Eureka! Institutional Repository

It is reported that human saliva contains about 20% v/v gas, trapped as foam. This raises questions on the physiological role of saliva as foam. Human saliva contains ingredients, such as mucins, that interact and affect food ingredients and especially foams that have been studied below. Initially, the effect of caseinates on artificial saliva was observed in the presence or absence of mucin with mechanical stirring. There was found to be an optimum concentration of casein and mucin for maximum foaming ability and stability. It was necessary for both ingredients to be added for optimum results. In addition, two methods of foam production were compared, with gas injection being the most powerful method with a large volume of foam, but caused its rapid collapse. On the other hand, with mechanical stirring the foam volume was lower but had greater relative stability over time. Finally, it was found that the change in pH strongly affects the amount of foam, which is lower at acidic pH, below the isoelectric point of caseins, where they precipitate. The foaming capabilities turned out to be better at neutral than at acidic pH.