Xylitol: A Review on Bioproduction, Application, Health Benefits, and Related Safety Issues

Abstract

Xylitol is a pentahydroxy sugar-alcohol which exists in a very low quantity in fruits and vegetables (plums, strawberries, cauliflower, and pumpkin). On commercial scale, xylitol can be produced by chemical and biotechnological processes. Chemical production is costly and extensive in purification steps. However, biotechnological method utilizes agricultural and forestry wastes which offer the possibilities of economic production of xylitol by reducing required energy. The precursor xylose is produced from agricultural biomass by chemical and enzymatic hydrolysis and can be converted to xylitol primarily by yeast strain. Hydrolysis under acidic condition is the more commonly used practice influenced by various process parameters. Various fermentation process inhibitors are produced during chemical hydrolysis that reduce xylitol production, a detoxification step is, therefore, necessary. Biotechnological xylitol production is an integral process of microbial species belonging to Candida genus which is influenced by various process parameters such as pH, temperature, time, nitrogen source, and yeast extract level. Xylitol has application and potential for food and pharmaceutical industries. It is a functional sweetener as it has prebiotic effects which can reduce blood glucose, triglyceride, and cholesterol level. This review describes recent research developments related to bioproduction of xylitol from agricultural wastes, application, health, and safety issues.

Acute Hepatic Failure in a Dog after Xylitol Ingestion

“…It is incompletely absorbed in the stomach and upper gastrointestinal tract by an amount of 20-30 % less than that of glucose [1]. Absorption and peak plasma levels occur within 3-4 h in humans, yet, peak plasma levels are rapidly reached within 30 min in dogs [8].…”

“…Xylitol, a pentahydroxy sugar alcohol, with a sweetness index similar to sucrose [1], was first discovered by a German scientist named Emil Fisher in 1891 [2]. It occurs naturally in many fruits and vegetables, such as strawberries, raspberries, plums, and lettuce [1], and is manufactured by extracting xylan (a polysaccharide found in hardwoods), hydrolyzing xylan to monosaccharide units (D-xylose), and then hydrogenating the D-xylose to produce xylitol [3].…”

“…It occurs naturally in many fruits and vegetables, such as strawberries, raspberries, plums, and lettuce [1], and is manufactured by extracting xylan (a polysaccharide found in hardwoods), hydrolyzing xylan to monosaccharide units (D-xylose), and then hydrogenating the D-xylose to produce xylitol [3]. A sucrose shortage during World War II caused an increased production and use of xylitol.…”

“…A sucrose shortage during World War II caused an increased production and use of xylitol. Its popularity was short lived, however, and use decreased after the war when sucrose was once more available and the need for extensive purification made continued production costly and time consuming [1]. The use of xylitol resurfaced in the 1970s when it was found not only to be an excellent sweetener, but also have numerous health benefits.…”

“…Xylitol has been shown to be anticariogenic and has antimicrobial properties against common oral bacteria, which make it a popular addition to gums and candies [1,4]. It has a low glycemic index and requires few carbohydrates for metabolism, as seen with its lower calorific value, 2.4 kcal/g compared with 4.0 kcal/g for sucrose, making it an ideal sweetener for diabetics [5].…”