Effect of the Volume of HCl in Minimizing Amino Acid Losses when Carbohydrate-Containing Samples Are Hydrolyzed

Abstract Investigations were conducted to determine the optimum level of hydrochloric acid required to minimize amino acid destruction during hydrolysis with samples containing carbohydrate. With the exception of serine, recoveries for all of the amino acids from hydrolysates containing the (HCl to Glucose) ratio of 2851:1 were not lowered more than 3.2% when compared with the hydrolyzed standard mixture. When the (HCl to Glucose) ratio was lowered from 2851:1 to 712:1, the following statistically significant percent losses to basic and hydroxyl amino acids occurred: histidine 1.2, lysine 2.8, serine 6.0 and threonine 6.8. With corn hydrolysates, the basic-hydroxyl amino acid degradative trend continued as the calculated (HCl to Carbohydrate) ratio of 712:1 was lowered to 260:1. The statistically significant percent losses which occurred were as follows: arginine 4.5, serine 4.3, methionine 9.8 and glycine 5.5. With the types of carbohydrate investigated, the results indicate that a reasonable milligram (HCl to Carbohydrate) ratio for minimizing amino acid destruction during hydrolysis be greater than 700:1 and preferably 2800:1. The ratios used in both studies are of practical importance, since they span carbohydrate: amino acid ratios which exist in various feedstuffs and mixed diets.