Effect of light and packages on stability of spreadable processed cheese

As Requeijão cremoso is a processed cheese preferably packed in transparent retail containers, which are exposed to light at the retailers. The aim of this study was to evaluate the influence of light (1000 lux) on the stability of the product at 10 °C, when packed in five different packaging systems: (1) glass cup with an easy-open tinplate cap, (2) glass, (3) polypropylene cups heat-sealed with aluminum foil, and (4 and 5) polyethylene squeeze tubes with and without oxygen barrier. No microbiological changes were observed. The oxygen in the headspace of the packages exposed to light decreased rapidly, indicating its consumption by photo-oxidative reactions. Increasing TBA values and intense sensory changes in the product were observed, which differed depending on the packaging type. The overall quality loss was significantly higher when Requeijão cremoso was exposed to light, leading to its rejection and end of shelf-life. The overall quality loss was predominantly determined by both oxygen availability and package type.