Texture and consistency in oatmeal: A study on the effects of plant-based protein : A dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Food Innovation at Lincoln University

Oatmeal is a very popular breakfast cereal all over the world. Oatmeal is known for its practicality as well as its health benefits. This fast and nutritious breakfast meal can provide high carbohydrate and dietary fiber such as β-glucan, which can reduce LDL cholesterol. However, it is also known that plant-based foods such as oatmeal has low protein content. This study investigated the rheological and textural changes on oat paste when fortified with five different plant proteins such as fava bean, mung bean, pea protein, chickpea, and green lentil in order to boost its nutritional value. The study of this particular topic is very important for food developers since having a better understanding of starch-protein interaction will allow food developers to modify the rheological properties and to improve the organoleptic quality of various food products better, so that they can be more appealing and satisfying to consumers. In this experiment, oat flour was combined with different plant proteins and distilled water, then the mixture was put into a waterbath for 30 minutes at 95 °C. The textural analysis showed that the addition of some plant proteins such as mung bean and pea protein can increase the firmness, consistency, and cohesiveness; while the addition of chickpea and green lentil can decrease those factors. When exposed to increasing shear rate, the oat-protein mixture can maintain its viscosity better than the oatmeal alone. However, the addition of plant protein to oat paste in rising temperature can make the oatmeal more vulnarable to shear rate, which resulted to a decreased in viscosity. Meanwhile, the dynamic rheology tests such as amplitude sweep test and frequency test showed the crossover point in which the mixture turn from visoelastic solid to viscoelastic liquid and the rheological stability of the mixture in an increasing angular frequency range. Furthermore, the findings from this study can be used as a reference for food developers to expand the application of plant-based proteins in oatmeal or any oat-based/starch-based food products.