RSC Advances View Article Online REVIEW View Journal | View Issue Products of sugar beet processing as raw materials for chemicals and biodegradable polymers Cite this: RSC Adv.,2018,8,3161 a b a c c J. Tomaszewska, D. Bielinski,´ M. Binczarski, J. Berlowska, P. Dziugan, d e a J. Piotrowski, A. Stanishevsky and I. A. Witonska´ * This paper presents an overview of alternative uses for products of sugar beet processing, especially sucrose, as chemical raw materials for the production of biodegradable polymers. Traditionally, sucrose has not been considered as a chemical raw material, because of its use in the food industry and high sugar prices. Beet pulp and beetroot leaves have also not been considered as raw materials for chemical production processes until recently. However, current changes in the European sugar market could lead to falling demand and overproduction of sucrose. Increases in the production of white sugar will also increase the production of waste biomass, as a result of the processing of larger quantities of sugar beet. This creates an opportunity for the development of new chemical technologies based on the use of products of sugar beet processing Received 25th November 2017 as raw materials. Promising methods for producing functionalized materials include the acidic hydrolysis of Creative Commons Attribution 3.0 Unported Licence. Accepted 3rd January 2018 sugars (sucrose, biomass polysaccharides), the catalytic dehydration of monosaccharides to HMF followed DOI: 10.1039/c7ra12782k by catalytic oxidation of HMF to FDCA and polymerization to biodegradable polymers. The technologies rsc.li/rsc-advances reviewed in this article will be of interest both to industry and science. Introduction ever greater difficulties. Market projections for the year 2016/2017 indicate that sugar consumption in the EU will reach the Most sugar production in Europe is from sugar beets. Both the maximum ceiling, largely as an effect of health-education cultivation of sugar beets and sugar production processes are campaigns and activities aimed at reducing the amount of This article is licensed under a subject to strict regulation by the Common Market Organisa- sugar in the diet.3 Another problem facing European sugar tion, including quotas, minimum sugar prices and import producers is the inux of cheap cane sugar. Sweeteners are also volumes. This unique legal regulatory system was introduced in likely to become more competitive.4 Food manufacturers will Open Access Article. Published on 17 January 2018. Downloaded 9/30/2021 2:38:00 AM. 2006,1 with changes beginning in 2013. In autumn 2017, the probably use more high-fructose corn syrup (HFCS), which has current production quotas, which guarantee minimum prices several advantages over conventional sugar, in terms of taste, for sugar, will be abolished. This will cause dramatic changes in stability, freshness and consistency. The potential effects of these the European sugar market, in particular regarding the trends can already be observed in the USA, where HFCS is the competitiveness of EU producers. These changes are intended predominant sweetener used in beverages, sauces and other food to end the predominance of the largest manufacturing products.5 Finally, with the loosening of EU restrictions, the companies, which have plants in several EU Member States export of white sugar will no longer be subject to tight limitations. simultaneously, and to allow even small entrepreneurs to The most competitive companies therefore intend to increase survive in the market.2 export production and look for new markets. However, these Consumption of sugar in the EU is rising steadily, mainly as actions will have very low protmargins,andgrowthwillbe a result of increasing immigration and the growing population of achieved by optimizing processes, rather than through additional Europe. However, sugar beet growers and sugar producers face investment. Less competitive manufacturers are likely to be eliminated or absorbed by the more powerful companies. The market is thus becoming increasingly difficult for aInstitute of General and Ecological Chemistry, Lodz University of Technology, 116 producers of white sugar derived from sugar beet. An alternative Zeromskiego Street, Lodz 90-924, Poland. E-mail: [email protected]; Tel: use of white sugar is for the production of bioethanol. However, +48 42 631 30 94 in 2015 the competitive market conditions made the European bInstitute of Polymer & Dye Technology, Lodz University of Technology, 12/16 Stefanowskiego Street, Lodz 90-924, Poland bioethanol industry based on white sugar and sugar beet juice cInstitute of Fermentation Technology and Microbiology, Lodz University of fermentation economically unpro table. Reasons for this Technology, 171/173 Wolczanska Street, Lodz 90-924, Poland included a reduction in petroleum prices and the falling price of dNational Sugar Company S.A., 12 John Paul II Avenue, Warsaw 00-001, Poland cereals, from which bioethanol is also produced. It is estimated eDepartment of Physics, University of Alabama at Birmingham, Birmingham, AL 35294, that, unless petroleum prices rise signicantly, levels of USA This journal is © The Royal Society of Chemistry 2018 RSC Adv.,2018,8,3161–3177 | 3161 View Article Online RSC Advances Review bioethanol production from white sugar or sugar beet juice will discovery was not acted upon. Half a century later, in 1747, the at best remain stable.4 German chemist Andreas Marggraf demonstrated that the sugar Producing larger quantities of white sugar will also result in crystals formed in a water solution of sugar beet juice were identical the production of more bio-waste from technological processes. with sugarcane crystals. His student, Karl Achard, then developed This requires the development of new technologies for using an industrial process for extracting sugar from beets. This was the waste from sugar factories, in addition to uses as feed or green beginning of the sugar production from sugar beets in Europe.6 manure in agriculture. Sucrose is extracted from sugar beet using hot water. This In view of the current and projected changes in the sugar results in raw juice, which is then puried, ltered and concen- market, producers are looking at developing alternative busi- trated by cyclic rinsing and evaporation. To obtain the nal ness models. This is a task not only for sales and marketing product, the thick juice is crystallized. The resulting white sugar specialists, but also for chemists, bio-technologists and inno- is then recrystallized, which ultimately leads to the production of vators, who may be able to nd unconventional applications for high quality rened sugar (Fig. 1). Various sugar beet products sucrose. For economic reasons, sucrose has never been are produced at different stages of beet processing. The by- considered as a chemical raw material. However, in the context product, which contains a large amount of water, comprises up of falling prices and surplus capacity in the sugar industry, to 75% of the beet pulp. This is used as a heat source and, sucrose could be used in the production of valuable chemical circulating in a closed system, can be used repeatedly to provide compounds, such as biodegradable polymers. a large proportion of the heat demands of a sugar production line. Following the extraction of sucrose, the sugar beet pulp and beet splinters are used primarily in animal feed or biogas By-products obtained from the production. Attempts are also being made to use beet leaves in sucrose manufacturing processes the production of methanol.7 Aer the centrifugation of the thick syrup (the nal process of sugar production), the molasses ob- Creative Commons Attribution 3.0 Unported Licence. The fact that beet roots contain sugar was discovered in 1705 by tained are used mainly for the production of alcohol, in animal Oliver de Serres, the famous French agronomist. However, the feed, or as a medium for yeast biomass production.8 This article is licensed under a Open Access Article. Published on 17 January 2018. Downloaded 9/30/2021 2:38:00 AM. Fig. 1 Simplified scheme for the production of sugar from sugar beet. 3162 | RSC Adv.,2018,8,3161–3177 This journal is © The Royal Society of Chemistry 2018 View Article Online Review RSC Advances Sugar products can be processed in a variety of ways, to principally CH4,CO2 and N2,H2S, NH3), biogas rich in produce not only sugar for food or feed additives but also valu- hydrogen, bioethanol, biobutanol and lactic acid.16–19 The able chemicals that can be used in biofuels, synthetic materials biotechnological transformation of biomass requires appro- and pharmaceuticals.9 For example, raw sugar beet juice is priate pre-treatment, involving mechanical, physico-chemical, considered an attractive feedstock for ethanol fermentation, due enzymatic or chemical steps, to obtain a mixture of sugar to its high fermentable sugar content. Ozonation is an effective products that can serve as a microbiological medium. The way to stabilize new kinds of fermentation media used in the result of enzymatic hydrolysis is a complex mixture of sugars. biotechnological production of liquid fuel additives.10 Ethanol In the case of chemical hydrolysis, non-sugar products, which obtained in this way is relatively inexpensive and can be used as are oen fermentation inhibitors, are also included in the a fuel or fuel additive. Hydrolysates of sucrose are also being hydrolyzate (Fig. 2). The use of sucrose in biotechnological considered as alternative raw