Screening of cider yeasts for sparkling cider production (Champenoise method).
A total of 350 colonies isolated from a cider cellar in Asturias (Spain) were identified by rDNA ITS-RFLP restriction analysis. Saccharomyces spp. strains were characterized by mitochondrial DNA (mtDNA) restriction analysis. Fifty-four different Saccharomyces spp. strains were identified and tested to ascertain their capacity to carry out secondary fermentation of sparkling ciders. The screening of yeasts to determine their principal enological characteristics (tolerance to ethanol, production of volatile acidity and hydrogen sulphide) was accomplished by means of rapid, non-expensive assays (plate agar). As a result, 13 (24%) of the 54 initial Saccharomyces spp. yeast strains were eliminated. The technological properties assessed were flocculation capacity, ethanol and sulphite tolerance, and production of major volatiles. Ten Saccharomyces cerevisiae strains were characterized as true flocculants; all of these strains were able to grow in ethanolic medium and in the presence of 200mg/l of sulphite. Applying cluster analysis to the production of amyl alcohols, isobutanol, propanol and 2-phenylethanol, the strains were classified in two natural groups. Two flocculent yeast strains referred to as 3' and 50', representative of the each statistical group, were selected together with two reference strains (Saccharomyces bayanus C6 and S. cerevisiae Levuline CHP) to elaborate four sparkling ciders by the Champenoise method. The analysis of variance (p<0.01) among ciders revealed that glycerol, acetaldehyde, ethyl acetate, methanol, propanol, i-butanol and 2-phenylethanol were significantly influenced by the secondary yeast strain. The results of sensory analysis indicated that all the sparkling ciders were scored as good. No significant differences among sparkling ciders were found for odour attributes and taste intensity.
Area de Tecnología de los Alimentos, Servicio Regional de Investigación y Desarrollo Agroalimentario (SERIDA), 33300 Villaviciosa, Asturias, Spain.
Belén
B
Suárez Valles
Rosa
R
Pando Bedriñana
Ana
A
Lastra Queipo
Juan José
JJ
Mangas Alonso
D000434:Alcoholic Beverages / Q000382:microbiology*; D000704:Analysis of Variance; D016000:Cluster Analysis; D004262:DNA Restriction Enzymes; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000235:genetics; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D016533:Mycological Typing Techniques; D009812:Odorants / Q000032:analysis; D012440:Saccharomyces / Q000302:isolation & purification*; D012441:Saccharomyces cerevisiae / Q000302:isolation & purification; D013045:Species Specificity; D013649:Taste / Q000502:physiology
D004271:DNA, Fungal; D004272:DNA, Mitochondrial; D000431:Ethanol; D004262:DNA Restriction Enzymes