Utilization of Wheat Bran and Wheat Germ for Bioethanol Production through Solid Substrate Fermentation.

Paulraj, V. (2013) Utilization of Wheat Bran and Wheat Germ for Bioethanol Production through Solid Substrate Fermentation. [Student Project Report] (Submitted)

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Abstract

With efforts to reduce global reliance on fossil fuels and lower the greenhouse gas emission, an increasing search for renewably sourced materials, which can be used as feedstock for biofuel production, is ongoing in the past few decades. At the present, ethanol is the most common alternate fuel and is already produced on a fair scale, representing a sustainable substitute for gasoline in passenger cars. Due to rapid growth in population and industrialization, worldwide ethanol demand is increasing continuously. Conventional crops such as corn and sugarcane are unable to meet the global demand of bioethanol production due to their primary value of food and feed. Therefore, lignocellulosic substances such as agricultural wastes are attractive feedstocks for bioethanol production. Agricultural wastes are cost effective, renewable and abundant. Wheat has been used as supplementary staple food for thousands of years. Wheat bran is produced as a by-product in milling industries and one million tons of wheat can produce up to 0.25 million tons of wheat bran. The germ constitutes approximately 2.5 percent of the total weight of the wheat kernel. The germ probably contains about 20% of soluble carbohydrate, chiefly sucrose and raffinose. The other consideration is the presence of polyphenols in many varieties of wheat bran and wheat germ which are believed to reduce overall ethanol production. The yeast cultures of Saccharomyces cerevisiae, Candida tropicalis from Food Microbiology Dept. CSIR-CFTRI. The Exiguobacterium isolated from soil sample was able to produce the enzyme which could hydrolyze some of the lignocellulosic waste and was hence used for the pretreatment of wheat bran and wheat germ. The comparative study of wheat bran and wheat germ fermentation showed decrease in the concentration of sugars, this indicates the utilization of pentose and hexose by the yeast. Fish meal extract from the, byproduct of fish waste processing was used as a replacement for yeast extract which worked better for alcohol production with Saccharomyces cerevisiae by using wheat germ as substrate which produced 2.7% alcohol. Qualities analysis of the alcohol showed 64.99% Ethanol, 14.86%Methanol, and 15.34% Isoamyl alcohol. Polyphenol degradation was observed in the fermented samples of wheat bran and wheat germ carried out by Saccharomyces cerevisiae and Candida tropicalis. The major fraction of phenolic acids obtained was Tannic acid, Galic acid and Caffeic acids. Therefore maximum recovery of sugars from wheat bran and wheat germ with less inhibitor concentration and subsequently their conversion into ethanol with desired yields and productivities are important factors to make bioethanol program successful at industrial scale.

Item Type:	Student Project Report
Uncontrolled Keywords:	wheat bran, wheat germ, bioethanol production, fermentation
Subjects:	600 Technology > 05 Chemical engineering > 04 Fermentation Technology 600 Technology > 08 Food technology > 16 Nutritive value > 07 Waste utilization
Divisions:	Food Microbiology
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	29 Apr 2014 06:46
Last Modified:	29 Apr 2014 06:46
URI:	http://ir.cftri.res.in/id/eprint/11508

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