Validation Study of Total Fat Content by Automated Acid Hydrolysis (HYDROTHERM) – ISO 8262-1
Total fat is a crucial measurement in food analysis. Where fatty acids are bound to glycerides, sterol esters, glycol and phospholipids acid or alkaline hydrolysis is required. Hydrolysis disrupts cell walls, breaks up fat emulsions and lipid protein bonds.
Multiple AOAC methods exist for various matrices that incorporate acid or alkaline hydrolysis to accomplish total release of fat from various products followed by total fat extraction by mixed ethers.These AOAC methods are labour intensive with variations in reproducibility across matrices.
The HYDROTHERM is an automated, fully enclosed acid hydrolysis system according to ISO 8262-1 the Weibull-Berntrop gravimetric method. Paired with the SOXTHERM (rapid soxhlet extraction) the fat analysis of food products is fully automated with minimal labour. Presented in this validation study, HYDROTHERM data is compared to AOAC 922.06 method data which is a manual acid digestion utilizing Mojonnier tube extraction for acid hydrolysis. NIST 1546 Meat Homogenate (n=36) was analysed using both methods in which the HYDROTHERM performed equivalent to the AOAC method.
21 products including cheese, soups/sauces, meats (raw/cooked, deli, breaded), pet treats, tortillas, and taco shells were analysed in which the HYDROTHERM was found to have higher hydrolysis efficiency in comparison to the AOAC method. Utilizing the HYDROTHERM for automated acid hydrolysis, good repeatability, high productivity, precise results, and universal applicability is achievable.