Bitter flavour in dairy products. I. A review of the factors likely to influence its development, mainly in cheese manufacture

Following a definition of bitte mess and a mention of the Iink between the bitterness of peptides and their content of hydrophobie amino acid residues, a detailed description is given of the numerous factors Iikely to influence the development of bitter off-flavour defect in dairy products with emphasis on cheese. Factors such as milk quality, pH, psychrotrophic bacteria, fat and minerai content, the cheese manufacturing process including the cooking temperature, salt concentration and manner of draining the curd, the acidity or the pH of cheese, and sanitary processing and hygienic packaging conditions are less important than bacterial proliferation in the cheese vat and the type and amount of starter and rennet used. The major roles played by these last three factors are better understood since the development of the aseptic vat technique. Finally, possible ways are mentioned of keeping the concentration of bitter peptides below the threshold level for bitter taste detection.