Quality Changes in Kefir: Influence of Fat Content and Fermentation Time

Hatice Sıçramaz; Buse Ebrar Güven

Quality Changes in Kefir: Influence of Fat Content and Fermentation Time

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

Authors thank to Elif Aşbay and Derya Ünal for their valuable supports.

References

J. M. R. Tingirikari, A. Sharma, and H.-J. Lee, “Kefir: A fermented plethora of symbiotic microbiome and health,” Journal of Ethnic Foods, vol. 11, 2024, Art. no. 35, doi: 10.1186/s42779-024-00252-4.
Z. B. Guzel-Seydim, T. Kok-Tas, A. K. Greene, and A. C. Seydim, “Review: Functional properties of kefir,” Crit. Rev. Food Sci. Nutr., vol. 51, no. 3, pp. 261–268, 2011, doi: 10.1080/10408390903579029.
M. R. Prado, L. M. Blandón, L. P. S. Vandenberghe, C. Rodrigues, G. R. Castro, V. Thomaz-Soccol, and C. R. Soccol, “Milk kefir: Composition, microbial cultures, biological activities, and related products,” Front. Microbiol., vol. 6, 2015, Art. no. 1177, doi: 10.3389/fmicb.2015.01177.
C. P. Vieira, A. I. L. S. Rosario, C. A. Lelis, B. S. S. Rekowsky, A. P. A. Carvalho, D. K. A. Rosário, T. A. Elias, M. P. Costa, D. Foguel, and C. A. Conte-Junior, “Bioactive compounds from kefir and their potential benefits on health: A systematic review and meta-analysis,” Oxid. Med. Cell. Longev., vol. 2021, Art. no. 9081738, 2021, doi: 10.1155/2021/9081738.
J. Ebner, A. Aşçı Arslan, M. Fedorova, R. Hoffmann, A. Küçükçetin, and M. Pischetsrieder, “Peptide profiling of bovine kefir reveals 236 unique peptides released from caseins during its production by starter culture or kefir grains,” J. Proteomics, vol. 117, pp. 41–57, 2015, doi: 10.1016/j.jprot.2015.01.005.
L. Fels, F. Jakob, R. F. Vogel, and D. Wefers, “Structural characterization of the exopolysaccharides from water kefir,” Carbohydr. Polym., vol. 189, pp. 296–303, 2018, doi: 10.1016/j.carbpol.2018.02.037.
V. Ganatsios, P. Nigam, S. Plessas, and A. Terpou, “Kefir as a functional beverage gaining momentum towards its health promoting attributes,” Beverages, vol. 7, no. 3, Art. no. 48, 2021, doi: 10.3390/beverages7030048.
H. Temiz and G. Kezer, “Effects of fat replacers on physicochemical, microbial and sensorial properties of kefir made using mixture of cow and goat’s milk,” J. Food Process. Preserv., vol. 39, no. 6, pp. 1421–1430, 2015, doi: 10.1111/jfpp.12361.
H. Rizqiati, N. Nurwantoro, E. Prayitno, I. W. Muttaqin, and R. Pangestu, “The effect of fermentation time on the physicochemical and microbiological qualities of buffalo colostrum kefir,” J. Appl. Food Technol., vol. 10, pp. 31–36, 2023, doi: 10.17728/jaft.20732.
A. M. O. Leite, D. C. A. Leite, E. M. Del Aguila, T. S. Alvares, R. S. Peixoto, M. A. L. Miguel, J. T. Silva, and V. M. F. Paschoalin, “Microbiological and chemical characteristics of Brazilian kefir during fermentation and storage processes,” J. Dairy Sci., vol. 96, no. 7, pp. 4149–4159, 2013, doi: 10.3168/jds.2012-6263.

M. A. Farag, S. A. Jomaa, A. Abd El-Wahed, and H. R. El-Seedi, “The many faces of kefir fermented dairy products: Quality characteristics, flavour chemistry, nutritional value, health benefits, and safety,” Nutrients, vol. 12, no. 2, Art. no. 346, 2020, doi: 10.3390/nu12020346.
B. Dwiloka, H. Rizqiati, and B. E. Setiani, “Physicochemical and sensory characteristics of green coconut (Cocos nucifera L.) water kefir,” Int. J. Food Stud., vol. 9, no. 2, pp. 346–359, 2020, doi: 10.7455/ijfs/9.2.2020.a7.
G. Dimitreli, D. Petridis, N. Kapageridis, and M. Mixiou, “Effect of pomegranate juice and fir honey addition on the rheological and sensory properties of kefir-type products differing in their fat content,” LWT, vol. 111, pp. 799–808, 2019, doi: 10.1016/j.lwt.2019.05.071.
B. Ertekin and Z. B. Guzel-Seydim, “Effect of fat replacers on kefir quality,” J. Sci. Food Agric., vol. 90, no. 4, pp. 543–548, 2010, doi: 10.1002/jsfa.3855.
C. Tan, Y. Tian, L. Tao, J. Xie, M. Wang, F. Zhang, Z. Yu, J. Sheng, and C. Zhao, “Exploring the effect of milk fat on fermented milk flavor based on gas chromatography–ion mobility spectrometry (GC-IMS) and multivariate statistical analysis,” Molecules, vol. 29, no. 5, Art. no. 1099, 2024, doi: 10.3390/molecules29051099.
D. Cais-Sokolińska, J. Wójtowski, J. Pikul, R. Danków, M. Majcher, J. Teichert, and E. Bagnicka, “Formation of volatile compounds in kefir made of goat and sheep milk with high polyunsaturated fatty acid content,” J. Dairy Sci., vol. 98, no. 10, pp. 6692–6705, 2015, doi: 10.3168/jds.2015-9441.
F. Yıldız-Akgül, “Microbiological, physicochemical, and sensory characteristics of kefir produced by secondary fermentation,” Mljekarstvo, vol. 68, no. 3, pp. 201–213, 2018, doi: 10.15567/mljekarstvo.2018.0305.
S.-H. Yoo, K.-S. Seong, and S.-S. Yoon, “Physicochemical properties of kefir manufactured by a two-step fermentation,” Korean J. Food Sci. Anim. Resour., vol. 33, no. 6, pp. 744–751, 2013, doi: 10.5851/kosfa.2013.33.6.744.
J. L. Paredes, M. L. Escudero-Gilete, and I. M. Vicario, “A new functional kefir fermented beverage obtained from fruit and vegetable juice: Development and characterization,” LWT, vol. 154, Art. no. 112728, 2022, doi: 10.1016/j.lwt.2021.112728.
J. Isanga and G. Zhang, “Production and evaluation of some physicochemical parameters of peanut milk yoghurt,” LWT – Food Sci. Technol., vol. 42, no. 6, pp. 1132–1138, 2009, doi: 10.1016/j.lwt.2009.01.014.
A. M. Abdeldaiem, A. H. Ali, N. Shah, M. Ayyash, and A. H. Mousa, “Physicochemical analysis, rheological properties, and sensory evaluation of yogurt drink supplemented with roasted barley powder,” LWT, vol. 173, Art. no. 114319, 2023, doi: 10.1016/j.lwt.2022.114319.
T. I. Magra, K. D. Antoniou, and E. I. Psomas, “Effect of milk fat, kefir grain inoculum and storage time on the flow properties and microbiological characteristics of kefir,” J. Texture Stud., vol. 43, no. 4, pp. 299–308, 2012, doi: 10.1111/j.1745-4603.2011.00343.x.
E. Alves, E. N. Ntungwe, J. Gregório, L. M. Rodrigues, C. Pereira-Leite, C. Caleja, E. Pereira, L. Barros, M. V. Aguilar-Vilas, C. Rosado, and P. Rijo, “Characterization of kefir produced in household conditions: Physicochemical and nutritional profile, and storage stability,” Foods, vol. 10, no. 5, Art. no. 1057, 2021, doi: 10.3390/foods10051057.
R. Xiao, M. Liu, Q. Tian, M. Hui, X. Shi, and X. Hou, “Physical and chemical properties, structural characterization and nutritional analysis of kefir yoghurt,” Front. Microbiol., vol. 13, Art. no. 1107092, 2023, doi: 10.3389/fmicb.2022.1107092.
M. Bensmira and B. Jiang, “Effect of some operating variables on the microstructure and physical properties of a novel kefir formulation,” J. Food Eng., vol. 108, no. 4, pp. 579–584, 2012, doi: 10.1016/j.jfoodeng.2011.07.025.
D. Saygılı, D. Döner, F. İçier, and C. Karagözlü, “Rheological properties and microbiological characteristics of kefir produced from different milk types,” Food Sci. Technol., vol. 42, 2022, doi: 10.1590/fst.32520.
K. T. Magalhães, G. V. de M. Pereira, C. R. Campos, G. Dragone, and R. F. Schwan, “Brazilian kefir: Structure, microbial communities and chemical composition,” Braz. J. Microbiol., vol. 42, no. 2, pp. 693–702, 2011, doi: 10.1590/S1517-83822011000200034.
J. R. Manurung, H. Rizqiati, and V. P. Bintoro, “Viscosity, total acid, protein and hedonic level of kefir made from buffalo milk with different concentration of kefir grain,” J. Appl. Food Technol., vol. 9, pp. 1–4, 2022, doi: 10.17728/jaft.6777.

Details

Primary Language

English

Subjects

Dairy Technology

Journal Section

Research Article

Authors

Hatice Sıçramaz ^*
0000-0002-5943-9566
Türkiye

Buse Ebrar Güven
0009-0000-1342-5823
Türkiye

Early Pub Date

March 14, 2026

Publication Date

March 14, 2026

Submission Date

November 26, 2025

Acceptance Date

February 5, 2026

Published in Issue

Year 2026 Volume: 1 Number: 1

IZ

https://izlik.org/JA23YY37NS

APA

Sıçramaz, H., & Güven, B. E. (2026). Quality Changes in Kefir: Influence of Fat Content and Fermentation Time. Food Science Insights, 1(1), 1-9. https://izlik.org/JA23YY37NS

AMA

1.Sıçramaz H, Güven BE. Quality Changes in Kefir: Influence of Fat Content and Fermentation Time. Food Science Insights. 2026;1(1):1-9. https://izlik.org/JA23YY37NS

Chicago

Sıçramaz, Hatice, and Buse Ebrar Güven. 2026. “Quality Changes in Kefir: Influence of Fat Content and Fermentation Time”. Food Science Insights 1 (1): 1-9. https://izlik.org/JA23YY37NS.

EndNote

Sıçramaz H, Güven BE (April 1, 2026) Quality Changes in Kefir: Influence of Fat Content and Fermentation Time. Food Science Insights 1 1 1–9.

IEEE

[1]H. Sıçramaz and B. E. Güven, “Quality Changes in Kefir: Influence of Fat Content and Fermentation Time”, Food Science Insights, vol. 1, no. 1, pp. 1–9, Apr. 2026, [Online]. Available: https://izlik.org/JA23YY37NS

ISNAD

Sıçramaz, Hatice - Güven, Buse Ebrar. “Quality Changes in Kefir: Influence of Fat Content and Fermentation Time”. Food Science Insights 1/1 (April 1, 2026): 1-9. https://izlik.org/JA23YY37NS.

JAMA

1.Sıçramaz H, Güven BE. Quality Changes in Kefir: Influence of Fat Content and Fermentation Time. Food Science Insights. 2026;1:1–9.

MLA

Sıçramaz, Hatice, and Buse Ebrar Güven. “Quality Changes in Kefir: Influence of Fat Content and Fermentation Time”. Food Science Insights, vol. 1, no. 1, Apr. 2026, pp. 1-9, https://izlik.org/JA23YY37NS.

Vancouver

1.Hatice Sıçramaz, Buse Ebrar Güven. Quality Changes in Kefir: Influence of Fat Content and Fermentation Time. Food Science Insights [Internet]. 2026 Apr. 1;1(1):1-9. Available from: https://izlik.org/JA23YY37NS