A method for the determination of small quantities of mixed reducing sugars and its application to the estimation of the products of hydrolysis of starch by taka-diastase.

PRELIMINARY investigations on the carbohydrates in the developing apple have shown that the concentration of sugars in the fruit is less than 1 % during the first weeks of growth, and further, that the maximum starch concentration reached at any time is only about 2 %. Estimation of these carbohydrates by the usual methods would require the collection of a very large number of apples, especially in the early stages of development, when the fruit is small, with the resultant risk that the crop on any tree would be so seriously depleted that the development of the remaining fruit might be abnormal. Since starch appears to be most satisfactorily estimated by determination of the glucose and maltose produced by hydrolysis with taka-diastase, a method for the estimation of small quantities of reducing sugars has been investigated. With such a method, determinations of starch could be carried out during the development of the apple, and furthermore, a delicate method of estimation of reducing sugar would enable the size of the samples required for sugar determination on the young and very small fruits to be kept within reasonable limits.