DETERMINATION OF CALCIUM, IRON AND PHOSPHORUS IN FERMENTED SOY PRODUCT OBTAINED BY ULTRAFILTRATION

The aim of this study was to obtain a fermented soy product from a concentrate of soy milk, using ultra filtration to achieve the total solids content required for yoghurt production of (12-14 % w/w). Another proposal was to evaluate the use of X-ray fluorescence as a technique to quantify the content of Ca, Fe and P and the final distribution by the tested process. The analytical determinations were conducted on soy milk, concentrate, permeate and fermented product using X-ray fluorescence wavelength dispersive (WDXRF). Results showed that these elements are concentrated by the membrane through association with proteins, maintaining the contribution of minerals of the product. In addition, it was shown that the analytical tool used allows a direct determination on the samples, avoiding the pre-treatment required by other conventional techniques.