Yeasts in table olive processing: desirable or spoilage microorganisms. Int J Food Microbiol

Food Biotechnology Department, Instituto de la Grasa (CSIC), Avda. Padre García Tejero 4, 41012 Seville, Spain. Electronic address: .
International journal of food microbiology (Impact Factor: 3.08). 11/2012; 160(1):42-9. DOI: 10.1016/j.ijfoodmicro.2012.08.003
Source: PubMed


Yeasts are unicellular eukaryotic microorganisms isolated from many foods, and are commonly found in table olive processing where they can play a double role. On one hand, these microorganisms can produce spoilage of fruits due to the production of bad odours and flavours, the accumulation of CO(2) leading to swollen containers, the clouding of brines, the softening of fruits and the degradation of lactic acid, which is especially harmful during table olive storage and packaging. But on the other hand, fortunately, yeasts also possess desirable biochemical activities (lipase, esterase, β-glucosidase, catalase, production of killer factors, etc.) with important technological applications in this fermented vegetable. Recently, the probiotic potential of olive yeasts has begun to be evaluated because many species are able to resist the passage through the gastrointestinal tract and show beneficial effects on the host. In this way, yeasts may improve consumers' health by decreasing cholesterol levels, inhibiting pathogens, degrading non assimilated compounds, producing antioxidants and vitamins, adhering to intestinal cells or by maintaining epithelial barrier integrity. Many yeast species, usually also found in table olive processing, such as Wicherhamomyces anomalus, Saccharomyces cerevisiae, Pichia membranifaciens and Kluyveromyces lactis, have been reported to exhibit some of these properties. Thus, the selection of the most appropriate strains to be used as starters, alone or in combination with lactic acid bacteria, is a promising research line to develop in a near future which might improve the added value of the commercialized product.

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Available from: Francisco Noe Arroyo-López, Jan 22, 2014
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    • "In this context, several authors have studied, among others, the lipolytic (lipase and esterase) and b-glucosidase activities (technological characteristics) of different yeast species related to table olives or oleic ecosystems (Psani and Kotzekidou, 2006; Hern andez et al., 2007; Bevilacqua et al., 2009, 2012; Aponte et al., 2010; Romo-S anchez et al., 2010; Bautista-Gallego et al., 2011; Rodríguez-G omez et al., 2012). It has also been widely proven that many yeast species have excellent aromatic profiles, can improve lactic acid bacteria growth and inhibit undesirable microorganisms (Psani and Kotzekidou, 2006; Querol and Fleet, 2006; Arroyo-L opez et al., 2012). Recently, the probiotic potential of table olive related yeasts has also begun to be evaluated (Psani and Kotzekidou, 2006; Silva et al., 2011). "
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    ABSTRACT: Yeasts are unicellular eukaryotic microorganisms with a great importance in the elaboration on many foods and beverages. In the last years, researches have focused their attention to determine the favourable effects that these microorganisms could provide to table olive processing. In this context, the present study assesses, at laboratory scale, the potential technological (resistance to salt, lipase, esterase and β-glucosidase activities) and probiotic (phytase activity, survival to gastric and pancreatic digestions) features of 12 yeast strains originally isolated from Greek natural black table olive fermentations. The multivariate classification analysis carried out with all information obtained (a total of 336 quantitative input data), revealed that the most promising strains (clearly discriminated from the rest of isolates) were Pichia guilliermondii Y16 (which showed overall the highest resistance to salt and simulated digestions) and Wickerhamomyces anomalus Y18 (with the overall highest technological enzymatic activities), while the rest of strains were grouped together in two clearly differentiated clusters. Thus, this work opens the possibility for the evaluation of these two selected yeasts as multifunctional starters, alone or in combination with lactic acid bacteria, in real table olive fermentations.
    Food Microbiology 04/2015; 46:66–73. DOI:10.1016/ · 3.33 Impact Factor
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    • "Arroyo-López et al. (2012b) reported that an excessive growth of fermentative yeast species also cause spoilage of olives. Production of high amounts of CO2 which results in blister formation reported frequently (Arroyo-López et al., 2012b). Mould genera such as Aureobasidium, Geotrichum, and Penicillium were also detected in olives to a lesser extent (Table 2). "
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    ABSTRACT: Fermentation is one of the oldest methods for preserving of olives applied worldwide for thousands of years. However, olive processing is a speculative area where whether olives are fermented products or pickled products produced by organic acids and salt. Although lactobacilli and yeasts play a major role in the process, literature survey indicates that lactobacilli are less relevant at least in some types of natural green olives during fermentation. There have been significant advances recently in understanding the process to produce olives, especially the role of lactic acid bacteria and yeasts including biofilm formation on olive surfaces by these organisms. The purpose of this paper is to review the latest developments regarding the microbiota of olives on the basis of olive types, their role on the fermentation process, the interaction between both group of microorganisms and the olive surface, the possibility to use starter cultures and the criteria to select appropriate cultures.
    Frontiers in Microbiology 06/2013; 4:143. DOI:10.3389/fmicb.2013.00143 · 3.99 Impact Factor
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    • "The development of pectinolytic (Saccharomyces oleaginosus, S. kluyveri, Hansenula anomala, Pichia manshurica, Pichia kudriavzevii, Candida boidinii, Rhodotorula minuta, R. rubra, Rhodotorula glutinis, Aspergillus niger, Penicillium sp. and Fusarium sp.) and cellulolytic (Cellulomonas sp.) yeast and moulds is associated with “softening” of the fruit. This is due to the action of their degrading enzymes that, respectively, act on pectic substances that form the middle lamella, which leads to cell separation, and act on cellulose, hemicellulose and polysaccharides, which damages the cell walls (Vaughn et al., 1969; Vaughn et al., 1972; Arroyo-López et al., 2012; Golomb et al., 2013). The softening of the fruits is also associated with the presence of Bacillus and Gram-negative organisms that are normally present in this phase (Nortje and Vaughn, 1953) "
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    ABSTRACT: The process of transformation of table olives from tree to table is the result of complex biochemical reactions that are determined by the interactions between the indigenous microflora of the olives, together with a variety of contaminating microrganisms from different sources [fiber-glass fermenters, polyvinyl chloride (PVC) tanks, pipelines, pumps, and water], with the compositional characteristics of the fruit. One of the most important aspects of improving the quality of table olives is the use of selected microorganisms to drive the fermentation. These can supplant the indigenous microflora and, in particular, the complementary microflora that are responsible for spoilage of canned olives. In this context, from a technological point of view, a well-characterized collection of microrganisms (lactic acid bacteria, yeast) that can be isolated from the matrix to be processed (the olive fruit) will provide the basis for the development of starter culture systems. These cultures can be fully compatible with the typical products and will guarantee high quality standards. Inoculation of the brine with such selected starter cultures will reduce the probability of spoilage, and help to achieve an improved and more predictable fermentation process. Control of the fermentation processes can thus occur through chemical, chemico-physical and microbiological approaches, and since 2008, also through organoleptic evaluation (COI/OT/MO/Doc. No 1. Method for the sensory analysis of table olives). This last has established the necessary criteria and procedures for sensory analysis of the negative, gustatory and kinaesthetic sensations of table olives, which can also be attributed to abnormal proliferation of microrganisms. It also sets out the system for commercial classification, through assessment of the median of the defect predominantly perceived.
    Frontiers in Microbiology 05/2013; 4. DOI:10.3389/fmicb.2013.00091 · 3.99 Impact Factor
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