Low-temperature vacuum drying of lactic acid bacteria for use as inoculant for cocoa bean fermentation

Date

6-2016

Degree

Bachelor of Science in Chemical Engineering

College

College of Engineering and Agro-Industrial Technology (CEAT)

Adviser/Committee Chair

Catalino G. Alfafara

Restrictions

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

Abstract

A Response Surface Methodology (RSM) designed experiment via the Split-Plot Central Composite Design (chosen due to the presence of hard to change factors) was done to generate a statistical model relating the three low-temperature vacuum drying (LTVD) parameters, temperature, pressure, and maltodextrin concentration, to the responses, % surviving cells and moisture content of Lactic Acid Bacteria Strain DOL 2 after LTVD. The generated model was used for optimization of the drying parameters to maximize % surviving cells and minimize the moisture content after drying. In preparation for the optimization experiment, the growth curve and standard curve of the isolate was generated and analysed to determine its mid-exponential phase (determined to be at 6 hours after the start of fermentation) and the initial viable cell count (109 CFU/mL) at absorbance reading of 1.0 at a wavelength of 600 nm. The suggested optimum LTVD conditions were found to be at: 35°C Temperature, 15 mbar pressure, and 0.3 g maltodextrin per mL of cell suspension. The moisture content after LTVD agreed with the expected results of the experimental verification, but the % surviving cells did not. This may be due to the variability of the model (with a low coefficient of determination of 0.56).

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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