Fermentation profiles of Manzanilla-Aloreña cracked green table olives in different chloride salt mixtures.
NaCl plays an important role in table olive processing affecting the flavour and microbiological stability of the final product. However, consumers demand foods low in sodium, which makes necessary to decrease levels of this mineral in fruits. In this work, the effects of diverse mixtures of NaCl, CaCl2 and KCl on the fermentation profiles of cracked directly brined Manzanilla-Aloreña olives, were studied by means of response surface methodology based in a simplex lattice mixture design with constrains. All salt combinations led to lactic acid processes. The growth of Enterobacteriaceae populations was always limited and partially inhibited by the presence of CaCl2. Only time to reach half …
Use of Logistic Regression for Prediction of the Fate of Staphylococcus aureus in Pasteurized Milk in the Presence of Two Lytic Phages
The use of bacteriophages provides an attractive approach to the fight against food-borne pathogenic bacteria, since they can be found in different environments and are unable to infect humans, both characteristics of which support their use as biocontrol agents. Two lytic bacteriophages, vB_SauS-phiIPLA35 (phiIPLA35) and vB_SauS-phiIPLA88 (phiIPLA88), previously isolated from the dairy environment inhibited the growth of Staphylococcus aureus. To facilitate the successful application of both bacteriophages as biocontrol agents, probabilistic models for predicting S. aureus inactivation by the phages in pasteurized milk were developed. A linear logistic regression procedure was used to desc…
Temperature Adaptation Markedly Determines Evolution within the Genus Saccharomyces
12 pages, 7 figures, 3 tables
Susceptibility and resistance to ethanol in Saccharomyces strains isolated from wild and fermentative environments
11 pages, 3 figures, 3 tables.-- Article first published online: 8 SEP 2010
A comparative study of the wine fermentation performance of Saccharomyces paradoxus under different nitrogen concentrations and glucose/fructose ratios
8 pages, 1 figure, 4 tables.-- Online version published: May 2009.-- The definitive version is available at www3.interscience.wiley.com
Quantifying the individual effects of ethanol and temperature on the fitness advantage of Saccharomyces cerevisiae
The presence of Saccharomyces cerevisiae in grape berries and fresh musts is usually very low. However, as fermentation progresses, the population levels of this species considerably increase. In this study, we use the concept of fitness advantage to measure how increasing ethanol concentrations (0-25%) and temperature values (4-46 °C) in wine fermentations affects competition between S. cerevisiae and several non-Saccharomyces yeasts (Hanseniaspora uvarum, Torulaspora delbrueckii, Candida zemplinina, Pichia fermentans and Kluyveromyces marxianus). We used a mathematical approach to model the hypothetical time needed for S. cerevisiae to impose itself on a mixed population of the non-Saccha…
Exploring the yeast biodiversity of green table olive industrial fermentations for technological applications
In recent years, there has been an increasing interest in identifying and characterizing the yeast populations associated with diverse types of table olive elaborations because of the many desirable technological properties of these microorganisms. In this work, a total of 199 yeast isolates were directly obtained from industrial green table olive fermentations and genetically identified by means of a RFLP analysis of the 5.8S-ITS region and sequencing of the D1/D2 domains of the 26S rDNA gene. Candida diddensiae, Saccharomyces cerevisiae and Pichia membranifaciens were the most abundant yeast species isolated from directly brined Aloreña olives, while for Gordal and Manzanilla cultivars th…
Lipolytic activity of the yeast species associated with the fermentation/storage phase of ripe olive processing.
9 páginas, 4 figuras, 5 tablas.-- El Pdf del artículo es la copia de autor.
Role of yeasts in table olive production
Table olives are a traditional fermented vegetable of the Mediterranean countries, but their production and consumption are now spread all around the world. Yeasts can play a double role in this food. They are present throughout the fermentative process and it is generally accepted that they can produce compounds with important organoleptic attributes determining the quality and flavour of the final product. However, yeasts can also be spoilage microorganisms in olive fermentation/storage and packing causing gas pockets, swollen containers, cloudy brines and off-flavours and off-odours. Candida boidinii, Debaryomyces hansenii, Pichia anomala, P. membranifaciens, Rhodotorula glutinis and Sac…
Differences in the glucose and fructose consumption profiles in diverse Saccharomyces wine species and their hybrids during grape juice fermentation
7 pages, 4 figures, 5 tables.
Modelling the effect of ascorbic acid, sodium metabisulphite and sodium chloride on the kinetic responses of lactic acid bacteria and yeasts in table olive storage using a specifically implemented Quasi-chemical primary model
he goal of this work was to apply the Quasi-chemical primary model (a system of four ordinary differential equations that derives from a hypothetical four-step chemical mechanism involving an antagonistic metabolite) in the study of the evolution of yeast and lactic acid bacteria populations during the storage of Manzanilla–Aloreña table olives subjected to different mixtures of ascorbic acid, sodium metabisulphite and NaCl. Firstly, the Quasi-chemical model was applied to microbial count data to estimate the growth–decay biological parameters. The model accurately described the evolution of both populations during storage, providing detailed information on the microbial behaviour. Secondly…
Effect of sequential inoculum of beta-glucosidase positive and probiotic strains on brine fermentation to obtain low salt sicilian table olives
In the present study, the β-glucosidase positive strain Lactobacillus plantarum F3. 3 was used as starter during the fermentation of Sicilian table olives (Nocellara Etnea cultivar) at two different salt concentrations (5 and 8%), in order to accelerate the debittering process. The latter was monitored through the increase of hydroxytyrosol compound. In addition, the potential probiotic Lactobacillus paracasei N24 strain was added after 60 days of fermentation. Un-inoculated brine samples at 5 and 8% of salt were used as control. The fermentation was monitored till 120 days through physico-chemical and microbiological analyses. In addition, volatile organic compounds and sensorial analyses …