| 摘要 |
The storage stability of aldose-containing liquid food, e.g whole egg, eggwhite, egg yolk and milk, is improved by enzyme conversion of the aldose to the corresponding sugar acid, e.g. to glutonic acid, in the case of glucose, the conversion being effected by mixing the food with an enzyme having aldose-oxidase activity, adding acid to adjust the pH to below 8, preferably to between 5.0 and 7.5 saturating the mixture with free oxygen, maintaining it between 30 DEG and 65 DEG F., and foaming it, e.g. either by passing oxygen or air through it, or by reducing an initial superatmospheric pressure to release dissolved gas, or by incorporating into it hydrogen peroxide, or a precursor therefor, and a decomposition catalyst for the peroxide, e.g. catalase. The foaming floats up particles of fat, bacteria and foreign matter and facilitates their removal. The liquid food may be pasteurized before treatment and dried, e.g. spray dried or frozen afterwards. The final pH of a dry powder can be adjusted by buffering or by adding volatile alkali such as ammonia to the liquid before the drying. Specification 740,379 and U.S.A. Specification 2,758,934 are referred to. |
