently reduce heat treatment time by quickly raising the food temperature, thereby preserving its nutritional and functional components. This study aimed to investigate the effect of microwave treatment on the antioxidant, anti-diabetic, and anti-hypertensive activity of sorghum, focusing on variations in microwave power and processing time. The results showed that sorghum subjected to a low-power long-term (LL) microwave treatment showed the highest total polyphenol content at 123.48 gallic acid equivalent mg/g residue, which was an 80.34% increase compared to the untreated sample. The radical scavenging activity was the highest with the LL treatment at 192.03 Trolox equivalent mg/g residue, showing the same trend as the total polyphenol content. Moreover, with this treatment, the α-glucosidase inhibitory activity and glucose consumption of microwave-treated sorghum increased by 128.93% to 298.48% and 5.99% to 97.00%, respectively. The angiotensin-converting enzyme inhibitory activity increased by 28.12% to 144.23%, and the protective effects in EA.hy926 cells increased by up to 50.43%. These results indicate that the 100-watt 660-second (LL) microwave treatment is favorable for enhancing the antioxidant, anti-diabetic, and anti-hypertensive activities of sorghum. Additionally, subjecting sorghum to long-term treatment at the same power can further improve its beneficial activity.

Keywords: sorghum, microwave, antioxidant, anti-diabetes, anti-hypertension