Evaluation of the alcoholic fermentation of aqueous extract of the apple pomace

Abstract

The main by-product of apple agroindustry, the apple pomace, may represent from 20 to 40% of the total amount of processed raw material. Indeed, this apple pomace has been used for animal breeding or simply delivered on the soil. However, due to its composition it may cause diarrhea in cattle and also show a high environmental impact. This work was designed to evaluate such a rejected industrial residue concerning the quality of the aqueous extract for alcoholic fermented production. The variety Fuji was processed in a laboratory scale and its apple juice was a reference. The apple pomace was divided in three parts with the same weight. The first one was treated with water 1/1 (v/m), homogenized and pressed; this extract was added to the second part and homogenized and pressed. This second extract was added to the last part, and also homogenized and pressed. The composition of the apple juice and of the extract were determined before and after the fermentation. The extract showed 60% as yield of the total sugars and total acidity were the same in the apple juice. The total nitrogen and N a-amino acid concentration were both higher in the extract as compared to the apple juice. The yeast did not present any lack for the fermentation process. Apple pomace extract was suitable substrate for alcohol fermentative process. The apple juice, extract pomace and extract pomace added with sacarose fermentation show 6,9ºGL, 4,30ºGL e 7,30ºGL, respectively.