Accelerated light protection performance measurement technology validated for dairy milk packaging design

摘要

We report an accelerated measurement technology for prediction of light protection performance of milk packaging by quantifying the ability of a package to preserve a light-sensitive nutrient present in milk. This measurement technology consists of a light exposure instrument and a detection approach to track changes to the light-sensitive nutrient, riboflavin (RF), in a light-exposed solution sample. The light exposure instrument provided an intense, controlled light exposure and a consistent sample environment for an aqueous RF marker solution. Coupled with the light exposure instrument, two alternative detection approaches were used to determine the RF concentration of light-exposed marker solutions: an accelerated ex situ (AES) approach by high-performance liquid chromatography or an accelerated in situ (AIS) approach by ultraviolet-visible spectrometry. The capability of each RF determination method was confirmed using measurement systems analysis, and their statistical equivalency was demonstrated. To explore application of the measurement technology for use in package design, a set of high-density polyethylene packages incorporating surface-treated TiO2 pigments was evaluated for light protection performance by AES and AIS. For the same package set, experiments monitoring RF degradation in extended-shelf-life milk products under retail dairy storage conditions showed strong correlation with the AIS method (R-2>0.97). Riboflavin retention increased under both retail and accelerated light exposure conditions for package designs containing greater loadings of surface-treated TiO2 confirming its light protection efficacy. This research illustrates the utility of the accelerated methods to quantitatively evaluate package designs for light protection performance for nutrient preservation.