Understanding your product
A dairy company was looking to launch a new product ‘milk in a can'. Designed to increase the sales of semi- skimmed milk to young adults, the ‘can' was a white plastic container with an aluminium ring pull lid. It was designed to be sold from chiller cabinets with other ‘food to go'. Supermarkets interested in the milk had requested a shelf life of at least five days in a chiller cabinet and the Client needed to understand how the product characteristics changed during 5 days storage.
Our approach focused on the need to understand what was changing in the milk during storage so that learnings could be applied to any further pack development whilst providing the most cost-effective solution.
What We Did
We evaluated the ‘milk in a can' in comparison to control samples (milk in glass and plastic cartons) during storage. Samples were stored at 5o under fluorescent light levels typical of chiller cabinet conditions. Trained sensory panellists evaluated the milk every day for six days using Descriptive Sensory Profiling. The attributes evaluated were derived by the panel and were agreed and defined. Attributes included creamy, oxidised, fatty, sweet and thick.
What We Found
After 3 days of storage the panel noticed a sharp increase in ‘oxidised' and a reduction in ‘fresh' flavour, which made the milk unpleasant to drink. By Day 5 the oxidised aftertaste was so pronounced the milk was undrinkable. In comparison, the sensory profile of the control samples remained constant up to Day 5.
With a shelf life of only two days, the milk can sadly fell short of the shelf life required by the supermarkets. After investigation, the reason for the oxidised aftertaste was found to be a chemical reaction in the milk caused by light permeating the plastic container. Alternative containers would provide a viable solution.