Including vitamin E (tocopherol) in a probiotic formulation was found to enhance the viability of the bacteria, whereas vitamin C (in the form of sodium ascorbate) was found to produce detrimental effects, according to researchers from CSIRO Division of Food and Nutritional Sciences in Australia and Zurich University of Applied Sciences in Switzerland.
The findings, published in the Journal of Agricultural and Food Chemistry, may have important implications for probiotic product formulators
“The main insight from this work is that both the chemical eﬀects of additives and their metabolic fate in the presence of probiotic bacteria have to be taken into account when they are incorporated into probiotic preparations,” wrote the researchers, led by CSIRO’s Mary Ann Augustin.
According the FAO/WHO, probiotics are defined as "live microorganisms which when administered in adequate amounts confer a health benefit on the host".
Many probiotic ingredients are supplied as freeze-dried cultures, explain the researchers, while spray drying is an attracting alternative to freeze drying because of a reduced cost.
However, spray drying and storage may decrease the number of viable probiotic cells, techniques such as encapsulation may “largely offset this to enhance the survival”, they added.
A particular threat to the viability of probiotics is chemical deteriorative reactions, and in oxidation of the cell membranes in particular. “Probiotic bacteria may therefore benefit from the incorporation of antioxidants within probiotic formulations intended for spray drying and extended storage.”
In order to test their hypothesis, the researchers produced spray-dried micro-encapsulated probiotic formulations using the Lactobacillus rhamnosus GG (LGG, Valio Ltd), and included tocopherol (Covi-ox T-70, Cognis), sodium ascorbate (DSM Nutritional Products), or both.
Results showed that tocopherol improved the viability of the probiotics during storage, which was attributed to its antioxidant activity.
On the other hand, the vitamin C salt “had detrimental effects on probiotic survival”, even when included with tocopherol.
“The reduced viability in Na-ascorbate containing microcapsule formulations is hypothesized to be due primarily to the production of acetic acids arising from chemical degradation reactions and the catabolism of ascorbate by LGG,” explained the researchers.
“This study highlights the importance of considering the detrimental consequences of degradative chemical reactions and the metabolic fate of additives on the viability of probiotics when designing probiotic encapsulant formulations,” they concluded.
Source: Journal of Agricultural and Food Chemistry
Published online ahead of print, Article ASAP, doi: 10.1021/jf202358m
“Tocopherol and Ascorbate Have Contrasting Effects on the Viability of Microencapsulated Lactobacillus rhamnosus GG”
Authors: DY. Ying, L. Sanguansri, R. Weerakkody, T.K. Singh, S. Freimller Leischtfeld, C. Gantenbein-Demarchi, M.A. Augustin