Spanish-style Green Olives Research Articles

Table Olive Powder: A new ingredient from food industry discards

This study aimed to obtain olive powder from table olive industry discards to use it as a valuable ingredient for developing new products or for replacing commercial additives. The drying process was conducted by convective drying (50 °C and 70 °C) and freeze-drying. The raw material came from Spanish-style green pitted olives and anchovy-stuffed olives. Table olive powders were characterised by their proximate composition, physico-chemical characteristics, antioxidant properties and lipid oxidation. The drying process did not affect the final product's nutritional value, which was determined mainly by the employed raw material, but high temperatures strongly impacted colour and caused a reduction in the bioactive compounds between 60 and 70 %. The freeze-dried table olive powder had the highest phenolic content at over 2500 mg GAE/kg and antioxidant properties, which reduce product lipid oxidation below 2 mg MDA/kg. This work expounds the best drying process to obtain a novel high-quality ingredient from table olive discards.

Comparative study of Spanish-style and natural cv. Chalkidiki green olives throughout industrial-scale spontaneous fermentation and 12-month storage: safety, nutritional and quality aspects

Table olives are among the most popular fermented foods and cv. Chalkidiki green table olives are particularly popular in both Greek and international markets. This work aimed at comparatively investigating the effect of processing method on the production of Spanish-style and natural cv. Chalkidiki green olives during fermentation and 12-month storage in brines with different chloride salts composition (NaCl, KCl, CaCl2) at industrial scale. All delivered products were safe with satisfactory color and texture characteristics. Employment of UPLC-HRMS revealed differences in metabolites’ profile of polar extracts from olives and brines between the processing methods. Τhe application of alkali treatment drastically decreased the content of hydroxytyrosol and tyrosol in drupes, still an essential amount (1037–2012 and 385–885 mg/kg dry flesh, respectively) of these health-promoting phenolic compounds was retained in all products, even after storage. Noteworthy, fermentation of natural olives in brine (5 % NaCl) yielded in products with significantly lower Na levels in olive flesh (1.7 g/100 g), followed by Spanish-style olives fermented in low (4 %) and high (8 %) NaCl brines (2.7 and 5.2 g Na/100 g, respectively), supporting the efforts toward the establishment of table olives as functional food. Moreover, maslinic and oleanolic acids content was 1.5–2-fold higher in the natural table olives compared to the Spanish-style ones owing to the detrimental effect of alkali treatments. The processing method did not exert a differential effect on α-tocopherol content of olives. Sensory analysis indicated that all the final products were acceptable by consumers, with a slight preference for Spanish-style green olives fermented in brines with 50 % lower NaCl content. Present findings could be beneficial to the ongoing endeavor directed for the establishment of table olives as a source of bioactive compounds that concerns both industrial and scientific communities.

Characterization and safety of commercial table olives from the Algerian market

In this study, a comprehensive physicochemical characterization of commercial table olives from the Algerian market was conducted, revealing significant discrepancies with international regulations and indicating non-compliance with established standards. Spanish-style green olives and natural turning color olives, for the most part, did not meet the established standards regarding pH and salt concentration. Additionally, samples of oxidized black olives were found, which, due to their high pH, should undergo sterilization but were stored in non-sterilized containers. Microbiological analysis revealed high populations of Enterobacteriaceae and other spoilage microorganisms in the brines, indicating possible deficiencies in hygiene practices during production. The study evaluating the survival of pathogenic microorganisms in the samples indicated that the physicochemical conditions of the product, such as pH and salt concentration, played a crucial role in the non-survival of these pathogens. Furthermore, an antimicrobial effect of certain phenolic compounds present in olives was observed, highlighting the importance of these compounds in food safety.In summary, this study provides a snapshot of the quality of table olives available in the outlets surveyed and underscores the importance of strict microbiological control, quality, and appropriate production practices in the table olive industry in Algeria. The use of preservatives and heat treatments, along with good manufacturing and hygiene practices, are useful tools as control measures to reduce spoilage in table olives. Adhering to established standards in international regulations for table olive processing and implementing effective control measures are essential steps to ensure the quality, safety, and consumer acceptance of this traditionally valued food product.

Machine olfaction discrimination of Spanish-style green olives inoculated with spoilage mold species

As an alternative to traditional sensory analysis evaluation, machine olfaction represents a valuable tool for detecting incipient defects caused by microorganisms. For this purpose, different strains of spoilage molds were inoculated into Spanish-style table olives and the effect on their sensory quality and volatile profile were analyzed using an electronic nose (E-nose). The main defects obtained for the different inoculated microorganisms associated with abnormal fermentation were mold and humidity. A total of 36 volatile compounds were identified and classified into phenolics, alcohols and carboxylic acids, while minor ones included derivatives of acids and oxygenated compounds. In general, a decrease in the concentrations of acetic acid, phenolic compounds and creosol was observed in olives inoculated with mould strains. However, propanoic acid, 2-methoxy-phenol, 2,4-dimethyl-heptane, among others, increased after mold inoculation. Sensorial and volatile compound analysis showed the table olives inoculated with the strains of Aspergillus flavus A.F.18 and Penicillium expansum P.E.20 to be the most altered. The E-nose data were able to classify the inoculated olives into different categories and distinguish them from the control treatment, regardless the intensity of the defect. The principal component analysis (PCA) of table olives inoculated showed that 70.23% of the total variance of data was explained by PC1 and 23.27% by PC. The sum of the elements of the diagonal of the confusion matrix gives the percentage of success in discrimination of 95.5%. Therefore, these results show the capacity and precision of E-nose to discriminate between the alterations caused by different mold strains.

Microbial and Biochemical Profile of Different Types of Greek Table Olives.

Analysis of table olives microbiome using next-generation sequencing has enriched the available information about the microbial community composition of this popular fermented food. In this study, 16S and 18S rRNA sequencing was performed on table olives of five Greek popular cultivars, Halkidikis, Thassou, Kalamon, Amfissis, and Konservolia, fermented either by Greek style (in brine or salt-drying) or by Spanish style, in order to evaluate their microbial communities. Moreover, analytical methods were used to evaluate their biochemical properties. The prevailing bacterial species of all olives belonged to Lactobacillaceae, Leuconostocaceae, and Erwiniaceae families, while the most abundant yeasts were of the Pichiaceae family. Principal coordinates analysis showed a clustering of samples cured by salt-drying and of samples stored in brine, regardless of their cultivar. The biochemical evaluation of total phenol content, antioxidant activity, hydroxytyrosol, oleuropein, oleocanthal, and oleacein showed that salt-dried olives had low amounts of hydroxytyrosol, while Spanish-style green olives had the highest amounts of oleocanthal. All the other values exhibited various patterns, implying that more than one factor affects the biochemical identity of the final product. The protocols applied in this study can provide useful insights for the final product, both for the producers and the consumers.

Assessing Listeria monocytogenes growth during Spanish-style green table olive fermentation

Table olives are one of the most important fermented vegetables in the Mediterranean countries. Although this fermented vegetable has a long record of microbial safety, various studies have shown the presence of Listeria monocytogenes during table olive processing. This study focused on evaluating the behaviour of a cocktail of L. monocytogenes strains during fermentation of Spanish-style green Manzanilla olives. For this purpose, a challenge test consisting of artificial inoculation of olive fermentation with high levels of the food-borne pathogen (7.0 log10 CFU/ml) was performed. The Fermentation was carried out at the laboratory scale in sealed glass bottles (n = 168) under controlled conditions to avoid the initiation of lactic acid fermentation intentionally. This point was confirmed by the evolution of pH, which ranged from an initial 9.0 to final 6.0 units (decrease kinetic constant of −0.0016 h−1), as well as by the behaviour of lactic acid and mesophilic bacteria during the study (55 days). The fate of L. monocytogenes during fermentation was described using mathematical models, including the two-term Gompertz model. During this time, the food-borne pathogen showed an initial growth phase which lasted until 250 h, reaching a maximum population level close to 9.0 log10 CFU/ml, even in the presence of high salt concentrations (>6.0% NaCl). Then, a rapid decline phase was observed but continuously detecting a residual tail of around 2 log10 CFU/ml. Data obtained in this work shows the importance of the control of olive fermentation, especially during the first weeks when pH is alkaline-neutral and environmental conditions could favour L. monocytogenes growth.

Study of the factors affecting growth of Celerinatantimonas sp. and gas pocket formation in Spanish-style green olives

The defect of gas pocket formation still leads to substantial losses of yield and quality of Spanish-style green olives worldwide. This spoilage has recently been associated with the growth of Celerinatantimonas sp., and this study was aimed at investigating the influence of several factors on the growth of Celerinatantimonas , both in synthetic media as well as in the olive brines of the three olive cultivars Gordal, Manzanilla and Hojiblanca. Using synthetic media, it was found that the concentration of NaCl within current industrial levels (3.5–7.0%) did not affect the growth of Celerinatantimonas , whereas the pH was a crucial factor, the range of growth being 4.5–7.5 units. Among the acids tested, lactic acid presented the highest inhibitory action against this microorganism. The assays carried out with olive brines disclosed that the population of Celerinatantimonas and its normal fermentation products (acetic acid and ethanol) increased in all of the inoculated brines, while the reduction of gas pocket defect depended on the combined use of several factors including addition of lactic acid, control of pH and inoculation with a lactic acid bacteria starter. Hence, the maintenance of a pH below 4.5 units at the beginning of fermentation along with the addition of 0.2–0.8% lactic acid was considered necessary to inhibit growth of Celerinatantimonas and to prevent gas pocket defect. The tools proposed as conclusions of this work should be used by table olive processors in the future to reduce the incidence of this olive spoilage. • Celerinatantimonas caused gas pocket defect in processed green olives. • NaCl up to 10% did not inhibit the growth of Celerinatantimonas . • Celerinatantimonas grew in a pH range of 4.5–7.0 units. • Lactic acid at 0.2–0.8% retarded growth of Celerinatantimonas . • The combined use of pH and lactic acid may control growth of Celerinatantimonas .

Determination of table olive characteristics of new olive varieties obtained by crossbreeding of Gemlik and Memecik variety

Objective: The objective of this study was to investigate the physical and chemical characteristics of 10 hybrid type table olives obtained as a result of a national level hybridization program in the Olive Research Institute. Material and Methods: The samples selected from Memecik x Gemlik and Gemlik x Memecik combinations, which came to the pre-elimination stage in the project, were evaluated in terms of table olives characteristics. These products were obtained in four olive seasons. Olives were subjected to some physical and chemical tests and analyzes. The main olive processing techniques (green split olive, natural turning black olives and Spanish style green olives) were applied to test the suitability of the cultivar candidates to processing techniques. Results: The olive variety candidates, GM 41, GM 39, MG 11 and MG 5 attracted more attention than the main varieties of the cross breeding project, “Memecik” and “Gemlik”, in terms of some table olive characteristics like high flesh/pit ratio and the number of olive fruits per kilogram. Especially, The variety, GM 41 was found to be significantly important candidate for the natural black olive processing because of having high number of olives per kilogram. Conclusion: As a result of this study, it was concluded thata the hybrid variety candidates, MG5 and MG13 were found to be promising in terms of table olive characteristics and registered as HAYAT and ARSEL, respectively.

Formation of gas pocket defect in Spanish-style green olives by the halophile Celerinatantimonas sp.

Gas pocket defect causes substantial losses every season to Spanish-style green table olive processors. This defect has been thought to be caused by microorganisms that are able to produce gaseous compounds that break the flesh and/or the epidermis of olive fruits. This study was focused on the search for the microorganism actually responsible for this spoilage. Metataxonomy analysis of industrial spoiled brines demonstrated the presence of Celerinatantimonas as the most probable source leading to gas pocket formation. Several bacterial isolates were obtained from different industrial spoiled brines whose 16S rRNA sequence closest homologue was Celerinatantimonas diazotrophica (94–96% similarity). Vigorous gas production (H 2 and CO 2 ) by these isolates in broth cultures was confirmed. Inoculation of microbial pellets from one of these spoiled brines did indeed provoke gas pocket formation in fresh batches of Spanish-style green olives. Although the species C. diazotrophica has been previously reported in metataxonomy studies in samples of table olives, this is the first time that it was isolated from fermenting table olive samples. In addition, this is the first report that associates this species to the gas pocket defect in table olives. Thus, inoculation with one of the wild-type isolates identified as C. diazotrophica in table olive brines confirmed the involvement of this microorganism in the formation of the gas pocket defect in Spanish-style green olives. • Celerinatantimonas was detected by metataxonomy in every spoiled table olive brine. • Celerinatantimonas was isolated from brines of table olives with gas pockets. • Gas pocket defect in olives was reproduced by Celerinatantimonas inoculation. • Celerinatantimonas yields acetic acid-ethanol-H 2 -CO 2 disturbing lactic acid fermentation.

E-Nose Discrimination of Abnormal Fermentations in Spanish-Style Green Olives.

Current legislation in Spain indicates that table olives must be free of off-odors and off-flavors and without symptoms of ongoing alteration or abnormal fermentations. In this regard, the International Olive Council (IOC) has developed a protocol for the sensory classification of table olives according to the intensity of the predominantly perceived defect (PPD). An electronic nose (e-nose) was used to assess the abnormal fermentation defects of Spanish-style table olives that were previously classified by a tasting panel according to the IOC protocol, namely zapateria, butyric, putrid, and musty or humidity. When olives with different defects were mixed, the putrid defect had the greatest sensory impact on the others, while the butyric defect had the least sensory dominance. A total of 49 volatile compounds were identified by gas chromatography, and each defect was characterized by a specific profile. The e-nose data were analyzed using principal component analysis (PCA) and partial least square discriminant analysis (PLS-DA). The different defects were clearly separated from each other and from the control treatment, independently of PPD intensity. Moreover, the e-nose differentiated control olives from table olives with combined sensory defects despite the dilution effect resulting from the combination. These results demonstrate that e-nose can be used as an olfactory sensor for the organoleptic classification of table olives and can successfully support the tasting panel.

Natural β-Carotene Production by Blakeslea trispora Cultivated in Spanish-Style Green Olive Processing Wastewaters.

In the current research, the potential of Spanish-style green olive processing wastewaters (lye and washing waters) exploitation toward natural β-carotene production by Blakeslea trispora was tested for the first time. Mating culture generated by the joint cultivation of the heterothallic fungal strains ATCC 14271 and 14272 in the non-sterile lye and washing waters was able to grow, achieving the phytotoxic hydroxytyrosol degradation by 57.3% and 66.8%, respectively. However, the low sugar and nitrogen content of the streams did not favor carotenogenesis. Alternatively, in the nutrient-enriched effluents, a notable quantity of β-carotene was produced, accounted for 61.2 mg/L (lye) and 64.1 mg/L (washing waters) (82–88% of total carotenoid content). Above all, enriched streams had a noteworthy stimulating effect on the β-carotene synthesis, because both the maximum β-carotene yield per volume of enriched effluents and specific β-carotene production rate were higher when compared with the respective values obtained from trials with synthetic reference medium without added effluents. Hydroxytyrosol and tyrosol showed high stability during the non-sterile process for β-carotene production by B. trispora grown in the enriched effluents. This finding strengthens the potential toward the generation of multiple high-value products, which could lower the natural β-carotene production costs.

Progress on green table olive processing with KOH and wastewaters reuse for agricultural purposes

Table olive wastewaters are seriously polluting and a difficult to treat effluent worldwide, mainly due to their high content in sodium. An alternative approach could be the treatment of the olives with KOH instead of NaOH, in order to reuse the olive streams as biofertilizers. In this study, the debittering of olives with KOH was investigated at pilot plant scale in two olive seasons. The results indicated that a concentration between 1.7 and 2.0% of KOH (similar to that employed with NaOH) led to a fermented product with the same physicochemical and organoleptic characteristics than the traditional one. The spent lyes and washing waters from the KOH treatments were gathered and vacuum evaporated, giving rise to a concentrated solution rich in potassium (52 g/L) that was tested as biofertilizer in open tomato fields. Furthermore, the drip irrigation of the tomato plants with a combined olive solution and mineral fertilizer (NH4NO3) produced similar tomato yield and quality than the irrigation with only mineral fertilizer (NH4NO3 + KNO3). Overall, it has been demonstrated that Spanish-style green olives can be processed with KOH and the effluents valorized to be used as biofertilizer.

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 table olive wastewaters on growth and yield of cucumber, pepper, tomato and strawberry

The table olive factory generates a large amount of wastewaters and this is a big environmental problem. The aim of this study was to look for a solution of this issue, using table olive waste as irrigation water during the growth of four Mediterranean crops: tomato (Solanum lycopersicum L.), strawberry (Fragaria x ananassa L.), cucumber (Cucumis sativus L.) and pepper (Capsicum annuum L.). These solutions were rich in sugars (17–85 mmoles L−1) and polyphenolic compounds (13–21 mmoles L−1), being hydroxytyrosol the main component (5.5–14.5 mmoles L−1). Also, some minerals were identified (carbon, nitrogen, sodium, potassium and phosphorus). The solutions were free of sodium chloride and no phytotoxic effect was detected, neither on the fruits or the leaves. The irrigation with the tested solutions originated an increase of the plant growth, fruit size and cumulative yield by at least 20% compared to the dipping and spraying applications mode. Also, it was observed a decrease of the powdery mildew disease in strawberry plants. Particularly, the fruit medium weight of cucumbers treated with table olive solutions was 40 g higher that the untreated fruits. Among the wastewaters generated during table olive processing, the wash water solution from Spanish-style green olives and the acidified storage liquids from black ripe olive processing could be employed as natural fertilizers and fungicide in substitution of synthetic products.

Processing of table olives with KOH and characterization of the wastewaters as potential fertilizer

In Mediterranean countries the table olive industry produces a huge volume of wastewaters that are phytotoxic due to their high sodium content. Olives intended for Spanish-style green olives are currently debittered with NaOH that generates lyes and washing waters that cannot be used for agronomic purposes. In this study, the substitution of NaOH with KOH during the debittering of Manzanilla and Hojiblanca cultivars was assessed as well as the vacuum evaporation of the olive wastewaters to comply with fertilizer requirements. Typical lactic acid fermentation occurred in brines of olives treated with KOH and a final product with similar color and flavor characteristics to those treated with NaOH was achieved. However, lower texture was found in olives debittered with KOH than those with NaOH, using them at the same molar concentration. Furthermore, the lyes and washing waters from the KOH treatment were concentrated up to 10% of their initial volume and they complied with Spanish requirements to be considered as organo-mineral fertilizers (Corganic > 4%, K2O > 2%, Ntotal + K20 > 6%) although an external source of nitrogen would be needed. They also had a high content in phenolic compounds, particularly hydroxytyrosol. This research demonstrates that table olives can be processed with KOH and the generated waste streams could have potential applications in agriculture or being a source of bioactive substances.

Enrichment in phenolic compounds of black ripe olives through nano-filtration and vacuum evaporation techniques

Abstract The aim of this work was to obtain ripe olives enriched in bioactive compounds of phenolic nature. For this, two partially purified solutions rich in phenols from the table olive processes were used as cover in the packaging: washing waters of Spanish-style green olives or previous preservation acid solutions of ripe olives. Both solutions were nano-filtered through a 4000 Da membrane and vacuum evaporated at pilot plant scale. Regenerated liquids were employed at 50% and 100% in the packing brine. Results demonstrated that it is possible to achieve a >3-fold higher concentration of phenolic compounds in olives than with the traditional method when using the regenerated washing water at 100% to enrich the packing brine. Moreover, a Industrial relevance Among the different types of commercial table olives, black ripe have the lowest content in phenolic compounds. The methodology developed in this work will allow the enrichment of black olives in these bioactive substances, in particular hydroxytyrosol, which has been attributed to many beneficial properties for human health. The methodology is simple and easy to implement by processors. Hence, these results will contribute to the nutritional valorization of black ripe olives.

Stability of color in Spanish-style green table olives pasteurized and stored in plastic containers.

There is an increasing interest in the use of pasteurizable plastic packaging by the olive industry. In order to investigate the change from traditional glass or varnished can containers to plastic packaging, the proper plastic material that is compatible with fermented olives while maintaining color quality during pasteurization treatment and storage must be selected. This work is focused on color stability in two distinct pasteurizable plastic containers with different oxygen permeability. In PET + MDPE/EVOH (polyethylene terephthalate + medium-density polyethylene/ethylene vinyl alcohol) pouches, pasteurization provoked severe browning which drastically decreased their color shelf life (<6 weeks). However, this browning did not occur in the unpasteurized product without preservatives owing to the presence of microorganisms. In AlOx-coated PET + MDPE (aluminum oxide coating on polyethylene terephthalate + medium-density polyethylene) pouches, color changes were small or negligible throughout storage, especially if ascorbic acid was added to the packing solution (shelf life > 6.5 months). The plastic material had a significant effect on the retention of color of the pasteurized product. The use of AlOx-coated PET + MDPE pouches could be an alternative to traditional packaging for the pasteurization and storage of Spanish-style green olives from a color quality standpoint. © 2017 Society of Chemical Industry.

Oleuropein hydrolysis by lactic acid bacteria in natural green olives

The presence of phenolic compounds in raw olives, particularly the bitter glucoside oleuropein, requires transforming this substance into other non-bitter to make the fruit palatable. An alkali treatment is currently carried out to hydrolyze the oleuropein but a high volume of wastewater is generated. The aim of this study was to develop a natural product without an alkali treatment and with appropriate organoleptic characteristics similar to those of Spanish-style green olives. Mild heat treatments (60 °C for 10 min) were sufficient to inactivate the β-glucosidase activity which prevented the formation of antimicrobial compounds and thereby the growth of lactic acid bacteria was promoted. By contrast, heating released a high concentration of oleuropein in fruits that remained at a very high level even after 6 months of fermentation. The inoculation of the brines of Manzanilla olives with selected lactic acid bacteria with oleuropeinolytic activity was insufficient for reducing the high concentration of the bitter glucoside. However, favorable results were obtained with varieties such as Gordal and Aloreña, which have lower oleuropein contents. The product obtained showed a very attractive color, similar to that of Spanish-style green olives and lighter than natural green olives, which is a positive aspect for consumer acceptability.

Fermentation profile of green Spanish-style Manzanilla olives according to NaCl content in brine

This work studies the effects of the partial substitution of NaCl with potassium and calcium chloride salts on the fermentation profile of Spanish-style green Manzanilla olives. For this purpose, response surface methodology based in an enlarged simplex centroid mixture design with constrain (∑salts = 100 g/L) was used. Regarding to physicochemical characteristics, pH decreased when CaCl2 increased, titratable acidity was lower in presence of KCl while combined acidity increased as the contents of KCl and CaCl2 were close to the barycentre of the experiment (∼33.33% each salt). Regarding to microbiological profile, Enterobacteriaceae growth was slight stimulated in presence of high CaCl2 contents, yeast patterns were not linked to the initial brine compositions, while the maximum lactic acid bacteria population decreased slightly as KCl and CaCl2 increased in the proportion 1:1, although a moderate (equilibrated) content of both may be stimulating. Results obtained in this work show that Spanish-style green Manzanilla cv. can be fermented in diverse mixtures of chloride salts, albeit the initial CaCl2 should be limited to 20–30 g/L to prevent excessive Enterobacteriaceae growth; combining it with a similar proportion of KCl may also improve LAB predominance.

Combined use of nitrogen and coatings to improve the quality of mechanically harvested Manzanilla olives

The combined effect of an edible coating and a nitrogen atmosphere on the quality of Manzanilla olives mechanically harvested and processed as Spanish-style green olives was assessed. The percentage of olives free of any brown spots ranged between 35–50%, 10–25% and 50–65% for fruit directly processed, storage under nitrogen and coated and storage under nitrogen respectively. Moreover, olives stored in the open air developed brown spots due to the oxidation of oleuropein. By contrast, the anoxic conditions prevented oleuropein from undergoing enzymatic oxidation but not from its enzymatic hydrolysis. Hence, the phenolic derivative HyEDA was formed in olives stored under nitrogen, and this substance was rapidly oxidized in the open air to give rise to brown spots although to a lesser extent in the coated fruit. Therefore, the postharvest storage of coated olives under nitrogen can be a good method to prevent bruise damage in mechanically harvested fruit.