Hydrogen sulphide production during cider fermentation is moderated by pre-fermentation methionine addition

Abstract

Yeast assimilable nitrogen (YAN) concentration and composition impact hydrogen sulphide (H2S) production and fermentation kinetics during wine fermentation, but this phenomenon has not been extensively studied in cider fermentation. Our hypothesis was that H2S production during cider fermentation could be decreased through pre‐fermentation modification of concentrations of individual amino acids. Apple juice (53 mg L−1 YAN) was supplemented with asparagine, arginine, methionine or ammonium and fermented with EC1118 and UCD522 yeast strains. No difference in H2S production among fermentations was observed with addition of asparagine, arginine or ammonium. Methionine addition of 5 mg L−1 decreased H2S production by yeast strain EC1118 at 53 mg L−1 YAN. With 153 mg L−1 initial YAN, only methionine addition of 50 mg L−1 decreased H2S production, and no tested methionine rates decreased H2S production with 253 mg L−1 initial YAN. Supplementation to 153 mg L−1 YAN resulted in increased H2S production at all methionine concentrations tested. Sensory differences in aroma were detected in samples supplemented with ammonium and methionine, and these differences were correlated with observed differences in H2S production. Our results indicate that supplementing cider fermentations with methionine leads to lower H2S formation, especially in apple juice containing low YAN. © 2017 The Authors Journal of the Institute of Brewing published by John Wiley & Sons Ltd on behalf of The Institute of Brewing & Distilling

Juice Clarification with Pectinase Reduces Yeast Assimilable Nitrogen in Apple Juice without Affecting the Polyphenol Composition in Cider

“…Methionine levels in juice (1 to 2 mg/L) fell within the lower end of the previously reported range for apple juice (0 to 43 mg/L) (Wu et al., ; Ye, Yue, & Yuan, ). They are below the value to prevent production of sulfur off‐aromas by certain yeast strains during fermentation (Boudreau et al., ), and also lower than typical grape juice concentrations which range from 0 to 52 mg/L (Park, Boulton, & Noble, ). Since an increase in methionine was realized upon juice settling, the choice of juice clarification technique used in cider making has the potential to effect subsequent hydrogen sulfide production during the fermentation through modification of methionine concentration.…”

“…YAN concentration and composition in apple juice prior to fermentation is one of the rate‐controlling factors of the fermentation (Boudreau et al., ). YAN is composed of free amino acids and ammonium ions, which are soluble in the juice.…”

“…In the United States of America, cider sales revenue has increased at an average rate of 27.3% annually from 2011 to 2016 (Petrillo, ), reaching $1.3 billion in retail sales in 2016 (Brager & Crompton, ). A common problem in cider making is the production of sulfur off‐aromas by yeast during fermentation (Boudreau et al., ). Fermentation of cloudy juice is often associated with sulfur off‐aromas in white wine production; therefore, prefermentation juice clarification is considered an important and routine step in white winemaking practice (Boulton, Singleton, Bisson, & Kunkee, ).…”

“…Sensory properties of amino acid metabolites in wine have also been extensively explored and reported (Ardö, ). Since many of the same yeast strains used in wine production are also widely applied in cider fermentation, it is reasonable to expect that the amino acid profile of apple juice would similarly impact cider aroma, although there is currently limited information available on this topic (Boudreau et al., , ; Santos et al., ).…”

Yeast Assimilable Nitrogen Concentrations Influence Yeast Gene Expression and Hydrogen Sulfide Production During Cider Fermentation

“…The SRS pathway is multifaceted and responsive to numerous regulatory inputs. Both cysteine and methionine are chemically reactive under reductive fermentation conditions, which induces H 2 S and other undesirable sulfur-containing compounds (Boudreau et al, 2017a). Sulfite reductase is responsible for reducing sulfite to sulfide and is regulated by general amino acid control, cysteine, and methionine (Mountain et al, 1991).…”