Food & Supplements : Ingredients


Creating ‘Designer’ Yeast Hybrids for Brewing and More

UW–Madison researchers have developed HyPr, a simple and efficient method for generating synthetic Saccharomyces hybrids without sporulation or modification of the nuclear genome.

Specifically, using the new method, induction of HO endonuclease expression by a promoter in two diploid cultures, followed by co-culture and subsequent double-drug selection, will produce hybrids at a rate approaching 1 out of 1,000 cells plated. Plasmids can then be easily cured or spontaneously lost to produce strains without genome modifications.

The resulting strains can be rapidly screened for plasmid loss, opening an efficient route towards meeting the Generally Recognized as Safe (GRAS) standards of the U.S. Department of Agriculture and FDA.

Production of Milk Protein Concentrate with Energy and Environmental Savings and Reduced Equipment Needs

UW–Madison researchers have developed a novel approach for removing lactose from skim milk and other dried milk-derived products that reduces energy use and environmental impact. First, milk is concentrated under conditions that encourage the growth of large lactose crystals. The mixture is spray dried to form a powder, which contains small aggregates of proteins mixed with small molecules and large lactose crystals. The mixture then is sorted by particle size in a high speed air classifier, which uses an air stream and centrifugal forces to separate particles by shape, size and density. This method will produce a product with the same chemical and physical characteristics as moderately fortified milk protein concentrate, as well as a co-product with increased lactose content.

Cost-Saving Dairy Protein Separation Method

UW–Madison researchers have discovered that charged ultrafiltration membranes can be used to make separated dairy proteins of chromatographic purity without the need for sophisticated chromatography equipment, water or buffers. The method makes use of ultrafiltration membrane systems common in essentially every dairy processing facility worldwide.

After modifying the pH of the protein solution, the charged ultrafiltration membrane repels the charged proteins that are not of interest, and allows the protein of interest to freely pass through. The researchers made the surprising discovery that membranes having a pore size rating of 150-500 kDa can be used to fractionate dairy proteins much smaller in size such as GMP, ALA and beta-lactoglobulin. Purity and yields up to 98 percent can be attained using the new method.

Improved Methods for Producing Low-Cost Protein-Polysaccharide Conjugates for Use in Foods and Beverages

UW–Madison researchers have developed novel methods of producing protein-polysaccharide complexes using a wet heat treatment.  The process involves heating aqueous solutions containing protein in the presence of a polysaccharide with a reducing sugar.  High concentrations of a stabilizing polysaccharide, such as dextran, are used to prevent unwanted protein denaturation. The resulting PPCs exhibit improved thermal stability, more desirable color and excellent emulsifying properties.  They are superior to both unmodified protein and gum Arabic.

Purification of Beta Casein from Milk

UW-Madison researchers have developed a novel, low-cost separation protocol for removing functional beta-casein from milk without adding unwanted by-products. This process allows a significant amount of highly soluble beta-casein to be extracted from milk, while also improving the cheese-making properties of the milk. Beta-casein is separated from other milk serum components using non-ceramic, cross-flow polymeric microfiltration membranes to form a permeate enriched in beta-casein. Milk may be cooled prior to microfiltration to enhance the separation. Beta-casein is then easily purified from this enriched permeate through demineralization. Cheese formed using the milk partially depleted of beta-casein has enhanced meltability and reduced bitterness, while the purified beta-casein exhibits improved yield, purity and solubility; excellent foaming and emulsification properties; and is suitable for use as a food product additive.

Endopeptidases from L. helveticus Remove Bitterness in Cheese and Treat Gluten Intolerance

UW-Madison researchers have developed endopeptidase enzymes from L. helveticus that cleave bitter peptides and peptides involved in gluten inflammation. The enzymes, which were identified from a genomic library of L. helveticus, may be added to cheese or other foods during processing. They can be used for reducing bitterness in foods, particularly cheese, or for treating or preventing celiac sprue (gluten intolerance).

Wisconsin-Sourced Lager Yeast

The researchers have now found three new strains of S. eubayanus in Wisconsin. They were isolated from an old beech tree stand at Sheboygan Indian Mound Park. The strains were sequenced, and each was found to represent an admixture or mosaic of two Argentinian populations.

Locally Sourced Yeast from the Chicago Area

UW–Madison researchers and others recently identified novel strains of Saccharomyces cerevisiae, Torulaspora delbrueckii and Hanseniaspora uvarum. The strains were isolated in the Chicago region from soil, bark and fruit samples submitted through the citizen science branch of the Wild YEAST Program. The multiple strains may be of interest to the craft brewing industry.

Phage-Cured Lactobacillus Strains for Therapeutic Delivery

Using a newly developed counterselection method and promoter construct, UW–Madison researchers have created a modified strain of L. reuteri cured of two prophages and variations thereof. In the process of deleting the phages from the genome the researchers also deleted the recognition site (attB), thereby preventing future phage integration at the site.

The approach used to develop the novel strain does not induce DNA damage and effectively eliminates bacteriophages that could otherwise reactivate and lyse the host cell. The strain is more robust for surviving transit through the gastrointestinal tract, which the researchers envision will enhance its ability to deliver therapeutic proteins in vivo.