Abstract
Kefir has attracted global interest as both a traditional fermented beverage and a functional food, owing to its probiotic potential and health-promoting properties. Balancing nutritional benefits with consumer-acceptable sensory attributes remains an important research focus. This study investigated the combined effects of milk fat content and fermentation time on the physicochemical and sensory characteristics of kefir. Kefir was produced from ultra-high-temperature (UHT) cow’s milk with two fat levels—low-fat (0.1%) and full-fat (3.1%)—and fermented for 20 or 26 hours. Samples were analyzed for pH, water-holding capacity (WHC), viscosity, and sensory attributes. The pH exhibited a more pronounced decline in low-fat kefir after 26 h (4.46) compared to full-fat kefir (4.48), reflecting the buffering capacity of fat. WHC increased from 28.1% in low-fat kefir (20 h) to 57.1% in full-fat kefir (26 h). Likewise, viscosity was lowest in low-fat kefir at 20 h (16.0 P) and highest in full-fat kefir at 26 h (21.7 P). Sensory evaluation indicated that full-fat kefir fermented for 26 h received the highest scores for flavor (7.1) and overall acceptability (6.8), whereas low-fat kefir fermented for 26 h was rated lowest (flavor: 5.5; overall acceptability: 5.1). Principal component analysis confirmed that fat level was the primary determinant of kefir properties, while fermentation time accounted for secondary differentiation. These findings emphasize the critical role of fat in shaping kefir’s texture, acidity, and sensory perception, providing relevant insights for optimizing industrial production and consumer-oriented product development.
Keywords
Kefir Fat content Fermentation time Physicochemical properties Viscosity Sensory evaluation
Ethical Statement
A sensory panel was carried out with the approval of the Sakarya University Ethics Committee (E-61923333-050.99-525054), with the attendance of 17 trained participants (9 female, 8 male), aged 18–40 years and including staff and graduate students from Sakarya University.
Thanks
The authors thank to Elif Aşbay and Derya Ünal for their valuable supports.
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Details
| Primary Language | English |
|---|---|
| Subjects | Dairy Technology |
| Journal Section | Research Article |
| Authors | |
| Submission Date | November 26, 2025 |
| Acceptance Date | February 5, 2026 |
| Early Pub Date | March 14, 2026 |
| Publication Date | March 14, 2026 |
| IZ | https://izlik.org/JA23YY37NS |
| Published in Issue | Year 2026 Issue: Advanced Online Publication |
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