Technology for Production of Fluoride Enriched Beer
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Journal of the UniversityG. Yonkova, of Chemical A. Surleva, Technology T. Ginova-Stoyanova and Metallurgy, 47, 1, 2012, 53-58 TECHNOLOGY FOR PRODUCTION OF FLUORIDE ENRICHED BEER G. Yonkova, A. Surleva, T. Ginova-Stoyanova University of Chemical Technology and Metallurgy, Received 15 September 2011 8 “Kl. Ohridski” blvd, 1756 Sofia, Bulgaria Accepted 20 January 2012 E-mail: [email protected] ABSTRACT The production of protective foods has gained mush research attention recently due to their ability to reduce the level of radio contamination of human organism. Usually protective foods are widely used foods or drinks specifically designed to have decontaminative properties. The present work proposes a technology for production of fluoride enriched beer with radio protective properties. Naturally fluorinated mineral water was used as a source of fluoride. A mixture of fluorinated mineral and tap water in ratio 1:1 was used and pH adjustment with citric acid was applied during the mashing-in process. Fermentation of the fluoride enriched wort normally occurred. A 17 % decrease of fluoride content during the brewing process was observed. The fluoride enriched beer produced by the proposed technology met the physicochemical and sensory standards. Keywords: fluoride, wort, beer, decorporation, radio protection. INTRODUCTION 3) altered products obtained by replacing the exciting components with beneficial components; 4) Enhancing natural radio resistance of human or- enhanced commodities changes in the raw commodi- ganism by food has gained much researchers attention ties that altered the nutrient composition. in the functional food industry [1]. Functional food is a The term protective food or drink stands for natural or processed food or beverage that contains known a functional dietary product reducing the level of ra- biologically active compounds which when in defined dio contamination in two ways [4,5]: quantitative and qualitative amounts provides a clinically a) decorporation cleaning of the body of ra- proven and documented health benefit [2]. Different types dionuclide contaminants; of functional food have been defined [3]: b) hindering the radionuclide contaminant ad- 1) fortified products obtained by increasing sorption. Usually it is produced by fortifying a widely the content of exciting nutrients; used food by an appropriate decorporative agent. The 2) enriched products obtained by adding new radioprotective agents minimise or prevent the dam- nutrients or components not normally found in a par- age from radiation exposure caused by nuclear power ticular food; facility, food radiation or other devices that releases 53 Journal of the University of Chemical Technology and Metallurgy, 47, 1, 2012 radiation [6,7]. Protective food and drinks are effec- tive radio prophylaxis means due to the possibility for application to large groups of people for extended pe- riods of time. The annual consummation of beer in Bulgaria is around 70 litres per person and the drink is considered as the most consumed [8]. Moreover, it is known that the beer enhances the excretion function of kidneys and thus intensifies the elimination of toxins from the body. Hence, beer could be used in the radionuclide prophy- laxis if an appropriate agent could be found. Fluoride is well recognised as an essential micro- nutrient which participates in tooth and bone building. Fig. 2. Number of suspended cells in the control (n) and the Humans obtain fluoride mainly from their diet. All of the experimental (l) worts. fluoride available in water reaches the blood cycle. In con- trast, between 50 - 80 % of food fluoride is absorbed by human organism [9]. Furthermore, it was proved that fluoride lowers the bodys radioactive contamination and thus acts as a radionuclide decorporation agent espe- cially for cerium and strontium [10-12]. It was estab- lished that the decorporation activity of fluoride is higher if naturally fluorinated waters are used. The content of fluoride in mineral waters is between 5 and 25 mg dm- 3. Usually water is considered as mineral when it con- tains various soluble substances at high concentrations and its temperature in the spring is above 20oC [13,14]. Due to the biological activity of the micronutri- ent and the drink, fluoride containing beer can be ex- Fig. 3. Apparent extract of the control (n ) and the pected to have a radio protective activity. As water is a experimental (l) worts. basic beer ingredient, it was supposed that a higher ef- fect can be achieved if the fluoride containing mineral water was used in brewing. As we reported previously, mineral water spoiled the quality of the obtained wort and the mashing technology had to be modified [15]. The present study is aimed at developing a tech- nology for production of fluoride enriched beer with potential radio protective properties. As water influences the quality of the produced beer, the characteristics of the products have been carefully examined in every stage of the brewing process. EXPERIMENTAL Fluoride containing mineral water from the Fig. 1. pH decrease during the fermentation of the control Blagoevgrad region was used. Composition of used n l wort ( ) and the experimental wort ( ) obtained using tap mineral and tap water is presented in Table 1. A mix- and mineral water in ratio 1:1 54 G. Yonkova, A. Surleva, T. Ginova-Stoyanova Fig. 4. Fluoride concentration at different stages of the brewing process. ture of mineral and tap water in ratio 1:1 was used. Yeast strain Saccharomyces carlsbergensis was The mashing-in pH adjusted by citric acid was 5.4. used in the fermentation at temperature 9oC. Yeast propa- Wort was produced from malt with 5.3 % of gation was 15 - 20x106 cells cm-3. Beer maturation took moisture; 78.7 % of grist extract; 12.6 % proteins and place at 4oC. Apparent extract, temperature, concentra- 142 mg dm-3 α-amine nitrogen. The saccharizification tion of suspended yeast cells and active acidity of the time was 10 - 15 min, colour was 3.5 EBC and viscosity wort were controlled daily during the fermentation pro- 1.64 mPa s. cess. A single-step mash decoction method was used. Standard analytical methods for beer quality as- Sparing water was at the same composition as in the sessment were used according to the European Brew- mashing. The wort was produced by boiling with á-bitter ing Convention [16]. The fluoride concentration was acids containing hop products (90 mg dm-3). 70 % of hops determined at every stage of the brewing. A protocol were added 15 minutes, and 30 % of hops were added 45 for ion-selective potentiometric determination of fluo- minutes, after the start of the boiling process. The over- ride in mineral water, wort and beer has been devel- all procedure continued 105 minutes. oped [17]. Sample was acidified with HCl before analy- Table 1. Chemical composition of the used water. parameter tap water mineral water pH 6.7 8.5 calcium hardness, oH 1.0 0.1 magnesium hardness, oH 1.4 0.2 carbonate hardness, oH 2.6 13.0 residual alkali 2.2 12.9 Ca2+, mg dm-3 14.4 2.0 Mg2+, mg dm-3 3.9 1.6 F-, mg dm-3 0.3 11.5 55 Journal of the University of Chemical Technology and Metallurgy, 47, 1, 2012 Table 2. Physicochemical characteristics of the control wort and the fluoride enriched wort. parameter control worth experimental worth pH 5.25 5.58 colour, EBC 8.0 8.5 viscosity, mPa s 1.72 1.71 α-amine nitrogen, mg dm-3 157 136 final degree of fermentation, % 78.0 79.1 bitterness, BU dm-3 24.6 25.8 fluoride concentration, mg dm-3 0.11 5.0 Table 3. Characteristics of the fluoride enriched beer. parameter control beer fluoride enriched beer alcohol, % 2.84 2.96 apparent degree of fermentation, % 76.7 79.1 final degree of fermentation, % 78.0 79.1 colour, EBC 5.5 5.5 pH 4.1 4.4 bitterness, BU dm-3 16.2 17.0 fluoride concentration, mg dm-3 0.11 4.75 sis to dissolve any formed CaF . 15 ml of filtered and the wort, influencing the pH of the mash and the wort. 2 acidified sample was thoroughly mixed with 15 ml of The higher alkalinity of the mash hindered the activity mixture of 0.25 M Na Cit and 1 M NaCl. Natrium cit- of the enzymes and affected negatively starch hydroly- 3 rate was used as a masking and buffering agent and NaCl sis. The incomplete starch degradation lowered the fi- as an ionic strength adjustor. Potential of the potentio- nal degree of fermentation. Moreover, higher pH of the metric cell (fluoride selective and silver/silver chloride mash, of the sweet wort and of the sparing waters en- reference electrodes) was measured before and after stan- hance the extraction of some undesirable substances such dard addition of NaF. Method accuracy and precision as polyphenols from malt flakes, thus spoiling the qual- were 4% and 1,7 %, respectively. ity of wort and beer. We tested some technological so- lutions: (1) a mixture of tap and mineral water in ratio RESULTS AND DISCUSSION 1:1 was used and (2) pH and hardness adjustment was applied adding citric acid during mashing-in. The fluo- Mashing and wort production ride content of the mineral water was lowered after di- Our previous study had shown that higher re- lution with tap water, thus achieving the health levels sidual alkali and carbonate hardness of the mineral water recommended by authorities [18]. Additionally, a de- from the region of Blagoevgrad had a negative effect on crease of the fluoride content during the mashing pro- 56 G. Yonkova, A. Surleva, T. Ginova-Stoyanova cess was observed. The final concentration of fluoride was 17 %. The final fluoride concentration in beer was in the cold wort was 5 mg dm-3.