Green Table Olives Research Articles

The use of multifunctional yeast-lactobacilli starter cultures improves fermentation performance of Spanish-style green table olives

In this work, Lactobacillus pentosus LPG1, Lactobacillus pentosus Lp13, Lactobacillus plantarum Lpl15, and Wickerhanomyces anomalous Y12, all of them previously isolated from fermented table olive biofilms, were used (alone or in combination) as multifunctional starters for Manzanilla Spanish-style green table olive fermentations. Their performances were evaluated through the changes in the key physico-chemical and microbiological parameters, correlation between AI-2 production and biofilm formation, inoculum imposition, metataxonomic analysis and sensory characteristics of the finished products. Inoculation only with lactic acid bacteria (LAB) strains led to higher titratable acidities and lower pH values than the spontaneous fermentation (non-inoculated control), mainly during the first steps of processing. However, the sequential inoculation of the yeast and then the combination of the 3 LAB strains showed the most favourable evolution. LPG1 strain and, particularly Lp13, were excellent biofilms former and showed the major imposition on the fruit epidermis, as corroborated by rep-PCR analysis. Production of AI-2 was lower in the treatment inoculated exclusively with yeast Y12 but had the highest presence in the sequential yeast-LAB inoculum, with its maximum concentration and maximum LAB population on fruits (19th days) strongly related. Metataxonomic analysis of the biofilms at the end of the fermentation revealed, in addition to Lactobacillus, high proportions of sequences from genera Marinilactobacillus, Alkalibacterium, Halolactobacillus, and low levels of Halomonas and Aerococcus. Compositional data analysis of the omics data revealed that Lpl15 was scarcely efficient for controlling the spontaneous microbiota since its treatment presented the highest proportions of Aerococcus genus. Finally, the sensory analysis showed similar characteristics for the treatment inoculated with LPG1 and the spontaneous process, with olives inoculated with the yeast (alone or in combination with Lactobacillus strains) showing attractive scores. Then, inoculation of Spanish-style table olive fermentations with a sequential yeast and LAB combination could be an advisable practice.

Challenges in the Processing Line of Spanish Style cv. Chalkidiki Green Table Olives Spontaneously Fermented in Reduced NaCl Content Brines

AbstractIn this work, the effect of different treatments using selected combinations of chloride salts (NaCl, KCl, CaCl2, MgCl2) in fermentation brine to assess the safety, quality, and nutritional value of the Spanish style cv. Chalkidiki green table olives spontaneously fermented is studied. Examination of safety parameters (bacteria/yeasts, pH, acidity) and changes in olive color and texture characteristics in brines during fermentation, and in mineral content of olives upon storage up to 12 months, is conducted using appropriate methods. Sensory evaluation takes place in certain cases. Among the tested salt combinations, those of 4.08% NaCl, 2.8% KCl, 1% CaCl2, and 0.12% MgCl2 (w/v) are found to be the most effective regarding safety, color, texture, and taste. Findings support that Spanish style cv. Chalkidiki green olives can be spontaneously fermented in reduced NaCl content brine. The 50% lower NaCl content of the fermented olives compared with that in traditionally fermented ones suggests that reformulation of cv. Chalkidiki green table olives by safe intervention is feasible.Practical Applications: cv. Chalkidiki green table olives are of high importance for the Greek economy. Traditionally they are spontaneously fermented in NaCl brine (8% w/v). Partial replacement of NaCl content with other salts in such a line results in a product acceptable in terms of safety and quality characteristics. The Greek table olive industry may profit from the findings in an attempt to remodel the traditional spontaneous fermentation in green olive processing according to international dietary guidelines.

Quantitation of copper chlorophylls in green table olives by ultra-high-performance liquid chromatography with inductively coupled plasma isotope dilution mass spectrometry

Table olives, a widely consumed delicacy, are often selected by consumers based on the shade of their green color. The appealing coloration of fresh olives fades to brown or pale yellow during the industrial processing necessary for commercialization and storage, as a result of the degradation of chlorophyll a and b to their corresponding pheophytins and other chlorophyll degradation products (CDP). The re-greening of table olives may be achieved by complexation of CDP with Cu2+, to form stable bright green copper CDP (Cu-CDP) complexes. To study this phenomenon, we developed a novel method to separately extract lipophilic and hydrophilic Cu-CDP and quantify Cu-CDP by UHPLC combined with inductively coupled plasma isotope dilution mass spectrometry (UHPLC-ICP-ID-MS) using post-column isotopic dilution with 65Cu. This technique does not require species-specific calibration standards and was applied to survey the Cu-CDP composition of the various types of table olives sold in the US market. The CDP and Cu-CDP extracted from table olives were identified by high resolution full-scan mass spectrometry. Total elemental Cu in table olives was measured by microwave digestion followed by ICP-MS detection and correlated with the content of Cu-CDP. Pale yellow olives contained <1 mg/kg lipophilic Cu-CDP and <3.5 mg/kg total elemental Cu. Bright green table olives contained 4–22 mg/kg lipophilic Cu-CDP and 14.4–161 mg/kg total elemental Cu in contrast to <6 mg/kg reported for natural abundance, indicating the formation of Cu-CDP was achieved by addition of copper salts. A dark green sample with 2.5 mg/kg of total copper and 0.267 mg/kg lipophilic Cu-CDP may have been processed by addition of sodium copper chlorophyllin (SCC); the higher content of Cu isochlorin e4 compared to Cu 152-Me-chlorin e6 supports this conclusion.

Effect of Washing with Acidified Water during Processing on the Quality of Spanish-Style Green Table Olive

Table olives are one of the most consumed appetizers in the world. Egypt is currently the largest producer of table olives in the world. Manzanilla is the most valued table olive variety of preparation for Spanish-style green olive, in this technique, the olive fruits are sorted, graded by size and finally treated with a dilute 1.5% (w/v) sodium hydroxide solution to remove bitterness (glucoside oleuropein). After this treatment, olives are washed with tap water several times at least 3 times to eliminate the excess of alkali. Washing waters of Spanish-style green olive processing are heavily contaminated waste streams that represent an important environmental problem that needs to be solved. The aim of this study was to evaluate the use of acidified water (HCl 1% or H2SO4 1%) in washing of olive fruits treated with alkaline as well as the efficacy of this technique on the resultant fruits quality and sustainability of water used. The obtained results demonstrated that the possibility of olive fruits were washed after lye- treatment to only one time, by using acidified water with HCl 1% (WAWHCl) or with 1% H2SO4 (WAWH2SO4) compared with fresh water (3 times), and the re-use of resultant wastewater after neutralization with HCl 7% as a safe water for irrigation. Oleuropein is responsible for bitterness, its content decreased during processing and fermentation in all treatments. Regarding sensory properties of olive pickles (WAWH2SO4) gave the lowest score of defects 0.5% meanwhile high score of smell (8) and taste (9). The study concluded obviously that the possibility to use acidified water (H2SO4 1%) in olive fruits washing after lye-treatment without any changes in the olive pickles quality.

Effect of ozone treatment on the physical, microbiological and sensorial properties of Spanish-style table olives

Ozone has been widely used in the food industry as an effective antimicrobial agent. In this study the possibilities of using ozone in table olive preservation was investigated for the first time. For this purpose, the Domat variety of table olives was processed according to the Spanish style and treated with aqueous ozone for 5, 10, and 20 minutes at 0.5, 1, 2 and 4 ppm. The effects of ozonation on the microbiological, physical and sensory characteristics of the table olives were evaluated during the storage period (up to 180 days). The pH, color and firmness of the ozone treated table olives showed higher stability. Statistically significant reductions in the total bacteria and yeast/mould counts were obtained (p &lt; 0.05). Enterobacteriaceae and Escherichia coli were not found in the samples. After 60 days of storage the control samples (ozone untreated olives) obtained low values for sensory analysis, and did not meet market requirements. The results indicate that treating green table olive with ozon (1 ppm concentration) for 10 min in aqueous form reduces the microbial population without any negative effects on the firmness, color (L*, a* b*) or sensory attributes of the table olives.

Effect of different fermentation processes on the phytochemical properties of green table Olives

Abstract Most olive varieties are grown in Jordan using Baladi, Nabali, Crosodi and k18 table olives. This study evaluated the effect of de-bittering fermentation methods on the total phenolic, flavonoid contents, and antioxidants. The phytochemical results of fresh and fermented table olives showed significant decrease after fermentation process and during three months of storage. Baladi fresh table olive presented the highest phenol content (350.9mg GAE/100g) followed by Nabali, Crosodi and k18 varieties, respectively. The highest antioxidant value was found in Baladi variety (42.2%) followed by k18, Crosodi and Nabali varieties, respectively. Crosodi fresh table olive presented the highest flavonoid content (107.4 mg CE/100G), followed by k18, Nabali and Baladi varieties, respectively. The storage results showed that total phenol content decreased and significantly varied among de-bittering fermentation methods in all storage periods. Higher content in fresh olives was found, followed by those treated with NaOH, ticked and scratchy, respectively. The antioxidant activity and flavonoid content decreased during fermentation periods. The results of de-bittering fermentation methods varied among storage periods and showed that higher antioxidant activities and flavonoid contents were found in olives treated with NaOH followed by ticked, scratchy, and fresh olives, respectively.

Chemical composition of table olive wastewater and its relationship with the bio-fortifying capacity of tomato (Solanum lycopersicum L.) plants

Recently, the potential use as fertilizer of some wastewaters from table olive factories has been reported but the cause of this activity has not been disclosed up to now. In this study, a huge number of table olive waste solutions were analyzed from three consecutive seasons. Sugars, phenolic and mineral compounds were the main chemical groups identified. The individual effect of these components was tested on the growth of tomato plants and the quality of their fruits. Two factorial designs were assayed (24 and 23), in which the individual groups of chemical substances were sugars, minerals (nitrogen, potassium and phosphor), simple and polymeric phenols. Also, fresh wash water from Spanish-style green table olive processing was tested. The main conclusion was that no one individual group caused the fertilizer activity but a synergetic action of all of them was efficient and the fresh waste solution tested was the most effective.

Occurrence of toxigenic Penicillium polonicum in retail green table olives from the Saudi Arabia market

Abstract In Saudi Arabia, table olives are widely consumed as appetizers, pickles, and food additives. Many food-borne fungal pathogens such as Penicillium specie have ability to survive on prepared and preserved green table olives. Penicillium polonicum, an important mycotoxin producer, is much more frequently found in cereals, peanuts, onions, dried meats, citrus fruits and recently in frozen food. The aim of this study was to determine, identify and characterize the occurrence of mycotoxin producing Penicillium species from retail green table olives purchased in the Saudi Arabia markets and used for human consumption. Our results revealed that Penicillium expansum, P. citrinum, P. verrucosum and P. polonicum were isolated form all samples. P. polonicum was the only species that able to grow producing vegetative and reproductive structures in refrigerators. The qualitative determination of citrinin, penicillic acid and cyclopiazonic acid is positive in all investigated samples. This study provides insight into the presence of toxigenic P. polonicum not only as a mould but also as a source of toxic metabolites that produced inside food products. Thus, the application of prevention actions should be attained. Furthermore, P. polonicum is reported here for first time as both an inhabitant and a pathogen on green table olives.

Lactic Acid Bacteria and Yeast Inocula Modulate the Volatile Profile of Spanish-Style Green Table Olive Fermentations

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 analyses segregated fermentations inoculated with Lp13 and Y12 from the rest of the processes. The use of sequential lactic acid bacteria and yeasts inocula, or their mixture, in Spanish-style green table olive fermentation could be advisable practice for producing differentiated and high-quality products with improved aromatic profile.

Monitoring the debittering of traditional stoned green table olives during the aqueous washing process using an electronic tongue

Stoned green olives are traditional table olives produced in the Northeast of Portugal. They are highly appreciated due to their sensory characteristics and levels of complex phenols with strong antioxidant activity, having a significant agro-economic relevance. During debittering, stoned olives are immersed in water, which is changed each 2 d during 20 d, leading to the reduction of initial bitterness turning them edible olives. So, monitoring the basic taste, total phenols contents and the bitterness index during washing is very important being a time-consuming and expensive task. Thus, the possibility of using an electronic tongue, coupled with chemometrics, for monitoring debittering of stoned green olives (cvs. Cobrançosa and Negrinha de Freixo), was evaluated for the first time. The electronic tongue allowed discriminating the different debittering time-periods (sensitivity ≥ 62%, internal-validation), monitoring the decrease of bitter and pungent intensities and the increase of the sweet intensity (0.793 ≤ R-Pearson ≤ 0.971; RMSE ≤ 1.388), assessing the decrease of the total phenols (R-Pearson≥0.934; RMSE ≤ 19.1 g GAE/kg) and of the bitterness index (R-Pearson ≥ 0.892; RMSE ≤ 0.864 g Oleuropein/kg). Therefore, the device could be a practical tool to monitor debittering of stoned green olives during washing.

New insights into the molecular effects and probiotic properties of Lactobacillus pentosus pre-adapted to edible oils

In this study, the survival and growth of seven probiotic Lactobacillus pentosus strains isolated from Aloreña green table olives in the presence of vegetable-based edible oils (i.e., sunflower, olive, linseed, soy, corn, almond and argan) and mint essential oil were determined for the first time. Slight decreases in bacterial viability were observed depending on the strain and oil exposure, mainly mint essential oil. However, pre-adaptating the strains to the corresponding oils significantly increased their cell viabilities. As such, this study examined whether pre-adaptating probiotic L. pentosus strains with oils will constitute a new strategy to increase stress resistance, e.g., acids (pH 1.5) or bile (up to 3.6%) in food production and/or during digestion, and improve functional probiotic properties. Improvements in stress resistance (acidic and bile conditions) were noticed in some pre-adapted strains with oils; further, pre-adaptations with olive, argan, sunflower and linseed oils induced gene expression (e.g., fus, rpsL, pgm, groEL, enol and prep) for moonlighting proteins involved in several stress responses and other functions. As such, pre-adaptation with vegetable edible oils may represent a novel approach for manufacturing probiotic products by improving the stability of bacteria during industrial processes that would otherwise reduce their viability and functionality.

Multiple Genome Sequences of Lactobacillus pentosus Strains Isolated from Biofilms on the Skin of Fermented Green Table Olives.

The draft genome sequences of five Lactobacillus pentosus strains isolated from biofilms on the skin of green table olives are presented here. These genome sequences will assist in revealing the potential probiotic properties of these strains, as the intake of fermented olives implicates the passage of millions of Lactobacillus spp. throughout a consumer's gastrointestinal tract.

Sensory properties of green table olives prepared by different fermentation processes

ABSTRACTThis study evaluated the effect of debittering fermentation methods on the sensory properties of green table olives. The panelist results of appearance, aroma, taste, and texture showed that the most preference sensory attributes are found in treated with NaOH followed significantly by the whole, scratchy and ticked. The panelist results varied and showed the higher values of overall appearance found in NaOH followed by the whole, scratchy, and ticked. Also, the higher values of overall flavor and taste found in treated with NaOH followed by ticked, scratchy, and whole. The higher values of overall texture found in whole followed by treated with NaOH, scratchy and ticked. The higher values of overall bitter taste found in whole followed by scratchy, ticked and treated with NaOH. In conclusion, despite of NaOH processing fermentation debittering method has the most sensory parameters but in general not big differences were found comparison with other methods.

Microbiota and Metabolite Profiling of Spoiled Spanish-Style Green Table Olives.

The aim of the present study was to assess the malodorous spoilages of Spanish-style green table olives through microbial and metabolite composition using current measuring techniques (e.g., high-throughput DNA sequencing, headspace solid-phase microextraction combined with gas chromatography-mass spectrometry). Under different alkaline and washing conditions, the spoilage fermentations were reproduced with Gordal and Manzanilla olive cultivars using a low salt concentration (71 g L−1 NaCl) in the initial brine. The degradation of lactic acid and significant increases in volatile fatty acids and phenols were found in all the spoiled samples in comparison with the unspoiled control samples. According to high-throughput DNA sequencing, Cardiobacteriaceae and Ruminococcus were the dominant bacteria in the spoiled samples. PLS regression and Pearson’s correlation coefficient analyses revealed positive and negative correlations among microbial communities, metabolites, and sensory spoilage descriptors. Notably, the “zapatera” descriptor was significantly associated with Propionibacterium, which was positively correlated with acetic acid, propionic acid, succinic acid, and methyl propanoate; while the “butyric” descriptor exhibited a significant positive relationship with the genus Ruminococcus, which gave an almost significant correlation with propionic and butyric acids.

Enterococci Isolated from Cypriot Green Table Olives as a New Source of Technological and Probiotic Properties

Τable olive is one of the main fermented vegetable worldwide and can be processed as treated or natural product. Lactic Acid Bacteria (LAB) are responsible for the fermentation of treated olives. The aim of this work was to study the technological characteristics and the potential probiotic properties of LAB isolated from Cypriot green table olives. This is the first comprehensive report on the isolation and characterization of LAB isolates retrieved from Cypriot green table olives. From a collection of 92 isolates from spontaneously fermenting green olives, 64 g positive isolates were firstly identified to genus level using biochemical tests, and secondly to species level using multiplex species specific polymerase chain reaction (PCR) amplifications of the sodA gene. Moreover, each of our isolates were tested for their technological and probiotics properties, as well as for their safety characteristics, using biochemical and molecular methods, in order to be used as starter cultures. Finally, to discriminate the most promising isolates on the base of their technological and probiotics properties, Principal component analysis was used. All the isolates were identified as Enteroccocus faecium, having interesting technological properties, while pathogenicity determinants were absent. Principal component analysis showed that some isolates had a combination of the tested parameters. These findings demonstrate that enteroccoci from Cypriot table olives should be considered as a new source of potential starter cultures for fermented products, having possibly promising technological and probiotic attributes.

Fruit characteristics of six candidate olive cultivars

AbstractSome important physical, chemical and sensory characteristics of raw and processed olives (processed by the same scratched table olive process) were investigated. In the study, six candidate cultivars obtained by cross-breeding and one standard cultivar (‘Domat’) grown together in an olive breeding and observation plot in the Ataturk Central Horticultural Research Institute in Turkey were investigated. Fruit weight and flesh-to-seed ratio of fresh raw olives ranged from 5.18 to 7.65 g and 4.8 to 6.3, respectively. LT011 had the highest fruit weight, whereas LT001 and LE001 had the highest flesh-to-seed ratio. Total phenolic content and antioxidant activity of the produced table olives were estimated between 102 and 141 mg gallic acid equivalents per 100 g−1fresh weight, and 13.4 and 14.9 µmol Trolox 100 g−1, respectively. Fruits of LT001 had higher appearance, taste, bitterness and general appreciation scores than the others. LT001 showed a lesser loss of oleuropein absorbance and antioxidant activity than the others during processing. The results of this study revealed that LE001, LT001 and LT011 had superior characteristics for the production of scratched green table olives.

Proteomic analysis of Lactobacillus pentosus for the identification of potential markers of adhesion and other probiotic features

We analyzed the adhesion capacity to mucus of 31 Lactobacillus pentosus strains isolated from naturally fermented Aloreña green table olives using an immobilized mucin model. On the basis of their adhesive capacity to mucin, three phenotypes were selected for cell-wall protein proteomic analysis to pinpoint proteins involved in the adhesion process: the highly adhesive L. pentosus CF1-43 N (73.49% of adhesion ability), the moderately adhesive L. pentosus CF1-37 N (49.56% of adhesion ability) and the poorly adhesive L. pentosus CF2-20P (32.79% of adhesion ability). The results revealed four moonlighting proteins over-produced in the highly adhesive L. pentosus CF1-43 N, which were under/not produced in the other two L. pentosus strains (CF1-37 N and CF2-20P). These proteins were involved in glycolytic pathway (phosphoglycerate mutase and glucosamine-6-phosphate deaminase), stress response (small heat shock protein) and transcription (transcription elongation factor GreA). Furthermore, the relative fold change in gene expression analysis showed significant up-regulation of the genes coding for these four moonlighting proteins in the highly adhesive L. pentosus CF1-43 N versus the poorly adhesive L. pentosus CF2-20P and also in response to mucin for 20 h which clearly indicate the significant role of these genes in the adhesion capacity of L. pentosus. Thus, these proteins could be used as biomarkers for mucus adhesion in L. pentosus. On the other hand, mucin exposure induced other probiotic effects in L. pentosus strains, enhancing their co-aggregation ability with pathogens and possible inactivation.

Draft Genome Sequences of Six Lactobacillus pentosus Strains Isolated from Brines of Traditionally Fermented Spanish-Style Green Table Olives

ABSTRACTHere, 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.

Assessment of the Minor-Component Transformations in Fat during the Green Spanish-Style Table Olive Processing.

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.

Effects of selected bacterial cultures on safety and sensory traits of Nocellara Etnea olives produced at large factory scale

This work investigates the effects of different combinations of selected lactic acid bacteria strains on Lactobacillus species occurrence, on safety and on sensory traits of natural green table olives, produced at large factory scale. Olives belonging to Nocellara Etnea cv were processed in a 6% NaCl brine and inoculated with six different bacterial cultures, using selected strains belonging to Lactobacillus plantarum, Lactobacillus paracasei and Lactobacillus pentosus species.The fermentation process was strongly influenced by the added starters and the identification of lactic acid bacteria isolated throughout the process confirms that L. pentosus dominated all fermentations, followed by L. plantarum, whereas L. casei was never detected. Pathogens were never found, while histamine and tyrosine were detected in control and in two experimental samples. The samples with the lowest final pH values showed a safer profile and the most appreciated sensory traits.The present study highlights that selected starters promote prevalence of L. pentosus over the autochthonous microbiota throughout the whole process of Nocellara Etnea olives.