Table olives can suffer different types of spoilage during fermentation. In this work, a multi-st... more Table olives can suffer different types of spoilage during fermentation. In this work, a multi-statistical approach (standard and compositional data analysis) was used for the study of the volatile organic compounds (VOCs) associated with altered (butyric, sulfidic, and putrid) and non-altered (normal) Manzanilla Spanish-style table olive fermentations. Samples were collected from two industrial fermentation yards in Seville (Spain) in the 2019/2020 season. The VOC profiles of altered (n = 4) and non-altered (n = 6) samples were obtained by headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS). Ninety-one VOCs were identified and grouped into alcohols (30), esters (21), carbonyl compounds (12), acids (10), terpenes (6), phenols (6), sulfur compounds (2), and others (4). The association of the VOCs with spoilage samples depended on the standard or compositional statistical methodology used. However, butyric spoilage was strongly link...
This article contains processed data related to the research published in "Sensory profile o... more This article contains processed data related to the research published in "Sensory profile of green Spanish-style table olives according to cultivar and origin" [1]. It provides information on the physicochemical characteristics of the analysed samples and the results of the multivariate analysis used in the above-commented paper. Particularly, it includes: i) the values of pH, titratable acidity, combined acidity, and NaCl for batches according to samples, ii) the scores given to each descriptor by the panelists according to samples, iii) the histogram of the overall scores for descriptor, iv) the boxplot of descriptors over samples, v) the effect of samples and contribution of panelists to the interaction sample∙panelist, vi) correlation between the panelists and the whole panel, vii) panelist performance, viii) panel repeatability, ix) sensory profile of samples (spider graph), x) adjusted means for descriptor according to samples, xi) prevalence of descriptors on sampl...
The use of bacteriophages for killing pathogenic bacteria is a feasible alternative to antibiotic... more The use of bacteriophages for killing pathogenic bacteria is a feasible alternative to antibiotics and disinfectants. To obtain the large quantities of phages required for this application, large-scale production of bacteriophages must be optimized. This study aims to define conditions that maximize the phage yield of the virulent and polyvalent staphylococcal bacteriophage vB_SauM-phiIPLA-RODI in broth culture, using the food-grade species Staphylococcus xylosus as the host strain to reduce the risk of growing massive quantities of pathogenic bacteria and therefore, to ensure the safety of the final phage stock. The effect of four variables, namely initial bacterial concentration (5.66-8.40 logcolony-forming unit (CFU)/mL), initial phage concentration (5-8 logplaque-forming unit (PFU)/mL), temperature (21-40 °C) and agitation (20-250 rpm), on phage yield (response) was studied by using response surface methodology (RSM). Successive experimental designs showed that agitation did not...
Content of biogenic amines in flesh and brines of table olives was determined by high-pressure li... more Content of biogenic amines in flesh and brines of table olives was determined by high-pressure liquid chromatography analysis of their benzoyl derivatives. No biogenic amines were found in the flesh of fresh fruits at any stage of ripeness. Contents of biogenic amines in Spanish-style green or stored olives increased throughout the brining period but were always higher in the former. Putrescine was the amine found in the highest concentration. Small quantities of cadaverine were found in the samples taken after 3 months of brining. This compound and histamine, tyramine, and tryptamine were also found in samples taken after 12 months. Gordal cultivar showed the highest contents, followed by Manzanilla and Hojiblanca. No relationship was found between contents of biogenic amines and lactic acid production or table olive spoilages, although zapatera olives had considerably higher amounts than those brines that had undergone a normal process. Concentrations in directly brined olives wer...
Journal of Industrial Microbiology & Biotechnology, 2008
The combined effect of NaCl, KCl, CaCl(2), and MgCl(2) on the water activity (a (w)) and the grow... more The combined effect of NaCl, KCl, CaCl(2), and MgCl(2) on the water activity (a (w)) and the growth parameters of Saccharomyces cerevisiae was studied by means of a D-optimal mixture design with constrains (total salt concentrations < or = 9.0%, w/v). The a (w) was linearly related to the concentrations of the diverse salts; its decrease, by similar concentrations of salts, followed the order NaCl > CaCl(2) > KCl > MgCl(2), regardless of the reference concentrations used (total absence of salts or 5% NaCl). The equations that expressed the maximum specific growth (mu (max)), lag phase duration (lambda), and maximum population reached (N (max)) showed that the values of these parameters depended on linear effects and two-way interactions of the studied chloride salts. The mu (max) decreased as NaCl and CaCl(2) increased (regardless of the presence or not of previous NaCl); however, in the presence of a 5% NaCl, a further addition of KCl and MgCl(2) markedly increased mu (max). The lambda was mainly affected by MgCl(2) and the interactions NaCl x CaCl(2) and CaCl(2) x MgCl(2). The further addition of NaCl and CaCl(2) to a 5% NaCl medium increased the lag phase while KCl and MgCl(2) had negligible or slightly negative effect, respectively. N (max) was mainly affected by MgCl(2) and its interactions with NaCl, KCl, and CaCl(2); MgCl(2) stimulated N (max) in the presence of 5% NaCl while KCl, NaCl, and CaCl(2) had a progressive decreasing effect. These results can be of interest for the fermentation and preservation of vegetable products, and foods in general, in which this yeast could be present.
This survey studies the influence of different zinc chloride concentrations (0.050, 0.075, and 0.... more This survey studies the influence of different zinc chloride concentrations (0.050, 0.075, and 0.100%, wt/vol) on the shelf life of “Aceituna Aloreña de Málaga” table olives. The Enterobacteriaceae population significantly (P ≤ 0.05) decreased in treatments containing 0.050 and 0.100% ZnCl2, and those with 0.075% ZnCl2 had also lower average counts than those observed under the usual packaging conditions (0.12% potassium sorbate). Lactic acid bacteria increased for treatments with 0.050 and 0.075% ZnCl2, but in the presence of 0.100% they practically disappeared at the end of the shelf life period (~3 months). With respect to yeasts, populations of these microorganisms significantly decreased with the first two concentrations (0.050 and 0.075%) but showed a slight increase in the presence of 0.100% of ZnCl2, although remaining markedly below populations observed with potassium sorbate packing. The use of this chloride salt also led to products with higher concentrations of sugars in...
This work was conducted to determine the effect of the partial replacement of NaCl by KCl and CaC... more This work was conducted to determine the effect of the partial replacement of NaCl by KCl and CaCl2 (expressed as percentages, wt/vol) on the microbial stability and physicochemical characteristics of seasoned cracked olives using a simplex centroid mixture design. Neither Enterobacteriaceae nor lactic acid bacteria were found during the 50 days that olive packages were monitored. Therefore, microbial instability was considered due to the growth of yeasts, which were the only detected microorganisms; Saccharomyces cerevisiae and Pichia membranifaciens were the most relevant species. Yeasts decreased during the first 21 to 30 days after packing, but their populations rose to 3.5 log CFU/ml by the end of the storage period, clearly causing product deterioration. The partial substitution of NaCl with the other chloride salts slightly altered the phase of microbial inhibition and regrowth. Most of the quality characteristics were not affected by the use of the alternative salt mixtures,...
The changes in chloroplastic pigments, mineral nutrients, and characteristics related to freshnes... more The changes in chloroplastic pigments, mineral nutrients, and characteristics related to freshness were studied during storage and packing of cracked seasoned olives. Cracking produced an initial loss in green pigments and color degradation. Later, storage caused a progressive degradation of chlorophylls and carotenoids, with a slower rate in refrigerated fruits (which preserved the greenish tones better), but after packing (and storage at room temperature), the differential effect disappeared and, at the end of the study, all olives showed similar pigment transformations, which were correlated with CIE a* and hue. Processing led to a Na content increase in olive flesh (and Ca and Zn, when added) but marked losses in the other mineral nutrients. Sodium metabisulfite and ZnCl₂ promoted LAB growth while inhibiting yeast, thus enhancing product stability, and erythorbic acid caused yeast growth and firmness deterioration.
Table olives can suffer different types of spoilage during fermentation. In this work, a multi-st... more Table olives can suffer different types of spoilage during fermentation. In this work, a multi-statistical approach (standard and compositional data analysis) was used for the study of the volatile organic compounds (VOCs) associated with altered (butyric, sulfidic, and putrid) and non-altered (normal) Manzanilla Spanish-style table olive fermentations. Samples were collected from two industrial fermentation yards in Seville (Spain) in the 2019/2020 season. The VOC profiles of altered (n = 4) and non-altered (n = 6) samples were obtained by headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS). Ninety-one VOCs were identified and grouped into alcohols (30), esters (21), carbonyl compounds (12), acids (10), terpenes (6), phenols (6), sulfur compounds (2), and others (4). The association of the VOCs with spoilage samples depended on the standard or compositional statistical methodology used. However, butyric spoilage was strongly link...
This article contains processed data related to the research published in "Sensory profile o... more This article contains processed data related to the research published in "Sensory profile of green Spanish-style table olives according to cultivar and origin" [1]. It provides information on the physicochemical characteristics of the analysed samples and the results of the multivariate analysis used in the above-commented paper. Particularly, it includes: i) the values of pH, titratable acidity, combined acidity, and NaCl for batches according to samples, ii) the scores given to each descriptor by the panelists according to samples, iii) the histogram of the overall scores for descriptor, iv) the boxplot of descriptors over samples, v) the effect of samples and contribution of panelists to the interaction sample∙panelist, vi) correlation between the panelists and the whole panel, vii) panelist performance, viii) panel repeatability, ix) sensory profile of samples (spider graph), x) adjusted means for descriptor according to samples, xi) prevalence of descriptors on sampl...
The use of bacteriophages for killing pathogenic bacteria is a feasible alternative to antibiotic... more The use of bacteriophages for killing pathogenic bacteria is a feasible alternative to antibiotics and disinfectants. To obtain the large quantities of phages required for this application, large-scale production of bacteriophages must be optimized. This study aims to define conditions that maximize the phage yield of the virulent and polyvalent staphylococcal bacteriophage vB_SauM-phiIPLA-RODI in broth culture, using the food-grade species Staphylococcus xylosus as the host strain to reduce the risk of growing massive quantities of pathogenic bacteria and therefore, to ensure the safety of the final phage stock. The effect of four variables, namely initial bacterial concentration (5.66-8.40 logcolony-forming unit (CFU)/mL), initial phage concentration (5-8 logplaque-forming unit (PFU)/mL), temperature (21-40 °C) and agitation (20-250 rpm), on phage yield (response) was studied by using response surface methodology (RSM). Successive experimental designs showed that agitation did not...
Content of biogenic amines in flesh and brines of table olives was determined by high-pressure li... more Content of biogenic amines in flesh and brines of table olives was determined by high-pressure liquid chromatography analysis of their benzoyl derivatives. No biogenic amines were found in the flesh of fresh fruits at any stage of ripeness. Contents of biogenic amines in Spanish-style green or stored olives increased throughout the brining period but were always higher in the former. Putrescine was the amine found in the highest concentration. Small quantities of cadaverine were found in the samples taken after 3 months of brining. This compound and histamine, tyramine, and tryptamine were also found in samples taken after 12 months. Gordal cultivar showed the highest contents, followed by Manzanilla and Hojiblanca. No relationship was found between contents of biogenic amines and lactic acid production or table olive spoilages, although zapatera olives had considerably higher amounts than those brines that had undergone a normal process. Concentrations in directly brined olives wer...
Journal of Industrial Microbiology & Biotechnology, 2008
The combined effect of NaCl, KCl, CaCl(2), and MgCl(2) on the water activity (a (w)) and the grow... more The combined effect of NaCl, KCl, CaCl(2), and MgCl(2) on the water activity (a (w)) and the growth parameters of Saccharomyces cerevisiae was studied by means of a D-optimal mixture design with constrains (total salt concentrations < or = 9.0%, w/v). The a (w) was linearly related to the concentrations of the diverse salts; its decrease, by similar concentrations of salts, followed the order NaCl > CaCl(2) > KCl > MgCl(2), regardless of the reference concentrations used (total absence of salts or 5% NaCl). The equations that expressed the maximum specific growth (mu (max)), lag phase duration (lambda), and maximum population reached (N (max)) showed that the values of these parameters depended on linear effects and two-way interactions of the studied chloride salts. The mu (max) decreased as NaCl and CaCl(2) increased (regardless of the presence or not of previous NaCl); however, in the presence of a 5% NaCl, a further addition of KCl and MgCl(2) markedly increased mu (max). The lambda was mainly affected by MgCl(2) and the interactions NaCl x CaCl(2) and CaCl(2) x MgCl(2). The further addition of NaCl and CaCl(2) to a 5% NaCl medium increased the lag phase while KCl and MgCl(2) had negligible or slightly negative effect, respectively. N (max) was mainly affected by MgCl(2) and its interactions with NaCl, KCl, and CaCl(2); MgCl(2) stimulated N (max) in the presence of 5% NaCl while KCl, NaCl, and CaCl(2) had a progressive decreasing effect. These results can be of interest for the fermentation and preservation of vegetable products, and foods in general, in which this yeast could be present.
This survey studies the influence of different zinc chloride concentrations (0.050, 0.075, and 0.... more This survey studies the influence of different zinc chloride concentrations (0.050, 0.075, and 0.100%, wt/vol) on the shelf life of “Aceituna Aloreña de Málaga” table olives. The Enterobacteriaceae population significantly (P ≤ 0.05) decreased in treatments containing 0.050 and 0.100% ZnCl2, and those with 0.075% ZnCl2 had also lower average counts than those observed under the usual packaging conditions (0.12% potassium sorbate). Lactic acid bacteria increased for treatments with 0.050 and 0.075% ZnCl2, but in the presence of 0.100% they practically disappeared at the end of the shelf life period (~3 months). With respect to yeasts, populations of these microorganisms significantly decreased with the first two concentrations (0.050 and 0.075%) but showed a slight increase in the presence of 0.100% of ZnCl2, although remaining markedly below populations observed with potassium sorbate packing. The use of this chloride salt also led to products with higher concentrations of sugars in...
This work was conducted to determine the effect of the partial replacement of NaCl by KCl and CaC... more This work was conducted to determine the effect of the partial replacement of NaCl by KCl and CaCl2 (expressed as percentages, wt/vol) on the microbial stability and physicochemical characteristics of seasoned cracked olives using a simplex centroid mixture design. Neither Enterobacteriaceae nor lactic acid bacteria were found during the 50 days that olive packages were monitored. Therefore, microbial instability was considered due to the growth of yeasts, which were the only detected microorganisms; Saccharomyces cerevisiae and Pichia membranifaciens were the most relevant species. Yeasts decreased during the first 21 to 30 days after packing, but their populations rose to 3.5 log CFU/ml by the end of the storage period, clearly causing product deterioration. The partial substitution of NaCl with the other chloride salts slightly altered the phase of microbial inhibition and regrowth. Most of the quality characteristics were not affected by the use of the alternative salt mixtures,...
The changes in chloroplastic pigments, mineral nutrients, and characteristics related to freshnes... more The changes in chloroplastic pigments, mineral nutrients, and characteristics related to freshness were studied during storage and packing of cracked seasoned olives. Cracking produced an initial loss in green pigments and color degradation. Later, storage caused a progressive degradation of chlorophylls and carotenoids, with a slower rate in refrigerated fruits (which preserved the greenish tones better), but after packing (and storage at room temperature), the differential effect disappeared and, at the end of the study, all olives showed similar pigment transformations, which were correlated with CIE a* and hue. Processing led to a Na content increase in olive flesh (and Ca and Zn, when added) but marked losses in the other mineral nutrients. Sodium metabisulfite and ZnCl₂ promoted LAB growth while inhibiting yeast, thus enhancing product stability, and erythorbic acid caused yeast growth and firmness deterioration.
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Papers by Antonio Garrido Fernández