The aims of this experiment were to investigate the effect of milk solid content and the varying temperatures of heat pretreatment on yoghurt quality to determine the difference in pH and titratable acidity of fermented milk. In order to carry out this experiment and gain accurate results three variations were tested: yoghurt produced with whole milk pasteurised at 72 °C for 15 seconds, 85 °C for 15 minutes and then whole milk with added 5 % milk solids also heated at 85 °C for 15 minutes, after this pretreatment stage all variables were fermented for 120 min at 44°C.
Table 1 shows the varying results of whole milk and whole milk with 5% SMP; in regards to °Brix, pH and titratable acidity, as shown in figure 1 indicates that whole milk with added 5% SMP treatment excels in all three testing components especially with °Brix. The °Brix score for whole milk 5% SMP sample result is 4.56° higher than the °Brix measurement for the whole milk sample. Brix is the total dissolved solids in a liquid; which includes sugars, salts, organic acids, and other soluble components in food. …show more content…
While treatment method C, which is the method I conducted, obtained the highest average rating in terms of acceptability, which I believe was due to the amount of lactic acid produced during pasteurisation, which gives yoghurt its distinctive taste of being sharp and acidic, along with its average firmness rating of 5 allowing it to be not to firmly set but, yet not to runny in consistency. Yet I believe my yoghurt could have used more time to become firmer in set as I rated it as semi set in my sensory analysis, suggesting whey proteins were not left long enough to coagulate for a firmer set (Tamime & Robinson,
Table 1 shows the varying results of whole milk and whole milk with 5% SMP; in regards to °Brix, pH and titratable acidity, as shown in figure 1 indicates that whole milk with added 5% SMP treatment excels in all three testing components especially with °Brix. The °Brix score for whole milk 5% SMP sample result is 4.56° higher than the °Brix measurement for the whole milk sample. Brix is the total dissolved solids in a liquid; which includes sugars, salts, organic acids, and other soluble components in food. …show more content…
While treatment method C, which is the method I conducted, obtained the highest average rating in terms of acceptability, which I believe was due to the amount of lactic acid produced during pasteurisation, which gives yoghurt its distinctive taste of being sharp and acidic, along with its average firmness rating of 5 allowing it to be not to firmly set but, yet not to runny in consistency. Yet I believe my yoghurt could have used more time to become firmer in set as I rated it as semi set in my sensory analysis, suggesting whey proteins were not left long enough to coagulate for a firmer set (Tamime & Robinson,