Fermentation for Polyols

What are Polyols

Polyols are sugar alcohols naturally occurring in certain fruits, vegetables and sugar-free sweeteners, and are formed through the catalytic hydrogenation of carbohydrates. For example, sorbitol (glucitol) is found in fruits such as strawberries, and mannitol is also found in various kinds of algae. Polyols currently produced industrially include compounds like glycerol, erythritol, xylitol, sorbitol, mannitol, hydrogenated starch hydrolysates and some other special compounds like maltitol or lactitol.

Fig 1. Chemical structures of polyols. (Tyler, C. A.; et al. 2016)

Application of Polyols in Food Industry

Polyols are widely used as a component of chemicals, resins, food, drugs, cosmetics, etc. In general, polyols are produced by certain bacteria, fungi, yeasts and algae, and they have been widely used in the food industries due to their unique physicochemical properties. Polyols are an attractive alternative to sucrose because they provide fewer calories per gram, and are not associated with an elevated blood glucose response.

Advantages of Fermentation in Polyols Production

Polyols can be produced today at a millions of tons scale by hydrogenation or fermentation of carbohydrates from renewable raw materials. Compared to chemical synthesis method, the fermentation method is more practical because it is a very simple process and requires less time, allowing the use of less expensive materials such as glucose that can be used as a substrate of some species of fungi and yeasts such as Moniliella, Trigonopsis or Torulopsis. For example, during the fermentation process, erythritol can be continuously produced and accumulated in a medium containing glucose or sucrose.

Fermentation Techniques for Polyols Production

In the food industry, polyols are used as natural sweeteners for light and diabetic foods. In the last decade, biotechnology production methods for polyol by lactic acid bacteria (LAB) has been investigated, in which heterofermentative LAB can naturally produce mannitol and erythritol under specific culture conditions.

Nowadays, the production of erythritol by biofermentation techniques has become increasingly important due to the increasing demand for erythritol as a low-calorie sweetener in the food industry. The Y. lipolytica strain DSM70562 has been reported to be capable of fermenting from glucose for the production and optimization of erythritol. A series of fermentation conditions including carbon source, nitrogen source, temperature and initial pH were optimized to achieve the maximum yield of erythritol.

During the solid state fermentation (SSF), high concentrations of glycerol, erythritol and arabinitol accumulated on whole wheat grains or wheat dough containing Aspergillus oryzae. The mycelium of A. oryzae accumulated various polyols at low water activity and contained at least four different polyol dehydrogenases, with the highest activities for glycerol, erythritol, D-arabinitol and mannitol.

In addition, polyols can also be produced by fermentation of sugars. Polyols, especially glycerol and erythritol, can be obtained by fermenting sugars with Moniliella tomentosa. In order to avoid or minimize the contamination problems. The pH of the fermentation broth was carefully controlled, and the whole process was also improved by adding conventional defoamers to the fermentation medium. In the fermentation process, yeast extract, urea or corn steep liquor can be employed as nitrogen sources.

Our Services

BOC Sciences provides fermentation CDMO service for polyols. With a well-established strain cultivation platform and strong fermentation capability, we produce polyols through microorganisms. We are committed to providing quality services and products to our customers.

Workflow of Our Service

Reference

Tyler, C. A.; et al. A Systematic Review of the Effects of Polyols on Gastrointestinal Health and Irritable Bowel Syndrome. Applied Microbiology International. 2016. 120(5): 1336-1345