Ben-Shalom et al. [8] studied the effect of acidification (pH values: 6.2, 4.4 and 3.9) following blanching on the firmness of the carrot tissue. Blanching the carrot tissue at pH 6.2 caused a significant reduction (about 70 %) in the firmness of the carrot tissue. Acidifying and blanching the tissue at pH 4.4 improved the firmness almost 50 %, as compared with blanching the tissue at pH 6.2. But acidi- fying the tissue to pH 3.9 and blanching it decreased its firmness to the same value as at pH 6.2. It appeared that the degradation of firmness in carrot tissue during heat treat- ment occurred by two different mechanisms—one at neu- tral pH and another at pH 3.9 since at an intermediate pH the degradation was much less. They concluded that
reducing the pH of the carrot tissue before blanching at 4.4, the loss of tissue firmness was reduced.