The molecular and physicochemical mechanisms by which mushroom functional foods affect obesity associated metabolic diseases : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy

Obesity is rising around the world as a result of many factors, including an imbalance in food intake, an increased consumption of high-calorie diets, and a lack of physical exercise. Obesity not only leads to an increased risk for type 2 diabetes, cardiovascular disease and cancer, but also negatively affects longevity and quality of life. Anti-obesogenic approaches which are safe, widely available, and inexpensive are required to combat metabolic diseases. Mushrooms contain antioxidants, fibre and other phytochemicals, and have been shown to have anti-obesogenic and anti-diabetic effects through the modulation of diverse cellular and physiological pathways. In this thesis, three edible mushroom species (white button mushroom, shiitake mushroom and oyster mushroom) were selected as sustainable and functional food ingredients. Wheat-flour noodles were enriched with mushroom powder sourced from different parts (cap, stem, whole) at different levels (5%, 10%, 15%) to investigate the effects of mushroom addition on the nutritional composition, physical and textural properties. Noodles containing mushrooms had a nutritional advantage with higher protein and dietary fibre contents compared with wheat-flour noodles. The addition of 15% mushroom powder in the noodles resulted in a significant (p < 0.05) decrease in glycaemic glucose equivalents after in vitro digestion. The antioxidant levels of the samples increased following the in vitro digestion, and were positively correlated with the fibre content (p