Relationship of acid phosphatase activity and Brix/acid ratio in apples

This research was undertaken to determine the relationship of acid phosphatase and Brix/acid ratio in apples. High-acid cultivars of apples (Zapata, Cap of Liberty, and Edward VII) exhibited low Brix/acid ratios while low-acid cultivars of apples (Empire and Idared) had high Brix/acid ratios. The coefficient of correlation (r(2)) for acid phosphatase and Brix/acid ratio in apples was calculated to be 0.96. An inverse relationship appeared to exist between the acid phosphatase activity and the acidity in apples (r(2) = 0.83). The results of this study indicate that acid phosphatase could serve as a marker for breeding new fruit cultivars with a desirable Brix/acid ratio. (C) 2004 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.