Search

3 Tablas.-- 3 Figuras, The present work investigates the feasibility of re-using partially purified iron fixation solutions by electro-coagulation followed by ozonation in another fixation stage of black ripe olive processing and/or as cover brines in packaging. Re-use after the addition of ferrous gluconate during the color fixation stage involves a slightly lower amount of iron penetrating into the olives than when tap water is used. As a result, the olives are slightly less dark before packing when a gluconate solution is re-used. However, it is possible to completely re-use the partially purified solution using 50% of it as a color fixing liquid and 50% to prepare the cover brine in the packaging or to fix the color using tap water to prepare the gluconate solution and 100% purified solution as cover brine, in which case this waste-water is completely eliminated from the industry. Iron concentration in the flesh and surface color are the same for these two working methods and ripe olives present the same flavor as olives produced following the traditional procedure using only tap water., This work was supported by the Spanish Government (project AGL2010-15494 and AGL2013-42739-R, partially financed by European regional development funds, ERDF), and the Junta de Andalucía (through financial support to group AGR-125).

Spent brines or osmotic solutions are, in general, wastewaters heavily polluted with suspended solids and either inorganic or organic dissolved matter. The possibilities of introducing salt-free or reduced salt processes as well as segregating brines or osmotic solutions from current processes from the general drainage systems should always be considered. The paper especially describes the steps followed during the development of the regeneration treatments with active carbon and ultrafiltration for the fermentation brines of Spanish-style green table olives. Similar methodology might be used in the regeneration of other osmotic solutions. System for brine elimination (evaporation ponds, injection in deep wells, multi-stage evaporation, co-generation, etc.), and results of physico-chemical and biological treatments of wastewaters (including brines) from the table olive industry are also commented.

The paper studies the characteristics of the several procedures that might be used to regenerate green table olive fermentation brines with the aim of reusing them in other stages of the elaboration process and specially for the final packaging of these fruits. The reuse may considerably reduce the waste water pollution of the canning industry as brines make up about 80% of the organic pollutant lead of its waste waters. The two most interesting methods are: adsorption with activated carbon, followed by a cross filtration to separate the adsorbent; and ultrafiltration. The former, should be GA activated carbon, which is the most efficient, in a proportion ranging between 5 and 10 g per litre. For the second, a polysulphone 1.000 daltons molecular weight cut membrane at 18 bars pressure should be used. A previous treatment of brines with bentonite (2 g/l), a range of temperatures between 30 and 45°C as well as low suspended solids and polyphenol contents, increases efficiency notably. In principle, an approximate study of costs shows that regenerated brines are obtained, using either of the two procedures, at slightly lower prices than fresh brines prepared from their ingredients.El trabajo compara las características de los diversos tratamientos de regeneración aplicables a las salmueras de fermentación de aceitunas verdes estilo sevillano para poderlas reutilizar en otras operaciones dentro del proceso productivo, en especial en el envasado final de los frutos. Con ello, se reduciría el vertido de estas soluciones que son las responsables de la carga contaminante del efluente de estas industrias. Los dos métodos más interesantes son: adsorción con carbón activo, seguido de una filtración tangencial para separar el absorbente; y la ultrafiltración. En el primer caso, el tipo de carbón activo más eficaz es el denominado GA, que necesita ser utilizado en una proporción entre 5 y 10 g por litro. En el segundo una membrana de polisulfona de 1.000 daltons de corte molecular es lo más adecuado, trabajando a una presión de 18 bars. Un pretratamiento con bentonita (2 g/l), temperatura entre 30 y 45°G y la menor concentración inicial de polifenoles y sólidos en suspensión aumentan el rendimiento de forma considerable. En principio, un estudio económico aproximado de costes indica que la regeneración por cualquiera de los dos sistemas daría una salmuera regenerada a un precio algo inferior al obtenido al preparar el líquido de gobierno para envasar a partir de sus componentes.

The development of lactic fermentation processes for the storage of directly brined olives (Alorena cultivar) was investigated by three procedures: (1) a modification of the traditional method with an initial brine containing 9% (w/v) NaCl and 0.2% (w/v) acetic acid; (2) induced lactic fermentation with 6% NaCl and 0.2% acetic acid; and (3) conservation in acidified brine containing 6% NaCl and 0.6% acetic acid. In all cases, strains of Lactobacillus plantarum and Pediococcus spp. were present in each, indicating the great tolerance of these micro-organisms to high levels of lactic and acetic acids. They also appeared in an altered sequence. Counts of Pediococcus remained moderate (higher than Lact. plantarum) throughout the last part of the preservation period. A commercial starter improved colonization by Lact. plantarum. Yeasts coexisted with the lactic bacteria throughout the preservation period although their importance in the fermentation process was very limited. The brine characteristics obtained after fermentation were suitable for assured product preservation. There was no spoilage. These results encourage research on the mechanism of lactic acid bacteria inhibition in brines and the development of lactic fermentation processes for directly brined olives from other olive cultivars.

The composition in phenols of olive, the changes they undergo during the processing of ripe olives, and their relationships with surface color development were studied. The main phenols of these olives are identified as hydroxytyrosol (3,4-dihydroxyphenylacetic acid), verbascide, tyrosol, vanillic acid, p-coumaric acid, and oleuropein. After the sodium hydroxide treatment, they are hydroxytyrosol, tyrosol, vanillic acid, caffeic acid, and p-coumaric acid

Aplicability of flame photometric and ion selective (sodium or chloride) methods to determinate NaCI concentration in olive brines in comparison with the official one (Volhard), which uses AgNO3, is studied. According to the results using standard solutions or fermentative olive brines without previous lye treatment, no proportional systematic or constant systematic errors are detected and the percentaje of NaCl is evaluated by them with the same accuracy as by the reference. However, when the flame photometric or sodium ion-selective methods are used to determine this compound in Spanish olive brines, there is a deviation in comparison with the values obtained by the official one (Volhard) that is correlated with the combine acidity concentration of the solution. This fact is due to the presence of sodium organic salts, called combined acidity, that are formed during the lye treatment or "cocido" that these fruits are given before fermentation. Nevertheless, is does not represent any problem as there is a good correlation between such combined acidity and the magnitude of the deviation, that permit to calculate the corresponding correction factor. In addition these problems can be solved using the chloride selective ion method.Se estudia la aplicación de la fotometría de llama y el empleo de electrodos selectivos de iones cloruro o sodio, para la determinación de la concentración de NaCl en las salmueras de aceitunas de mesa, comparándolos con el actualmente utilizado de valoración de nitrato de plata (Volhard). De acuerdo con los resultados, la utilización de los mismos a soluciones patrones o de aceitunas en salmuera no da lugar a errores sistemáticos porporcionales ni constantes, pudiéndose analizar dicho compuesto con la misma precisión que con el procedimiento de referencia. Sin embargo, cuando se analizan las correspondientes a las elaboradas al estilo español, los valores que se obtienen con la fotometría de llama y el electrodo selectivo de sodio se encuentran desplazados en relación al obtenido por el método de Volhard. Ello se debe a la presencia en ellas de sales sódicas de tipo orgánico, denominadas lejía residual, que se forman durante el tratamiento con la solución de hidróxido sódico, "cocido", a que estos frutos se someten antes de la fermentación. Ello, no obstante, no representa ningún obstáculo ya que existe una buena correlación entre dicha lejía residual y la magnitud de la desviación, lo que permite obtener el factor de corrección correspondiente. Además, estos problemas también pueden soslayarse aplicando el método de análisis basado en el electrodo selectivo de cloruros.

This paper shows the physico-chemical and microbiological results of the brines from three procedures of previous conservation of Gordal cultivar olives and its effects on the main quality attributes of the final product: colour and texture. Two of them have used low NaCl levels and initial pH correction to facilitate the growth of lactic bacteria. The other has consisted of a solution highly acidified with acetic. In all procedures, a fermentation process has been found. During it the growth of lactic bacteria, mainly Lactobacillus plantarum and Pediococcus (that has predominated in some cases) and yeats, which have coexisted with the previous mentioned microorganisms thought the whole conservation period, has been detected. The evolution of the physico-chemical characteristics has been different in the three processes, however they have not had any influence on the elaborated final product. For industrial work, the aerobic system is recommended due to its CO 2 purging action which could have a favorable effect on shriveling. It would consist of putting the olives in a 6% NaCl brine, with the initial pH corrected with acetic to 4.00 units and bubbling air throughout the column at a rate of 0.3 l/h.l.c. during 8 h/day. The salt percentage should be raised to 8% once the lactic fermentation has finished.

First-order softening rates for cucumber mesocarp tissue were determined as a function of pH (2.6-3.8), calcium (0-72 mM), and temperature (25-65°C). Fermented tissue, unlike blanched, nonfermented tissue, often showed two softening rates in first-order plots. A five-variable, empirical equation was derived (R 2 = 0.913) which predicted softening rates as a function of pH, calcium concentration, and temperature. Comparison of softening rates in tissue fermented with and without 18 mM added calcium indicated the softening rate depended upon the concentration of calcium present during the period of measurement and not upon previous history of calcium exposure.

Content of biogenic amines in flesh and brines of table olives was determined by high-pressure liquid chromatography analysis of their benzoyl derivatives. No biogenic amines were found in the flesh of fresh fruits at any stage of ripeness. Contents of biogenic amines in Spanish-style green or stored olives increased throughout the brining period but were always higher in the former. Putrescine was the amine found in the highest concentration. Small quantities of cadaverine were found in the samples taken after 3 months of brining. This compound and histamine, tyramine, and tryptamine were also found in samples taken after 12 months. Gordal cultivar showed the highest contents, followed by Manzanilla and Hojiblanca. No relationship was found between contents of biogenic amines and lactic acid production or table olive spoilages, although zapatera olives had considerably higher amounts than those brines that had undergone a normal process. Concentrations in directly brined olives were markedly lower than contents in Spanish-style olives. With respect to partition between flesh and brine, there was equilibrium between both media in the case of Spanish-style olives, whereas the contents in directly brined olives were higher in flesh than brine.

15 páginas, 4 figuras.-- Articulo de revisión., [ES] El trabajo hace una revisión de las características del desarrollo de las bacterias ácido lácticas (BAL) en la elaboración de los tres tipos de aceitunas de mesa más importantes en el comercio internacional. El único proceso espontáneo típicamente láctico es el de las verdes estilo español. La presencia de las BAL en la etapa de conservación de las aceitunas tipo negras y en la fermentación de las negras naturales depende de diversos factores tales como variedad, concentración de cloruro sódico, corrección inicial del pH, etc. El conocimiento de las condiciones en las que se produce el crecimiento natural puede permitir un mejor control microbiológico y la utilización eficaz de cultivos iniciadores en dichas fermentaciones., [EN] The paper reviews the characteristics for the lactic acid bacteria (LAB) growth in the three main table olive types in the international trade. The only typical spontaneous lactic process is that followed in the Spanish-style green olives. The growth of LAB throughout storage in brine of ripe olives and fermentation of naturally ripe (black) olives depends on various factors such as olive cultivars, sodium chloride concentration, initial pH correction, etc. The knowledge of the spontaneous growth conditions is essential for a better microbiological control and the efficient use of starter cultures in these fermentations., La CICYT por la ayuda concedida dentro del Proyecto ALI94-0980-C02-01, dentro de cuyas actividades se encuadra este trabajo.

10 páginas, 7 tablas., [ES] La conservación de aceitunas en salmuera, sin tratamiento previo con una solución de hidróxido sódico, da lugar a una fermentación de características relativamente diversas. El desarrollo de microorganismos depende de la materia prima (variedades), flora adherida a ésta, y condiciones físico-químicas. La presencia de levaduras se observa en todos los casos, aunque sólo algunas especies se encuentran de forma sistemática. El desarrollo de bacterias lácticas (cocos y lactobacilos) está influenciado por la variedad y la concentración de sal (no crecen por encima del 8%). La presencia inicial de bacterias Gram-negativas así como la contaminación con otros gérmenes capaces de causar alteraciones se controla bien mediante la corrección del pH inicial de la salmuera con acético a valores en torno a 4.2 unidades. Cuando la conservación se hace a niveles elevados de acidez acética, láctica o de ambas, el crecimiento de gérmenes prácticamente se inhibe. La aplicación del sistema aeróbico puede ser útil, en ciertos casos, para evitar el arrugado., [EN] Preservation of olives in brine, without sodium hidroxide treatment, leads to a fermentative process, which characteristics are diverse. The growth of microorganisms depends on the raw material (cultivars) microflora adhered to the exterior olive surface, and physico-chemical conditions. The presence of yeasts is always observed, although only a few species are systematically found. Lactic acid bacteria (cocci and lactobacilli) depends on the cultivar and the NaCI concentration (a level over 8% is inhibitory for them). The presence of Gram-negative bacteria and other spoiling germs are effectively prevented by the initial correction of brines with acetic acid up to a pH level of aprox. 4.2. Preservation by high concentrations of acetic, lactic or both acids prevents the growth of practically any microorganism. When preservation is carried set by the aerobic system, shrivelling of fruits is avoided in send sensitive cultivars.

The characteristic phenolic content of NaOH-treated and untreated olive brines is reported. Detection, quantification and isolation of the phenolic compounds were carried out by HPLC. Viability of Lactobacillus plantarum in the presence of single or combined fractions of these isolated compounds was tested. When assayed at the concentrations found in brines, only the single phenolic fraction containing hydroxytyrosol strongly inhibited Lact. plantarum. However, inhibition of Lact. plantarum was also observed when double phenolic fractions (e.g. the glucosides, oleuropein and verbascoside) were used; this showed a combined effect in the inhibition. The different permeability of fruit for polyphenols and organic compounds is discussed as the primary cause of the rapid fermentation of alkaline-treated, but not of untreated, olives.

The paper studies the characteristics of the several procedures that might be used to regenerate green table olive fermentation brines with the aim of reusing them in other stages of the elaboration process and specially for the final packaging of these fruits. The reuse may considerably reduce the waste water pollution of the canning industry as brines make up about 80% of the organic pollutant lead of its waste waters. The two most interesting methods are: adsorption with activated carbon, followed by a cross filtration to separate the adsorbent; and ultrafiltration. The former, should be GA activated carbon, which is the most efficient, in a proportion ranging between 5 and 10 g per litre. For the second, a polysulphone 1.000 daltons molecular weight cut membrane at 18 bars pressure should be used. A previous treatment of brines with bentonite (2 g/l), a range of temperatures between 30 and 45°C as well as low suspended solids and polyphenol contents, increases efficiency notably. In principle, an approximate study of costs shows that regenerated brines are obtained, using either of the two procedures, at slightly lower prices than fresh brines prepared from their ingredients. El trabajo compara las características de los diversos tratamientos de regeneración aplicables a las salmueras de fermentación de aceitunas verdes estilo sevillano para poderlas reutilizar en otras operaciones dentro del proceso productivo, en especial en el envasado final de los frutos. Con ello, se reduciría el vertido de estas soluciones que son las responsables de la carga contaminante del efluente de estas industrias. Los dos métodos más interesantes son: adsorción con carbón activo, seguido de una filtración tangencial para separar el absorbente; y la ultrafiltración. En el primer caso, el tipo de carbón activo más eficaz es el denominado GA, que necesita ser utilizado en una proporción entre 5 y 10 g por litro. En el segundo una membrana de polisulfona de 1.000 daltons de corte molecular es lo más adecuado, trabajando a una presión de 18 bars. Un pretratamiento con bentonita (2 g/l), temperatura entre 30 y 45°G y la menor concentración inicial de polifenoles y sólidos en suspensión aumentan el rendimiento de forma considerable. En principio, un estudio económico aproximado de costes indica que la regeneración por cualquiera de los dos sistemas daría una salmuera regenerada a un precio algo inferior al obtenido al preparar el líquido de gobierno para envasar a partir de sus componentes.

The paper studies the changes of the physico-chemical and microbiological characteristics of the fermentation in aerobic conditions that occur during the storage stage of Hojiblanca cultivar used to elaborate ripe olives. Assayed treatments include all the conditions used at industrial level (correction of initial pH to 4,0-4,2 units with acetic acid, sodium chloride concentration ranging between 3 and 6%, green to yellow-pink green fruits and bubling of air at a rate of 0,3 liter per hour and liter of the vessel capacity). The process was characterized by a maintenance of the pH values, a slow sugar consumption, very low content of carbon dioxide and progressive increase of the salt concentration. Gram-negative rods and Bacillus grew at the beginning of the process; however, the most representative germs of these fermentation were the yeasts, whose population grew rapidly from brining (at higher rate as the salt content was slower). They remained throughout the storage, although after 180 days a decrease tendency was observed. The most representative species were: Pichía membranae faciens (51% of frequency), Pichía fementans (6%) and Hansenula polymorpha (6%). No gas-pocket or shrivelling was appreciated in any treatment. El trabajo estudia la evolución de las características físico-químicas y microbiológicas de la fermentación en medio aeróbico durante la conservación de aceitunas de la variedad Hojiblanca, en las diversas condiciones de los actuales procesos industriales (pH corregido inicialmente con acético a 4,0-4,2 unidades, concentración de sal entre 3 y 6%, frutos verdes o con una mayor madurez y aireación a razón de 0,3 litros de aire por hora y litro de capacidad del recipiente). La misma se caracteriza por un mantenimiento del pH, lenta utilización de los azúcares, bajos niveles de anhídrido carbónico disuelto y progresiva subida de la concentración de sal. Asimismo, se desarrollan bacilos Gram-negativos y Bacillus al comienzo del proceso, pero los microorganismos verdaderamente representativos de la fermentación son las levaduras cuya población aumenta rápidamente (mayor velocidad a medida que la concentración de sal es más baja) y permanecen durante toda la conservación en niveles elevados, si bien, después de 180 días existe una tendencia general a disminuir. Las especies más abundantes son: Pichía membranae faciens (51%); Pichía fermentans (6%) y Hansenula polimorpha (6%). En ningún tratamiento se observa arrugado ni alambrado en las aceitunas.

Ultrafiltration was applied to regenerate brines from green table olive fermentations. Experiments were conducted to select optimum membrane pore size and working conditions, as well as effects on characteristics of brines and olives packed with these regenerated brines. According to the results, good decoloration of such solutions was achieved with polysulfonate membranes of 1,000 daltons pore size. Best working conditions were : 18 bars, room temperature, room temperature (25°C), and without any previous filtration. Very low reduction of NaCl and slight decrease of lactic acid were noted. No effect on the quality of packed olives with the treated brines was detected.

The content of biogenic amines in different commercial preparations of table olives and other pickled foods was determined. Concentration of amines in packed table olives, capers, caperberries, and cucumbers was less than 60 mg of total biogenic amines per kg of fruit, and, therefore, these products represent no risk to human health. The highest concentrations of putrescine (50 mg/kg) and histamine (38 mg/kg) were found in untreated natural black olives and caperberries, respectively. Canned ripe olives were completely free of biogenic amines. Putrescine was found in all the samples of green olives and cucumbers but at levels lower than 18 mg/kg.