Maria Soral-Smietana

Comparison of solubility of pea protein hydrolysate by three analytical methods

Pea protein hydrolysate was obtained by enzymatic hydrolysis with trypsin. The degree of hydrolysis (DH) was controlled by using the pH-stat method. Solubility of the trypsin-treated hydrolysate was tested at nine different pH values starting from 2 up to 10. Protein determinations were carried out using Kjeldahl, Lowry and modified Lowry methods. The results revealed that samples analysed with either the Kjeldahl or Lowry method gave similar values. However, systematic consistent differences existed for those results obtained by the Kjeldahl and the modified Lowry as well as between those results obtained by the Lowry and the modified Lowry.

Effect of acid whey-fortified breads on caecal fermentation processes and blood lipid profile in rats

Two types of diet - standard and atherogenic - were used to study the effect of wheat or wheat-rye breads supplemented with 20 % acid whey concentrate after ultrafiltration on the physiological response of growing rats. The acid whey concentrate after ultrafiltration used in rat diets caused reduced weight gain (for atherogenic diet with wheat bread); growth of caecum tissue and digesta weight; a decrease in the pH of caecum digesta (for atherogenic diet); reduced activity of bacterial glycolytic enzymes; and a significant increase in total SCFA for both types of diet with wheat-rye breads containing acid whey concentrate. For wheat bread with acid whey, in standard diet, a statistically significant increase was found in the population of bifidobacteria. The results showed that the acid whey concentrates could be used as a valuable food ingredient.