Abstract
Orange liquor, a by-product of the Brazilian citrus industry, is currently destined for the production of animal feed as also the industrial brewer’s yeast discarded after five production cycles, but still containing a high percentage of viable cells. The aim of this study was to evaluate the reuse of the yeast discarded by the brewing industry in the production of orange liquor spirit without replacing the yeast, and evaluate the impact of this practice on the chemical and sensory quality of the final product. Thus nine batch fermentations were carried out without replacement of the yeast, and the fermented liquor double distilled in copper stills, yielding three beverage samples that were aged in chestnut barrels for six months. The ethanol, copper, volatile acidity, aldehyde, ester, methanol, higher alcohols and furfural contents were determined, and the samples submitted to a consumer acceptance and purchasing intention test. At the end of the nine batch fermentations, the reuse of the yeast to produce the beverage resulted in a 15% reduction in viable cells. All the chemical determinations conformed to current legislation, except for the methyl alcohol and n-butyl alcohol contents of sample C. The acceptance test revealed no significant differences between the three beverages for the attributes of colour and aroma, although there was a significant difference for sample B with respect to the attributes of flavour and overall impression. Based on the results obtained, the reuse of discarded industrial brewer's yeast was shown to be a good option to obtain orange liquor spirit, ensuring at least three fermentation batches without undesirable changes in the drink.
Keywords:
Spirit; Acceptance test; By-product; Double distillation
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