Browsing by Subject "Geeliytyminen"

Demand for plant-based food is growing and alternative protein sources are explored to replace dairy and meat products. Due to weak functional properties of plant proteins compared to milk protein, it is challenging to create the desirable food structure. The coagulation of milk proteins plays an essential role in structure formation of many fermented milk products, but plant pro-teins may not behave in the same way. It is important to study the use of plant proteins in vari-ous food applications to bring organoleptically and nutritionally better plant-based products to the market. The aim of the work was to study transglutaminase (TG) induced gelling of plant-based proteins and determine whether calcium, pH, or enzyme dosage affects the quality of the gel structure. Pea protein isolate and oat protein concentrate were selected as the main raw materials for the study. Three different levels of calcium, pH and enzyme dosages and their effects on protein content (%), firmness (g) and dry matter content (%) of the samples was measured. Experi-mental plan and predictive models of the results was performed with Minitab software. Protein content of the samples was measured by using nitrogen analyzer, firmness of the samples by us-ing TAXT texture analyzer and dry matter content of the samples with moisture analyzer. Tricalcium phosphate was found to weaken the firmness of the samples when the dosage was 0,3 % or more. The most solid gel sample was found in pH 5,1, with small amount of enzyme and 0,05-0,3 % level of tricalcium phosphate. Dry matter of the samples was noted to increase at low pH level. TG increased the dry matter, especially when tricalcium phosphate was not ap-plied. TG was found to be an effective tool to improve protein gelling by forming a solid struc-ture for the samples. Higher amount of TG increased the protein content. It was shown to be possible to modify food characteristics by the studied process parameters, but the data set used in this study was small to provide reliable models. Further research should be done on the ef-fects and relationships between these factors to confirm results of the study.