Stability of biofortified sweet potato chips in different packaging systems

The consumption of sweet potatoes orange pulp with a high content of pro-vitamin A carotenoid can overcome the deficiency of this micronutrient, benefiting poor populations in developing countries suffering from malnutrition. The development of products such as chips, offers an alternative for consumption, with a longer shelf life compared to the product in natura. However, information concerning the influence of the packaging on the loss of carotenoids from the products during storage is scarce and sometimes conflicting or little explored, although the following aspects are basically the relevant ones: oxygen availability in the head space of the package, oxygen dissolved in the product, oxygen permeability through the packaging material, light transmission, faults in the hermiticity of the seal, and the storage time and temperature. The aim of the study was to evaluate the stability of biofortified baked sweet potato chips, packaged with nitrogen in PET/Al/LDPE (polyester/aluminum/low density polyethylene), PETmet (polyester metalized)/LDPE and BOPP (biaxially oriented polypropylene)/metBOPP, BOPP/metBOPP with an oxygen scavenger and without nitrogen in BOPP/metBOPP, stored at 25 ± 2°C and 75 ± 5% RH (relative humidity) during a period of 212 days. The oxygen transmission rate of the films at 23°C/1 atm was <0.05, 0.45 and 18.69 mL (STP) m-2.day-1, respectively, and the water vapor transmission rate of the films at 38°C/90% RH was <0.01, 1.09 and 0.31 g water.m-2.day-1, respectively. The chips packed in BOPP/metBOPP without nitrogen presented lower retention of total carotenoids and β-carotene, 41.56% and 38.80% after 212 days of storage, respectively. The chips packed with nitrogen PET/Al/LDPE, PETmet/LDPE BOPP/metBOPP with oxygen scavenger and BOPP/metBOPP showed retention of total carotenoids 80%, 78%, 75% and 75% and retention of β-carotene of 90%, 90%, 83% and 80% respectively after 212 days of storage. The packaging of biofortified sweet potato chips in atmosphere with nitrogen coupled with high oxygen barrier packaging materials resulted in high retention of carotenoids throughout the storage.