Quality of sugar beet molasses for alcohol production
Molasses is defective, healthy, and of good quality. Molasses is the final mother liquor or runoff obtained when separating sucrose crystals in centrifuges. Molasses contains sugars that are not economically viable to separate through crystallization methods. Molasses contains sugars that are unprofitable to isolate by crystallization, but these sugars have found their purpose in the production of alcohol and bioethanol.
Molasses is a concentrated solution of various mineral and organic substances, some of which are in a colloidal state. The density of molasses ranges from 1.35 to 1.40.
Based on qualitative and physicochemical indicators, molasses can be classified as normal or defective. The technological quality of beet molasses primarily depends on the duration and storage conditions of sugar beets. Molasses obtained from long-stored sugar beets has reduced quality indicators and results in decreased yields of alcohol and baker’s yeast during processing at distilleries, making it defective.
Defective molasses, unlike normal molasses, ferments poorly and leaves a significant percentage of unfermented sugar, resulting in reduced alcohol and yeast production. The poor fermentability of defective molasses is attributed to the unfavorable chemical composition of molasses, which contains harmful impurities that suppress yeast activity, as well as the influence of bacterial infection.
Sugar beet storage conditions at sugar factories.
Defective molasses obtained at a sugar factory during the second half of the sugar production season (January-March) differs from normal molasses obtained during the first half of the production season (September-December). Defective molasses ferments slowly and retains a significant amount of unfermented sugar during processing. The poor fermentation dynamics can be attributed to the unfavorable chemical composition of molasses or biological changes occurring due to bacterial infection, or a combination of both factors.
During beet processing at sugar factories from January to March, molasses with lower dry matter content, high color intensity, a large amount of water-soluble colloids, calcium salts, and sulfurous acid, increased amounts of invert sugar and raffinose, as well as organic volatile acids such as formic and propionic acid, are obtained. This molasses has a strong infection and usually exhibit acidic reactions.
Features of defective molasses compared to normal:
- Dry matter content: Defective molasses has a lower dry matter content compared to normal molasses.
- Color intensity: Defective molasses has higher color intensity, indicating the presence of a larger amount of pigments.
- Water-soluble colloids: Defective molasses contains a higher amount of water-soluble colloids.
- Calcium salts and sulfurous acid content: Defective molasses has a higher content of these substances, which can negatively affect the quality of products obtained from molasses.
- Invert sugar and raffinose content: Defective molasses contains a higher amount of these substances, which can affect the fermentation process and the quality of the resulting products.
- Acidity: Defective molasses exhibits acidic reactions, indicating the presence of bacterial infection.
- Nitrogen content: Defective molasses has a lower content of total and formol-titratable nitrogen compared to normal molasses.
- Soluble phosphorus compounds content: Defective molasses contains a lower amount of soluble phosphorus compounds compared to molasses produced during other periods.
These indicators allow for assessing the technological benefits of molasses and determining its quality. Defective molasses that fails to meet these criteria can have a detrimental effect on processing processes and the quality of the resulting products.