Production of single cell oil from whey and determination of some physical and chemical properties of produced oils

In this study using of whey as a substrate in the microbial oil fermentation which is residual during cheese production that most common produced dairy product in our country was researched. By the using of whey which regarded a waste as a substrate in microbial oil fermentation will be provided some benefits as means preventing environmental polution and production of a valuable product which have increasing demand in the world markets for its health benefits. The additive value to country economy of production of microbial oil would be provided by means of individual product value and also reuse of valuable whey contituents. For this purpose with using of whey powder, reconstitute whey was prepared then by heat treatment and filtration processes denaturated proteins were removed so finally deproteinized whet permeate (DP-WP) was obtained. By regarding of their lactose content DP-WP's were prepared at 4 different initial dry matter contents. And then by dividing these DP-WP's in two groups, one of them was applied lactase enzyme and partially hydrolised lactose to glucose and galactose. Finally obtained DP-WP's which have 8 different contents were divided in two groups again, and one of them inoculated with Mortierella isabellina and another one inoculated with Mortierella ramanniana, and fermentations were performed. With using same fungus inoculation was carrying out to growth medium contain %3 glucose and then fermentations were performed. These fermentations were the control groups of this study. The biomass and microbial oil amounts and the residual sugar levels that not used in the growth medium were determined during the 9 days of fermentation performed. By the way the chaninging in fatty acid contents of the microbial oils obtained were also determined. At the end of the fermentations the kinetic parameters belonging to fermentations and some physical and chemical properties of final product were determined. The biomass and microbial oil values were not affected by the initial dry matter in which the fermentations performed with Mortierella isabellina that the groups enzyme un-applied. But at the groups applied enzyme, by the increasing of initial dry matter the biomass and microbial oil levels were also increased. At the groups applied lactase enzyme these values were higher. The lowest oil content was obtained as 3.26 g/kg by fermentating of DP-WP which has %8 lactose content. The highest oil content was obtained as 18.21 g/kg by fermentating of DP-WP which has %16 lactose content and enzyme applied. By the statistical evaluation of fatty acid composition the highest γ-linolenic acid value (%5.28) was achieved by the fermenting of DP-WP's having %16 lactose contents. The lactose un-applied groups were execute the highest γ-linolenic acid values (%5.53). The biomass and microbial oil values were affected by the initial dry matter in which the fermentations performed with Mortierella ramanniana that the groups enzyme un-applied and these values get lower by increasing the initial dry matter. At the enzyme applied groups the biomass and microbial oil values were the highest by fermentating of DP-WP which has %8 lactose content but further increase in initial dry matter of DP-WP's cause get lower these values. At the groups applied lactase enzyme theese values were higher. The lowest oil content was obtained as 0.92 g/kg by fermentating of DP-WP which has %16 lactose content. The highest oil content was obtained as 10.61 g/kg by fermentating of DP-WP which has %8 lactose content and enzyme applied. By the statistical evaluation of fatty acid composition the highest γlinolenic acid value (%5.24) was achieved by the fermenting of DP-WP's having %8 lactose contents. The lactase un-applied groups were execute the highest γ-linolenic acid values (%5.17). The microbial oil values at the fermentations performed with Mortierella isabellina were higher than that of performed with Mortierella ramanniana. But the γlinolenic acid values of the obtained microbial oils were resemble to each other. So it was concluded that the fermentations performed with Mortierella isabellina were more successful.