EMAP technique application to obtain minimally processed eights and slices fresh cut of ‘Spinoso Sardo’ globe artichoke

The artichoke is characterized by a high respiration rate even higher when processed into eighths or slices. The EMAP technique allows controlling the concentration of O(2) and CO(2) at equilibrium inside a package of the fresh produce, increasing the shelf life. Several reports showed that the use of MAP and EMAP to obtain minimally processed whole artichokes are in progress as well as the attempts to apply the same technique to packaged eighths and slices. The aim of this research is to determine the required gas transmission rates of the sealing film for eighths and slices fresh cut artichokes by using a gas mixture composed by 5% O(2), 5% CO(2) and N(2) balance. The artichokes are subjected to cut off the upper thorns and to pull out of the harder lateral bracts, followed by sanitizing treatment in chlorinated water. Subsequently the artichokes are processed to obtain eights and slices, placed in chlorinated water, washed in tap water, dipped in anti-browning solution and dried by means of a centrifuge. Finally, the different products are packaged using polypropylene food trays (800 mL) wrapped with PP films of know gas permeability (O(2) TR=3.000-13.000 mL m‑2 24 h‑1 atm(‑1). The film features have been identified through respiration rate tests carried out by using the static and permeable methods. To calculate the respiration rate, the gas composition inside the packages was measured daily until an equilibrium atmosphere was reached. Evaluation of the designed packages was carried out for packages with different combinations of net weights (120 and 150 g) and chilled storage conditions (1°C passive refrigeration and 6°C conventional refrigeration). The microbiological shelf life of the products up to 10 days was assessed. All the samples stored at 6°C in conventional refrigeration conditions showed redness coloration on the products’ surface due to oxidation phenomena of the exposed plant tissues. The longer shelf life was obtained by using a film with lower permeability to oxygen, stored at 1°C in passive refrigeration conditions.