| Abstract [eng] |
Evaluation of protein hydrolysis during in vitro digestion is important as ability to understand products of hydrolysis. They might be important to people, in particular with special needs or disorders of eating. In example, dysphagia is a symptom, commonly found in the elderly and defined as a difficulty or inability to swallow thin fluid foods. Such physical disorder may contribute to malnutrition due to limited food and liquid intake. The effective treatment of dysphagia requires that fluid foods are consistently prepared with the correct viscosity. On the other hand, increasing the protein content in food is an effective way for the prevalence of malnutrition. Recent studies have proposed new concepts such as the ‘‘slow vs. fast’’ protein concept based on the speed of protein digestion which is a limiting factor for the loss of muscle mass long with lowered strength and physical endurance. The purpose of this study was to investigate the digestibility of protein based beverages containing proteins from different sources (egg, pea and milk) and characterized by different viscosity. The viscosity of protein based beverages was designed by changing protein concentration (10 and 15 %) and/or adding polysaccharide Konjac Glucomannan. The digestibility of proteins was defined by the content of peptides and free amino acids that is released from beverages in the gastrointestinal tract and thus becomes available for intestinal absorption. In vitro digestion method proposed by INFOGEST was used to simulate the conditions in gastrointestinal tract. Kjeldal, Lowry, Fluorescamine assay where used to determine the nitrogen, peptides, free amino groups and amino acids content in the gastrointestinal fluids. As well as SDS-PAGE and densitometry was performed in the University of Manchester. Results of nitrogen and free amino groups content released during digestion showed that the rate of hydrolysis varied depending on the origin of proteins in the beverages. The pea proteins have been digested faster than milk and egg proteins. The free amino acids profiles obtained after digestion of pea, egg and milk proteins are in agreement with the results about nitrogen content in the gastrointestinal fluids. It was found that the addition of thickener – Konjac Glucomannan, to the protein based beverages may effect proteolysis during gastrointestinal digestion. |
