Date

3-2009

Degree

Bachelor of Science in Chemical Engineering

College

College of Engineering and Agro-Industrial Technology (CEAT)

Adviser/Committee Chair

Rex B. Demafelis

Co-adviser

Bayani M. Espiritu

Committee Member

Marilyn C. Del Barrio, Jovita L. Movillon

Abstract

Studies show that Jatropha curcas press cake has high crude protein content of 53-58%. However, the cake has been found to be very toxic to fish, rats, and chickens. Jatropha press cake was detoxified using heat treatment, solvent extraction and fermentation with mix microbial inoculants for three weeks. Using Tilapia fingerlings (Oreochromis niloticusa L.), a two-week experiments was conducted to evaluate the nutritional quality of the detoxified Jatropha press cake. Fingerlings were randomly distributed in eight treatment groups and fed the following diets: standard diet of commercial feed (T1) , fermented cake (T2), 50% commercial feed +50% fermented cake (T3), methanol treated cake (T4), 50% commercial feed +50% methanol treated cake (T5), heat treated cake (T6), 50% commercial feed +50% heat treated cake (T7), and raw Jatropha press cake (T8). The body weight gain (BWG%) and specific growth rate (SGR%) were statistically similar for T1 and T3 and significantly higher compared to other groups.Percent mortality based on tilapia test was used as the index of toxicity of treated and untreated press cake instead of phorbol ester analysis. Determination of phytic acid concentration was also conducted as a means to quantify toxins present in the cake before and after fermentation. Highest mortality of 46.67% was observed for the raw press cake. Comparing with other treatments, T3 gave the results closest to that of commercial feed T1 for all feeding parameters: body weight gain, specific growth rate and daily food consumption. This treatment seemed to be the best choice as fish feed from among the treatments used in the experiment. The method of fermentation with mix microbial inoculants was most effective in detoxifying the Jatropha curcas meal for fish as it gave a low mortality rate of 26.67%. This method also had the highest BWG and SGR of 32.05% and 1.85% respectively. Upon measurement of the phytic acid content,the fermented cake gave a result of 76.7mg/kg indicating a decrease of 63.92% from the 120mg/Kg concentration of raw Jatropha press cake. Results showed that the fermentation of the cake was effective in detoxifying the press cake.

Language

English

LC Subject

Jatropha, Detoxification, Fermentation

Call Number

LG 993 2009 E62 N86

Document Type

Thesis

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