Effects of nitrogen supplementation on Saccharomyces cerevisiae JP14 fermentation for mead production

Eduardo Luís Menezes de ALMEIDA,Mayara Salgado SILVA,Igor de Albuquerque VASSALLI,Gustavo MOREIRA E SILVA,Monique Renon ELLER,Weyder Cristiano Santana,Paulo Henrique Alves da SILVA

doi:10.1590/fst.11219

Abstract

Abstract Honey must supplementation is necessary for mead production due to the deficiency in nitrogen materials in this feedstock, despite its high fermentative sugar content. The nitrogen limitation can halt or slow fermentation and lead to the production of unpleasant sensorial compounds, such as sulfur derivatives. The yeast JP14, a Saccharomyces cerevisiae isolated from Jatai bee’s pollen, was inoculated in 25 °Brix honey must with – 0 (control); 0,3; 0,7 and 1,0 g∙L-1 – of di-ammonium phosphate (DAP) and ammonium sulfate (AS). The addition of both supplements resulted in increased cell viability in the first 5 days of fermentation at 20 °C, but did not affect the final acidity of the produced meads. Supplementation also leads to increased sugar consumption, and sugar conversion into ethanol increased as nitrogen supplementation increased, especially with DAP. This indicates that these compounds also regulate yeast metabolic pathways. Supplementary nitrogen acts both in protein anabolism and the gene expression of glycolytic and fermentative pathway components, favoring, in this case, sugar conversion into ethanol. This is the first work describing how different DAP and AS concentrations influences mead production and showing the comparison between these two supplements.

Highlights

In nature, yeasts are capable of using a wide range of compounds containing nitrogen
Nitrogen supplementation leads to musts with similar free amino nitrogen (FAN) and reducing sugar concentrations, but supplementation with di-ammonium phosphate (DAP) leads to more efficiency in sugar conversion into ethanol by the yeast
The study on the supplementation of honey musts is fundamental for the optimization of the process of mead production, considering the need for using nitrogen supplements, such as DAP and ammonium sulfate (AS), in order to supply FAN deficiency in honey for fermentation by yeasts

Summary

Introduction

Yeasts are capable of using a wide range of compounds containing nitrogen. Some of these compounds are metabolized more efficiently and optimize growth and the metabolic activity, Barbosa et al (2012). Nitrogen limitation can halt or slow fermentation, besides stimulating the production of unpleasant sensorial compounds, such as sulfur derivatives, Mendes-Ferreira et al (2004). Mead is considered the oldest known alcoholic beverage Aquarone et al (1983). Mead production is not standardized and techniques and ingredients from winemaking are often used. Using different feedstocks requires different upstream operations, including honey must supplementation, which is a feedstock deficient in nitrogen sources

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