Efficacy of microorganisms isolated from indigenous starter cultures for starch saccharification of three sweet potato (Ipomoea batatas L.) varieties

Date

12-2014

Degree

Bachelor of Science in Agricultural Biotechnology

College

College of Agriculture and Food Science (CAFS)

Adviser/Committee Chair

Erlinda I. Dizon

Restrictions

Restricted: Not available to the general public and to those bound by the confidentiality agreement. Access is available only after consultation with author/thesis adviser.

Abstract

The study evaluated the efficacy of selected microorganisms (Rhizopus oryzae PHL isolated from the Philippine bubod, R. oryzae Cam and Saccharomycopsis fibuligera, both isolated from Cambodia?s medombae) starch saccharification of three sweet potato (Ipomoea batatas L.) varieties (white var, super buro and inubi). Various treatments were done to identify the best strain of microorganism, variety, pH level and dilution level for sweet potato starch saccharification. The physicochemical properties [pH, total titratable acidity (TTA), total soluble solids (TSS), reducing sugar and total sugar] of sweet potato varieties were analyzed before and after fermentation. After saccharification, the R. oryzae PHL inoculated samples obtained the lowest pH values followed by the R. oryzae Cam. Decrease in pH had a corresponding increase in the TTA. The efficiency of starch conversion into fermentable sugar is affected by sweet potato variety and starter culture used for fermentation. TSS values increase by 2.5 to 3.5 times after saccharification. Results revealed that samples with initial pH of 4.5 obtained the best growth for R. oryzae Cam at 30°C. In conclusion, among the microorganisms tested, Rhizopus oryzae Cam was found most efficient for sweet potato starch saccharification process. On the other hand, the white sweet potato variety was found most suitable as substrate for conversion of starch into fermentable sugars at pH 4.5 with 1:3 dilution (steamed sweet potato: water). It is recommended that further studies be done to optimize the processing parameters for upscale production of saccharified sweet potato for alcohol production.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993 2014 A127 /H67

Notes

major: Food Biotechnology

Document Type

Thesis

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