Antioxidant compound changes during cold storage of minimally processed globe artichoke heads

In order to prevent damages of perishable vegetables during storage, it isnecessary to maintain their nutritional value and sensory properties. Artichoke isvery perishable because of its high respiratory activity and susceptibility to weightloss, decay and biochemical and physiological damages. The high amount inphenolic compounds makes globe artichoke heads a source of antioxidants, but onthe other hand the polyphenol oxidase (PPO) enzyme activity is the main factorcausing browning in head tissue, reducing the capitula shelf life. To avoidpostharvest disorders and extend shelf life, the use of different head treatmentsbefore storage could help to realize these goals. In this work, the total phenolic acidchanges of two globe artichoke genotypes (‘Violetto di Sicilia’ and ‘Violet ofProvence’) heads during cold storage subjected to four treatments such as dipping indistilled water (control – T1), 2% ascorbic acid in distilled water (T2), 1% citric acidin distilled water (T3) and coating with citric acid loaded with sodium alginate (T4),were investigated. The treated heads were placed inside perforated polypropylenefood bags (five × bag) and stored at the temperature of 4±1°C for four weeks. Atharvest and after every week of chilling storage for a total of five samplings on3 bags (experimental unit), head weight (g), dry matter (%), total phenolic acidcontent (mgGAE kg-1 FW) were analysed. During the weeks of storage, a constant lossof head weight was observed in each treatment; the T4 resulted in the lowest lossesin head weight. At harvest, total phenols resulted, on average of genotypes,1375 mgGAE kg-1 FW averaged for weeks of storage and genotypes, total phenolicacid degradation resulted more marked using T1 and T2 than the other treatments.The obtained results showed a good influence of the treatments on the capitulaweight losses and phenolic acid variation.