Maillard reaction in enteral formula processing: furosine, loss of o-phthaldialdehyde reactivity, and fluorescence

Abstract

In order to evaluate heat effects induced during the manufacture of enteral formula, the following indicators were determined: furosine; loss of available amino groups, measured by decrease in o-phthaldialdehyde (loss of OPA reactivity); and fluorescence intensity (FI) associated with Maillard reaction (345 nm excitation, 415 nm emission). In addition, furosine and fluorescence were determined in model systems performed with the protein and carbohydrate ingredients of these products. The precision obtained for furosine, loss of OPA reactivity and fluorescence was 2.93, 1.89 and 1.72%, respectively. Furosine values decreased during the manufacturing process (UHT, standardization and sterilization). Heating at 120 °C produced a decrease in furosine content in model systems with whey proteins and an increase in systems with casein-carbohydrates. During the manufacturing, the loss of OPA reactivity reached 26.5 and 14% in the two types of formulas assayed. FI increased during heating in the formula processing and model systems