Maintaining the antioxidant compounds in minimally processed globe artichoke heads using natural anti-browning molecules

The heads of globe artichoke are used worldwide and represent a fundamental ingredient of the Mediterranean diet. Many studies have focused on its health and antioxidant properties and it seems that these actions could be strictly related to the polyphenolic fraction, mainly composed of mono- and dicaffeoylquinic acids and flavonoids, inulin and protein content. On the other hand the PPO enzyme activity is the main factor causing browning in head tissue, reducing the shelf life of minimally processed capitula. To avoid postharvest disorders and maintain the amount of nutraceuticals the use of different head treatments before storage could help to realise these goals. In this work, the total phenolic acids changes of two globe artichoke genotypes (cv. "Violetto di Sicilia" and "Apollo") heads during cold storage subjected to two treatments were investigated. The two treatments were T0: dipping in chlorine solution (5% v/v) for 30 minutes at room temperature; T1: dipping in solution containing 5% (w/v) citric acid + 2.5% (w/v) ascorbic acid for 30 minutes at room temperature, followed by a cycle of hydro cooling for 30 minutes. The treated heads were placed inside perforated polypropylene food bags (five x bag) and stored at the temperature of 1±1°C for twelve days. At harvest and after every two days storage for a total of five sampling, on 3 bags (experimental unit) heads weight (g), dry matter (%), total phenolic acids content (uHPLC - Thermofisher) were analysed. During the storage, a constant lost of head weight was observed in each treatment. The total amount of phenols showed differences related to genotypes and treatments. Apollo gave the best performance to be processed. Moreover the contents picked after 2 days of storage, remaining constant until 8 days of storage. On average of genotypes the "T1" increased the amount in phenols vs "T0".