Formation of L-Xylosone from Ascorbic Acid

Sugar Composition of Varietal Juices Produced from Fresh and Stored Apples

“…Fructose, glucose, sucrose, and the sugar-alcohol sorbitol are major components of apple juice. The minor sugar contents reported for apples or apple juice are as follows: 0.01-0.25 g/100 g D-xylose (Aso and Matsuda, 1951;Guichard, 1954;Siegelman, 1954; Ash and Reynolds, 1955;Whiting and Coggins, 1960;Buchloh and Neubeller, 1969; Chong et al, 1972; Mákinen and Soderling, 1980; Sharma etal., 1988;Chapman and Horvat, 1989; Prabha et al, 1990;Schols et al, 1991), trace-0.05 g/100 g galactose (Ash and Reynolds, 1955;Sharkasi, 1981; Sharma et al, 1988; Chapman and Horvat, 1989;Schols et al, 1991), 0.02-0.08 g/100 g raffinose (Chan et al, 1972; Chong et al, 1972), traces of arabinose (Wall and Hassan, 1965; Sharma et al, 1988;Schols et al, 1991), mannose (Guichard, 1954;Schols et al, 1991), rhamnose (Schols et al, 1991), and maltose (Lee et al, 1970(Lee et al, ,1972Prabha et al, 1990). It should be noted that xylose, arabinose, and galactose along with glucose, mannose, and rhamnose are noncellulosic components of cell walls in apples (Gross and Sams, 1984) and they are released upon acid (Garleb et al 1989; Prabha et al, 1990) or enzymatic (Schols et al, 1991) hydrolysis of apple fiber.…”

Sulphite binding in ciders

“…It is present at much higher levels in apple juice concentrates, where it results from deliberate enzymic depectinization, so its contribution to modern ciders is greater than in the past. L-xylosone results from the breakdown of naturally occurring ascorbic acid in apple juice in the presence of SO 2 during the prefermentation stage (Whiting & Coggins, 1960) ] little is known of its typical levels in modern cider making. The five carbonyls produced by microbial activity in mould damaged fruit are known to contribute significantly to sulphite binding but should not be present at all in good quality fruit.…”

Analytical techniques for the estimation of sulphite binding components in ciders and wines

“…The method originally given by Whiting & Coggins (1960), using iodine oxidation of ascorbic acid to dehydroascorbate followed by sulphite oxidation and decarboxylation to L‐xylosone, did not work satisfactorily in our hands. Following a literature reference by Shin & Feather (1990), and the gift of a small impure sample of L‐xylosone from Dr Feather, we investigated their procedure and found it more satisfactory.…”

“…Glucose and galacturonic acid (resulting from pectin breakdown) also contribute. A specific binder associated with ciders is L‐xylosone, which results from the breakdown of ascorbic acid in the presence of sulphite ( Whiting & Coggins, 1960). Other carbonyls with high binding power are those such as 5‐keto fructose and 2,5 diketo gluconate which result from the microbial activity associated with rotten fruit ( Burroughs & Sparks, 1973a, b, c)…”

“…Glucose and galacturonic acid (resulting from pectin breakdown) also contribute. A specific binder associated with ciders is L-xylosone, which results from the breakdown of ascorbic acid in the presence of sulphite (Whiting & Coggins, 1960). Other carbonyls with high binding power are those such as 5-keto fructose and 2,5 diketo gluconate which result from the microbial activity associated with rotten fruit (Burroughs & Sparks, 1973a, b, c) As part of a major project to understand these factors in fermented apple ciders (Jarvis & Lea, 2000), this paper describes: 1 the development of an high performance liquid chromatography (HPLC) methodology for analysis of carbonyl sulphite-binders; 2 the determination of experimental sulphite binding power by the measurement of free and total SO 2 after the addition of standard amounts of sulphite; 3 the use of the HPLC data for the calculation of predicted sulphite binding power; 4 the synthesis of the DNPH derivative of L-xylosone, which was required for this work but is unavailable commercially.…”