DE-2529 (RP 192) -- 18-Month Storage Study of Prepared Frozen Foods Containing Protein Concentrates ✓ Most Recent

Ground beef patties or steaks prepared with seasoning, with or without sauce, may be enriched by the addition of textured vegetable protein at a level of 8.5% and probably more (dry weight basis) with no adverse effect on sensory quality retention. There is an approximately doubling of protein content, but the PER (protein efficiency ratio) is reduced somewhat. These products maintained high, quality shelf-life when stored at -20°C or lower at fairly constant temperatures. . Addition of yeast single-cell protein had to be limited to 3% (dry weight basis) because of its high nucleic acid content. Even this small addition, however, increased total protein content by 40%, and improved the protein efficiency ratio. Sensory quality, however, was reduced so that high quality shelf-life was limited to 6 months. Even after 3 months there was a discernible rancid off-flavor. When stored at constant -30°C, high quality shelf-life was retained for 12 months. Non-fat milk solids, or cheese could be added where appropriate (e.g., pizza - as much as 10% dry weight basis), doubling and even tripling in some instances protein, and maintaining essentially the same PER. From the sensory acceptability standpoint, however, they behave quite similarily to the single-cell protein.