The Effects of Gellan Gum on the Acute Glycaemic and Appetitive Responses to a White Rice Meal and Impact on Energy Intake Over 7 Days

BACKGROUND: Rice is a carbohydrate-rich staple source of food for around half of the world population. Consumption is estimated to be 480 million tonnes per year. According to The Food and Agriculture Organization of the United Nations (FAO), rice is easily accessible to people in Asia, Pacific region, parts of Latin America and the Caribbean and, increasingly in Africa. Rice plays an important role in achieving an adequate dietary intake in these countries.

However high consumption of white rice has been linked with high obesity rates and increased risk for type 2 diabetes . However, it is still the favoured type of rice among consumers, contributing to the observed increasing trends in diet-related diseases in countries with high rice consumption . Modifying the properties of white rice products (e.g. reducing the glycaemic index and/or increasing satiety) with relatively simple interventions can contribute to producing foods that may promote better health due to modified digestion and post prandial metabolic and appetitive profiles. One way to reduce the glycaemic index of white rice may be the addition of hydrocolloids. These have previously been shown to modify the digestibility of foods . The health advantage derived from such modifications would be beneficial for consumers worldwide. Preliminary in-house in vitro digestion data suggested that the addition of gellan gum to rice cooking may reduce digestibility rates though mechanisms yet to be understood. Gellan gum (GG) "is a high molecular weight, water-soluble anionic, extracellular polysaccharide which is produced by the microorganism Sphingomonas elodea during fermentation". GG is commonly used as a gelling agent in foods. Gels formed by gellan gum have high resistance to acid, heat, and enzyme activity. The United States Food and Drug Administration (FDA) has approved the use of GG as a food additive for the human consumption (US.FDA, 2018). It is also approved by the European Community as a food additive with code (E-418). Gellan Gum is gluten free and broadly applied in gluten free foods to provide improved texture and good taste to pasta, biscuits, candy and dairy products. Therefore, it has been proved safe in the amounts the investigators intend to use, it is also suitable for people diagnosed with Coeliac disease as well as suitable for vegetarians, kosher and Halal diets, which make it acceptable for consumption and dietary intervention across different populations.

AIM: The overall purpose of this study is to explore the impact of cooking rice with gellan on the glycaemic and appetitive responses in healthy participants. Both the acute response to one meal will be considered, and the impact on the acute response having consumed the rice once a day over the preceding 7 days. Tolerance will also be considered.