Biotechnology Journal International

Aim: This study aimed to investigate the microbiological and nutrient composition of naturally fermented apple cider.  

Place and Study Duration: Department of Microbiology, between June and August 2023.

Methodology: The purchased apples were weighed, cut into dice, cleaned, and incorporated into distilled water. Subsequently, they were allowed to ferment spontaneously at room temperature in a 500 mL conical flask. The sample was inoculated onto sterilized glucose yeast carbonate agar and subsequently incubated at 30°C for 48 hours. The colony characteristics of the isolates on glucose yeast carbonate agar were observed. Gram’s staining and other standard biochemical tests were performed to identify the isolates. During the fermentation period, the pH of the sample was determined. The proximate content (moisture, protein, crude fat, and carbohydrate) of the apple cider was also analyzed.

Results: Microscopy revealed the isolates to be Gram-negative bacteria with rod-shaped morphology. The growth characteristics of the isolates on selective media and the results of biochemical tests suggested the presence of Acetobacter sp. The pH of the sample tends towards 4.0, suggesting the production of acidic compound. The apple cider produced had a high moisture content (78.04%), and the protein content was 20.04%. The results showed low concentrations of ash content (0.49%), carbohydrate (0.44%), and lipid (0.99%).

Conclusion: The presence of macro and micronutrients in apple cider has been associated with some positive health effects, which are enhanced through fermentation, making them a valuable option for health-conscious consumers.