Abstract :
[en] Probiotic-based products, including functional ingredients, fermented foods, and diet supplements, are today widely distributed in the market, owing to their recognized promoting
effects on the human, animal and plant health. However, such products are much more
complex than we believe, based mainly on the living state and specificity of each
microorganism strain used for their formulation. It is therefore not surprising to encounter a
variability in the commercialized probiotic product quality and performance from various
manufacturers and different countries, even for the same formulation brands. Consequently, it
is highly expected to develop and validate a rapid standard test of quality and integrity control
for probiotic-based products in order to guarantee the same performance and authenticity
before their use. A thermal profiling and fingerprint generating method using a coupling
thermogravimetry - differential scanning calorimetry (TGA-DSC) responds to this goal,
which is the main purpose of the present communication. This calorimetric coupling
technique has been recently used for the first time as a fingerprinting tool for probiotic-based
powder products [1]. Such original approach provides unique qualitative and quantitative data
related to the decomposition and transition phases for each probiotic powder sample,
whatever its complexity, by monitoring the changes in the material mass and energetic
content under a constant temperature rise with well defined conditions. This new method has
a lot of advantages compared to the gold standard ones such as phenotypage and genotypage
techniques for the quality control and authentication of probiotic products. It reveals not only
the probiotic strain features but also those of the other functional ingredients (e.g.
cryoprotectors, antioxidants, etc.) added into the formulation. In fact, these additional
ingredients can also contribute to the functionality and performance of the product. In
addition, the method is rapid, highly reproducible, sensitive, adaptable to a high throughput
analysis, and requires only a small amount of sample without pretreatment. Its potential
validity has been shown by a comparative analysis using proteomics and in vivo test of
intestinal permeability [2], and inter laboratory analyses performed on a multi-strain probiotic
sample reference. Besides the pure analytical aspects, this method can also provide some
relevant fundamental information on the thermostability of the probiotic strains. More than
100 products containing, either mono-strain or multi-strain formulations, and pure strain
samples, have been tested with this method, and each sample shows a unique qualitative
profile and significant different quantitative thermophysical data. Comparative analyses with
other techniques and database creation are among the future investigations to be conducted in
such a promising quality and integrity control approach, which is also valuable for other food
and non food products.
