Author

Yu Ting Chen

Advisor

Silva, Juan L.

Committee Member

Kim, Taejo

Committee Member

Tidwell, Diane K.

Committee Member

Matta, Frank B.

Date of Degree

1-1-2013

Document Type

Graduate Thesis - Open Access

Major

Food Science, Nutrition and Health Promotion

Degree Name

Master of Science

Department

Department of Food Science, Nutrition and Health Promotion

Abstract

Yacon (Smallanthus sonchifolius) root products are susceptible to oxidation, reduced quality and functional properties. The optimum water blanching process for yacon root slices was determined through a central composite design with variable temperature (80-100 degrees Celsius), blanching time (2-6 min), and citric acid concentration (0.04-0.20%). Phenolics and fructooligosaccharides of yacon slices were also evaluated after blanching. Yacon slices (3-4 mm) blanched at 90 degrees Celsius, 3.9 to 4.1min, and 0.05% to 0.07% citric acid showed the lowest polyphenol oxidase activity, highest whiteness value, and the highest sensory appearance scores. A second experiment showed that blanching at 100 degrees Celsius with 0.07% citric acid can maintain higher chlorogenic acid (3.52 mg/g more), inulin (5.41% more), and total sugar (34.9%) in yacon slices than blanching without citric acid. Thus, addition of less than 0.1% citric acid to boiling water can minimize loss of functional components of yacon slices during blanching.

URI

https://hdl.handle.net/11668/20111

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