Storage Induced Changes of Phenolic Acids and the Development of Hard‐To‐Cook in Dry Beans (Phaseolus vulgaris var. Seafarer)

Navy beans were stored for 9 months under three conditions (5°C/ 40% RH, 20°C/73% RH, and 35°C/80% RH) to produce different degrees of hard‐to‐cook (HTC) defect. Changes in free hydroxycinnamic acids, hexane soluble and methanol soluble hydroxycinnamic acids, cell wall bound hydroxycinnamic acids, and lignin content were determined. Storage induced HTC beans contained higher levels of hydroxycinnamic acids (especially ferulic acid) than the control beans in all fractions prepared from seed coats and cotyledons except for the methanol soluble and cell wall bound phenolic acid fractions from cotyledons. No significant changes in lignin content were detected among the treatments. Large increases in free hydroxycinnamic acid content associated with increased hardening, suggest a relationship between these two factors.