School of Engineering Department of Chemical and Biological Engineering 78 Design and Development of Functional Food Supervisor: LIU, Yuanshuai / CBE Student: KAO, Tzu Yuan / BIEN Course: UROP1100, Fall The objective of the project is designing lab manuals for food experiments, which can be referred to for those who want to do related experiment in the future. The experiment applies food processing technology and contains two parts: (1) a. blending different materials with oil and emulsifier to get ice cream base mixture; b. crystalizing liquid base into solid particles with liquid nitrogen under low temperature. (2) a. preparing yeast growth medium in sterile environment; b. fermenting yeast in bioreactor with suitable pH value, temperature, and aerobic environment. There are many ways to crystallize liquid particles into solid phase, while the freezing method used in lab is different from manufacturing, in addition, the size of liquid particles matters in determining the texture of tasting. The ice cream manual is designed with different materials for making ice cream base which gives a basic concept of cryogenic freezing. Yeast is a very familiar material widely used in fermentation, which converts sugar into carbon dioxide gas in baking field. While we are interested in the growing pattern of yeast in a bioreactor under certain environment condition and oxygen applied. The manual is designed with the method of operating bioreactor and observing growing rate. Design and Development of Functional Food Supervisor: LIU, Yuanshuai / CBE Student: WAN, Ching Natalie / BIEN Course: UROP1100, Spring This report is about the formation of scoby from fermentation of kombucha which involves the aspect of food processing. It involves 2 stages of fermentation with yeast and bacteria. The bacteria oxidizes sugar added into the fermentation medium to gluconic acid and is synthesized to form chains of cellulose. A thin membrane is resulted when the chains of cellulose integrate and is grown into a suspended structure called a scoby. The growth of scoby stops when all the bacteria is entrapped and oxygen supply is insufficient. Through feeding the fermentation medium with more sugar and black tea, subsequent scobies can be formed.
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