Apple Aminoacid Profile and Yeast Strains in the Formation of Fusel Alcohols and Esters in Cider Production C: Food chemistry
Caroline Mongruel Eleut´erio dos Santos, Giovana de Arruda Moura Pietrowski, C´ıntia Maia Braga, M´arcio Jos´e Rossi, Jorge Ninow, Tˆamisa Pires Machado dos Santos, Gilvan Wosiacki, Regina Maria Matos Jorge, and Alessandro Nogueira
The amino acid profile in dessert apple must and its effect on the synthesis of fusel alcohols and esters in cider were established by instrumental analysis. The amino acid profile was performed in nine apple musts. Two apple musts with high (>150 mg/L) and low (90%) during fermentation in all the ciders. Principal component analysis (PCA) explained 81.42% of data variability and the separation of three groups for the analyzed samples was verified. The ciders manufactured with low nitrogen content showed sluggish fermentation and around 50% less content of volatile compounds (independent of the yeast strain used), which were mainly 3-methyl1-butanol (isoamyl alcohol) and esters. However, in the presence of amino acids (asparagine, aspartic acid, glutamic acid and alanine) there was a greater differentiation between the yeasts in the production of fusel alcohols and ethyl esters. High contents of these aminoacids in dessert apple musts are essential for the production of fusel alcohols and most of esters by aromatic yeasts during cider fermentation. Abstract:
Keywords: apple must, bio-aromas, chemometrics, nitrogen compounds, yeast
This study presents the variability of amino acids in dessert apple musts. Lack of amino acids in the apple must affect not only the fermentation kinetics but also the formation of volatile compounds and, therefore, the aroma of the product. This study identifies the key amino acids (Asn, Asp, Glu, and Ala) and the effect of the yeast strain on the formation of fusel alcohols and esters in cider.
Practical Application:
Introduction Cider, or hard cider, (2.0 at 7.0 o GL, sparkling or still) and apple wine (7.1 at 12 o GL) are beverages obtained by the total or partial alcoholic fermentation of blends of dessert apples and/or industrial apple musts. The raw material and processing technology can vary in the more than 20 countries around the world that produce cider (Lea and Drilleau 2003; Nogueira and Wosiacki 2012). However, regardless of the raw material, or the technology used, a fruity aroma is the main sensorial quality in cider (Xu and others 2006; Rita and others 2011; Pietrowski and others 2012). Various volatile compounds of different classes have been found in ciders, mainly higher alcohols, esters, fatty acids, and aromatic MS 20141841 Submitted 11/5/2014, Accepted 3/4/2015. Authors Eleut´erio dos Santos and Jorge are with Postgraduate Program in Food Engineering, Federal Univ. of Paran´a, R. Cel. Francisco Her´aclito dos Santos 210, Polytechnic Campus, CEP 81531–980, Curitiba, PR, Brazil. Author Eleut´erio dos Santos is also with Technical Course in Food, Federal Inst. of Paran´a, Av. Dr. Tido s/n, CEP 86400-000, Jacarezinho, PR, Brazil. Author Pietrowski is with Dept. of Food Technol., Federal Technological Univ. of Paran´a, Av. Monteiro Lobato, s/n- Km 04, CEP 84016–210, Ponta Grossa, PR, Brazil. Authors Braga, Rossi, and Ninow are with Postgraduate Program in Food Engineering, Federal Univ. of Santa Catarina, Campus Reitor Jo˜ao David Ferreira Lima, Bairro Trindade, CEP 88040–900, Florian´opolis, SC, Brazil. Authors Machado dos Santos, Wosiacki, and Nogueira are with MA Program in Food Science and Technol, State Univ. of Ponta Grossa, Av. Carlos Cavalcanti 4748, Uvaranas Campus, CEP 84.030-900 Ponta Grossa, PR, Brazil. Direct inquiries to author Nogueira (E-mail:
[email protected]).
C1170
Journal of Food Science r Vol. 80, Nr. 6, 2015
compounds such as 2-phenylethanol (Xu and others 2007; Peng and others 2009; Rita and others 2011; Fan and others 2011; Braga and others 2013; Ye and others 2014; Haider and othres 2014). Some of these are derived from the fruit and are typical of the cultivar (ethyl butanoate and hexyl ethanoate) but most are formed during alcoholic fermentation as secondary metabolites (Xu and others 2006; Madrera and Mangas 2011). The volatile amyl alcohols, 3-methyl-1-butanol (150.00 mg/L) and low nitrogen content (
