In Vitro Evaluations of Protein and Protein-Safflower Oil Complexes Treated with Formaldehyde

Abstract

Casein, safflower meal and kernels, sesame meal and kernels, soy protein and alfalfa meal were treated with formaldehyde and the subsequent protection of the protein from rumen microbial digestion was determined from the ammonia produced during a 21-hr. in vitro incubation. Safflower oil was added to some casein and alfalfa meal samples and the protection of unsaturated fatty acids and protein were studied. If the reaction mix was not washed after treatment, casein treated with formaldehyde at 1% or more of sample weight had less than 10% as much ammonia released as untreated casein. Heating the protein tended to enhance the protection of formaldehyde-treated casein from microbial degradation, but this enhancement apparently was an additive effect rather than a formaldehyde-temperature interaction. Linoleic acid content of formaldehyde-treated samples were approximately twice that of an untreated casein-safflower oil sample after incubation. Cracked safflower kernel protein was readily protected from rumen microbial degradation. Copyright © 1974. American Society of Animal Science . Copyright 1974 by American Society of Animal Science.