Reducing water activity and softening texture of Areca catechu L. by phosphates and Maillard peptides and their improvement on flavor

Many studies have focused on reducing Aw to prevent the growth of spoilage bacteria. The effects of complex phosphates (CP) and Maillard peptide complexes (MPCs) on water activity (Aw), water status, sensory attributes, flavor, and hardness of the areca nuts were studied to extend their shelf life and improve their eating quality. The results showed that the addition of 1.6% CP and 0.6% MPCs significantly reduced the Aw of areca nuts (Aw = 0.8116). Low field nuclear magnetic resonance indicated that it was due to that the CP and MPCs promoted the conversion of free water to bound water through hydrogen bonding or electrostatic interaction. In addition, CP combined with MPCs reduced the extrusion hardness and puncture hardness of areca nuts, accompanied with a significant increase in softness and pulpiness as assessed through sensory analysis, which might be due to the improved water binding capacity of areca nuts. Moreover, MPCs increased the content of N, S heterocyclic compounds of the areca nuts and contributed to an increased "kokumi" attribute compared with CP.