Crystallization, sugars sucrose

In the canning and preserving industries, com symps are used to prevent crystallization of sucrose, provide body, accentuate tme fmit flavors, and improve color and texture. In the beverage industry, the predominant use is in the beer and malt-Hquor areas. High conversion symps are used to replace dry cereal adjuncts, provide fermentable sugars, enhance flavor, and provide body. These symps contain controlled amounts of dextrose and maltose for proper fermentation. 

Sugar (sucrose) is obtained from either sugar beets or sugarcane. Sugar beets are traditionally diffused with water to extract the sugar from the pulp. The sugar is then crystallized, mechanically separated, and washed to produce white sugar. 

In the initial stages of purification, sucrose is recovered in juice form by crushing cane stalks or by extraction of sliced sugarbeets (cossettes) with hot water. The resulting solutions are clarified with lime, then evaporated to thick syrups from which sugar is recovered by crystallization. The final syrup obtained after exhaustive crystallization of sucrose is known as molasses. Enhanced recovery of sucrose from beet molasses is accomplished by ion-exclusion chromatography, a process used in some sugar mills in the United States, Japan, Finland, and Austria. 

The mineral constituents of the raw cane juice persist in the final molasses. The principal difference in relative amounts of these substances in molasses arises from the use of lime in defecation which causes an increase in calcium. Egyptian cane molasses solids contained 0.66% of titanium.181 The cations are believed to complex with the sugars and to thus inhibit the crystallization of sucrose, which latter is known to form compounds with inorganic salts, such as its well known compound with sodium chloride. Decationization of cane juice with ion exchange resins greatly reduces molasses formation but sucrose inversion is a concomitant problem.182... 

Ethanol fermentation can be conducted on any carbohydrate-rich substrate. Molasses, which is the waste mother liquor that remains after the crystallization of sucrose in sugar mill operations, is widely used. Blackstrap molasses contains 35-40 percent sucrose and 15-20 percent invert sugars (glucose and fructose). High-test molasses contains 22-27 percent sucrose and 50-55 percent invert sugars. Most of the blackstrap molasses do not... 

Comments an equimolecular mixture of dextrose and fructose prepared by the hydrolysis of sucrose with a suitable mineral acid such as hydrochloric acid. Invert sugar may be used as a stabilizing agent to help prevent crystallization of sucrose syrups and graining in confectionery. A 10% aqueous solution is also used in parenteral nutrition. 

The aroma compounds should therefore be incorporated into a sucrose glass. (The chance that compound crystals of sucrose and aroma components can be formed is very small.) The sugar can be melted, mixed with the aroma compounds, and then cooled to below Tg. However, owing to its high melting temperature (192°C Table 16.1), the sucrose will show caramelization and browning, which is presumably undesirable moreover, aroma compounds may be lost or broken down. 

There are many components in foods that crystallize, either partially or completely (Hartel 2001). Most important are sugars (sucrose, lactose, glucose, and fructose), ice, lipids, and starches. However, crystallization of salts, sugar alcohols, organic acids, proteins, and emulsifiers may be important in certain applications. Table 13.1 lists some of the main crystallizing components in foods with some examples of products where controlling this crystallization is important. 

The process of making sugar depends on the source from which it is extracted. With sugar cane, the plant stalks are crushed to obtain the sweet juice they contain. The juice is treated with lime to remove impurities and then boiled until the juice thickens into a syrup. Evaporation of the syrup produces crystals of sucrose. Juice remaining after the evaporation step is sold as molasses. Stalks remaining after the juice has heen extracted can he used as a fuel in the plant s boilers. 

Although crystals of table salt (sodium chloride) and table sugar (sucrose) look very similar to the naked eye, the melting point of sucrose (186 "C) is several hundred degrees less than the melting point of sodium chloride (801 C). Explain. 

Reports on the crystallization of sucrose (41 pp.). on the solubility of sucrose in pure water, sugar-containing water and some other solvents (24 pp.) and on the rheological properties of pure and impure sucrose solutions and suspen-sions(28 pp.) have been published. 

Kishihara S, Wakiuchi N, Hosokawa T, Fnjii S, Tamaki H. Clarification of sugar solution by nltrafiltration. Effect on crystallization of sucrose. Proc. Res. Soc. Jpn. Sugar Refineries Technol. 1997 45 1-14. 

Another food industry residue that has been investigated is molasses, the residue left after the crystallization of sucrose from sugarcane juice. The material can be stored in its concentrated form for long time periods and can be diluted to the optimum sugar content prior to use. Normally, very little nutrient supplementation is required for the conversion of molasses. Afschar et al. (1991, 1993) found that K. oxytoca could ferment molasses at high concentrations. In one batch experiment, quantities of molasses as high as 280 g/L was converted to 118 g/L of 2,3-BD. 

Rock candy is composed of large crystals of sucrose (sugar, C 20,H22). A ball-and-stick model (C = black,... 

In the production of sucrose from sugar beets (cf. 19.1.4.1.2), the enzymatic preparation from Mortiella vinacea hydrolyzes raffinose and, thus, improves the yield of granular sugar in the crystallization step. Raffinose in amounts >8% effectively prevents crystallization of sucrose. 

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