Sensory Characteristics of UHT Milk Processed by Indirect and Direct Heating Methods: Studies on the Sensory Characteristics and Physicochemical Properties of UHT Processed Milk Part IV

Sensory evaluation by an expert panel and by a housewife panel was conducted to determine sensory characteristics of UHT milk processed at 140°C for 2 seconds by the indirect and direct heating methods. The effect of UHT processing on the physicochemical properties of milk was the greatest for plate-type pasteurization and less for infusion and injection in that order. Appropriate indicators for the heating degree were denaturation rate of whey proteins, rennetability and lactulose content. An evaluation of the sensory attributes and the principal component analysis of these attributes revealed that UHT milk processed by plate-type pasteurization provided thickness of body. Of the three types of UHT milk in the evaluation, this type was judged to be most unique in character. UHT milk processed by injection and infusion was judged to be thin in body and acceptable in other sensory attributes. The housewife panel judged the plate-type processed milk to have the best palatability.