Flavor deterioration and shelf‐life extension of millet–highland barley composite milk: sensory, microbial, and volatile profiling

BACKGROUND: Millet and highland barley, as low glycemic index (GI) grains, are considered promising ingredients for the development of new plant-based milks. In this study, a millet-highland barley compound milk (MHM) was created by boiling the grains after baking. The product achieved the highest sensory and e-tongue ratings when the millet-to-barley ratio was 1:4. RESULTS: During storage, MHM showed increasing acidity and colony count, accompanied by an increase in particle size and a decrease in centrifugal sedimentation rate. The flavor of MHM changed significantly with the increase in microbial activity, as evidenced by a shift from an initial sweet and fresh aroma to a rancid and sour odor. A database of volatile compounds and their correlation heat map with storage time was established by gas chromatography-ion mobility spectrometry (GC-IMS). CONCLUSIONS: This study provides a theoretical basis and robust data to support the development of personalized, precision-nutrition plant milk beverages and flavor prediction. © 2026 Society of Chemical Industry.