Effects of Traditional Processing Methods on the Mineral and Antinutrients of Fresh and Squeezed-Washed Bitter Leaf

Abstract

Bitter Leaf is a vegetable that is widely consumed and cherished in SouthEastern Nigeria. Palm oil, Potash, Salt and boiling process was used in the squeeze-washing at 3 pre-processing methods of squeeze-wash and periods of 3 to 8 minutes. The percentage retention and losses of mineral and antinutrient increased simultaneously during squeeze-washing. Copper, magnesium, calcium and antinutrient had retention of 55 to 100% for samples squeezed-washed with palm oil than the other squeeze-washed samples. This could be due to rigidity of the cells which did not allow much nutrient leached into the squeezed leaf/water; whereas, the loss of mineral and antinutrients was practically of the same magnitude (27.3 to 80.5%) in all the samples. Loss of minerals and antinutrients was observed to be influenced directly by the cause-and-effect of disintegration changes which usually leads to softening due to the severity of the squeeze-washing on the bitter leaf instead of cellular composition or level of minerals and antinurients initially present. The results are discussed in relation to traditional commercial practice of bitter leaf processing.