ARTICLE 76 FEED & ADDITIVE MAGAZINE July 2024 and obtain a pressed yeast (30 – 32 % dry weight) (7- Figure 2). Pressed yeast is extruded to form vermicelli (8) which are thoroughly dried (9). Different processing can be applied, for example in the case of TITAN protection. This patented technology enables the probiotic yeast to survive the harsh conditions of feed processing such as pelleting (heat, pressure, humidity) but also the chemical interactions with other aggressive ingredients and minerals. In this case, fermentation and drying conditions have been adapted and the active dry yeast undergoes a specific drying process before being microencapsulated. PACKAGING Packaging is done under strict conditions using appropriate packaging material. Tight control of temperature, O2 and humidity during packaging ensures product stability and activity. Packaging material is also important as they have varying levels of oxygen and moisture permeability. For example, live yeast products are packaged in oxygen and humidity impermeable laminates. Strain screening & selection process Yeast producers profile and select specific strains based upon their function and the specific outcome that is desired (e.g. benefits on digestive microflora of certain animal species). This screening is complex, time consuming and requires strict selection procedures to obtain strain purity. For example, the selection of ruminant specific yeast strain S. cerevisiae CNCM I-1077, performed at INRAE, was based on a set of desired functional traits. This single strain was selected among thousands of yeast strains through a stepwise screening process based on genetic and functional analysis for its ability to improve rumen function and microbiota balance. The final candidate has then been deposited at the Pasteur Institute under a unique registration number (CNCM I-1077), and its uniqueness is verified by its DNA profile. Yeast cells bank screening Functional assays Delta-PCR strain identification Selection of a unique strain to maximize energy from forage Saccharomyces cerevisiae CNCM I- 1077 Fiber Degradation Rate (MG/H) 0 0.1 0.2 0.3 0.4 0.5 0.6 Figure 2. Yeast filtration (Lallemand yeast plant, Montreal, CAN) Live pressed yeast (close-up on filtration) Vermicelli
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