The Pure Probiotic Initiative: The triad of probiotic quality: Timing, temperature and moisture

By Kelly C. Heim, Ph.D.

Probiotics are living organisms with unique sensitivities to their surroundings. Decades of research in microbiology have determined numerous predicates of their survival in different environments. Even with full GMP compliance, manufacturing poses many threats to probiotic survival and storage durability.1 Pure Encapsulations has developed a tightly regulated manufacturing process, in which every step is designed to optimize three well-established viability determinants. Collectively known as the Viability Triad, these determinants are temperature control, moisture control and timing.

Temperature control

The most familiar variable affecting probiotic viability is temperature.1,2 At Pure Encapsulations, ambient temperature is maintained within a specific range throughout all stages of receiving, handling and manufacturing. Finished probiotic products are stored in designated walk-in coolers until shipment, which are maintained at 4°C, a scientifically established and widely recognized storage temperature for microorganisms. While these measures are vital, maintaining a cool ambient environment comprises only one aspect of temperature optimization. An equally important consideration is the control of temperature fluctuations.

Freezing and thawing probiotics too quickly causes lethal condensation. This fluctuation in temperature is a major cause of potency reductions during standard manufacturing processes. Harmful temperature differentials are circumvented by gradually bringing the material from storage temperature to the manufacturing temperature in a controlled procedure known as tempering. To optimize tempering protocols from start to finish, probiotics are purchased in small packages and the protocol is determined based on weight and the stage of manufacturing.

Moisture control

Control of moisture in the air and in the probiotic material itself is even more important to survival than control of temperature.1,2 One of the advantages of low relative humidity is that manufacturing temperatures can be higher without loss of viability. Relative humidity is monitored and recorded in all rooms every two hours, including the warehouse, walk-in coolers and every production room, and operations proceed only within specific limits. During the blending of raw material, compressed dry air is used at a low, tightly controlled dew point, the temperature at which moisture in the air condenses to water.

Controlling ambient moisture through these procedural refinements is fundamental to ensuring probiotic viability. However, once encapsulated, moisture in the material itself can reduce stability and potency during manufacturing and storage.3 To minimize moisture inside the capsule environment, Pure Encapsulations probiotics are formulated to include a proprietary rice base to minimize water activity (Aw), which refers to the ability of water to interact with microorganisms. Together with rigorous temperature and humidity specifications for all stages of production, low-Aw formulation ensures viability of the finished product through its date of expiration.


Operating efficiently within strict time limits reduces incidental exposure to both humidity and temperature. Accordingly, timing is incorporated into relevant standard operating procedures (SOP). Upon receipt of raw material, the sequence of entering stock into our system and sample collection for identity testing is performed rapidly and with precision specified by the SOP. Other sensitive steps, such as weighing and blending, are also temporally regulated in a manner that keeps the raw material cool and dry.

The Viability Triad has afforded systemic innovations in manufacturing that exceed standard GMP compliance and ensure stability, potency and reliability of every finished probiotic product. This is just one aspect of Pure Encapsulations’ long-standing commitment to excellence in probiotic innovation and quality control. Adherence to the most scientifically validated methods for maintaining probiotic quality ensures that practitioners can be confident in the potency and efficacy of each product through its date of expiration.



  1. Mattila-Sandholma T, Myllärinena P, Crittendena R, et al. Technological challenges for future probiotic foods. Int Dairy J. 12(2–3);173–182, 2003.
  2. Stanton C, Ross RP, Fitzgerald G, Collins K. Application of probiotic bacteria to functional foods. Dairy Products Research Centre, End of Project Report, DPRC (31), 2000.
  3. Vesterlund S, Salminen K, Salminen S. Water activity in dry foods containing live probiotic bacteria should be carefully considered: A case study with Lactobacillus rhamnosus GG in flaxseed. Int J Food Microbiol 157(2);319–321, 2012.