CHANGES IN STRAWBERRY ANTHOCYANINS AND OTHER POLYPHENOLS IN RESPONSE TO CARBON-DIOXIDE TREATMENTS

Carbon dioxide-enriched atmospheres are used to reduce the incidence a nd severity of decay and to extend the postharvest life of strawberrie s. The influence of CO2 on the postharvest quality parameters of straw berries, particularly the stability of anthocyanins and other phenolic compounds, was investigated. Freshly harvested strawberries were plac ed in jars ventilated continuously with air or air enriched with 10%, 20%, or 40% CO2 at 5 degrees C for 10 days. Samples were taken initial ly, and after 5 and 10 days of storage, and color (L a* b* color spac e), pH, TA, TSS, and firmness were measured. Anthocyanins and other ph enolics were analyzed by HPLC. Elevated CO2 degraded internal color wh ile air-treated fruit remained red. Internal and external tissues diff ered in composition and concentration of phenolic compounds. CO2 had a minimal effect on the anthocyanin content of external tissues but ind uced a remarkable decrease in anthocyanin content of internal tissues. Factors, such as pH and copigmentation, that could explain this degra dation are discussed.