Changes in phenol content during strawberry (Fragaria x ananassa, cv. Chandler) callus culture

Total soluble phenols, soluble flavanols, (+)-catechin, ferulic acid and 1- O-feruloyl-beta -D-glucose were analyzed during the development of a strawb erry (Fragaria x ananassa, ev. Chandler) callus culture. The time-course ch anges of the different phenols assayed were well correlated with callus gro wth and morphology. The changes in polyphenol oxidase (EC 1.10.3.12) and be ta -glucosidase (EC 3.2.1.21) activities in the callus were also examined. The total phenol, soluble flavanols and (+)catechin contents were high duri ng the preexponential and exponential phases of growth. The subsequent decr ease in ( +)-catechin concentration coincided with high levels of polypheno l oxidase activity. The 1-O-feruloyl-beta -D-glucose content was highest as callus growth ceased, and its subsequent decrease was accompanied by the i ncreased production of ferulic acid. This increase in ferulic acid was acco mpanied by an increase in beta -glucosidase activity. The ferulic acid cont ent decreased at the end of culture, when callus growth had stopped and sho wed clear symptoms of senescence. This decrease in the ferulic acid concent ration was accompanied by an increase in the levels of ferulic acid bound t o cell wall components.