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1.
Front Nutr ; 11: 1467724, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39360269

RESUMEN

Fermented foods have regained popularity in Western diets for their health-promoting potential, mainly related to the role of lactic acid bacteria (LAB) during the fermentation process. Nowadays, there is an increasing demand for vegetable-based fermented foods, representing an environmentally sustainable options to overcome the limitations of lactose intolerance, vegetarian, or cholesterol-restricted diets. Among them, table olives and their co-products (i.e., olive pomace) represent important plant-origin matrices, whose exploitation is still limited. Olives are an important source of fiber and bioactive molecules such as phenolic compounds with recognized health-promoting effects. Based on that, this minireview offer a brief overview about the potential beneficial role of fermented table olives/olive pomace, with a particular focus on the role of LAB to obtain healthy and/or probiotic-enriched fermented foods.

2.
J Sci Food Agric ; 2024 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-39248037

RESUMEN

Biopreservation is a powerful strategy to prolong the shelf life of food products by applying naturally occurring microorganisms and/or their metabolites. Current food trends emphasise the need to develop alternatives for chemical or thermal preservation methods. In this line, different fermentation starters from table olives present the potential to control spoilage or pathogen-occurring microorganism in table olives storage. One of the most interesting family used as biopreservative culture is Lactobacillaceae and it has also been used in combination with yeasts as olive fermentation starter. Lactic acid bacteria, from Lactobacillaceae family, are characterised by the production of bacteriocins, proteins with the potential for preserving food by changing the organisation of the membrane of spoilage microorganisms. These bacteriocins-producing bacteria can be directly inoculated, although nanosystem technology is the most promising incorporation strategy. In table olives, the most commonly used starters are Lactiplantibacillus plantarum, Lactiplantibacillus pentosus, Saccharomyces cerevisiae, Wickerhamomyces anomalus, among others. These strains with biopreservation characteristics, inoculated alone or in mixed cultures, ensure food safety by conferring the product added value and prolonging product shelf life. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

3.
Talanta ; 280: 126641, 2024 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-39142126

RESUMEN

Foodomics employs advanced analytical techniques to provide answers regarding food composition, authenticity control, marker identification and issues related to food quality and safety. Nuclear magnetic resonance (NMR) spectroscopy and chromatography hyphenated to mass spectrometry (MS) are the main analytical platforms used in this field. Nevertheless, they are rarely employed in an integrated manner, and even then, the contribution of each technique remains vague. Table olives (Olea europaea L.) are a food commodity of high economic and nutritional value with an increasing production tendency over the last two decades, which, however, suffers from extensive fraud incidents and quality determination uncertainties. Thus, the current attempt aims towards two axes with the first being the multilevel integration of LC-HRMS and NMR data of the same samples and table olives being the selected matrix. In more detail, UPLC-HRMS/MS-based analysis was compared at different stages within an untargeted metabolomics workflow with an NMR-based study and the complementarity of the two platforms was evaluated. Furthermore, statistical heterospectroscopy (SHY), rarely employed in foodomics, combining the spectroscopic with spectrometric datasets and aiming to increase the confidence level of annotated biomarkers was applied. Amongst these lines, the second parallel axis of this study was the detailed characterization of table olives' metabolome in search for quality markers considering the impact of geographical (from Northern to Southern Greece) and botanical origin (Kalamon, Konservolia, Chalkidikis cultivars), as well as processing parameters (Spanish, Greek). To that end, using deep dereplication tools including statistical methods, with SHY employed for the first time in table olives, different biomarkers, belonging to the classes of phenyl alcohols, phenylpropanoids, flavonoids, secoiridoids and triterpenoids were identified as responsible for the observed classifications. The current binary pipeline, focusing on biomarkers' identification confidence, could be suggested as a meaningful workflow not only in olive-based products, but also in food quality control and foodomics in general.


Asunto(s)
Espectroscopía de Resonancia Magnética , Olea , Olea/química , Espectroscopía de Resonancia Magnética/métodos , Espectrometría de Masas/métodos , Cromatografía Liquida/métodos , Metabolómica/métodos , Flujo de Trabajo
4.
Food Res Int ; 191: 114710, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39059960

RESUMEN

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.


Asunto(s)
Fermentación , Almacenamiento de Alimentos , Valor Nutritivo , Olea , Olea/química , Almacenamiento de Alimentos/métodos , Manipulación de Alimentos/métodos , Alcohol Feniletílico/análisis , Alcohol Feniletílico/análogos & derivados , Humanos , Sales (Química)/química , Frutas/química , Alimentos Fermentados/análisis , Fenoles/análisis , Inocuidad de los Alimentos
5.
Foods ; 13(12)2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38928822

RESUMEN

Monascus ruber is an important fungus that causes spoilage in table olives, resulting in the darkening of the brine, the softening of the fruit, increased pH, and apparent mycelial growth. This study aimed to evaluate this resistance, providing a model to determine the optimal processing conditions for mitigating fungal contamination and prolonging shelf life without antifungal agents while optimizing pasteurization to reduce energy consumption. The resistance in brine (3.5% NaCl; pH 3.5) from Arauco cultivar green olives imported from Argentina was assessed. Four predictive models (log linear, log linear + shoulder, log linear + tail, log linear + shoulder + tail) estimated kinetic parameters for each survival curve. Log linear + shoulder + tail provided the best fit for 70 °C and 75 °C, with low RMSE (0.171 and 0.112) and high R2 values (0.98 and 0.99), respectively, while the log linear model was used for 80 °C. Decimal reduction times at 70, 75, and 80 °C were 24.8, 5.4, and 1.6 min, respectively, with a z-value of 8.2 °C. The current regulatory processes are insufficient to eliminate M. ruber at requisite levels, considering reduced antifungal agents.

6.
Molecules ; 29(10)2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38792098

RESUMEN

The olive oil industry recently introduced a novel multi-phase decanter with the "Leopard DMF" series, which gives a by-product called pâté, made up of pulp and olive wastewater with a high content of phenolic substances and without pits. This study aims to create a new culture medium, the Olive Juice Broth (OJB), from DMF pâté, and apply it to select bacteria strains able to survive and degrade the bitter substances normally present in the olive fruit. Thirty-five different bacterial strains of Lactiplantibacillus plantarum from the CREA-IT.PE Collection of Microorganisms were tested. Seven strains characterized by ≥50% growth in OJB (B31, B137, B28, B39, B124, B130, and B51) showed a degradation of the total phenolic content of OJB ≥ 30%. From this set, L. plantarum B51 strain was selected as a starter for table olive production vs. spontaneous fermentation. The selected inoculant effectively reduced the debittering time compared to spontaneous fermentation. Hydroxytyrosol, derived from oleuropein and verbascoside degradation, and tyrosol, derived from ligstroside degradation, were produced faster than during spontaneous fermentation. The OJB medium is confirmed to be useful in selecting bacterial strains resistant to the complex phenolic environment of the olive fruit.


Asunto(s)
Medios de Cultivo , Fermentación , Olea , Fenoles , Olea/microbiología , Olea/metabolismo , Olea/química , Fenoles/metabolismo , Fenoles/química , Medios de Cultivo/química , Lactobacillales/metabolismo , Aceite de Oliva/química , Aceite de Oliva/metabolismo , Alcohol Feniletílico/metabolismo , Alcohol Feniletílico/química , Alcohol Feniletílico/análogos & derivados , Glucósidos Iridoides/metabolismo , Glucósidos/metabolismo , Glucósidos/química , Lactobacillus plantarum/metabolismo , Polifenoles
7.
J Photochem Photobiol B ; 256: 112945, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38795655

RESUMEN

In this study, for the first time, red LED light radiation was applied to the fermentation process of table olives using the Negrinha de Freixo variety. Photostimulation using LED light emission (630 ± 10 nm) is proposed to shorten and speed up this stage and reduce time to market. Several physical-chemical characteristics and microorganisms (total microbial count of mesophilic aerobic, molds, yeasts, and lactic acid bacteria) and their sequence during fermentation were monitored. The fermentation occurred for 122 days, with two irradiation periods for red LED light. The nutritional composition and sensory analysis were performed at the end of the process. Fermentation under red LED light increased the viable yeast and lactic acid bacteria (LAB) cell counts and decreased the total phenolics in olives. Even though significant differences were observed in some color parameters, the hue values were of the same order of magnitude and similar for both samples. Furthermore, the red LED light did not play a relevant change in the texture profile, preventing the softening of the fruit pulp. Similarly, LED light did not modify the existing type of microflora but increased species abundance, resulting in desirable properties and activities. The species identified were yeasts - Candida boidinii, Pichia membranifaciens, and Saccharomyces cerevisiae, and bacteria - Lactobacillus plantarum and Leuconostoc mesenteroides, being the fermentative process dominated by S. cerevisiae and L. plantarum. At the end of fermentation (122 days), the irradiated olives showed less bitterness and acidity, higher hardness, and lower negative sensory attributes than non-irradiated. Thus, the results of this study indicate that red LED light application can be an innovative technology for table olives production.


Asunto(s)
Fermentación , Luz , Olea , Olea/microbiología , Olea/efectos de la radiación , Levaduras/efectos de la radiación , Levaduras/metabolismo , Fenoles/metabolismo , Fenoles/química , Fenoles/análisis , Frutas/efectos de la radiación , Frutas/microbiología , Microbiología de Alimentos
8.
Heliyon ; 10(7): e28408, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38560111

RESUMEN

The probiotic potential of Lactiplantibacillus pentosus CF-6HA isolated from traditionally fermented Aloreña table olives was analyzed in vitro and in silico. Results obtained suggested that this strain can be catalogued as "talented" bacterium exhibiting bacteriocin production with antimicrobial activity against human/animal and plant pathogens, such as Pseudomonas syringae and Verticillium dahliae. The robustness, safety and probiotic potential of L. pentosus CF-6HA was confirmed by in silico analysis. In addition, a plethora of coding genes for defense and adaptability to different life styles besides functional properties were identified. In this sense, defense mechanisms of L. pentosus CF-6HA consist of 17 ISI elements, 98 transposases and 13 temperate phage regions as well as a CRISPR (clustered regularly interspaced short palindromic repeats)/cas system. Moreover, the functionality of this strain was confirmed by the presence of genes coding for secondary metabolites, exopolysaccharides and other bioactive molecules. Finally, we demonstrated the ability of L. pentosus CF-6HA to biotransform selenite to nanoparticles (SeNPs) highlighting its potential role in selenium bioremediation to be exploited in foods, agriculture and the environment; but also for the bio-enrichment of fermented foods with selenium.

9.
Food Microbiol ; 120: 104477, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38431323

RESUMEN

The Castelvetrano method is the most widely used among the various table olive processing styles in Sicily. After debittering, the product is stored at low temperatures to prevent the growth of undesirable microorganisms. In an effort to enhance the production process, yeast isolates underwent genotypic characterization and technological screening. The screening process identified two yeast strains Candida norvegica OC10 and Candida boidinii LC1, which can grow at low temperatures and tolerate high pH values (up to 10) and salinity [10% (w/v)]. During the monitoring period, the inoculated trials showed limited presence of spoilage/pathogenic microorganisms. Additionally, the yeasts limited oxidative phenomena and softening of the drupes. The organic compounds detected were higher in the inoculated trials than in the control, and cold storage induced aromatic decay, which was less pronounced in the trial inoculated with C. norvegica. Sensory analysis revealed that the inoculated trials scored higher in sweetness, hardness and crispness.


Asunto(s)
Olea , Olea/química , Saccharomyces cerevisiae , Fermentación , Microbiología de Alimentos , Levaduras
10.
J Oleo Sci ; 73(3): 321-331, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38432996

RESUMEN

Gemlik is a cultivar that grows in a distinct region of Turkiye and is ideal for brine fermentation of brine black table olives. Bursa Protected Designated Origin (PDO) and Izmir non-PDO Gemlik table olives have high levels of oleic acid (74%), total phenol (190 mg/kg), and dry matter (57%), while being low in linoleic acid (8%). The pH values and salt contents were observed to be in the range of 4.1 to 4.3 and 3.9% to 4.8%, respectively. During the fermentation of Gemlik table olives, a mass transfer occurred, resulting in a reduction in reducing sugar and total sugar contents as well as an increase in the salt content of the olives. Despite the reduction of phenolic content in both Gemlik PDO and non-PDO table olives, their antioxidant capacity remains high after fermentation. The oil content, antioxidant activity, phenolic contents, palmitic, palmitoleic, oleic, and linoleic acids were all found to be significant variables in distinguishing between Gemlik PDO and non-PDO table olives using PLS-DA analysis. There is a statistically significant correlation between the phenolic content and oleic (0.588) and linoleic (-0.659) acids (p < 0.05). Bursa PDO and Izmir non-PDO exhibit enhanced nutritional quality and antioxidant activity, unequivocally differentiating them from Hatay and Mersin non-PDO Gemlik table olives with 98% accuracy through discriminant analysis (p < 0.05). PLS-DA and DA can effectively identify variations in the quality of Turkish-style black table olives preserved in brine, originating from PDO and non-PDO growing areas.


Asunto(s)
Olea , Sales (Química) , Antioxidantes , Turquía , Cloruro de Sodio , Fenoles , Cloruro de Sodio Dietético , Azúcares
11.
Food Microbiol ; 119: 104425, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38225036

RESUMEN

This study aimed to evaluate and identify the microbial community attached to the surfaces of fermenter tanks used in table olive Negrinha de Freixo cultivar processing through molecular analysis and verify if the cleaning/disinfection was done correctly. Four fermentation tanks previously used in table olive processing were sampled at three different inside areas: upper, middle, and lower. Before sampling, four cleaning/disinfection methods were applied to the tanks, including (i) pressurised water; (ii) a disinfectant product used to clean bowls (Vasiloxe); (iii) 10% sodium hydroxide solution (caustic soda liquid); and (iv) a disinfectant product used by the wine industry (Hosbit). For each sample collected, mesophilic aerobic bacteria, yeast and moulds (YMC), lactic acid bacteria (LAB), as well as total coliforms (TC) and Pseudomonas aeruginosa were evaluated. The results showed significant differences between the different cleaning/disinfection methods applied. The fermenter sanitised with only pressurised water showed a greater abundance of microorganisms than the others. Mesophilic aerobic bacteria were the predominant population, with counts ranging between 2.63 and 5.56 log10 CFU/100 cm2, followed by the moulds (3.11-5.03 log10 CFU/100 cm2) and yeasts (2.42-5.12 log10 CFU/100 cm2). High diversity of microbial communities was observed between the different fermenter tanks. The most abundant species belonged to Aureobasidium, Bacillaceae, Cladosporium, and Rhodotorula genera. LAB, TC, and P. aeruginosa were not detected. This study hopes to improve hygienic conditions and increase the quality assurance and safety of the final product.


Asunto(s)
Desinfectantes , Lactobacillales , Olea , Fermentación , Olea/microbiología , Desinfección , Bacterias Gramnegativas , Levaduras/genética , Desinfectantes/farmacología , Agua , Microbiología de Alimentos
12.
J Agric Food Chem ; 72(4): 2154-2164, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38232316

RESUMEN

The pharmacokinetics (PK) of hydroxytyrosol and its metabolites were characterized following oral administration to Sprague-Dawley rats of 3.85 and 7.70 g of destoned Arbequina table olives/kg. Plasma samples were analyzed using a fully validated method consisting of liquid extraction followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Noncompartmental PK analysis of hydroxytyrosol demonstrated linear PK between doses of 2.95 and 5.85 mg hydroxytyrosol/kg. Half-life was approximately 2.5 h, while mean residence time was around 4 h. Clearance occurred by conversion to two sulfate and two glucuronide conjugates. The area under the plasma concentration-time curve (AUC) ratios of metabolites versus parent hydroxytyrosol was approximately 7-9-fold for the sulfate and below 0.25 for the glucuronide, indicating sulfation as the predominant metabolic pathway. Despite extensive metabolism, hydroxytyrosol remained in plasma for up to 8 h with AUCs of 4293 and 8919 min·nmol/L for the doses of 3.85 and 7.70 g/kg, respectively. Therefore, table olives provide a more sustained plasma profile than other foods containing hydroxytyrosol, which may enhance its health-protecting activities.


Asunto(s)
Olea , Alcohol Feniletílico/análogos & derivados , Ratas , Animales , Ratas Sprague-Dawley , Cromatografía Liquida/métodos , Glucurónidos , Sulfatos , Espectrometría de Masas en Tándem/métodos , Administración Oral , Cromatografía Líquida de Alta Presión/métodos
13.
Foods ; 12(19)2023 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-37835365

RESUMEN

Climate change is a global emergency that is affecting agriculture in Mediterranean countries, notably the production and the characteristics of the final products. This is the case of olive cultivars, a source of olive oil and table olives. Table olives are the most important fermented vegetables in the Mediterranean area, whose world production exceeds 3 million tons/year. Lactic acid bacteria and yeast are the main microorganisms responsible for the fermentation of this product. The microbial diversity and population dynamics during the fermentation process are influenced by several factors, such as the content of sugars and phenols, all of which together influence the quality and safety of the table olives. The composition of fruits is in turn influenced by environmental conditions, such as rainfall, temperature, radiation, and the concentration of minerals in the soil, among others. In this review, we discuss the effect of climate change on the microbial diversity of table olives, with special emphasis on Spanish and Portuguese cultivars. The alterations expected to occur in climate change scenario(s) include changes in the microbial populations, their succession, diversity, and growth kinetics, which may impact the safety and quality of the table olives. Mitigation and adaptation measures are proposed to safeguard the authenticity and sensorial features of this valuable fermented food while ensuring food safety requirements.

14.
J Food Sci ; 88(12): 5191-5202, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37872810

RESUMEN

Different varieties of table olives have suitable morphological characteristics that allow them to be processed as Spanish-style green table olives. However, the Campiñesa cultivar presents difficulties when submitted to a lactic fermentation, in spite of being inoculated with dedicated starter cultures such as OleicaStarter. The strategy followed in this study to facilitate the start of lactic fermentation was to reinforce the OleicaStarter culture with the use of the Lactoplantibacillus pentosus Lp309 a strain that enhanced the survival of lactic acid bacteria (LAB) at the beginning of fermentation, reaching final pH values (4.08 ± 0.01), free acidity (1.00 ± 0.01 g/100 mL of brine), LAB population (6.17 ± 0.09 log CFU/mL), nutrient depletion (0.80 ± 0.09 g/kg of pulp), and lactic acid production (11.85 ± 0.72 g/L). These values allowed stabilization of the final product, thus complying with the quality and food safety standards established by the Codex Alimentarius for table olives.


Asunto(s)
Lactobacillus pentosus , Olea , Lactobacillus , Olea/microbiología , Fermentación , Concentración de Iones de Hidrógeno , Microbiología de Alimentos
15.
Molecules ; 28(18)2023 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-37764449

RESUMEN

This paper reviews the current knowledge regarding modifications to chlorophylls during the processing of green table olives treated with alkali. Particular attention is given to the pheophytinization reactions (substitution of Mg2+ by 2H+ in the chlorophyll chromophore group) that can take place because of pH and/or temperature changes and the possible sequential substitution of the 2H+ with Cu2+ within the chlorophyll porphyrin ring. These reactions may have a direct impact on the commercial value of olive productions as some naturally forming Cu-chlorophylls complexes (i) are identical to strictly forbidden colorants for table olives (E141) and (ii) have been identified as responsible for the unwelcome appearance of the so-called green staining alteration (characterized by bluish-green zones distributed over the olive skin of the drupes).


Asunto(s)
Olea , Porfirinas , Olea/química , Cobre/química , Clorofila/química
16.
Plants (Basel) ; 12(10)2023 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-37653905

RESUMEN

A prospecting campaign in the Maltese Islands has ensured the survival of several ancient olive trees (Olea europaea L.), genetically distant from known cultivars. Most of these plants were abandoned or partially cultivated. A two-year evaluation of fruit characteristics and compositions was performed on samples collected from the main representatives of these indigenous genotypes. Analyses were carried out using Gas Chromatography, High-Performance Liquid Chromatography and Near Infrared Spectrometry. Among the fruit samples, a wide range of variations was observed. Some of the genotypes showed fruit traits suitable for table olive production. This is the case of samples with a pulp/pit ratio higher than four, such as 1Wardija, 1Caritas, 1Plattini, 1Bingemma Malta and 3Loretu, whilst 1Bidni, 1Mellieha, 2Qnotta, 3Loretu, 1Bingemma Malta and 1Caritas were suitable for dual purpose. The total phenol content ranged from 6.3 (1Wardija) to 117.9 (2Mtarfa) g/kg of fresh pulp. The average percentage of MUFA was quite low for most of the varieties. These genotypes, which presumably originated in the Maltese Islands and are well adapted to the local pedo-climatic conditions, are being propagated for the following evaluation of their bio-agronomical performance (production, suitability to intensive cultivation, environmental sustainability, product quality, etc.). The purpose is to select, among these local genotypes, the most outstanding varieties, in terms of phenolic and FA profile and agronomical potential, to spread into cultivation, thereby contributing to an increase in the quality of the local table and olive oil production, strongly linked to the territory.

17.
J Agric Food Chem ; 71(36): 13508-13517, 2023 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-37647584

RESUMEN

Acrylamide was detected in considerable amounts in black table olives. In this study, besides black, also green and naturally black table olives were investigated for their acrylamide, free asparagine, and 3-aminopropionamide contents before and after heat treatment. Acrylamide amount was 208-773 µg/kg in black table olives and did not change due to heat treatment. In green and naturally black table olives acrylamide was ≤24 µg/kg before heat treatment and rose to 1200 µg/kg afterward. Asparagine content was 0.35-35 mg/kg in all samples before heat treatment and after heat treatment with no considerable change in the range. 3-Aminopropionamide showed amounts of ≤56 µg/kg in the unheated samples and increased up to 131 µg/kg due to heat impact. However, quantified asparagine and 3-aminopropionamide amounts were insufficient in almost all samples to explain the acrylamide quantities formed due to heat treatment based on the formation via the Maillard reaction.


Asunto(s)
Calor , Olea , Asparagina , Acrilamida
19.
Foods ; 12(12)2023 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-37372518

RESUMEN

The desalting process is critical for packaging table olives in brine with reduced NaCl or fortified mineral nutrients. In this study, the effect of desalting on the physicochemical characteristics and mineral content of green Manzanilla Spanish-style (plain and stuffed with pepper paste) and DOP Aloreña de Málaga table olives was investigated for the first time. The surface colour of the fruits turned slightly brownish, and the olives became somewhat softer. The lactic acid, the mineral macronutrients (mainly) and micronutrient contents decreased, while flesh moisture increased. The kinetic parameters of the minerals' losses depended on the presentation, with the estimated values for plain olives being the lowest (slowest desalting). Overall, the desalting process resulted in slight quality damage and a moderated decrease in the mineral concentration in the flesh, leading to some product degradation. This study provides quantitative information on these changes that may affect the commercial value of the final products and offers information for viable designs.

20.
Foods ; 12(12)2023 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-37372597

RESUMEN

Microbial and biochemical changes in the brine during the spontaneous fermentation of Gordal, Hojiblanca and Manzanilla olive cultivars processed according to the natural style were monitored. The microbial composition was assessed through a metagenomic study. Sugars, ethanol, glycerol, organic acids and phenolic compounds were quantified by standard methods. In addition, the volatile profiles, contents of phenolic compounds in the olives and quality parameters of the final products were compared. Fermentation in Gordal brines was conducted by lactic acid bacteria (mainly Lactobacillus and Pediococcus) and yeasts (mainly Candida boidinii, Candida tropicalis and Wickerhamomyces anomalus). In Hojiblanca and Manzanilla brines, halophilic Gram-negative bacteria (e.g., Halomonas, Allidiomarina and Marinobacter) along with yeasts (mainly, Saccharomyces) were responsible for the fermentation. Higher acidity and lower pH values were reached in Gordal brines compared to Hojiblanca and Manzanilla. After 30 days of fermentation, no sugars were detected in Gordal brine, but residual amounts were found in the brines from Hojiblanca (<0.2 g/L glucose) and Manzanilla (2.9 g/L glucose and 0.2 g/L fructose). Lactic acid was the main acid product in Gordal fermentation, whereas citric acid was the predominant organic acid in the Hojiblanca and Manzanilla brines. Manzanilla brine samples showed a greater concentration of phenolic compounds than Hojiblanca and Gordal brines. After a 6-month fermentation, Gordal olives were superior compared to the Hojiblanca and Manzanilla varieties regarding product safety (lower final pH and absence of Enterobacteriaceae), content of volatile compounds (richer aroma), content of bitter phenolics (lower content of oleuropein, which resulted in less perceived bitterness) and color parameters (more yellow and lighter color, indicating a higher visual appraisal). The results of the present study will contribute to a better understanding of each fermentation process and could help to promote natural-style elaborations using the above-mentioned olive cultivars.

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