This study investigated changes in nutrients (fatty acids, amino acids, and minerals), ginsenosides, and volatile flavors, and antioxidant activities during food processing of mountain-cultivated ginseng (MCG) with the cocktail lactic acid bacteria. Fatty acid content increased, but the free amino acid content decreased, and minerals were practically unaffected during processing. Total phenolic and flavonoid contents and maillard reaction products increased markedly according to processing stage. The total ginsenosides levels increased from 31.25 mg/g (DMCG) to 32.36 mg/g (red MCG, RMCG) and then decreased (27.27 mg/g, at fermented RMCG) during processing. Particularly, the contents of F2 (0.31 → 1.02 → 2.27 mg/g), Rg3 (0.36 → 0.77 → 1.93 mg/g), and compound K (0.5 → 1.68 → 4.13 mg/g) of ginsenosides and β-panasinsene (17.28 → 22.69 → 31.61%), biocycloelemene (0.11 → 0.84 → 0.92%), δ-cadinene (0.39 → 0.5 → 0.94%), and alloaromadendrene (1.64 → 1.39 → 2.6%) of volatile flavor compounds increased during processing, along with to the antioxidant effects (such as DPPH, ABTS, and hydroxyl radical scavenging activities, and FRAP). This study may provide several choices for the use of ginseng in functional foods and functional cosmetics.