Sucrose sources

Methods. Oat straw harvested in 1967 was treated with NaOH according to the method previously described. Eight female Cheviot lambs were used in this experiment which was designed to substantiate the results obtained in Experiments II and III, and to test in addition the effect of supplementation of straw with a soluble carbohydrate (sucrose) source. This experiment was designed as a 2 X 4 factorial with the effect of treatment (untreated vs. NaOH-treated) compared with four different supplementations (none, sucrose, urea, sucrose + urea). One sheep was fed each of the eight treatment combinations in each replicate, with six replicates constituting the experiment. As in the previous experiments, urea was added at a 2.5% level. Sucrose was added at a 3.5% level in three of the replicates, and an approximately equivalent amount of sucrose was supplied from a 7.0% level of molasses in the other three replicates. The percent of supplements added thus varied from 0-9.5% with the remainder of the ration (91.5-100%) consisting of treated or untreated straw. 

Maize juice produced from com starch, which has received considerable attention as a sucrose source, has been snccessfully deionized by conventional treatment with the result that improved sugar recoveries are possible. In the manufacture of dextrose, the organic acids and colored substances produced as degradation products during starch hydrolysis were eliminated economically by the use of the ion-exchange process to produce a high-quality sugar. 

Figure 3. Fiber precursors from sucrose (Source Private communication from both former and present associates of Merk and Co.)...

Starch deposition begins in the region of the furrow (the region nearest the sucrose source) after cell division in the endosperm ceases. The young endosperm cells have prominent nuclei, numerous mitochondria, endoplasmic... 

Figure 16.7 The depression of the freezing temperature of water is a iinear function of the concentration of glycerol (o), dextrose ( ), and sucrose ( ). Source CH Langford and RA Beebe, The Development of Chemical Principles, Dover Publications, New York, 1969.

An in vitro ensymatic synthesis of sucrose was carried out ia 1944 (5). A successful chemical synthesis was performed by Lemieux and Huber (6) ia 1953 from acetylated sugar precursors. However, the economics and chemical complexities of both processes make them unlikely sources of supply. 

Sugarcane is cultivated ia tropical and semitropical regions, eg. Central and South America, Cuba, India, AustraUa, Africa, and the Ear East. Sugarbeets are grown ia more temperate climates such as North America, Europe, and the former Soviet Union. In some nations, eg, the United States, China, and Japan, sucrose is produced from both sources. 

I onsucrose Components from Storage or Damag e of Beets. Some nonsucrose components are associated with the conditions under which the beets have been stored prior to processing, as respiration products or products of microbial attack In either case they direcdy and indirectly reduce sucrose yield and may cause other processing problems. Glucose and fmctose have already been discussed and can derive from either source. 

The most familiar of all the carbohydrates is sucrose—common table sugar. Sucrose is a disacchar ide in which D-glucose and D-fructose are joined at then anomeric carbons by a glycosidic bond (Figure 25.7). Its chemical composition is the same ine-spective of its source sucrose from cane and sucrose from sugar beets are chemically identical. Because sucrose does not have a free anomeric hydroxyl group, it does not undergo mutarotation. 

The yield was highest with starch or dextrin, intermediate and about the same with sucrose, glucose, maltose and lactose and poorest with glycerol. Kanamycin was produced by media containing soybean meal, peanut meal, cottonseed meal, corn steep liquor, peptone, yeast extract or meat extract, with or without sodium nitrate. Commercially available soybean meal was recognized to be one of the best nitrogen sources. The addition of corn steep liquor, peptone, yeast extract or nitrate to the soybean meal promoted the production of kanamycin. 

In more detail the nutrient medium used may contain sources of carbon such as starch, hydrolyzed starch, sugars such as lactose, maltose, dextrose, sucrose, or sugar sources such as molasses alcohols, such as glycerol and mannitol organic acids, such as citric acid and acetic acid and various natural products which may contain other nutrient materials in addition to carbonaceous substances. 

We can regard sucrose and starch as sources of glucose, for these react with water to form glucose in the body ... 

In Japan Chlorella spp has been produced for food in continuous aseptic systems in conventional bioreactors. The organisms are grown in the dark as heterotrophs using sucrose (in the form of molasses) or glucose as carbon and energy source. Production has been 2,000-3,000 tonnes per year at a selling price of (US)10-22 kg 1 (1990 prices). This product is sold as a high-value health food. 

The carbon source affects oxygen demand. In penicillin production, oxygen demand for glucose is 4.9 mol 1 1 h-1. The lactose concentration is 6.7 mol 1 1 h 1, sucrose is 13.4 mol l-1 h. The yield of oxygen per mole of carbon source for CH4 is YQjC = 1.34, T0j/C for Paraffins = 1, and Y(> /c for hydrocarbon (CH20)n = 0.4. The mass transfer coefficient k,a is for gas-liquid reactions, and the film thickness where the mass transfer takes place is 8... 

In Table 2, different carbon sources were evaluated and it was foimd that each strain produced different amounts of PHAs. For example, Alcaligenes eutrophus or Rastonta eutropha prefers to use fructose (Khanna Srivastava, 2005). A. latus is in favour of sucrose (Grothe... 

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