Molasses production

Composition. Molasses composition depends on several factors, eg, locality, variety, sod, climate, and processing. Cane molasses is generally at pH 5.5—6.5 and contains 30—40 wt % sucrose and 15—20 wt % reducing sugars. Beet molasses is ca 7.5—8.6 pH, and contains ca 50—60 wt % sucrose, a trace of reducing sugars, and 0.5—2.0 wt % raffinose. Cane molasses contains less ash, less nitrogenous material, but considerably more vitamins than beet molasses. Composition of selected molasses products is Hsted in Table 7. Procedures for molasses analysis are avadable (59). 

Molasses, molasses products and confectionery. Pass dry molasses samples (after reaching room temperature) containing lumps through a ca. 2 mm mesh sieve, crush the residue with a pestle in a dry mortar, and add to the... 

Only countries that have total sucrose production levels of 600,000 metric tons would have enough molasses available to provide the feedstock for the ethanol production capacity being considered here. The developing nations that have large sucrose production levels, and" thus large molasses production levels, are listed in Table III. 

Bioethanol Competitiveness Molasses Production cost Sugar... 

Molasses Production Industrial Potable Other Surplus... 

Table 5 presents typical operating conditions and cell production values for commercial-scale yeast-based SCP processes including (63) Saccharomjces cerevisae ie, primary yeast from molasses Candida utilis ie, Torula yeast, from papermiU. wastes, glucose, or sucrose and Klujveromjces marxianus var fragilis ie, fragihs yeast, from cheese whey or cheese whey permeate. AH of these products have been cleared for food use in the United States by the Food and Dmg Administration (77). 

Fig. 1. Conventional process for lactic acid production from dextrose, molasses, or whey.

In the United States and some European countries, beet-sugar-waste molasses, or Stefen s waste, has been used as raw material for MSG production. The 2-pyrrohdinone-5-carboxyhc acid [98-79-3] contained ia beet sugar as by-product, is hydrolyzed at weakly alkaline pH, and moderate temperature (eg, pH 10.5—11.5, at 85°C for 2 h) to avoid racemization (14). The pH of the hydrolyzate is adjusted to 3.2 with a mineral acid to precipitate crystals of L-glutamic acid. The L-glutamic acid crystals obtained are transformed to MSG as described above. 

Fermentation Feedstock. Sucrose, in the form of beet or cane molasses, is a fermentation feedstock for production of a variety of organic compounds, including lactic, glutamic, and citric acids, glycerol, and some antibiotics. Lesser amounts of itaconic, aconitic, and kojic acids, as well as acetone and butanol, are also produced (41,51—53). Rum is made by fermentation of cane molasses. Beet and cane molasses are used for production of baker s and brewer s yeast (qv). 

Moisture. In relatively pure sugar solutions, moisture is deterrnined as the difference between 100 and Brix. In crystalline products, it is usually deterrnined by loss-on-drying under specified conditions in an oven or by commercial moisture analyzers that have built-in balances. Moisture in molasses and heavy symps is deterrnined by a special loss-on-drying technique, which involves coating the sample onto sand to provide a greater surface area for oven drying. The result of this test is usually considered dry substance rather than moisture. 

Other Products. Other products from sugarcane, in addition to cane sugar, are cane fiber (known as bagasse) and molasses, the final thick symp from which no more sugar may be economically removed by crystallization. In some cane-growing countries, cane tops and leaves, separated during harvest, are used for catde feed. 

Condensed molasses solubles (CMS) is a product made by drying molasses (spray or dmm drying) on a neutral carrier CMS is a more portable and storable form of molasses for animal feed. 

Sucrochemistry. A wide range of fermentation and chemical products can be made from sucrose either per se or in juice or molasses. 

Chromatographic separation of diluted molasses streams into a high purity fraction suitable for concentration and crystallization and a second low purity by-product, which can be concentrated and sold as an animal feed product, has been employed in Finland since the 1970s and in the United States since the mid-1980s. Since the early 1990s, production of sugar from beet molasses has almost tripled, and the trend is expected to continue for the next two years to consume most of the domestic beet molasses (Fig. 7) (3,9). 

Fig. 7. U.S. production of beet sugar from molasses desugarization processes. Values for 1995 are estimated.

The product has purities typically in the 90—92% range and can be combined with thin juice, concentrated and crystallized, or concentrated and stored for later use. Crystallizing the desugarization thick juice apart from the normal beet campaign may be desired because the secondary molasses produced after the separation contains the nonsucrose components, which are the most difficult to separate from sucrose and perhaps should be set aside and sold instead of resubmitted to the columns. 

The desugarization by-product is normally sold as a low value molasses. Pulse method systems also produce a relatively high value betaine-rich (at least 50% on soHds) fraction. The concentrated betaine-rich by-product is used as a custom animal feed, whose European markets are well estabUshed and may provide a future opportunity in the U.S. feed industry. Beet sugar molasses contains from 3 to 6% betaine, by weight, about three-quarters of which may be recoverable as a potential by-product ( 40 50% purity). 

High test molasses (invert molasses) is produced from cane sugar when sucrose manufacture is restricted because of overproduction. The cane sugar at ca 55 wt % solids is en2ymatically converted to invert symp to prevent crystallisation and evaporated to a symp. The product is used in the same applications as blackstrap molasses. 

Molasses is also used as an inexpensive source of carbohydrate in various fermentations for the production lactic acid, citric acid, monosodium glutamate, lysine, and yeast (60). Blackstrap molasses is used for the production of mm and other distilled spirits. 

Table 8. Production, Imports, and Price of Molasses in the United States ...

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