RESUMO
The presence of acrylamide, a known human carcinogen, in various heated foods raises significant concerns among consumers. Therefore, the development of a good analytical method is of paramount interest to the scientific community. Keeping this in view, a rapid, simple, reliable, and low-cost analytical method was developed and validated for acrylamide quantification in black ripe olives. The method consisted of the water extraction of the compounds from crushed olives with the addition of (13C3)acrylamide as an internal standard. The quantification was performed using high-pressure liquid chromatography and mass detection with positive electrospray ionization. The limits of detection and quantification were determined to be 4 and 11 µg/kg, respectively. The developed method exhibited excellent results in terms of accuracy (98.4-104.8%) and intra- and inter-day precision limits, both less than 20%. This new method was carried out by analyzing 15 samples of Spanish commercial black ripe olives, revealing a wide range of values, from 79 to 1068 µg/kg of fruit. The new protocol reduces the analysis time to just one hour per sample versus the minimum 24 h required by gas chromatography and mass detection, meaning that it could be a good option for the routine analysis of acrylamide in black ripe olives, and may be extendable to the analysis of this compound in other foods.
RESUMO
A high volume of water is needed to produce black ripe olives, which also entails a significant volume of wastewater with a high organic and inorganic contaminant charge. To reduce this problem, the reuse of KOH solutions (lyes) in a new process was studied. Once the lyes were removed from the tanks, KOH was then added for a new darkening process. Reusing the lyes up to four times gave rise to a product with similar physico-chemical and organoleptic characteristics as obtained with fresh solutions. The application of this process reduced coadjutant consumption by 32% and water by 20%, while global wastewater presented a high K content whose concentration could be valorized as a fertilizer by replacing commercial potassium nitrate.
RESUMO
The type of container (airtight and pouches with different O2 permeability) and packing conditions (cover brine, air or N2 atmosphere) has been studied to preserve black ripe olives in acid medium for a year. Unlike the traditional sterilized product, these acidified olives only needed pasteurization to assure its microbial safety, the absence of acrylamide being an additional advantage. Surprisingly, an increase in the oxygen diffusion through the films (i) faded the black color of the olives, (ii) softened the fruit that lost around 33% of its initial firmness in only 6 months, and (iii) produced the lipidÌs oxidation forming volatile compounds that transmitted an abnormal flavor which tasters identified as rancid. Therefore, ripe olives in acid medium must be packed in airtight containers such as glass jars, cans o metallic pouches with cover brine or N2 atmosphere. The addition of calcium is recommended to avoid olive softening.
Assuntos
Embalagem de Alimentos/métodos , Olea/química , Acrilamida/análise , Cor , Frutas/química , Concentração de Íons de Hidrogênio , Fenômenos Mecânicos , Oxirredução , Pasteurização , PaladarRESUMO
Diatoms are important organisms in freshwater ecosystems due to their position as primary producers and therefore, analyzing their assemblages provides relevant information on ecosystem functioning. Diatoms have historically been identified based on morphological traits, which is time-consuming and requires well-trained specialists. Nevertheless, DNA barcoding offers an alternative approach to overcome some limitations of the morphological method. Here, we assess if both approaches are comparable methods to study patterns and mechanisms (including environmental filtering and dispersal limitation) of epiphytic diatom metacommunities using a comprehensive dataset from 22 Mediterranean ponds at different taxonomic resolutions. We used a fragment of rbcL barcode gene combined with High-Throughput Sequencing to infer diatom community composition. The overall degree of correspondence between both approaches was assessed by Procrustean rotation analysis and Procrustean randomization tests, whereas the role of local environmental variables and geographical distances was studied using a comprehensive combination of BIOENV, Mantel tests and distance-based redundancy analysis. Our results showed a relatively poor correspondence in the compositional variation of diatom metacommunity between both approaches. We speculate that the incompleteness of the reference database and the bioinformatics processing are the biases most likely affecting the molecular approach, whereas the limited counting effort and the presence of cryptic species are presumably the major biases related with the morphological method. On the other hand, variation in diatom community composition detected with both approaches was strongly related to the environmental template, which may be related with the narrow community-environment relationships in diatoms. Nevertheless, we found no significant relationship between compositional variation and geographical distances. Overall, our work shows the complementary nature of both approaches and highlights the importance of DNA metabarcoding to address empirical research questions of community ecology in freshwaters, especially once the reference databases include most genotypes of occurring taxa and bioinformatics biases are overcome.
Assuntos
Diatomáceas , DNA , Código de Barras de DNA Taxonômico , Diatomáceas/genética , Ecossistema , Água DoceRESUMO
This study was aimed at making progress on the valorisation of table olive wastewater that currently represent a big environmental problem for factories. Concentrates from vacuum evaporation of the wastewater generated during processing of black ripe olives treated with KOH were tested as fertilisers of tomato plants in open field assays for three consecutive crops. Fertilisation was performed by drip irrigation every 15 days; the first treatment being 15 days after transplanting, and a total of five fertilisation treatments were carried out. A phytotoxic effect was not observed on plants or fruit in any case but higher yield (fruit/plant and g/plant) was obtained in comparison to irrigation with only tap water. Moreover, the combined use of the olive concentrate with inorganic nitrogen supply (NH4NO3), in order to comply with the nutrient needs of plants, was also tested. The results demonstrated that the olive concentrates could be a good substitute for inorganic potassium (as KNO3) during the cultivation of tomato plants without any negative effect on the tomato quality (pH, °Brix, sugars, organic acids) or content of bioactive substances (phenolic compounds and carotenoids).
Assuntos
Olea , Solanum lycopersicum , Fertilização , Frutas , Águas ResiduáriasRESUMO
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 (52â¯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 (NH4NO3â¯+â¯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.
Assuntos
Olea , Agricultura , Fertilizantes , Minerais , Águas ResiduáriasRESUMO
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 (Corganicâ¯>â¯4%, K2Oâ¯>â¯2%, Ntotalâ¯+â¯K20â¯>â¯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.
Assuntos
Agricultura/métodos , Fertilizantes , Hidróxidos/química , Olea/química , Compostos de Potássio/química , Eliminação de Resíduos/métodos , Águas Residuárias/química , FermentaçãoRESUMO
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 (Lactobacillus pentosus 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 Overall score. When data from the consumer test were assessed by PLS analysis, regardless of the fermentation system, Overall score, and Buying predisposition were significantly driven by Appearance, Odor, Salty (negatively), Hardness, and Crispness.
RESUMO
Table olives constitute an important part of the Mediterranean diet and the diet of many non-olive-producing countries. The aim of this work was to determine the fiber, sugar, and organic acid contents in Spanish commercial presentations of table olives and characterize them by means of a multivariate analysis. The selection of variables was carried out on the basis of a canonical analysis and their classification, according to processing styles and cultivars, through a linear discriminant analysis. Values of dietary fiber in table olives ranged from 2 to 5 g/100 g edible portion (e.p.). Some stuffing materials (almond, hot red pepper, and hazelnut) or the addition of capers produced a significant increase in the total dietary fiber in green olives. Glucose, fructose, and mannitol were usually found in the ranges of 0-55, 0-70, and 0-107 mg/100 g e.p., respectively. Succinic acid was detected only in green and directly brined olives (0-40 mg/100 g e.p.), while lactic and acetic acids were used within the ranges of 0-681 and 5-492.8 mg/100 g e.p., respectively. A multivariate analysis showed that fiber, mannitol, and succinic, lactic, and acetic acids can be used to discriminate between processing styles (95.5% correct assignations) and cultivars (61.20%). Current data can also be used in the evaluation of the dietary value of table olives.
Assuntos
Ácidos Carboxílicos/análise , Carboidratos da Dieta/análise , Fibras na Dieta/análise , Frutas/química , Olea/química , Análise de Variância , Manipulação de Alimentos/métodosRESUMO
The crude extract of the polyphenol oxidase (PPO) enzyme from the Manzanilla cultivar (Olea europaea pomiformis) was obtained, and its properties were characterized. The browning reaction followed a zero-order kinetic model. Its maximum activity was at pH 6.0. This activity was completely inhibited at a pH below 3.0 regardless of temperature; however, in alkaline conditions, pH inhibition depended on temperature and was observed at values above 9.0 and 11.0 at 8 and 25 degrees C, respectively. The thermodynamic parameters of substrate oxidation depended on pH within the range in which activity was observed. The reaction occurred according to an isokinetic system because pH affected the enzymatic reaction rate but not the energy required to carry out the reaction. In the alkaline pH region, browning was due to a combination of enzymatic and nonenzymatic reactions that occurred in parallel. These results correlated well with the browning behavior observed in intentionally bruised fruits at different temperatures and in different storage solutions. The use of a low temperature ( approximately 8 degrees C) was very effective for preventing browning regardless of the cover solution used.
Assuntos
Catecol Oxidase/metabolismo , Frutas/metabolismo , Reação de Maillard , Olea/enzimologia , Concentração de Íons de Hidrogênio , Cinética , TermodinâmicaRESUMO
The development of a method for darkening black ripe olives during the washing step with a single NaOH treatment and preservation liquid was studied. Olives of the Hojiblanca cultivar were darkened at pilot plant scale, packed, sterilized, and analyzed after 2 mo of storage at ambient temperature. It was found that the use of a mixture of preservation liquid:water at a ratio of 1:1 during the first washing gave rise to darker olives with slightly better firmness and no effect on sensory quality. However, care must be taken with the concentration of acetic acid in the preservation solution, as a content of this organic acid higher than 25 g/L can cause adverse effects on olive color due to the low pH that can be reached in the flesh of the fruit. Additionally, the re-use of the preservation solution in the first washing resulted in enrichment in antioxidant compounds of the packed product. Black ripe olives processed with preservation liquid had a total phenolic content of 629 mg/kg, whereas those with only tap water had 376 mg/kg, in particular hydroxytyrosol and hydroxytyrosol-4-glucoside. These findings mean that it is possible to get darker olives with higher contents in bioactive substances by reusing the preservation liquid during the darkening step of black ripe olives.
Assuntos
Manipulação de Alimentos/métodos , Frutas/química , Olea/química , Antioxidantes/análise , Glucosídeos/análise , Lixívia/química , Fenóis/análiseRESUMO
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 (laboratory vs. industry pre-adapted) never had significant effects. Thus, this investigation discloses key issues for the survival and predominance of starter cultures in large-scale industrial fermentations of green Spanish-style olives. Results can be of interest for producing probiotic table olives and open new research challenges on the causes of inoculum vanishing during the storage phase.
RESUMO
The aim of this work was to develop a method for processing ripe olives with a single NaOH treatment (lye) instead of the well-known 3 lye treatments. Olives of the Hojiblanca variety were processed according to the 2 processes and the color, firmness, flavor, and content in phenolic compounds of the final product were similar in both cases but concentration in triterpenic acids was highest in the olives from the single lye treatment. In this process the concentration of NaOH must range between 20 and 35 g/L, especially to obtain good texture when working at 20 °C. If temperature during the oxidation up to 27 °C the firmness of olives was significantly decreased. The concentration of the NaOH did not exert a high effect on the color of the final product, although firmness decreased as the strength of the lye increased. Higher contents in phenolic compounds and triterpenic acids were also found in the olives processed with the lowest NaOH concentration tested (20 g/L). This new process reduces the volume of wastewaters and energy consumption, and gives rise to a product which is richer in bioactive substances than the traditionally processed one.
RESUMO
This work focuses on the persistence of the putative probiotic bacteria Lactobacillus pentosus TOMC-LAB2 on green Spanish-style Manzanilla olives according to different packaging conditions and storage temperatures. The lactic acid bacteria population decreased with time but the highest survival counts (and lowest yeasts) at the end of storage (8 months) were observed in plastic pouches under nitrogen atmosphere and glass jars with brine stored at 20°C. Molecular techniques showed a 100% presence of the putative probiotic bacteria in biofilms adhered to olive epidermis, while it was absent in PPB (plastic pouches with brine) and in olives stored at 7°C. No changes in NaCl, pH or combined acidity were observed during the storage except for a slight increase in titratable acidity at 20°C. The color of the fruits was stable but degraded at 20°C for olives in plastic pouches with brine.
RESUMO
Subjecting bruised olives to a nitrogen atmosphere during the postharvest period prevented the oxidation of phenols and subsequent browning. However, a rapid phenol oxidation and browning occurred when fruits were re-exposed to air. Based on models deduced from the effects of aqueous antioxidant solutions on changes in different color parameters in the fermented product, the treatments to prevent browning were optimized. The recommended procedure consists of placing the harvested olives in a cold (4 to 8 °C) solution of 3% sodium metabisulfite with the pH adjusted to 3.0 (by adding food grade HCl) and applying the lye treatment before 8 h from picking. The use of these conditions led to mechanically harvested Spanish style olives with hardly any visible browning.
Assuntos
Manipulação de Alimentos/métodos , Conservação de Alimentos/métodos , Frutas/química , Reação de Maillard/efeitos dos fármacos , Olea/química , Antioxidantes/análise , Ácido Ascórbico/análise , Cor , Colorimetria/métodos , Fermentação , Concentração de Íons de Hidrogênio , Nitrogênio/metabolismo , Fenóis/análise , Soluções/química , Sulfitos/análiseRESUMO
Yeasts play an important role in the food and beverage industry, especially in products such as bread, wine, and beer, among many others. However, their use as a starter in table olive processing has not yet been studied in detail. The candidate yeast strains should be able to dominate fermentation, together with lactic acid bacteria, but should also provide a number of beneficial advantages. Technologically, yeasts should resist low pH and high salt concentrations, produce desirable aromas, improve lactic acid bacteria growth, and inhibit spoilage microorganisms. Nowadays, they are being considered as probiotic agents because many species are able to resist the passage through the gastrointestinal tract and show favorable effects on the host. In this way, yeasts may improve the health of consumers by means of the degradation of non-assimilated compounds (such as phytate complexes), a decrease in cholesterol levels, the production of vitamins and antioxidants, the inhibition of pathogens, an adhesion to intestinal cell line Caco-2, and the maintenance of epithelial barrier integrity. Many yeast species, usually found in table olive processing (Wickerhamomyces anomalus, Saccharomyces cerevisiae, Pichia membranifaciens, and Kluyveromyces lactis, among others), have exhibited some of these properties. Thus, the selection of the most appropriate strains to be used as starters in this fermented vegetable, alone or in combination with lactic acid bacteria, is a promising research line to develop in the near future.
RESUMO
The aim of the work was to study the postharvest changes in Manzanilla olives and to find treatments to mitigate damages because of bruises. The phenolic content in bruised and unbruised fruits exposed to air always decreased, but the loss in phenols and the respiratory activity were greater in bruised olives; these changes were related to the appearance of brown spots. Immersion of the picked fruits in a cold (8 °C) acidic solution (pH 3), ascorbic acid solution (100 mM), or sodium metabisulfite solution (100 mM) significantly reduced the loss in phenols in olives and led to lighter brown bruised areas. This immersion did not affect the behavior of the fruits during the lye treatment and the subsequent fermentation. In the final product, no influence on the surface color of unbruised olives was observed and there was a significant color improvement in the bruised areas of damaged olives.
Assuntos
Frutas/química , Olea , Fenóis/análise , Antioxidantes , Dióxido de Carbono/metabolismo , Cor , Manipulação de Alimentos/métodos , Frutas/metabolismo , Concentração de Íons de Hidrogênio , Pigmentação , SoluçõesRESUMO
Tobacco use represents one of the major public health problems; the aim of the study was to determine the prevalence and opinions of tobacco consumption by university population; a descriptive cross-sectional design was used. The results showed a prevalence of use in the last year of 24.3 of participants, consumption once in a lifetime was 46.3%. Regarding dissenting opinions (cons) about tobacco use it is found that a high percentage of participants presents obstacles to the use of tobacco; items that reached the highest levels were in relation to opinions on health, such as tobacco causing cancer and directly affecting the lungs and heart...
O consumo de cigarro representa um dos principais problemas de saúde pública. O objetivo do estudo foi determinar a prevalência e as crenças sobre o consumo do cigarro pela população universitária. Para tanto, empregou-se um desenho descritivo transversal. Os resultados mostraram uma prevalência de consumo no último ano de 24.3% dos participantes (alguma vez na vida o consumo foi de 46.3%). Com relação às crenças desfavoráveis (contras) ao consumo de cigarro, observa-se que uma alta porcentagem dos participantes apresentou barreiras ao consumo de cigarro. Os itens que alcançaram os índices mais altos foram aqueles relacionados com as crenças na área da saúde, como o entendimento de que o cigarro provoca câncer e afeta diretamente os pulmões e o coração...
El consumo de tabaco representa uno de los principales problemas de salud pública, el objetivo del estudio fue determinar la prevalencia y las creencias sobre el consumo del tabaco en la población universitaria, para ello se empleó un diseño descriptivo transversal. Los resultados mostraron una prevalencia de consumo en el ultimo año de 24.3% de los participantes (el consumo alguna vez en la vida fue de 46.3%). En relación a las creencias desfavorables (contras) para el consumo de tabaco, se observa que un alto porcentaje de los participantes presentó barreras para el consumo de tabaco, los ítems que más altos índices alcanzaron fueron respecto a la creencias de la salud como que el tabaco provoca cáncer y afecta directamente a los pulmones y al corazón...
Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto Jovem , Universidades , Estudantes , Prevalência , Religião , Uso de Tabaco/epidemiologiaRESUMO
El estrés laboral actualmente tiene mucha importancia; sin embargo, aún se desconoce qué tipo de consecuencias negativas impone a la salud de los trabajadores en las empresas. El presente trabajo pretende dar a conocer la relación entre el Síndrome de Quemarse por el Trabajo (SQT), e indicadores de riesgo cardiovascular en los trabajadores de la industria maquiladora. El estudio fue correlacional y transversal. El tipo de muestreo fue no probabilístico y por conveniencia, formada por 47 trabajadores de los diferentes departamentos de una empresa del ramo automotriz. El instrumento que se utilizó para medir el SQT es el Cuestionario para la Evaluación del Síndrome de Quemarse por el Trabajo (CESQT), que está compuesto por 20 preguntas. Se tomaron muestras de sangre en ayunas para analizar indicadores de riesgo cardiovascular, tales como colesterol sérico y lipoproteínas de baja y alta densidad. Se midió la presión arterial, asimismo la talla, peso, diámetro de cintura y caderas de acuerdo a la NOM-030-SSA2-1999. Sólo el 2,12 por ciento de la muestra presentó SQT alto. No obstante lo anterior, los resultados muestran una relación significativa entre el componente de Desgaste Psíquico e indicadores de riesgo cardiovascular: Colesterol Total y Colesterol de Baja Densidad.
Work-related stress has a significant importance in the present days. However, the kind of negative consequences that it imposes on the manufacturing industry workers health is still unknown. The present study aims are to describe the relation between Burnout´s Syndrome and cardiovascular disease risk factors on automotive industry workers. The study was correlational and cross-sectional. The type of sampling was non probabilistic and by convenience, and the sample size was 47 workers of different departments from a manufacturingplant. The instrument used to measure the Burnout´s Syndrome was the Cuestionario para la Evaluación del Síndrome de Quemarse por el Trabajo (CESQT), consisting of 20 questions. Fasting blood samples were collected to analyze risk cardiovascular indicators such as seric cholesterol, low and high density lipoproteins. Blood pressure was measured as well as weight, size, waist and hip diameter according to the standard NOM-030-SSA2-1999. Only the 2.12 percent display high SQT. Nevertheless, the results show a significant relation between the following components: Exhaustion (Burnout Syndrome) and Total and Low Density Cholesterol (Cardiovascular).