Dairy products are susceptible to package off-flavors due to their mild flavor and minimal packaging. Few studies have addressed the effects of plastic package materials and the surrounding environment on adsorption and migration of volatile compounds in fluid dairy products. The objective of this study was to determine the effects of plastic package and storage on migration and scalping of volatile compounds from fluid milk and cream. Pasteurized skim milk (0.1% fat) or cream (12% fat) were packaged into three commonly used plastic package materials (polyethylene, metal polyethylene, and polypropylene) or glass (control). Samples were stored at 4C in the dark and sampled weekly for 3 weeks. Descriptive analysis (DA) was applied to document sensory profiles. Volatile compounds were extracted and identified using Solid Phase Micro-extraction (SPME) with gas chromatography mass spectrometry (GC-MS). Dairy products packaged in polyethylene pouches, metal polyethylene pouches and polypropylene cups for each fat content were compared using tetrad difference tests (n=30 milk consumers per tetrad, 12 tetrads) following 2 weeks storage. The experiment was replicated twice. Trained panelists determined that skim milk and cream (12%) had noticeable plastic and refrigerator/stale flavors by week 2 for each packaging type (p&lt;0.05). Aroma active compounds detected associated with inks, solvents, and plastic residues from packaging included caprolactum, trichloroethylene, 3-carene, 2-ethylhexyl acrylate, toluene, p-xylene, o-cymene, beta-pinene, styrene, ethyl acetate, methacrylamide, N-propyl acetate, 2(3H)-furanone, dihydro-5-propyl-, methyl isobutyl ketone, and maltol. Higher concentrations (p&lt;0.05) of package related off-flavor volatile compounds were documented in skim milk compared to cream. Consumers could detect differences between skim milk packaged in the polypropylene cups vs. polyethylene or metal polyethylene pouches (p&lt;0.05), but not for cream (p&gt;0.05). These results demonstrate that packaging choice plays a key role in the sensory and the chemical properties of fluid milk and cream.

Impact of plastic package and storage on off-flavors in fluid milk and cream

ACS Fall 2020 Virtual Meeting

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