Importância da parede celular de levedura (Saccharomyces sp.) como fonte de fibra na alimentação
The main objective of this investigation was to study the influence of 10 and 20% addition of yeast (Saccharomyces sp.) cell wall into a hypercholesterolemic (5% coconut fat plus 2% cholesterol) diet, on Wistar rats. The work is justified by the increasing amount of yeast generated as byproduct of the alcohol and brewer industries and the importance of yeast derivatives as functional ingredients in human foods. A casein standard reference diet (AIN-93G) with 5% cellulose as dietary fiber was used for comparison. Hypercholesterolemic diet with 10 and 20% addition of cellulose was also used. The following indices were determined: apparent digestibility and biological value, net apparent protein utilization, diet efficiency ratio, food intestinal transit velocity, small intestine length, and serum concentrations of total lipids, triacylglycerols and total cholesterol. Yeast cell wall and cellulose decreased apparent protein digestibility but did not influence other indices of protein utilization. A decrease in diet efficiency ratio was observed which did not affect body weight gain by the rats. Addition of 10 and 20% cell wall fraction or cellulose increased food intestinal transit and small intestine length. The cell wall fraction at 10% (1st experiment) and 20% (2nd experiment) produced a lowering effect on rat serum triacylglycerols. There was no influence on the total lipids and total cholesterol of the cell wall fraction.