Table 2.
Microbiological and nutritional characterization of the kefir used in the different studies and production protocols (when available).
| References | Concentration | Microbiological and nutritional composition | Production protocol |
|---|---|---|---|
| Bellikci-Koyu et al. (19) | – | - Culture DC1500I; - Lactococcus lactis subsp. lactis, L. lactis subsp. cremoris, L. lactis subsp. diacetylactis, Leuconostoc mesenteroides subsp. cremoris, Lactobacillus kefiri, Kluyveromyces marxianus, Saccharomyces unisporus. |
- Produced in whole milk 3.5%; - Distribution to volunteers twice a week. |
| Bourrie et al. (28) | 1% (w/v) | For commercial kefir: - Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, L. casei, L. acidophilus, L. delbrueckii subsp. lactis, L. rhamnosus, Bifidobacterium lactis, Lactococcus lactis subsp. lactis biovar diacetylactis, L. lactis subsp. cremoris, Leuconostoc mesenteroides subsp. cremoris; - 8.0 × 106 CFU/ml. For traditional kefir: - No information. |
- Produced daily in cow's milk 2%; - Fermentation at 22°C for 18 h. |
| Chen et al. (29) | – | - Lactobacillus mali APS1; - 107 to 1010 CFU/mg. |
- Fermentation at 30°C for 12 h. |
| Fathi et al. (23) | – | – | - Produced by Fars Pegah Dairy Co., Shiraz, Iran. |
| Golli-Bennour (31) | – | - Traditional Tunisian culture, containing lactic acid bacteria; - Predominant population are lactic acid bacteria (9.5 ± 0.15 × 1010 CFU/g) and yeast (9.2 ± 0.14 × 106 CFU/g). |
- Daily production. |
| Kim et al. (32) | 10% | - Each mL contains: 9.62 ± 0.19 Log CFU of lactic acid bacteria, 9.52 ± 0.12 Log CFU of acetic acid bacteria and 7.67 ± 0.30 Log CFU of yeast. | - Fermentation at 25°C for 24 h. |
| Kim et al. (33) | 5% (w/v) | - Lactobacillus kefiranofaciens, L. kefiri, L. lactis, Leuconostoc mesenteroides. | - Fermentation at 25°C for 24 h. |
| Kim et al. (20) | 10% | - Each mL contains: 9.32 ± 0.23 Log CFU of lactic acid bacteria and 7.12 ± 0.36 Log CFU of yeast. | - Fermentation at 25°C for 24 h. |
| Lim et al. (35) | 1:10 (w/w) | - Grains from the KU Center for Food Safety, College of Veterinary Medicine, Konkuk University. | - Produced in UHT milk; - Fermentation ate 30°C overnight; - Production for 6 continuous weeks followed by lyophilization and storage at - 20°C. |
| Noori et al. (36) | – | - pH: 4.8 | - Cow's milk UHT or soy milk; - Fermentation at 25°C for 24 h followed by storage at 4°C to interrupt the process. |
| Ostadrahimi et al. (24) | – | - Streptococcus thermophiles, Lactobacillus casei, L. acidophilus, Bifidobacterium lactis; - Fat: 0.3%. |
- Weekly production. |
| Ozcan et al. (25) | – | - Kefir produced by Altinkiliç Company, Turquia; - No sugar and no flavor. |
- Stored at 4°C and delivered to volunteers weekly. |
| Praznikar et al. (26) | – | - Lactobacillus parakefiri, L. kefiri, L. kefiranofaciens ssp. kefirgranum, Kluyveromyces marxianus, Kazachstania exigua, Rhodosporidium kratochvilovae; - 80% water; - pH 4.03. |
- Produced by Ljubljanske mlekarne (Ljubljana, Slovenia) |
| Rosa et al. (37) | 5% (w/w) | - Lactic acid bacteria: 2.78 × 107 CFU/ml; - Yeast: 2.94 × 108 cell/ml; - Lactic acid 0.806 ± 0.04 g/100 g; - Fat: 3.03 ± 0.16 g/100 g; - Protein: 3.03 ± 0.01 g/100 g; - pH 4.10 ± 0.10. |
- Produced in pasteurized milk (3.5% protein, 5% carbohydrate and 3% fat); - Fermentation at 25–28°C for 24 h. |
| St-Onge et al. (27) | – | – | - Produced by Liberty Co, Candiac, Québec. |
| Sun et al. (38) | – | - Culture Collection Center of the Institute of Microbiology, Chinese Academy of Sciences (accession number CGMCC2809); - Lactobacillus kefiranofaciens ZW3. |
– |
| Talib et al. (43) | 10% (w/v) | - Mainly: Lactobacillus harbinensis, L. paracasei, L. plantarum; - All: L. harbinensis B22, HBUAS5305, NBRC 100982, FQ003; L. brevis HDRS2; L. sp MS6; L. plantarum Gt2, ZDY36a, HBUAS52249, NWAFU1558, Akhavan-Q3, Y-2-9, MSD1-4, DSR M2, LQ80; L. paracasei HBUAS52231, HBUAS53273; L. casei YQ116, H19.9. |
- Produced in water solution with brown sugar; - Fermentation at room temperature for 24 h. |
| Tiss et al. (39) | 5% (w/v) | – | - Soy milk; - Fermentation at 24 h; - Storage at 4°C (Produced every 7 days before consumption). |
| Tung et al. (40) | 10% (w/v) | – | - Fermentation at 20°C for 20 h; - Kefir undergoes two fermentation processes: First at 5% w/v concentration and then at 10% w/v concentration. |
| Vinderola et al. (41) | – | – | - Produced in pasteurized milk with 1.8% fat by Les Produits de - Marque Liberté (Candiac, Québec, Canada) |
| Wouw et al. (42) | 2% (w/v) | – | - Produced in whole milk from Irish cows; - Fermentation at 25°C for 24 h. |
Where: CFU, colony forming unit; g, gram; mg, milligram; mL, milliliters; pH, hydrogen potential; UHT, ultra-high temperature; v, volume; w, weight.