Effects of Ultradisperse Humic Sapropel Suspension on Microbial Growth and Fermentation Parameters of Barley Distillate

Abstract

Barley and other cereal grains can be used in the production of ethanol. The quality and safety of the grains utilized have enormous effects on the overall yield and quality of the final product (ethanol). Therefore, the present paper seeks to elucidate the antimicrobial activities of ultradisperse humic sapropel suspensions (UDHSS) on barley, wort, fermentation, and the quality of the final product. A standard microbiological method was used to assess the biocidal activities. Physicochemical parameters and volatile compounds were determined. Treated samples exhibited least microbial growth (for grain: 1.145 ± 0.120 × 104 cfu/g) when compared to the control (3.425 ± 0.33 × 105 cfu/g). Mash from the treated sample had less Free Amino Nitrogen (35.14 ± 0.02 mg/L) than the control experiment (41.42 ± 0.01). However, the levels of °Brix and Free Amino Nitrogen (FAN) were unaffected by the UDHSS treatments. After the chromatographic analysis, it was revealed that the barley distillate obtained from treated grains had high volatiles concentration when compared to the control experiment. The volume of the methanol quantified in the distillate was low, and hence safe, and might find applications in the food industries or in domestic consumption after rectification.

Keywords

• antimicrobial effects
• mashing
• distillation
• volatile compounds
• gas chromatography
• reactive oxygen species