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... 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...
Research Interests:
Research Interests:
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... 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...
Research Interests: Mathematics and Medicine
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... 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...
Research Interests:
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... 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...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
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... 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.
Research Interests:
Research Interests:
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)... 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...
Research Interests:
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... 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,...
Research Interests:
Research Interests:
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... 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.
Research Interests:
Research Interests:
Research Interests: Microbiology, Kinetics, Biology, Industrial Biotechnology, Medicine, and 14 moreFood Microbiology, Food Preservation, Temperature, Prediction Model, Fermentation, Food Sciences, Central Composite Design, Elsevier, Hydrogen-Ion Concentration, Sodium Chloride, Response surface, Predictive value of tests, Olea, and Specific Growth Rate
Research Interests: Microbiology, Chemistry, Food Science, Kinetics, Industrial Biotechnology, and 15 moreFood Microbiology, Predictive Microbiology, Saccharomyces cerevisiae, Seasonality, Environmental Variables, Food Contamination, Food Sciences, Logistic Model, Culture Media, Citric Acid, Sodium Chloride, Response surface, Logistic Models, Olea, and Probabilistic Model
Research Interests:
Research Interests:
This work applies metataxonomic, standard statistics, and compositional data (CoDa) techniques to study the bacterial diversity of spoiled and normal Spanish-style table olive fermentations, analysing a total of 10-tons of industrial... more
This work applies metataxonomic, standard statistics, and compositional data (CoDa) techniques to study the bacterial diversity of spoiled and normal Spanish-style table olive fermentations, analysing a total of 10-tons of industrial fermentation containers from two processing yards. Forty percent were affected by butyric, sulfidic, or putrid spoilage, while 60% followed the ordinary fermentation course. The samples were obtained at 30 days of fermentation, determining their 16S rRNA gene Amplicon Sequence Variant compositions (ASVs). The butyric containers showed a bacterial profile strongly associated with the genera Enterococcus, Leuconostoc, and Atlantibacter, but also with Lactiplantibacillus and Melissococcus, and less confident to Raoultella, Enterobacter, Serratia, and Celerinatantimonas. The sulfidic fermentation was linked to Alkalibacterium and, to a lesser extent, Marinilactibacillus and the absence of Lactiplantibacillus. Putrid spoilage was mainly related to Halolactibacillus and Alkalibacterium. Sulfidic/putrid (together) differed from butyric spoilage by the presence of Alkalibacterium/Marinilactibacillus as well as by Halomonas/Halanaerobium. Lactiplantibacillus dominated normal fermentations, but Vibrio was also frequently found (0-46%), apparently not causing any alteration. These results contribute to a better microbial characterisation of non-zapatera spoiled table olive fermentations. They also suggest using several statistical techniques to discriminate normal vs spoiled fermentations adequately.
Research Interests:
This work aims to study the effect of the green Spanish-style table olive processing and extraction method of fat on its minor components. For this purpose, it uses standard multivariate analysis (developed for Euclidean space),... more
This work aims to study the effect of the green Spanish-style table olive processing and extraction method of fat on its minor components. For this purpose, it uses standard multivariate analysis (developed for Euclidean space), Compositional Data (CoDa) analysis (for data in the simplex) and Multiple Factor analysis (MFA). Overall, processing had a scarce effect on most of the minor components except ethyl and methyl esters and diacylglycerols, which markedly increased during fermentation; however, these compounds in table olive do not have the negative connotations that those in olive oil do since they are normal metabolites from the yeast microflora habitually present during the process. The work also showed that the quantification of minor components in table olive fat was an extraction-dependent method since Soxhlet increased the concentrations of fatty alcohols, triterpene dialcohols, sterols, waxes and polar compounds. Regarding statistical methods, CoDa analysis strategies w...
Research Interests:
Research Interests:
Research Interests:
Preserving the highly appreciated natural freshness of Aloreña de Málaga table olives and preventing their progressive darkening during processing is a major challenge. In this work, heat-shocked (60°C, 5 min) fruits were processed... more
Preserving the highly appreciated natural freshness of Aloreña de Málaga table olives and preventing their progressive darkening during processing is a major challenge. In this work, heat-shocked (60°C, 5 min) fruits were processed according to the three denominations referred to in the Protected Designation of Origen (cured, fresh green, and traditional) and their characteristics compared with those that followed the habitual industrial process (controls). The results revealed that the effects of the heat treatment on the evolution of pH, titratable acidity, salt, sugar, organic acid, ethanol content, texture, and color of fruits as well as on microbial populations (yeasts and lactic acid bacteria) were slight in the case of the fresh green and cured presentations. However, the differences between heat-shocked and its control were remarkable in the traditional process. Notably, the heat treatment favored lactic acid fermentation, retention of the green appearance of the fruits, sta...
In this work, a total of 72 samples of non-thermally treated commercial table olives were obtained from different markets of the world. Then, prokaryotic diversity in olive biofilms was investigated by metataxonomic analysis. A total of... more
In this work, a total of 72 samples of non-thermally treated commercial table olives were obtained from different markets of the world. Then, prokaryotic diversity in olive biofilms was investigated by metataxonomic analysis. A total of 660 different OTUs were obtained, belonging to Archaea (2.12%) and Bacteria domains (97.88%). From these, 41 OTUs with a proportion of sequences ≥ 0.01% were studied by compositional data analysis. Only two genera were found in all samples, Lactobacillus, which was the predominant bacteria in the biofilm consortium (median 54.99%), and Pediococcus (26.09%). Celerinatantimonas, Leuconostoc, Alkalibacterium, Pseudomonas, Marinilactibacillus, Weissella, and the family Enterobacteriaceae were also present in at least 80% of samples. Regarding foodborne pathogens, only Enterobacteriaceae, Vibrio, and Staphylococcus were detected in at least 91.66%, 75.00%, and 54.10% of samples, respectively, but their median values were always below 0.15%. Compositional ...
In this work, Manzanilla Spanish-style green table olive fermentations were inoculated with Lactobacillus pentosus LPG1, Lactobacillus pentosus Lp13, Lactobacillus plantarum Lpl15, the yeast Wickerhanomyces anomalus Y12 and a mixed... more
In this work, Manzanilla Spanish-style green table olive fermentations were inoculated with Lactobacillus pentosus LPG1, Lactobacillus pentosus Lp13, Lactobacillus plantarum Lpl15, the yeast Wickerhanomyces anomalus Y12 and a mixed culture of all them. After fermentation (65 days), their volatile profiles in brines were determined by gas chromatography-mass spectrometry analysis. A total of 131 volatile compounds were found, but only 71 showed statistical differences between at least, two fermentation processes. The major chemical groups were alcohols (32), ketones (14), aldehydes (nine), and volatile phenols (nine). Results showed that inoculation with Lactobacillus strains, especially L. pentosus Lp13, reduced the formation of volatile compounds. On the contrary, inoculation with W. anomalus Y12 increased their concentrations with respect to the spontaneous process, mainly of 1-butanol, 2-phenylethyl acetate, ethanol, and 2-methyl-1-butanol. Furthermore, biplot and biclustering an...
Research Interests:
Here, we report the genome sequences of six Lactobacillus pentosus strains isolated from traditional noninoculated Spanish-style green table olive brines. The total genome sizes varied between 3.77 and 4.039 Mbp. These genome sequences... more
Here, we report the genome sequences of six Lactobacillus pentosus strains isolated from traditional noninoculated Spanish-style green table olive brines. The total genome sizes varied between 3.77 and 4.039 Mbp. These genome sequences will assist in revealing the genes responsible for both technological and probiotic properties of these strains.
Research Interests:
This work presents the sensory characterization by consumers of traditionally and potentially probiotic green Spanish-style table olives. To this aim, green Manzanilla olives from the same lot were debittered, washed, and brined in the... more
This work presents the sensory characterization by consumers of traditionally and potentially probiotic green Spanish-style table olives. To this aim, green Manzanilla olives from the same lot were debittered, washed, and brined in the same way; then, one sub-lot was allowed fermenting spontaneously while another one was inoculated with a putative probiotic bacterium ( TOMC-LAB2). After fermentation, the olives from both sub-lots were packed with fresh brine to reach 5.5 g/100 mL NaCl and 0.6 g lactic acid/100 mL in the equilibrium. The stabilized olives were then subjected to sensory evaluation by 200 consumers, and the results were analyzed by ANOVA and multivariate statistical techniques. In a first approach, consumers perceived the spontaneously fermented olives as similar to the potentially probiotic product. However, a biplot based on Canonical Variate Analysis (CVA) showed differences between them in the Salty and . When data from the consumer test were assessed by PLS analys...
There is an increasing interest of consumers for natural and healthy products. This work assesses the transformations that green Spanish-style processing of Manzanilla and Hojiblanca table olives produces on the minor components of their... more
There is an increasing interest of consumers for natural and healthy products. This work assesses the transformations that green Spanish-style processing of Manzanilla and Hojiblanca table olives produces on the minor components of their fat. Discriminant analysis showed that most of the variability was not due to processing (24.4%) but to differences between cultivars (59.2%). Therefore, the final products have a similar quality to the original olive fat; that is, the quality of the fat was scarcely affected. The only systematic trends observed were the decrease in hexacosanol, tetracosanol, and octacosanol (fatty alcohols) and C46 (wax), after lye treatment, and the high levels of alkyl esters in the packaged product. Thus, minor-component levels in green table olives are, in general, within the limits established for extra virgin olive oil since the alkyl esters should be considered habitual products of fermentation and not as an alteration as in olive oil.
Research Interests:
This work studies the inoculation conditions for allowing the survival/predominance of a potential probiotic strain (Lactobacillus pentosus TOMC-LAB2) when used as a starter culture in large-scale fermentations of green Spanish-style... more
This work studies the inoculation conditions for allowing the survival/predominance of a potential probiotic strain (Lactobacillus pentosus TOMC-LAB2) when used as a starter culture in large-scale fermentations of green Spanish-style olives. The study was performed in two successive seasons (2011/2012 and 2012/2013), using about 150 tons of olives. Inoculation immediately after brining (to prevent wild initial microbiota growth) followed by re-inoculation 24 h later (to improve competitiveness) was essential for inoculum predominance. Processing early in the season (September) showed a favorable effect on fermentation and strain predominance on olives (particularly when using acidified brines containing 25 L HCl/vessel) but caused the disappearance of the target strain from both brines and olives during the storage phase. On the contrary, processing in October slightly reduced the target strain predominance on olives (70-90%) but allowed longer survival. The type of inoculum used (l...
Research Interests:
Research Interests:
ABSTRACT This work studies the effect of packaging material (glass jar or plastic pouches), olive environment (covered with brine, under N2 atmosphere or vacuum) and storage temperature (7, 13, and 22 °C) on the microbial survival, brine... more
ABSTRACT This work studies the effect of packaging material (glass jar or plastic pouches), olive environment (covered with brine, under N2 atmosphere or vacuum) and storage temperature (7, 13, and 22 °C) on the microbial survival, brine characteristics and colour of packaged fermented olives (Manzanilla cv.) subjected to preservation only by pH and NaCl levels. The highest lactic acid bacteria counts on olive epidermis (6.2-6.5 log10 CFU/olive) were found in fruits stored in glass jar and plastic pouches at 22 °C which, on the contrary, showed the lowest yeast population levels (5.2-6.5 log10 CFU/olive) due to the opposed growth trend observed between bacteria and yeasts. The pH increase in the packages with brine limited the product shelf life to about 2 months but without brine the shelf life could be longer. Changes in colour parameters did not affect the product’s shelf life. The verification of the high lactic acid bacteria on the olive surface, particularly for plastic pouches with brine, and under N2 atmosphere at room temperature, constitutes an essential step for producing probiotic table olives.
Research Interests:
A quantitative investigation on the individual effects of sodium (NaCl), potassium (KCl), calcium (CaCl2), and magnesium (MgCl2) chloride salts against Lactobacillus pentosus and Saccharomyces cerevisiae, two representative microorganisms... more
A quantitative investigation on the individual effects of sodium (NaCl), potassium (KCl), calcium (CaCl2), and magnesium (MgCl2) chloride salts against Lactobacillus pentosus and Saccharomyces cerevisiae, two representative microorganisms of table olives and other fermented vegetables, was carried out. In order to assess their potential activities, both the kinetic growth parameters and dose-response profiles in synthetic media (deMan Rogosa Sharpe broth medium and yeast-malt-peptone-glucose broth medium, respectively) were obtained and analyzed. Microbial growth was monitored via optical density measurements as a function of contact time in the presence of progressive chloride salt concentrations. Relative maximum specific growth rate and lag-phase period were modeled as a function of the chloride salt concentrations. Moreover, for each salt and microorganism tested, the noninhibitory concentrations and the MICs were estimated and compared. All chloride salts exerted a significant ...
Research Interests: Chemistry, Kinetics, Medicine, Multidisciplinary, Food Microbiology, and 13 moreSaccharomyces cerevisiae, Humans, Lactobacillus, Microbial genetic and drug resistance, Fermentation, Anti-Bacterial Agents, Microbial Sensitivity Tests, Calcium Chloride, Hydrogen-Ion Concentration, Sodium Chloride, Potassium Chloride, Olea, and magnesium chloride
Zinc chloride has been used previously as a preservative in directly brined olives with promising results. However, this is the first time that the effects of ZnCl2 addition (0-1 g L(-1) ) on green Spanish-style table olive (Manzanilla... more
Zinc chloride has been used previously as a preservative in directly brined olives with promising results. However, this is the first time that the effects of ZnCl2 addition (0-1 g L(-1) ) on green Spanish-style table olive (Manzanilla cv.) packaging has been studied. The presence of ZnCl2 affected the physicochemical characteristics of the products; the presence of the Zn led to lower pH values (particularly just after packaging) and titratable and combined acidity values than the control but did not produce clear trends in the colour parameters. No Enterobacteriaceae were found in any of the treatments evaluated. At the highest ZnCl2 concentrations, the lactic acid bacteria were inhibited while, unexpectedly, its presence showed a lower effect than potassium sorbate against the yeast population. Regardless of the use of potassium sorbate or ZnCl2 , the packages had a reduced microbial biodiversity because only Lactobacillus pentosus and Pichia galeiformis were found at the end of the shelf life. With respect to organoleptic characteristics, the presentations containing ZnCl2 were not differentiated from the traditional product. Zn chloride was less efficient than potassium sorbate as a yeast inhibitor in green Spanish-style olives, showing clear presentation style dependant behaviour for this property. Its presence produced significant changes in chemical parameters but scarcely affected colour or sensory characteristics.
Research Interests:
ABSTRACT The levels of microorganisms in food ecosystems can be controlled by diverse factors such as temperature, pH, water activity or preservatives, which determine their growth, survival or inactivation. Predictive microbiology is a... more
ABSTRACT The levels of microorganisms in food ecosystems can be controlled by diverse factors such as temperature, pH, water activity or preservatives, which determine their growth, survival or inactivation. Predictive microbiology is a multidisciplinary area of food microbiology which is devoted to studying and predicting, by means of mathematical models, the effects of the mentioned factors on microbial behaviour. The present chapter shows an overview of the successive steps to follow for the successful development and implementation of a predictive model, as well as the most common types of secondary models used in food microbiology. The chapter continues with a general review of the most powerful predictive microbiological tools that are currently available on the web, and finalizes by commenting on the direct implications and applications of predictive microbiology in food preservation.
Research Interests:
Research Interests:
Abstract This work explores novel Zn fortified table olive presentations, using “Aceituna Alorena de Malaga” as the model matrix. The addition of ZnCl 2 to the packing brine led to novel products with limited changes in colour and... more
Abstract This work explores novel Zn fortified table olive presentations, using “Aceituna Alorena de Malaga” as the model matrix. The addition of ZnCl 2 to the packing brine led to novel products with limited changes in colour and improved instrumental firmness. Partial Least Square (PLS) analysis linked the physicochemical characteristics and the sensory scores to the products, allowing for their characterization. The control had the highest scores for saltiness and bitterness as well as for the kinaesthetic sensations. The addition of 0.50 g/L ZnCl 2 led to a product with average physicochemical and sensory characteristics. The product added with 0.75 g/L ZnCl 2 had the highest titratable acidity and acid scores and the lowest pH while showing average values for the other variables. The olives prepared with 1.00 g/L ZnCl 2 produced a presentation with high firmness and Zn content in flesh but the lowest scores for the kinaesthetic sensations, bitterness and saltiness. Overall, the product with 0.75 g/L ZnCl 2 in the packing brine could be a good potential for novel Zn fortified table olive presentations. The consumption of 10 olives (50 g of flesh) of these fruits would supply around 79% of the recommended daily intake of Zn (or ∼12% in 15 g of an olive flesh serving size).
Research Interests:
Research Interests:
Publisher Summary Table olive processing implies several treatments with diverse water solutions. The alkaline treatment in green olives hydrolyzes the natural polyphenols and strongly modifies the flesh and skin structure. In ripe... more
Publisher Summary Table olive processing implies several treatments with diverse water solutions. The alkaline treatment in green olives hydrolyzes the natural polyphenols and strongly modifies the flesh and skin structure. In ripe olives, the successive lye treatments contribute to the polymerization of polyphenols and to fruit darkening. During the immersion in brine, olives usually undergo a fermentation process, with a predominance of lactic acid bacteria (green) or yeast (directly brined olives), which also contributes to the sweetening of the untreated fruits. During processing, washing, and brining of olives, most of the water-soluble compounds present in the olive flesh are lost. In addition, the fermentation/storage process also produces important modifications in the olive composition by using nutrients (sugars, vitamins, etc.) and producing new substances (lactic or acetic acids, volatiles, etc.). There are only a few studies about the fat composition of commercial table olives or the changes that these compounds suffer during processing. This chapter relates to the composition of table olives based mainly on the data available from the Spanish cultivars. The results presented here include 67 of the most usual commercial presentations.
Research Interests:
Publisher Summary This chapter focuses on protein and vitamin contents of commercial table olive oil. Proteins in table olives range mainly from 0.5 to 1.5 g 100 g –1 e.p. Green and directly brined olives are the best sources of this... more
Publisher Summary This chapter focuses on protein and vitamin contents of commercial table olive oil. Proteins in table olives range mainly from 0.5 to 1.5 g 100 g –1 e.p. Green and directly brined olives are the best sources of this compound and their essential amino acids range from 41 to 57 g 16 g –1 N. Regardless of processing styles, table olives are a good source of vitamin E, with an average of 3.04 mg 100 g –1 e.p. The mean content of pro-vitamin A (β-carotene) ranges from 305 in green olives to 200 μg 100 g –1 e.p. in directly brined olives. The mean concentration of vitamin B6 ranges from 35.4 in directly brined olives to 5.0 μg 100 g –1 e.p. in ripe olives. Vitamin C content in green and directly brined olives is diverse and depends on its addition in packing.
This survey uses a multivariate classification analysis to discriminate yeast strains with interesting biochemical activities for the processing of table olives among a collection of 32 isolates belonging to 16 different yeast species.... more
This survey uses a multivariate classification analysis to discriminate yeast strains with interesting biochemical activities for the processing of table olives among a collection of 32 isolates belonging to 16 different yeast species. Lipase, esterase and β-glucosidase activities (desirable characteristics) were quantitatively evaluated in both extracellular and cellular fractions for all isolates in different types of culture media. The study of the quantitative data by cluster and principal component analyses led to the identification of several Wickerhamomyces anomalus, Candida boidinii and Candida diddensiae isolates with promising characteristics (the best global activity levels), clearly differentiated from the rest of the yeasts. The results obtained in this work open up new alternatives to this methodology for the study, classification and selection of the most suitable yeasts to be used as starters, alone or in combination with lactic acid bacteria, during table olive processing.
Research Interests:
Biogenic amines in fermented vegetables have scarcely been studied. Available data show that in table olives and fermented cucumbers their presence is rare and any determinations made have been restricted mainly to histamine. However,... more
Biogenic amines in fermented vegetables have scarcely been studied. Available data show that in table olives and fermented cucumbers their presence is rare and any determinations made have been restricted mainly to histamine. However, some microorganisms, especially those related to spoilage, found in the fermentation brines of such products may have amino acid decarboxylase activity and give rise to biogenic amines by unusual processes. A method for the simultaneous determination of eight biogenic amines (tryptamine, beta-phenylethylamine, putrescine, cadaverine, histamine, tyramine, spermidine, and spermine) has been developed to study their occurrence in fermented vegetables in more detail. The method consists of extraction of the amines from olive paste with 5% m/v trichloracetic acid and successive transfers into water-saturated n-BuOH and 0.1 mol l-1 HCl. An aliquot of this mixture is dried and derivatized with dansyl chloride. The dansyl derivatives are then analysed by high-performance liquid chromatography. Special emphasis has been given to optimization of the n-BuOH and 0.1 mol l-1 HCl extractions and to the derivatization conditions. By applying this method to the analysis of spoilt olives, the presence of some biogenic amines has been demonstrated. Thus a new method for monitoring the presence of biogenic amines during the fermentation of olives and for detecting anomalous fermentations is envisaged.