Texture of Chinese water chestnut: Involvement of cell wall phenolics

Abstract

Abstract Chinese water chestnuts (CWC) fail to soften during cooking. This is due to thermal stability of cell wall polymers involved in cell‐cell adhesion. Information concerning these polymers was obtained by subjecting CWC tissues to a range of chemical and biochemical treatments designed to cleave selectively cell wall chemical bonds. Neither chelating agents nor weak base (Na 2 CO 3 , 0·05 M ) facilitated vortex‐induced cell separation (VICS) in fresh or canned tissues. However, VICS could be induced after extraction in dilute, cold alkali (0·1 M KOH), dilute hot acid, or a purified, specific endoxylanase. The CWC cell walls also exhibited considerable pH‐dependent autofluorescence which originated mainly from ferulic acid and its derivatives. This disappeared during alkali‐induced VICS. The results are consistent with the involvement of ferulic acid‐containing cell wall hemicelluloses in the thermal stability of cell‐cell adhesion and therefore texture in CWC tissues.