Increase of glycolytic enzymes in peanuts during peanut maturation and curing: Evidence of anaerobic metabolism

Previously, a substantial increase in the activity of alcohol dehydrogenase (ADH) during peanut maturation and curing was found. It was hypothesized that the increase of ADH is primarily due to the increased activities of glycolytic enzymes preceding ADH in the alcohol fermentation pathway. To verify this hypothesis, color assays were developed for detection of the following glycolytic enzymes: (1) aldolase; (2) glyceraldehyde-3-phosphate dehydrogenase; (3) pyruvate decarboxylase; and (4) ADH. Results showed that the activities of these enzymes increased significantly during peanut maturation and curing. The increased enzyme activities suggest that peanut maturation and curing are processes associated with anaerobic conditions. Enzyme activities were significantly higher in cured peanuts than in noncured peanuts, indicating that anaerobic conditions were more severe in the former. The potential contribution of water stress to the severity of anaerobic conditions is discussed.