Effects of modified atmosphere packaging conditions on quality preservation of powdered infant formula

Abstract

The effect of different modified atmospheres (100% N2, 100% CO2, 70% N2/30% CO2, 50% N2/50% CO2, and air) on the quality preservation of powdered infant formula was investigated by a storage test at 30°C. Metal can packages of 400 g per unit were stored for 493 days with periodic measurements of package gas composition and product quality attributes, which included peroxide value (POV), pH, titratable acidity, bifidobacteria count, hydroxymethylfurfural content, surface colour, and solubility. In the air package, POV as an oxidative quality index increased highly along with oxygen concentration decrease, reaching a maximum of 58.7 meq/kg lipid at 350 days. Compared with the air package, POV increase of the product was significantly lower, with all the O2‐excluded modified atmosphere packages showing a maximum of 28.5 to 29.3 meq/kg at 350 days. Packages of high CO2 concentration experienced a pH decrease and an acidity increase of the stored product caused by dissolution of CO2. The count of bifidobacteria in the product was maintained higher after 119 days in the package of 100% CO2 than in the other packages. Hydroxymethylfurfural content showed a slight increase after an initial period of slight decrease, with little difference among the package treatments. There were no significant changes in product solubility and surface colour during storage. Considering that the high CO2 atmosphere helps the survival of bifidobacteria and protects the product from oxidation without negative effects on the other quality attributes, it is suggested for use in packaging of powdered infant formula.