Some Chemical and Flavor Characteristics of a Milk Proteolysate of Pseudomonas Fluorescens

Abstract

Analyses were nmde for chemical components related to flavor during different processing stages. The flavor changed from bitter and undesirable during fermentation to beef broth-like in the low-pressure distilled, autoclaved product. Fraetionation on Sephadex G-25 showed four peaks of absorbaney at 280 mtL. The brothy flavor did not correlate closely with any peak maxima, but was concentrated in the effluent from the 145-ml volume to the 160-ml volume. This effluent contained 17 free amino acids. Spectrophotometrie analyses for carbohydrate, ninhydrin-reactive compounds, phosphate, and furfural derivatives in each case gave a small initial peak and a larger second peak. The latter corresponded closely to the brothy flavor fraction. Of neutral volatiles detected by GLC, none was associated exclusively with the brothy flavor fraction. The heating of combinations of amino acids and lactose gave flavors suggestive of but not identical to the brothy flavor. Apparently, the beef broth type flavor in the processed product resulted from an intricate balance among lactose content, protein breakdown, and browning.