1993 Volume 40 Issue 8 Pages 545-551
This study was aimed at investigating the demineralizing conditions of milk casein hydrolysates prepared enzymatically by electrodialysis (ED). The changes in ash, protein, free amino acid content and so on before and after ED treatment were investigated. All ED treatments were carried out after Low Rejection Reverse Osmosis Membrane (LRO) treatment.
(1) The demineralization of casein hydrolysates proceeded effectively as the operating temperature rose.
(2) The relationship between ash content and electric conductivity was expressed as a linear line.
(3) The amount of ash and free amino acid decreased with ED treatment. In treatment with recovery rates of 87.8, 78.4, and 81.4%, casein hydrolysates with deashing rates of 72.5, 75.7 and 78.6% were obtained, respectively.
(4) It was found that calcium was demineralized more easily than the other minerals in casein hydrolysates. On the other hand, it was difficult to deash sodium.
(5) Both glutamic acid and aspartic acid showed remarkable decreases. Arginine also showed a tendency to decrease. The other amino acids, however, didn't decrease and, on the contrary, showed a tendency to become more concentrated.
(6) ED treatment was proved to be as effective as LRO treatment in improving the taste of casein hydrolysates caused by free amino acids.
