HS-SPME-GC-MS Combined with ROAV to Analyze the Effect of Different Packaging Materials on the Quality of Milk Powder

In order to investigate the effects of packaging materials on the quality of milk powder, three common packaging materials were selected in this study (ordinary plastic packaging (polypropylene, PP), high barrier material packaging (polyethylene/polyvinyl alcohol/polyethylene, PE/PVA/PE), and aluminum-plastic packaging (polyethylene terephthalate/polyamide/aluminum foil/polyethylene, PET/PA/AL/PE)), and a variety of physicochemical indexes and volatile flavor substances were determined. The volatile compositions were determined using headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and combined with the relative odor activity value (ROAV) method for the identification of key aroma substances. The results showed that high barrier and aluminum-plastic packaging demonstrated strong efficacy in preserving the original physicochemical properties (moisture content, solubility, particle size, color, and fat content) of milk powder. A total of 53 volatiles were identified through GC-MS analysis. The ordinary plastic-packed milk powder exhibited a high degree of fat oxidation, leading to an increase in acid relative content. Additionally, there was extensive oxidation of oleic acid and the detection of capric acid in this sample, resulting in the development of rancidity taste. High barrier and aluminum-plastic packaging effectively inhibited the release of volatile substances such as furfural, 5-hydroxymethylfurfural, 2(5H)-furanone, furfuryl alcohol, and maltol generated during heat processing. These compounds imparted positive aromas to the milk powder including caramel aroma and butterscotch aroma. Conversely, ordinary plastic packaging with poor airtightness resulted in significant loss of flavor compounds during storage leading to a monotonous flavor profile. The ROAV analysis revealed that all samples contained 24 types of volatile components contributing to aroma. In comparison with ordinary packaging milk powder (12 types) and high barrier packaging milk powder (13 types), aluminum-plastic packaging milk powder (14, 15 types) exhibited a greater variety of positive aroma compounds. This study offered valuable insights for enterprises in selecting appropriate packaging technology to enhance the flavor, nutritional value, and quality safety level of milk powder.