DETERMINATION OF VITAMINS AS ADDITIVES FOR FORTIFICATION OF REFRESHING SOFT DRINKS

Soft drinks are sweetened, based on water, usually contain a certain amount of fruit juice, fruit pulp or other natural ingredients and they have a balanced acidity. Their nutritional and energy value is derived mainly from the content of sugars, but besides them there are also mineral elements, vitamins, enzymes and amino acids in minor amounts. Soft drinks are classified as fruit juices and refreshing beverages. Refreshing beverages can be clear or with pulp. The main ingredient is water, then sugar or artificial sweetener, fruit juice or fruit base or plant based extracts or based on cereals, with addition of carbon dioxide and allowed additives in the prescribed amounts. In recent times a trend is to fortify the refreshing beverages with certain vitamins or minerals. Ascorbic acid is commonly added in food as an antioxidant and stabilizer. The vitamins from B group are water soluble and played a significant role in human metabolism. In addition, it is important to consider the amount of the microelements that are necessary to meet our daily needs as nutrients. The research was made on refreshing beverages fortified with vitamins. The analysis was made on 20 different beverages in 2014, 2015 and 2016. The quantitative determination of the water soluble and fat-soluble vitamins in the refreshing beverages was performed by using by HPLC-DAD method. The vitamin C was determined by iodometric method. In the examined samples were usually present the following water soluble vitamins: В1 (from 0.18 to 0.3 mg/100ml), В3 (from 2.40 to 3.20 mg/100ml), В5 (from 0.8 to 1.04 mg/100ml), В6 (from 0.20 to 0,37 mg/100ml) and the vitamin С (from 9.06 to 16.41 mg/100ml), and more rarely were present vitamin В2 (from 0.22 to 0.28 mg/100ml) and the liposoluble vitamin Е (from 0.7 to 1.33 mg/100ml).