Analysis of Characteristic Aroma Substances of Different Processing Strawberry Varieties Based on GC-MS/GC-IMS

The quality stability of fresh fruit milk tea is largely determined by the properties of its raw materials. As a commonly used ingredients, strawberries contribute significantly to the final flavor profile through their distinct aromas. Subtle differences in key aroma components can impart distinct aroma profiles to the final product, leading to batch-to-batch flavor variations in fresh fruit milk tea. Therefore, identifying the main aroma compounds in three strawberry cultivars commonly used in processing can help determine the causes of flavor differences. A combined approach of GC-MS (gas chromatography-mass spectrometry) and GC-IMS (gas chromatography-ion mobility spectrometry) was employed to separate and identify VOCs (volatile organic compounds) in the strawberries. OAV (Odor activity value) analysis was utilized to pinpoint the key flavor compounds, and PCA (principal component analysis) combined with sensory evaluation was conducted to elucidate the aroma characteristic differences among the varieties. The results showed that a total of 110 VOCs were detected in 'Jiujiu' strawberry, 110 in 'Hani' strawberry, and 111 in 'Monterrey' strawberry. Through OAV analysis, 16 characteristic VOCs were identified, among which δ-decalactone, isoamyl acetate, linalool, (Z)-3-hexenal, (E,E)-2,4-nonadienal, 2,5-dimethyl-4-methoxy-3(2H)-furanone, ethyl isobutyrate, ethyl hexanoate, propionaldehyde, and 1-octen-3-ol were the key volatile components across all samples. PCA and sensory evaluation revealed significant differences in aroma characteristics among the three varieties, 'Jiujiu' strawberry exhibited strong sweet and floral aromas, attributed to the contributions of (Z)-3-hexenal and linalool, 'Hani' strawberry showed intense fruity and sour aromas, mainly derived from ethyl isobutyrate and ethyl hexanoate, while 'Monterrey' strawberry's fruity and fresh aromas were primarily influenced by ethyl isobutyrate and propionaldehyde. Additionally, differences in the quantitative levels of VOCs were also observed among the different strawberry cultivars. In summary, the combined GC-MS/GC-IMS technique clarified the key aroma substances and their differences across the three strawberries, and the established flavor fingerprint provided a theoretical basis for raw material selection in strawberry processing.