Fortification of rice crackers made from brown rice flour and black rice flour with protein from oyster and mussel powder : A dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science at Lincoln University

Abstract

Rice crackers popularity has been rising in recent years, largely due to increase in demand for gluten-free snacks. Even though rice crakcers are generally considered to be healthy snacks, over-consumption of rice crackers might lead to high glycemic responses, due to the fact that most of rice crackers in the market are using polished white rice flour. Therefore, in this experiment, brown rice and black rice flour are used to create the rice crackers. Another popular trend in food industry is the fortification process, which improve the nutritious quality of certain product. Oyster and Mussel Powder are two potential candidate that could be used to increase the antioxidant properties of rice crackers, at the same time reducing their glycemic responses. To evaluate the effectiveness of this fortification process, Glyceamic Glucose Equivalent (GGE) Assay is implemented in this experiment, along with in vitro starch digestion process. While for the assessing the antioxidant properties, Total Phenolic Content assay and Ferric-Reducing Antioxidant Power (FRAP) assay is used. Fortification process also influence other aspect such as texture, appearance, functional properties, pasting properties, which will be analysed in this study. The result indicates that brown rice flour shows lower GGE value compared to black rice flours, while the fortification process do affect the GGE value of rice crackers, but it only shows significant effect on brown rice crackers. In terms of Antioxidant properties, black rice crackers shows superiority than brown rice crackers, while the fortification by oyster and mussel powder process shows improvement on both brown and black rice crackers.