Physical Quality and Tannin Content of Sorghum (Sorghum bicolor L.) at Different Temperature and Soaking Immersion

Abstract

This study aimed to evaluate the effect of temperature and the type of immersion solution on the characteristics of the physical quality and tannin content of sorghum seeds. The material used were red sorghum seeds soaked for 24 hours in a neutral and alkaline solution at 30, 45, and 60°C. The parameters observed included moisture content, hardness, tannin content, and brightness of sorghum seeds which were then carried out statistical analysis and further tests with the DMRT method to determine the effect of treatment levels on parameter changes. The results showed that the increase in water content ranged from 28.22 - 32.16% with the highest final water content of 43.49% in the alkaline immersion treatment at 60°C. The value of decreasing hardness of seeds varied from 66.15 to 79.71% with the lowest hardness value of 11.10 Newton. Decreased levels of tannins by 46.98%; 68.13%; and 73.54% in the treatment of neutral solutions at temperature of 30, 45 and 60°C, and 52.30%; 70.74%; and 72.88% in the alkaline solution treatment at temperature of 30, 45 and 60°C. Soaking in the alkaline solution caused a decrease in the lowest brightness level of sorghum seeds compared to soaking at neutral pH at each temperature levels treatment.