Study on the use of food emulsion and xanthan gum in the composition of yogurt with blended oil

Abstract

The work is to study the use of food emulsion and xanthan gum in the composition of a yogurt with blended oil. To obtain the yogurt with blended oil, we used skimmed cows milk, skimmed cows milk powder, and a food emulsion consisting of drinking water, blended oil (sunflower and linseed), sodium caseinate, and an emulsifier (a mixture of polyglycerol esters and higher fatty acids). Xanthan gum was used as a stabilizer. The control was yogurt obtained from dairy raw materials. The titrimetric method determined the titrated acidity, which is based on the neutralisation of acids contained in the investigational product with a sodium hydroxide solution in the presence of an indicator. The fatty acid content was determined by chromatographic. Organoleptic quality indicators were assessed by tasting and compared with standard indicators according to DSTU 4418. The number of viable lactic acid bacteria was determined by the method of sowing serial dilutions in agar nutrient media. Samples of the milk-vegetable sour-milk base with 2.0 %, 4.0 % and 6.0 % fat content were obtained by fermenting the milk-vegetable normalized mixture, consisting of a food emulsion, cow's skimmed milk and cow's skimmed milk powder. It had been established that for the minimum value of the titrated acidity of the sour-milk curd of the milk-vegetable sour-milk base of 80 °T to be achieved, the fermentation duration of the milk-vegetable normalized mixture is different compared to the fermentation duration of the milk normalized mixture. Thus, the fermentation duration of the milk normalized mixture and the milk-vegetable normalized mixture with 2.0 % fat content is 8.0 hours and 10.5 hours, respectively, 4.0 % - 8.5 hours and 11.0 hours, respectively, 6.0 % - 8.5 hours and 12.0 hours, respectively. The samples of the obtained milk-vegetable sour-milk base with 2.0 %, 4.0 % and 6.0 % fat content have the number of viable lactic acid bacteria of 1.0 × 107 that corresponds to the standard indicator for the traditional yogurt. For obtaining the yogurt with blended oil of a homogenous, fine, creamy, thick consistency, 0.15-0.20 % xanthan gum should be added to the milk-vegetable sour-milk base with 6.0 % fat content. The content of omega-3 and omega-6 polyunsaturated fatty acids in the yogurt with blended oil with 6.0 % fat content is 1.06 % and 5.44 %, respectively, which is a higher indicator in comparison with the traditional yogurt. The possibility of using a food emulsion as part of a yogurt-type product was established. The resulting yogurt with blended oil is characterized by normative indicators of titrated acidity, the number of viable lactic acid bacteria, organoleptic quality indicators and a high content of polyunsaturated fatty acids. The developed yogurt with blended oil will make it possible to expand the range of the milk-containing sour-milk products and it is recommended for the consumption as the finished product as well as for the use as the semi-finished product.