Introduction:
Kefir is an acidic-alcoholic natural fermented milk drink with rich probiotic content that has been consumed since ancient times. This research study aims to develop a cow-milk kefir drink in household conditions and determine its bioactive compounds, nutritional and antioxidant properties.

Methodology:
For the preparation of the synbiotic drink, kefir grains (3% w/v) were inoculated in cow milk and further allowed to ferment at 25°C for 24 hours. The drink was formulated with the same procedure in triplicate, stored at 4°C, and then further used for analysis. Nutritional and physiochemical analyses were performed as per AOAC methods, DPPH radical-scavenging activity and phenolic compounds were estimated using a UV spectrophotometer, and bioactive compound identification was performed using GC-MS.
Results:
The nutritional and antioxidant profiling of kefir milk drink resulted in the following: protein 3.6g, carbohydrates 2.66g, fat 3.4g, iron 2.99mg, calcium 29.3mg, potassium 107mg, and sodium 59.4mg per 100ml, DPPH antioxidant potential 54%, and 18mg/100 GAE phenolic compounds. The GC-MS results show that the home-based kefir milk drink contains numerous volatile compounds, including phenols for antioxidants, esters for the aroma and to potentially inhibit pathogenic microbes, unsaturated fats for cardioprotective support and anti-inflammatory properties, steroids for stability, polyalkenes for clarity and possible antioxidant support, and aromatic aldehydes for aroma and antimicrobial components.

Conclusion:
This research study highlights the unique nature and characteristics of the home-based kefir milk drink, recognizing the inherent variety of different parameters in home environments. Physicochemical, nutritional and bioactive compound profiling helped us to establish promising prospects for milk kefir drinks as healthy nutritional biomarkers.