Does packaging influence the flavour of milk?

To date the dairy industry has largely focused on packaging milk in light-blocking containers to preserve freshness but there has been little research on how the packaging itself influences the flavour of milk. Now a study published in the Journal of Dairy Science by Elsevier confirms that packaging does affect taste — and paperboard cartons do not preserve milk freshness as well as glass and plastic containers.

“Milk is more susceptible to packaging-related off-flavours than many other beverages because of its mild, delicate taste,” said lead investigator of the study MaryAnne Drake, PhD, of the North Carolina State University Department of Food, Bioprocessing and Nutrition Sciences.

In addition to light oxidation, Drake said: “Milk’s taste can be impacted by the exchange of the packaging’s compounds into the milk and by the packaging absorbing food flavours and aromas from the surrounding refrigeration environment.”

To quantify the flavour impacts of packaging, the researchers examined pasteurised whole and skim milk stored in 236 mL containers: paperboard cartons, three plastic jugs (made from different plastics), a plastic bag, and glass as a control. The milk was stored in total darkness to control for light oxidation and kept cold at 4°C.

The samples were tested on the day of first processing, then again at five, 10 and 15 days after. A trained panel examined the sensory properties of each sample, and the research team conducted a volatile compound analysis to understand how the packaging was intermingling with the milk. Finally, the samples underwent a blind consumer taste test on day 10 to see whether tasters could tell any difference between milk stored in the paperboard carton or the plastic jug compared with milk packaged in glass.

The results showed that package type does influence milk flavour, and skim milk is more susceptible to flavour impacts than whole milk. Of the different packaging types, paperboard cartons and the plastic bag preserved milk freshness the least due to the paperboard’s absorption of milk flavour and the transfer of paperboard flavour into the milk. Milk packaged in paperboard cartons, in fact, showed distinct off-flavours as well as the presence of compounds from the paperboard. The final results show that, while glass remains an ideal container for preserving milk flavour, plastic containers provide additional benefits while also maintaining freshness in the absence of light exposure.

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