Investigation of the effect of different production conditions on flavour components and sensory properties in strawberry flavored milks

Milk with enhanced flavor through the addition of flavour is a product preferred by people of all age groups. The purpose of adding flavoured to milk is to enhance its flavor. The objective of the production process of flavored milk products is to produce a product of the desired quality without losing its flavor profile due to the applied heat treatment. In this study, changes in flavor components and sensory properties of both unflavored (raw milk) and flavored raw milk were examined based on heat treatment and fat content. In this context, strawberry flavour was added at doses of 0.1% and 0.2% to milk with two different fat contents (3.9%-4% and 3%-3.1%), followed by pasteurization (72°C for 15 seconds) and UHT (141°C for 4 seconds) treatments. Changes in the flavor components of the prepared samples were determined by the GC-MS-SPME method, while changes in sensory properties were determined by the QDA (Quantitative Descriptive Analysis) method. The analysis results revealed that heat treatment and fat content are two significant factors affecting the flavour components and their concentrations in both unflavored (raw milk) and flavored milk (p<0.05). The components of hexyl valerate, acetic acid, gamma-decalactone, and butyric acid in raw milk decreased with heat treatment. Among the strawberry flavour components, ethyl 2-methylbutyrate, methyl cinnamate, and vanillin decreased with heat treatment (P<0.05). Most flavour components of raw milk and strawberry flavour were detected more in high-fat milk than in full-fat milk. This suggests that flavour compounds are less detected in high-fat milk due to the likelihood of volatile components adhering to fat globules. Sensory analysis results showed that milk processed with UHT received lower scores for fruity-green profiles in sensory analysis, whereas low-fat flavored milk received higher scores for sweet-green profiles compared to full-fat milk. Therefore, the results of analytical analyses are supported by the results of sensory analyses. This study aims to support the development of new formulations and alternative solutions based on the thermal stability of flavour components and the type of milk product used.