Sugars in fruits

The sugars in fruits such as grapes are feimented by yeasts to produce wines. In winemaking, lactic acid bacteria convert malic acid into lactic acid in malolactic fermentation in fruits with high acidity. Acetobacter and Gluconobacter oxidise ethanol in wine to acetic acid (vinegar). 

Carbohydrates Sugars, starch, cellulose Structural components of plant cells easily released energy storage in plants and animals Sugars in fruits starch and cellulose in plants glycogen in animals below 1... 

Siddapa GS and Bhatia BS. 1954. The identification of sugars in fruits by paper chromatography. Indian J Hort 11 104. 

Carbohydrates Sugars, starch, ceiiuiose Structurai components of piant ceiis easiiy reieased energy storage in piants and animais Sugars in fruits starch and ceiiuiose in piants giycogen in animais beiow 1... 

There is evidence that the Greeks, Egyptians, Hebrews, Japanese, Chinese, and Russians made alcoholic beverages thousands of years ago. Alcohol (ethanol, ethyl alcohol, and grain alcohol) is produced by yeast fermentation of sugar in fruits and grains to make wine, beer, or a variety of alcoholic spirits, including gin, vodka, and scotch. 

Guillou, C., Koziet, J., Rossmann, A., and Martin, G. J. (1999). Determination of the 13C content of organic acids and sugars in fruit juices An inter-comparison study. Anal. Chim. Acta 388,137-143. 

Fructose is an abundant sugar in the human diet sucrose (table sugar) is a disaccharide which when hydrolyzed yields fructose and glucose (see Topic Jl) and fructose is also a major sugar in fruits and honey. There are two pathways for the metabolism of fructose one occurs in muscle and adipose tissue, the other in liver. 

The determination of sugars in fruits and other materials involves extraction of the sample with 80% ethanol, transfer of sugars into an aqueous phase with the aid of a chloroform—methanol—water system (64 32 24) and drying. The analysis is carried out on SE-54 or SE-52 stationary phase after silylation [424,425]. The concentrations of monosaccharides can similarly be determined in the course of a fermentation process [426] and, after hydrolysis, also in polysaccharides from cellular walls and apple tissues [427,428]. SE-30 served as a stationary phase for these analyses. 

Most of the energy that you get from food comes in the form of carbohydrates. For most of us, starch, found in such foods as potatoes, bread, and rice, is our major carbohydrate source. Sugars—in fruit, honey, candy, and many packaged foods—are also carbohydrates. Plants make carbohydrates, such as the starch in potato tubers, shown in Figure i. 

Chinnici, F., Spinabelli, U., Riponi, C., and Amati, A. 2005. Optimization of the determination of organic acids and sugars in fruit juices by ion-exclusion liquid chromatography. Journal of Food Composition and Analysis 18 121-130. 

Yeast cells ferment the sugars in fruits to produce ethanol and carbon dioxide. The anaerobic process must be carried out in tightly sealed containers such as these large tanks. One-way valves allow carbon dioxide to escape from the fermenting liquid without letting air in. ... 

A validated and collaborative study for the detection of beet sugar in fruit juices. SNIF-NMRREGISTERED Measurement of deuterium and carbon-13 levels. [68]... 

Because of the limited amount of sugar in fruit juices and the limits of alcoholic fermentation by yeasts, the amount of acetic acid in ordinary vinegar is kept down to from four to seven per cent. 

The sugar composition in A. chinensis fruit resembles that of Hayward. Glucose and fructose are the predominant soluble sugars in fruits of most A. chinensis genotypes (Esti et al, 1998). 

Kolhed, M. and Karlberg, B., Capillary electrophoretic separation of sugars in fruit juices using on-hne mid infrared Fourier transform detection, Analyst, 130, 772, 2005. 

Monosaccharides, oligosaccharides, uronic acid, especially o-glucose, D-fructose, sucrose Indirect UV detection D A = 256nm C Fused silica (90 cm x 50 pm i.d.) E 6 mmol r potassium sorbate, pH 12.2 V 20 kV Determination of sugars in fruit juices comparison of the results to those of liquid chromatography methods... 

Sugars A wide range of methods is available for the determination of sugars in fruit and fruit products. These include relatively simple refractometry and hydrometry techniques, polarimetry, copper(II) reduction, enzymatic/color detection, and various chromatographic techniques. These vary greatly in their sensitivity, specificity, and in the level of equipment and expertise required, and these considerations generally dictate the method chosen. 

Polarimetry The determination of sucrose and reducing sugars in fruit and fruit products by polarimetry is an AOAC recommended method. The polarimeter measures the rotation of plane polarized light caused by a solution containing an optically active compound. Separate measurements for the quantification of sucrose and reducing sugars can be made with the Clerget-Hertzfeld double-polarization method. 

Membrane contactors (MCs) are another interesting emerging membrane technology for desalination. MCs are devices that bring two phases (gas/liquid, liquid/liquid or liquid/gas/liquid) into contact at the entrance of pores (Fig. 2.1). MCs are today most commonly employed in the production of ultrapure water, wastewater treatments and water purification, as well as being used to control the concentration of several non-volatile solutes in aqueous solutions, such as salt and sugar in fruit juices and blood treatments. 

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