A NOVEL AND SIMPLE TECHNIQUE FOR THE DETERMINATION OF QUANTITY OF ALCOHOL PRODUCED IN WET PADDY RICE DUE TO FERMINTATION

Document Type : Original Article

Authors

1 Prof. Chemical Eng. Dept., Eng. Fac., Alex. Univ., Egypt.

2 Researcher, Rice Technology Training Center, Alex. A.R.C., Egypt.

3 Senior research, Rice Research &Training Center, Sakha, Kafer ElSheikh, A.R.C., Egypt.

Abstract

A novel and simple technique was devised to determine the quantity of ethanol produced in wet paddy rice due to fermentation, after harvesting. Undried rice has the potential of developing ethanol during storage due to fermentation. The latter process which is affected by both temperature and time, converts sugars to alcohol by the action of yeast, which is an undesirable process. A simple technique by which the quantity of alcohol produced is evaluated, as a function of both time and ambient temperature, has been applied, in which the alcohol- containing rice is leached by distilled water for a time ≥equilibrium time, followed by rapid filtration and the leachate's density is determined by weighing a standard volume of the leachate, followed by determining the concentration of ethanol from standard tables of densities of alcohol – water mixtures cited in the literature. The amount of alcohol is drawn versus the densities and the time after harvest (non ventilation) and finally equations for percent alcohol versus time of non ventilation and percent alcohol versus density are developed. High correlation coefficients (> 0.991) are obtained in both cases. The equations could be used for the rapid estimation of percent alcohol as a function of both time and density.

Keywords

Main Subjects


Banat, I.M., P. Nigam, D. Singh, R. Merchant, and A.P. McHale. 1998." Ethanol production at elevated temperatures and alcohol concentrations": A review; Part-I Yeast In General. World J. Microbiol. Biotechnol. 14:809-821.
Geng, S., J.F. Williams, and J.E. Hill. 1984." Harvest moisture effects on rice milling quality". In California Agriculture, Nov.-Dec: 11-12.
Ingledew, W.M. 1998. "Alcohol production by Saccharomyces cerevisiae": A yeast primer. Chapter 5 In: The alcohol textbook. 3rd ed. K.A. Jacques, T.P. Lyons and D.R. Kelsall Ed. Nottingham University Press. Nottingham,UK.
James F. Thompson, R. G. Mutters, David C. Slaughter, Jerry Knutson, and Eunice Tan 2001."Preventing off- odor development in undried rice",   ASAE Annual Meeting Paper number 016109.
John H. Perry, ed.1963."Chemical engineers' handbook" Fourth Edition, Densities of aqueous organic solutions, McGraw-Hill Book Comp. Inc.
Lin, Y., S. Tanaka. 2006." Ethanol fermentation from biomass resources": current state and prospects. Appl. Microbiol. Biotechnol. 69: 627-642.
Neish, A.C., and A.C. Blackwood. 1951. "Dissimilation of glucose by yeast at poised hydrogen ion concentrations". Canadian Journal of Technology. 29:123-129.
Pretorius, I.S. 2000."Tailoring wine yeast for the new millennium": Novel approaches to the ancient art of winemaking. Yeast 16:675-729.
Thomas, K.C., S.H. Hynes, and W.M. Ingledew. 1996." Practical and theoretical considerations in the production of high concentrations of alcohol by fermentation". Proc. Biochem. 31:321-331.
Torija, Ma. J., N. Rozès, M. Poblet, J.M. Guillamón, and A. Mas. 2003." Effects of fermentation temperature on the strain population of Saccharomyces cerevisiae" . International Journal of Food Microbiology. 80: 47-53.