Some Factors Affecting the Biological Availability of Amino Acids in Fish Protein

INTRODUCTION IN recent years considerable effort has been made to develop a satisfactory method of determining the biological availability of amino acids in proteins. Growth response is the most common method of evaluating the availability of amino acids. However this technique has had two major disadvantages: the ability to evaluate only one amino acid at a time and, the tendency to overestimate availability and thus often give questionable results of greater than 100% availability. Smith and Scott (1965), Buraczewski et al. (1967), and Porter and Williams 1963) have attempted to measure availability by plasma amino acid response. However, interpretation of such results into practical availability figures is difficult. De Muelenaere et al. (1967), Waring (1969), and Bragg (1969) and workers at this laboratory (Payne et al., 1968; Soares and Kifer, 1970) have studied the digestibility of amino acids by measuring the amino acids in the intestine and/or in feces. Most…