| 摘要 |
The invention relates to the production and use of soy protein hydrolysates enriched with branched amino acids. Commercial formulas for the nutritional treatment of cirrhotic patients and patients suffering from metabolic stress contain free-form branched-chain amino acids (BCAA), which limits the absorption of said formulas, restricts the functional and sensory properties thereof and increases costs. Soy protein can be modified by covalently binding the BCAAs in order to solve the aforementioned problems. The inventive method comprises two phases, namely: a first phase, in which the protein is hydrolysed using trypsin and chymotrypsin in an aqueous medium under suitable conditions (concentrations, pH, temperature and time) in order to obtain a degree of hydrolysis of between 30 and 45 % and the protein is then dried by means of spraying; and a second phase, in which the BCAA is bound to the hydrolysate by means of enzymatic synthesis, by reacting hydrolysate, leucine and valine methyl esters, chymotrypsin and glycerol in water. The reaction conditions are adjusted to obtain a minimum proportion of BCAA to aromatics of 3:1, 30-50 % BCAA and a valine:isoleucine:leucine ratio of 1:1:2. The product is subsequently ultra diafiltered to remove substances < 1 kDa and dried by means of spraying or lyophilisation. The protein thus modified has very acceptable functional properties as well as characteristics suitable for the nutritional treatment of cirrhotic patients and patients suffering from metabolic stress. |
