Bioethanol fermentation of clarified sweet sorghum (Sorghum bicolor (L.) Moench) syrups sealed and stored under vegetable oil

Sweet sorghum represents a readily available renewable carbohydrate feedstock for biofuel production. Generally, the sweet growing season and window processing is short it often desirable to store sugar-rich material future processing. Therefore, we investigated possibility of storing three different sugar syrups under layer soybean oil; then subsequent yeast bioethanol fermentation. A oil on surface syrup reduced loss in 30 40°Bx syrups, but was still 21–36 %. Storage 50°Bx resulted an 11–18 % sugars with or without oil. Elevated levels lactic acetic acids, caused by bacterial contamination, almost completely inhibited fermentation; however, when ethanol-producing microorganisms were part stored produced at yield 83–91 %, compared theoretical.