Fructose in fruit

T. Ikeda, F. Matushita and M. Senda, D-Fructose dehydrogenase-modified carbon paste electrode containing p-benzoquinone as a mediated amperometric fructose sensor, Agric. Biol. Chem. 54(11), 2919-24 (1990). (fructose in fruits). 

Another important biosensor feature to evaluate is susceptibility to electroactive interferents. In FDH electrode applications, such as the measurement of fructose in fruit juices or wine, the effects of ascorbic acid should be investigated. Ascorbic acid is oxidized quite readily at bare electrode surfaces. The blocking mercaptan layer of this system may have the advantage of hindering access of ascorbic acid to the electrode surface. Figure 4 illustrates the effect of 100 pM ascorbic acid on the measured current of a 2 mM fructose solution. The presence of ascorbic acid at 5% of... 

Extraction with 90 per cent ethanol precedes the determination of fructose in fruit. The ethanol is distilled off, and from the resulting aqueous solution the excess of acids is removed on an anion-exchange column. The fructose wave is recorded in the effluent after the addition of calcium chloride. 

D-fructose, C HijOo. Crystallizes in large needles m.p. 102-104 C. The most eommon ketose sugar. Combined with glucose it occurs as sucrose and rafftnose mixed with glucose it is present in fruit juices, honey and other products inulin and levan are built of fructose residues only. In natural products it is always in the furanose form, but it crystallizes in the pyranose form. It is very soluble in... 

Fructose is a sugar commonly found in fruit. A sample of fructose,... 

Glucose is the simplest carbohydrate. It is found in grapes and corn syrup. Fructose gives fruit its sweet taste. A condensation reaction between glucose and fructose produces sucrose, commonly called table sugar. Sucrose is found in sugar cane and sugar beets. 

Phosphoric acid esters of the ketopentose D-ribulose (2) are intermediates in the pentose phosphate pathway (see p.l52) and in photosynthesis (see p.l28). The most widely distributed of the ketohexoses is D-fructose. In free form, it is present in fruit juices and in honey. Bound fructose is found in sucrose (B) and plant polysaccharides (e.g., inulin). 

Fructose, another common monosaccharide found in fruits and honey, is more soluble in water than glucose and is also sweeter than glucose. It is used as a sweetener for diabetic patients, and in infusion for parenteral nutrition. 

Monosaccharides Glucose and fructose are the principal mono saccharides found in food. Glucose is abundant in fruits, sweet corn, corn syrup, and honey. Free fructose is found together with free glucose and sucrose in honey and fruits... 

Analyses of glucose and fructose in musts of commercially processed fruit have been made for several years (18). Glucose oxidase (Worthington Glucostat reagent) has been the method of choice for glucose analysis. Acid diphenylamine reagent (24), which is specific for the keto... 

D-fructose 102 -92.4 Free in fruit juices and honey combined as in sucrose and plant polysaccharides. 

The second method, using refractive index (RI) detection, is carried out using a resin-based polymer column. Sucrose elutes first from this column, followed by glucose, fructose and then sorbitol. This type of column is generally more robust than the amino-bonded column and if handled well will last much longer however, it is around three times more expensive. The method has been collaboratively tested for the analysis of sugars and sorbitol in fruit juices by the IFU. The HPLC conditions are given below. 

Matsumoto et al (41) prepared a multi-enzyme electrode using glucose oxidase, invertase, mutarotase, fructose-5-dehydrogenase, and catalase to simultaneously detect glucose, fructose, and sucrose in fruit juices and soft drinks. Detection of multi-components by enzyme sensors was also reported in analysis of sucrose and glucose in honey (42) and drinks (43), and L-malate and L-lactate in wines (44). 

Paredes et al. [15] Fructose Honey Fruit juices Soft drinks D-PQQ-fructose dehydrogenase/physically included in the electrode matrix, also containing mediator and polyethyleneimine (PEI) Carbon paste electrode/ 0.1 V vs. Ag/AgCl Os(bpy)2Cl2 (included in the electrode matrix)... 

Other common monosaccharides are fructose, the sugar found in fruits and honey that is also used as a preservative in foodstuffs, and galactose, found in milk sugar. Sucrose, or table sugar, is a disaccharide made up of glucose and fructose molecules bonded together. The chemical names of sugars always end in -ose. ... 

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. 

D-Fructose (I), also known as levulose and fruit sugar, occurs abundantly and widely in nature. In the free state it is found in fruits,... 

Fructose, fruit sugar, CgHi20g, is nonvolatile and nonionic. For a 2.46 m solution of fructose in water, calculate ... 

Table sugar, sucrose, is just one of a family of natural sugars for example, fructose (found in fruits), glucose (found in corn), and lactose (found in milk). Fructose has now become the sweeteneriof choice because of catalysis. 

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