Mastering the Art of Bifidobacteria Enumeration in Dairy Products

Precision Protocols for Safeguarding Dairy Purity and Nutritional Excellence
January 18, 2024 by
Desiree Okpiaifo


Bifidobacterium, a powerhouse probiotic, takes center stage in the realm of milk products, offering an array of health benefits such as reducing serum cholesterol, boosting immune function, and alleviating lactose intolerance. This essential bacterium often plays a key role in the starter culture for the production of fermented delights like beverages, cottage cheeses, ice creams, and frozen desserts.

​Procedure for Enumeration of Presumptive Bifidobacteria (ISO 29981:2010):

1. Preparation of Test Portion:
Dried Milk Products:
Weigh 90 g of Saline Peptone Water or Ringer 1/4 Solution in each bottle.
Heat in a bath at 45oC, then add 10g of the test sample.
Heat for 5' and cool while shaking for 2'.
Yogurt-Like Products (ISO 6887-5):
At room temperature, weigh 90 g of diluent, pour it into closed bottles, and mix.
Add 10 g of test samples and mix again.
2. Microscopic Examination:
Utilize microscopic examination or phase microscopy to determine proper dilutions.
3. Preparation of Decimal Dilutions:
Perform 1:10 dilutions in sterile diluent. Mix before and after, following four recommended steps.
4. Inoculation and Incubation:
Inoculate 1 mL per dilution into Petri dishes with TOS Propionate Agar Base  supplemented with MUP, with 2 replicates each.
Add 12 - 15 mL of medium, mix, and cultivate at 37oC for 72h.
5. Colony Counting:
Identify bifidobacterial colonies by their whitish color. Count plates with a countable amount of colonies.

The enumeration of presumptive bifidobacteria is a meticulous process involving precise steps from preparation to colony counting. Understanding and mastering this procedure is crucial for ensuring the quality and safety of dairy products. Bifidobacteria not only contribute to the deliciousness of dairy delights but also add a dose of well-being to each bite. This comprehensive guide serves as a valuable resource for dairy producers committed to excellence in their craft.

Condalab 1405| Saline Peptone Water ISO 500grams

Condalab 4101 | Ringer Solution 1/4 ISO Pack of 20Tubes

Condalab 2011 | TOS Propionate Agar Base ISO 500grams

Condalab 6074 | Selective Supplement MUP 10 Vials

REST Client (Huachao Mao)