Sweeting process

Process flavourings for application in sweet and bakery goods (e.g. flavourings with chocolate, malt, caramel, egg, coffee or biscuit tonality) have been known for an even longer time than their savoury counterparts. Sulphur-containing aroma precursors such a cysteine are not the main concern of sweet process flavourings, and in many cases they even have to be avoided in order to prevent the formation of off-flavours. 

The Sweet Process or Alkaline Process is an older method of steeping than the sulphurous acid method. The nature of this process is indicated by the name. This method was in use for many years and is in use to some extent to-day. By this process the com was placed in large tanks of lukewarm water to Which alkali had been added. The com in these tanks of alkali was allowed to rot for several days. The putrefaction became very foul and only the starch was used as a commercial product. The remainder of the constituents of com were made useless by the alkali or were destroyed by the putrefaction. A starch of high purity was made by this process but the process was too foul and wasteful to be practiced to any extent. It should be noted that this process utilized a combination of the actions of alkali and of bacteria. Little starch was lost in this form of steeping due to the fact that bacteria are practically helpless in their attack upon the starch granule so long as the starch cellulose wall remains intact. 

See the boxed essay How Sweet It Is I for more on this process... 

The sweet water from continuous and batch autoclave processes for splitting fats contains tittle or no mineral acids and salts and requires very tittle in the way of purification, as compared to spent lye from kettle soapmaking (9). The sweet water should be processed promptly after splitting to avoid degradation and loss of glycerol by fermentation. Any fatty acids that rise to the top of the sweet water are skimmed. A small amount of alkali is added to precipitate the dissolved fatty acids and neutralize the liquor. The alkaline liquor is then filtered and evaporated to an 88% cmde glycerol. Sweet water from modem noncatalytic, continuous hydrolysis may be evaporated to ca 88% without chemical treatment. 

Exceptions to the simple definition of an essential oil are, for example, gadic oil, onion oil, mustard oil, or sweet birch oils, each of which requires enzymatic release of the volatile components before steam distillation. In addition, the physical process of expression, appHed mostly to citms fmits such as orange, lemon, and lime, yields oils that contain from 2—15% nonvolatile material. Some flowers or resinoids obtained by solvent extraction often contain only a small portion of volatile oil, but nevertheless are called essential oils. Several oils are dry-distiUed and also contain a limited amount of volatiles nonetheless they also are labeled essential oils, eg, labdanum oil and balsam oil Pern. The yield of essential oils from plants varies widely. Eor example, nutmegs yield 10—12 wt % of oil, whereas onions yield less than 0.1% after enzymatic development. 

The existence of protein receptors in the tongues of mice and cows have been shown. Monosodium L-glutamate MSG [142-47-2] is utilized as a food flavor enhancer in various seasonings and processed foods. D-Glutamate is tasteless. L-Aspartic acid salt has a weaker taste of umami. Glycine and L-alanine are slightly sweet. The relationship between taste and amino acid stmcture has been discussed (222). 

Early Synthesis. Reported by Kolbe in 1859, the synthetic route for preparing the acid was by treating phenol with carbon dioxide in the presence of metallic sodium (6). During this early period, the only practical route for large quantities of sahcyhc acid was the saponification of methyl sahcylate obtained from the leaves of wintergreen or the bark of sweet bitch. The first suitable commercial synthetic process was introduced by Kolbe 15 years later in 1874 and is the route most commonly used in the 1990s. In this process, dry sodium phenate reacts with carbon dioxide under pressure at elevated (180—200°C) temperature (7). There were limitations, however not only was the reaction reversible, but the best possible yield of sahcyhc acid was 50%. An improvement by Schmitt was the control of temperature, and the separation of the reaction into two parts. At lower (120—140°C) temperatures and under pressures of 500—700 kPa (5—7 atm), the absorption of carbon dioxide forms the intermediate phenyl carbonate almost quantitatively (8,9). The sodium phenyl carbonate rearranges predominately to the ortho-isomer. sodium sahcylate (eq. 8). 

Methyl salicylate is produced synthetically for commercial purposes by the esterification of salicylic acid with methanol or by extraction by steam distillation of wintergreen leaves or sweet birch bark. The source, natural or synthetic, is declared on the label. The methyl salicylate NF must assay not less than 98.0% and not more than 100.5% and be processed by Good Manufacturing Practice described in USP (20). 

Uses. High fmctose symp is used as a partial or complete replacement for sucrose or invert sugar in food appHcations to provide sweetness, flavor enhancement, fermentables, or humectant properties. It is used in beverages, baking, confections, processed foods, dairy products, and other apphcations. Worldwide HES production in the 1994—1995 fiscal year was estimated at about 8.6 x 10 t (dry basis) (18). About 75% of total world production is in the United States. 

Com symps [8029-43 ] (glucose symp, starch symp) are concentrated solutions of partially hydrolyzed starch containing dextrose, maltose, and higher molecular weight saccharides. In the United States, com symps are produced from com starch by acid and enzyme processes. Other starch sources such as wheat, rice, potato, and tapioca are used elsewhere depending on avadabiHty. Symps are generally sold in the form of viscous Hquid products and vary in physical properties, eg, viscosity, humectancy, hygroscopicity, sweetness, and fermentabiHty. 

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