Performance of cost-effective PET packaging with light protective additives to limit photo-oxidation in UHT milk under refrigerated LED-lighted storage condition

Protection efficiency of polyethylene terephthalate (PET) packaging comprising light protective additives (LPA) was investigated for ultra-high temperature (UHT) 2% milk over 26 weeks in refrigerated LED-lighted retail case storage. For the first time, synergistic efficacy of titanium dioxide (TiO2) and carbon black (CB) pigments in PET packaging in protecting milk nutrients and flavor was evaluated in this study. Combination of TiO2 (6.8 wt%) and CB (23 ppm) pigments in PET packaging (S-PET) protected milk quality as effectively as light-proof packaging up to 13 weeks of storage, as demonstrated by improved riboflavin retention, lower TBARS value, and reduced production of volatiles associated with off-flavor including aldehydes compounds and dimethyl disulfide. Photolysis of riboflavin in milk packaged with S-PET packaging was limited to 7.0% within 13 weeks of storage under exposure of high intensity of LED light. The study demonstrated that selection of appropriate LPA combined with PET packaging provided a cost-effective solution for light protection of 2% milkfat UHT milk stored in refrigerated LED-lighted retail conditions for up to 26 weeks.