Abstract
Strains of Saccharomyces cerevisiae and Torulaspora delbrueckii isolated from traditional bread doughs displayed dough-raising capacities similar to the ones found in baker's yeasts. During storage of frozen doughs, strains of T. delbrueckii (IGC 5321, IGC 5323, and IGC 4478) presented approximately the same leavening ability for 30 days. Cell viability was not significantly affected by freezing, but when the dough was submitted to a bulk fermentation before being stored at -20 degrees C, there was a decrease in the survival ratio which depended on the yeast strain. Furthermore, the leavening ability after 4 days of storage decreased as the prefermentation period of the dough before freezing increased, except for strains IGC 5321 and IGC 5323. These two strains retained their fermentative activity after 15 days of storage and 2.5 h of prefermentation, despite showing a reduction of viable cells under the same conditions. The intracellular trehalose content was higher than 20% (wt/wt) in four of the yeasts tested: the two commercial strains of baker's yeast (S. cerevisiae IGC 5325 and IGC 5326) and the two mentioned strains of T. delbrueckii (IGC 5321 and IGC 5323). However, the strains of S. cerevisiae were clearly more susceptible to freezing damages, indicating that other factors may contribute to the freeze tolerance of these yeasts.
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- Eleutherio E. C., Araujo P. S., Panek A. D. Protective role of trehalose during heat stress in Saccharomyces cerevisiae. Cryobiology. 1993 Dec;30(6):591–596. doi: 10.1006/cryo.1993.1061. [DOI] [PubMed] [Google Scholar]
- Gélinas P., Fiset G., Leduy A., Goulet J. Effect of growth conditions and trehalose content on cryotolerance of bakers' yeast in frozen doughs. Appl Environ Microbiol. 1989 Oct;55(10):2453–2459. doi: 10.1128/aem.55.10.2453-2459.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hino A., Mihara K., Nakashima K., Takano H. Trehalose levels and survival ratio of freeze-tolerant versus freeze-sensitive yeasts. Appl Environ Microbiol. 1990 May;56(5):1386–1391. doi: 10.1128/aem.56.5.1386-1391.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hottiger T., Boller T., Wiemken A. Rapid changes of heat and desiccation tolerance correlated with changes of trehalose content in Saccharomyces cerevisiae cells subjected to temperature shifts. FEBS Lett. 1987 Aug 10;220(1):113–115. doi: 10.1016/0014-5793(87)80886-4. [DOI] [PubMed] [Google Scholar]
- Kyogoku Y., Ouchi K. Isolation of a cold-sensitive fermentation mutant of a baker's yeast strain and its use in a refrigerated dough process. Appl Environ Microbiol. 1995 Feb;61(2):639–642. doi: 10.1128/aem.61.2.639-642.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mackenzie K. F., Singh K. K., Brown A. D. Water stress plating hypersensitivity of yeasts: protective role of trehalose in Saccharomyces cerevisiae. J Gen Microbiol. 1988 Jun;134(6):1661–1666. doi: 10.1099/00221287-134-6-1661. [DOI] [PubMed] [Google Scholar]
- Nakagawa S., Ouchi K. Construction from a single parent of baker's yeast strains with high freeze tolerance and fermentative activity in both lean and sweet doughs. Appl Environ Microbiol. 1994 Oct;60(10):3499–3502. doi: 10.1128/aem.60.10.3499-3502.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Oda Y., Uno K., Ohta S. Selection of yeasts for breadmaking by the frozen-dough method. Appl Environ Microbiol. 1986 Oct;52(4):941–943. doi: 10.1128/aem.52.4.941-943.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Yoshikawa M., Yamaguchi S., Kunimi K., Matsuda H., Okuno Y., Yamahara J., Murakami N. Stomachic principles in ginger. III. An anti-ulcer principle, 6-gingesulfonic acid, and three monoacyldigalactosylglycerols, gingerglycolipids A, B, and C, from Zingiberis Rhizoma originating in Taiwan. Chem Pharm Bull (Tokyo) 1994 Jun;42(6):1226–1230. doi: 10.1248/cpb.42.1226. [DOI] [PubMed] [Google Scholar]