Enhanced biotransformation of bioactive components and volatile compounds of bamboo (Phyllostachys glauca McClure) leaf juice fermented by probiotic Streptococcus thermophiles

The potential probiotic starter Streptococcus thermophilus was selected to ferment Phyllostachys glauca McClure leaf (PML) juice to generate the favorite sensory flavor through 48 h. The polysaccharides, total flavonoids, and polyphenols in the fermented PML juice showed significant changes with increasing accumulation at 1210%, 46.8%, and 44.1%, respectively. Volatile profiles of PML juice showed that the number of aldehydes, ketones, and alcohols accounted for approximately 60% of the 65 identified compounds, while contents of volatiles in fermented PML juice increased by 8% with probiotics but those of unfermented juice decrease by over 16%. 23 key aroma compounds, such as dihydro-α-ionone, damascenone, dihydroactinidiolide, dodecanoic acid, 1-tetradecanol, and dodecanal are significantly affected by fermentation. The addition of S. thermophilus mainly promoted carotene oxidation and lipid degradation while enabling high-level biotransformation of aroma compounds that contribute to floral, fruity, waxy, and fatty senses to enhance the flavor of fermented PML juice.