Table 1.
Organisms in commercial yogurt products by region.
| Region | Type | Source | Analyzed microorganisms | Initial Count (log cfu/mL or g) | Final Count (log cfu/mL or g) | Age | CP* | References |
|---|---|---|---|---|---|---|---|---|
| Argentina | Full and reduced fat yogurt | Retail | S. thermophilus | 8.87–9.46 | – | Within shelf life | 6 | Vinderola and Reinheimer, 2000 |
| L. bulgaricusa | 5.58–7.95 | – | ||||||
| Bifidobacteriaa | 2.60–8.71 | – | ||||||
| L. acidophilusa | 4.62–8.39 | – | ||||||
| L. caseib | 8.02–8.33 | – | ||||||
| Set, skimmed set, drinking, and set with “dulce de leche” yogurtc | Industrially manufactured | Total LAB | 7.54–8.62 | – | Within shelf life | 25 | Birollo et al., 2000 | |
| S. thermophilus | 7.72–8.58 | – | ||||||
| L. bulgaricus | 7.29–7.38 | – | ||||||
| Australia | Full and reduced fat yogurtd | Commercially Manufactured | Streptococci | 9.15–9.6 | 8.79–9.15 | After manufacture and by expiration | 4 | Micanel et al., 1997 |
| L. bulgaricus | 9.08 | 8.36 | ||||||
| L. acidophilus | 6.66–8.08 | 6.38–8.04 | ||||||
| Bifidobacteria | 5.81 | 7.54 | ||||||
| Skim milk and regular yogurte | Did not specify | L. casei | – | 3.41–7.49 | Did not specify | 2 | Ravula and Shah, 1998 | |
| Variety of flavored, natural, and skinny yogurtf | Retail | S. thermophilus | 8.62–9.17 | – | After purchase | 5 | Tharmaraj and Shah, 2003 | |
| L. bulgaricus | 4.92–7.68 | – | ||||||
| L. rhamnosus | 7.36–7.72 | – | ||||||
| L. casei | 4.01–5.53 | – | ||||||
| B. lactis | 6.36–7.4 | – | ||||||
| L. acidophilus | 5.23–7.83 | – | ||||||
| Variety of flavored yogurtsg | Retail | L. acidophilus | < 2–8.34 | < 2–8 | After purchase (around 20–30 days before expiration) and at expiration | 26 CP from 14 companies | Shah et al., 2000 | |
| Bifidobacteria | < 2–6.86 | < 2–6.18 | ||||||
| L. casei | 5.65–8.18 | < 2–8.08 | ||||||
| Yogurth | Did not specify | L. acidophilus | – | 6.56 | – | 18 | Talwalkar and Kailasapathy, 2004 | |
| Bifidobacteria | – | 6.54 | ||||||
| L. casei | – | 6.38 | ||||||
| Yogurtij | Obtained from manufacturer | L. acidophilus | 4–8.5 | NVO−7.7 | After manufacture and 30 days | 5 | Shah et al., 1995 | |
| B. bifidum | 3.3–7 | NVO−2.5 | ||||||
| China | Yogurt | Retail | S. thermophilus + Lactobacillus | – | 4.0–8.18 | End of shelf life | 31 | Dong et al., 2014 |
| England | Yogurtk | Retail | Bifidobacteria | – | 4.9–7.62 | Does not specify | 8 | Iwana et al., 1993 |
| Greecei | Greek type yogurt | Obtained from manufacturer | S. thermophilus | 9.1 | 8.5 | 50 days (product shelf life) | 1 | Alexopoulos et al., 2017 |
| L. delbrueckii subsp. bulgaricus | 8.8 | 7.9 | ||||||
| Italy | Plain stirred style yogurt | Retail | S. thermophilus | 7.71–8.9 | – | 10 days after manufacture | 11 | De Noni et al., 2004 |
| L. bulgaricus | 5.48–8.41 | – | ||||||
| Sweetened stirred style yogurt | Retail | S. thermophilus | 8.3–9.59 | – | 10 days after manufacture | 11 | De Noni et al., 2004 | |
| L. bulgaricus | < 4–8.18 | – | ||||||
| South Africa | Low fat, fruit flavoredi | Obtained from manufacturer | S. thermophilus | 8.7–9.5 | 7.9−9.5 | Directly after production, and at expiration date | 3 | Lourens-Hattingh and Viljoen, 2002 |
| L. bulgaricus | 7–8.6 | 5.5–7 | ||||||
| L. acidophilus | 7–8.7 | 4.9–7 | ||||||
| B. bifidum | 2–5.2 | 2.2–4.9 | ||||||
| United States | Custard style yogurt—plain and flavoredi | Retail | Total LAB | 9.1 | – | 15 days after manufacture | 2 CP from 1 manufacturer | Hamann and Marth, 1984 |
| S. thermophilus | 9.1 | – | ||||||
| L. bulgaricus | 8.1 | – | ||||||
| Dannon, Breyers, Yoplait, YoBaby, Wal-Mart, and Kroger varieties | Retail | Lactobacillus | – | 7.68–8.98 | before expiration | 10 | Dunlap et al., 2009 | |
| Flavored yogurt | Retail | L. bulgaricus | 5.2–8.87 | 6.15–8.69 | 0 and 4 weeks after purchase | 58 CP/7 brands | Ibrahim and Carr, 2006 | |
| S. thermophilus | 7.51–8.94 | 7.9–8.99 | ||||||
| Bifidobacteria | < 1–4.7 | NVO** | ||||||
| Plain nonfat yogurt | Retail | S. thermophilus | 8.14–9.83 | – | After manufacture | 3 | Laye et al., 1993 | |
| L. bulgaricus | 9.04–9.33 | – | ||||||
| Stirred style yogurt–flavoredi | Retail | Total LAB | 8.6 | – | 6 days after manufacture | 1 | Hamann and Marth, 1984 | |
| S. thermophilus | 8.6 | – | ||||||
| L. bulgaricus | 7.3 | – | ||||||
| Yogurt | Retail | Total LAB | - | 7.2–8.1 | At expiration date | 2 | Shin et al., 2000 | |
| Bifidobacteria | – | 6.5–7.1 |
CP, commercial products.
NVO, No viable organisms.
Only viable in 4 of 6 CP.
Only viable in 3 of 6 CP.
Reported as average on duplicate agar plates.
L. delbrueckii spp. bulgaricus—reported in only one product. L. acidophilus −1 of 4 CP had NVO. Bifidobacteria−1 of 4 CP had NVO and 1 product had no detectable counts at initial enumeration (week 0).1
Lower end of range are microbial counts for skim milk yogurt and higher end are for regular yogurt. Both products claimed to contain L. casei.
S. thermophilus —Seen in 5 of 5 CP, “yogurt culture” claimed in all 5 CP. L. bulgaricus—Seen in 2 of 5 CP, “yogurt culture” claimed in all 5 CP. L. rhamnous—Claimed in 2 of 5 CP. L. casei—Claimed in 2 of 5 CP. B. lactis—Claimed in 4 of 5 CP. L. acidophilus—Claimed in 4 of 5 CP.
L. acidophilus—Claimed in 24 CP. Bifidobacteria—Claimed in 18 CP. L. casei—Claimed in 8 CP.
L. acidophilus—9 of 18 CP. Bifidobacteria-−8 of 18 CP. L. casei—6 of 18 CP.
Interpreted from graph.
L. acidophilus—2 of 5 CP had NVO. B. bifidum—4 of 5 CP had NVO.
Observed in 5 of 8 CP, claimed in all products.