4th Nordic Pet Food Seminar
At the 4th Nordic Pet Food Seminar 2018 in Prague, an event dedicated to pet health and well-being, Francesca Susca, Ph.D., DVM, Pet Development Manager at Lallemand Animal Nutrition, gave a lecture titled: “All you need to know about Yeasts – Benefits and applications in petfood”. She concluded that: “From flavor enhancer to source of nutrients and functional ingredients, yeast and yeast derivative products are versatile and natural ingredients to bear in mind when formulating for our beloved pets”.
Yeast has been utilized since at least the ancient Egypt to leaven bread and ferment wine, and Saccharomyces cerevisiae remains the organism the most used in the food industry. Its exceptional fermentative and nutritional qualities make yeast a valuable source of ingredients for pet nutrition too. But not all yeast nor yeast products are equivalent.
Francesca Susca reviewed the multiple benefits and applications of yeast and yeast derivatives products and proposed a rational way to classify these products according to their nutritional value and biological activities, their identity (yeast species), production process, stressing that the production processes influence ingredients characteristics, as well as their regulatory status:
- Live yeast, or probiotics: Saccharomyces cerevisiae boulardii is the most documented and used probiotic yeast in human, with benefits in digestive health.
- Whole cell inactive yeast: depending on the production process and the type of yeast used they can be used as flavor enhancers (different types of yeast bring different flavors, e.g. Torula yeast is used to bring a savory, buttery flavor notes). Whole inactive yeast is a great source of B vitamins and nutrients, such as high quality protein and minerals. Selenium enriched yeast is a source of highly bioavailable selenium (antioxidant and immune function).
- Yeast fractions: following yeast cells disruption, the soluble part, or yeast extracts, are separated from the insoluble yeast cell walls:
- Yeast extracts contain over 60% of proteins: they represent a valuable source of proteins, nutrients and minerals and can also be used as natural flavor enhancers.
- Yeast cell walls, rich in beta-glucan and mannan oligo saccharides, also called MOS, which are well described for their pathogen binding and immune-modulation activities. They can contribute to microbiota balance and digestive well-being. Production processes have a great influence on the end-product qualities, the MOS contents and hence efficacy. In particular, yeast cell walls issued from a primary production process with a selected yeast strain are preferable to by-products from brewery or distillery production as the quality and homogeneity of the MOS content is highly variable and purity of the product is not guaranteed in the later.