PROTEIN-QUALITY OF ENTERAL NUTRITION PRODUCTS IS CONSISTENT WITH LABEL CLAIMS DURING SHELF-LIFE AND BEYOND EXPIRATION DATE

Objective Enteral formulas were monitored during their shelf life and beyond expiration date to examine protein quality. Design Protein qual ity was determined by protein efficiency ratio (PER) bioassays and ami no acid analyses. Setting A certified laboratory performed the PER tes ts according to procedures established by the Association of Official Analytical Chemists and recognized by the US Food and Drug Administrat ion (FDA). The amino acid analyses were performed in our laboratory us ing validated methods. Samples Commercially available formulas (Ensure , Osmolite HN, TwoCal HN) that contained protein blends of caseinates or caseinates with soybean protein isolate were studied. Main outcome measures Achievement of protein-quality values greater than or equal t o 70% of the fresh reference casein value as determined by the PER met hod would be consistent with adequate protein quality as described by the FDA. Levels of indispensable amino acids that meet or exceed the s tandards established by the National Research Council of the National Academy of Sciences are considered high-quality proteins. Levers of am ino acids throughout shelf life were compared with published label cla ims. Results Amino acid analyses, which included measurement of trypto phan and total sulfur amino acids, revealed that both fresh and outdat ed products met or exceeded standards for proteins of high biologic va lue and were consistent with label claims. The PER values ranged from 90% to 96% of the control diet for fresh product and 82% to 87% for pr oducts evaluated after expiration. Conclusion The enteral products stu died provide high-quality protein throughout the shelf life of the pro duct.