Articles publicats (Tecnologia, Enginyeria i Ciència dels Aliments)

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Open Access
Influencia del pH en la fotodescomposición de piridina
(Asociación de Químicos e Ingenieros del Instituto Químico de Sarriá, 1985) Ibarz Ribas, Alberto; Esplugas Vidal, Santiago; Costa i Torres, Josep M.
Open Access
Influencia del oxígeno disuelto, peróxido de hidrógeno y sales de hierro en la fotodescomposición de piridina
(Asociación de Químicos e Ingenieros del Instituto Químico de Sarriá, 1989) Ibarz Ribas, Alberto; Esplugas Vidal, Santiago; Costa i Torres, Josep M.
Open Access
Fotodescomposición de benomilo en solución acuosa
(Asociación de Químicos e Ingenieros del Instituto Químico de Sarriá, 1996) Ibarz Ribas, Alberto; Panadés Ciprés, Ricard; Tejero, J. M.
Open Access
Fotodescomposición de Tiabendazol en solución acuosa
(Asociación de Químicos e Ingenieros del Instituto Químico de Sarriá, 1997) Panadés Ciprés, Ricard; Alonso, J. M.; Ibarz Ribas, Alberto
Open Access
Estudio de la calidad del aceite de oliva virgen de la Denominación de Origen «Les Garrigues» (Lleida) durante la campaña 1995/96
(Consejo Superior de Investigaciones Científicas (Espanya), 1998) Motilva Casado, Mª José; Jaria, Ismael; Bellart, Ismael; Romero Fabregat, Mª Paz
Departamento de Tecnología de Alimentos, Escuela Técnica Superior de Ingeniería Agraria, Universidad de Lleida. Centro UdL-IRTA. Avda. Alcalde Revira Roure, 177. 25198 Lleida, España. RESUMEN Estudio de la calidad del aceite de oliva virgen de la Denominación de Origen «Les Garrigues» (Lleida) durante la campaña 1995/96. La Denominación de Origen «Les Garrigues» se sitúa en el extremo meridional de la provincia de Lleida. La gran mayoría del aceite producido en esta D.O. corresponde a la categoría de virgen extra y posee unas características organolépticas muy peculiares, derivadas del fruto de origen, la variedad «Arbequina» y de su cuidada elaboración. La aplicación en la zona de modemas técnicas de cultivo del olivo y las nuevas tecnologías de extracción del aceite, hacen necesario un estudio de su composición en campañas sucesivas, con el fin de determinar si la calidad se pudiera ver afectada. El presente trabajo se centra en la caracterización de los aceites producidos en la D.O. «Les Garrigues» durante la campaña 1995/96. Los aceites obtenidos presentan un grado de acidez medio de 0.17%, índice de peróxidos de 6.9 meq/kg de aceite y un K270 de 0.21, valores todos ellos dentro de los criterios de calidad que establece la Reglamentación de la D.O. El contenido medio de polifenoles totales en el aceite es de 152 ppm, observándose una gran variabilidad entre las almazaras muestreadas. La concentración de clorofilas va de 15 mg/kg de aceite, al inicio de campaña, a 6 mg/kg al final de la misma. La concentración de carotenoides se reduce paralelamente, pasando de 12.6 a 4.6 mg/kg de aceite, al final de campaña. El color, en base a la escala visual ABT y a las coordenadas CIELAB, se mantiene dentro de los tonos del amarillo y no presenta diferencias importantes entre aceites de principio y final de campaña.
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Relationships between volatile production, fruit quality, and sensory evaluation in granny smith apples stored in different controlled-atmosphere treatments by means of multivariate analysis
(American Chemical Society, 1999) Lavilla, T.; Puy Llorens, Jaume; Recasens Guinjuan, Inmaculada; Vendrell, M.; López Fructuoso, Mª Luisa
Aroma compounds, quality parameters, and sensory evaluation of Granny Smith apples were analyzed after 3, 5, and 7 months of cold storage in three controlled-atmosphere (CA) treatments, in which oxygen and carbon dioxide were held at 1, 2, and 3%. During poststorage ripening, the apples were kept at 20 °C for 1, 5, and 10 days before analytical measurements were made. The highest volatile emission was obtained after 5 months of storage in all CA treatments, reaching its highest value when a low-oxygen CA (LO) was used. Ultralow-oxygen CA (ULO) showed the highest ability to maintain apple firmness. The correlation among analytical and sensory parameters suggests that ethyl 2-methylbutyrate, 1-butanol, pentyl acetate, and tert-butyl propionate are the aroma compounds with the highest influence in the sensorial score. Concerning CA treatments, LO and ULO appear to be very valuable technologies for maintaining the sensorial quality even after 7 months of storage.
Open Access
Caracterización geográfica de los aceites de oliva vírgenes de la denominación de origen protegida ’Les Garrigues’ por su perfil de ácidos grasos
(Consejo Superior de Investigaciones Científicas (Espanya), 2001) Motilva Casado, Mª José; Ramo Aparicio, Tomás; Romero Fabregat, Mª Paz
Se ha analizado el perfil de ácidos grasos en 190 muestras de aceite de oliva virgen de la DOP Les Garrigues (Lleida) de tres campañas consecutivas (1995/96, 1996/97 y 1997/98). Se ha encontrado que la mayor variabilidad entre los ácidos grasos es debida a aspectos relacionados con la climatología de la campaña oleícola y con la procedencia de los aceites. El análisis de componentes principales ha permitido obtener dos componentes principales que explican más del 80 % de la variabilidad observada. La representación de los aceites según sus componentes principales, permite separar aceites procedentes de dos subzonas con diferencias agroclimáticas. Se ha aplicado un análisis discriminante paso a paso y se ha obtenido una función que ha permitido clasificar correctamente en la subzona de procedencia más del 83 % de los 188 aceites. El modelo ha sido validado con 20 muestras de aceites procedentes de la campaña 1998/99, habiéndose clasificado correctamente el 84,6 % de las muestras.
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Beer consumption and changes in stability of human serum proteins
(American Chemical Society, 2001) Gorinstein, Shela; Caspi, Abraham; Goshev, Ivan; Moncheva, Snejana; Zemser, Marina; Weisz, Moshe; Libman, Imanuel; Lerner, Henry Tzvi; Trakhtenberg, Simon; Martín Belloso, Olga
The aim of this study was to evaluate the influence of beer consumption (BC) on the functional and structural properties of human serum proteins (HSP). Thirty-eight volunteers (after coronary bypass) were divided into two groups: experimental (EG) and control (CG). Nineteen volunteers of the EG consumed 330 mL per day of beer (about 20 g of alcohol) for 30 consecutive days. The CG volunteers consumed mineral water instead of beer. Blood samples were collected from EG and CG patients before and after the experiment. Albumin (Alb), globulin (Glo), and methanol-precipitable proteins (MPP) from human serum were denatured with 8 M urea. Fluorescence and electrophoresis were employed in order to elucidate urea-induced conformational changes and structural behavior of proteins. The measured fluorescence emission spectra were used to estimate the stability of native and denatured protein fractions before and after BC. It was found that before BC the fractions most stable to urea denaturation were Glo, Alb, and MPP fractions. After BC in most of the beer-consuming patients (EG) some changes in native and denatured protein fractions were detected: a tendency to lower stability and minor structural deviations. These qualitative changes were more profound in MPP than in Alb and Glo. Thus, Glo is more resistible to alcohol influence than Alb, which in turn is more resistible than MPP. No serum protein changes were detected in patients of CG.
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Comparative contents of dietary fiber, total phenolics, and minerals in persimmons and apples
(American Chemical Society, 2001) Gorinstein, Shela; Zachwieja, Zofia; Folta, Maria; Barton, Henryk; Piotrowicz, Jadwiga; Zemser, Marina; Weisz, Moshe; Trakhtenberg, Simon; Martín Belloso, Olga
Dietary fibers, major phenolics, main minerals, and trace elements in persimmons and apples were analyzed and compared in order to choose a preferable fruit for an antiatherosclerotic diet. Fluorometry and atomic absorption spectrometry following microwave digestion were optimized for the determination of major phenolics and minerals. Total, soluble, and insoluble dietary fibers, total phenols, epicatechin, gallic and p-coumaric acids, and concentrations of Na, K, Mg, Ca, Fe, and Mn in whole persimmons, their pulps, and peels were significantly higher than in whole apples, pulps, and peels (P < 0.01−0.0025). Conversely, the contents of Cu and Zn were higher in apples than in persimmons. In persimmons and apples all of the above components were higher in their peels than in whole fruits and pulps. The relatively high contents of dietary fibers, total and major phenolics, main minerals, and trace elements make persimmon preferable for an antiatherosclerotic diet.
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Browning evaluation of ready-to-eat apples as affected by modified atmosphere packaging
(American Chemical Society, 2001) Soliva-Fortuny, Robert; Grigelmo-Miguel, Nuria; Odriozola Serrano, Isabel; Gorinstein, Shela; Martín Belloso, Olga
The color and polyphenol oxidase (PPO) activity of fresh-cut Golden delicious apples were evaluated throughout cold storage under modified atmospheres. The shelf life of cut apples was extended to several weeks, especially when an initial atmosphere of 90.5% N2 + 7% CO2 + 2.5% O2 and plastic pouches of 30 cm3/cm2·bar·24 h were used. Under these conditions, a maximum 62% PPO activity depletion was observed. In all cases, the faster the initial PPO activity decays, the less the color changes. A fractional conversion first-order model was proposed for predicting color changes in minimally processed apples. Browning was better described through lightness (L*) (kL = 0.017 − 0.07 day-1) and color difference (ΔE*) values (kΔE = 0.015 − 0.073 day-1), which fitted the model with enough accuracy.
Open Access
Perspectivas del empleo del control biológico en post-cosecha de fruta
(Eumedia, 2002) Usall i Rodié, Josep; Teixidó i Espasa, Neus; Abadias i Sero, Mª Isabel; Torres Sanchis, Rosario; Viñas Almenar, Inmaculada
Actualmente se estudian diversos métodos alternativos a los procedimientos habituales de control de plagas y enfermedades de la fruta en post-cosecha, algunos de los cuales se utilizan ya a nivel comercial, como el empleo de microorganismos antagónicos, método en el que se centra el presente artículo. La fruta almacenada en cámaras frigoríficas supone una buena oportunidad para emplear sistemas de lucha biológica en el control de las enfermedades de post-cosecha, puesto que la fruta se encuentra bajo condiciones ambientales controladas, tanto de humedad relativa y temperatura como por la concentración de gases.
Open Access
Tratamientos químicos en postcosecha de fruta
(Eumedia, 2003) Usall i Rodié, Josep; Plaza Portolés, Ma. Pilar; Viñas Almenar, Inmaculada
Durante el periodo de conservación de algunas frutas se producen pérdidas que, en parte, se deben a la aparición de alteraciones fúngicas que provocan podredumbres. El sistema de control más extendido es el empleo de productos químicos de síntesis, aunque también es importante el correcto manejo de la plantación, la recolección y limpieza de envases y un correcto manejo del frio, entre otros.
Open Access
Compuestos aromáticos y calidad de manzanas ‘Fuji’ durante su maduración en campo y posterior almacenamiento frigorífico
(Asociación Interprofesional para el Desarrollo Agrario, 2003) Echeverría Cortada, Gemma; López Fructuoso, Mª Luisa; Graell i Sarle, Jordi
En el presente trabajo se estudian los compuestos aromáticos y la calidad en manzanas ' Fuji' (Nagafu 6) durante su maduración en campo y a lo largo de su almacenamiento. En campo, se realizaron 6 muestreos pre-cosecha. A Jos 185 y 195 días después de floración (DDPF) se cosecharon frutos, los cuales se almacenaban en atmósfera ULO ( 1, 1 % 0 2 + 0,9% C02, 1 ºC, 92% HR) durante 3 y 5 meses. Los análisis de los frutos se realizaron en cada fecha de muestreo en campo, y después de cada período de almacenamiento (tras 1, 5 y 10 días a 20ºC). En campo, se observó un incremento de la mayoría de ésteres y del 2-metil-1-butanol. La firmeza y acidez de los frutos se mantuvieron constantes, mientras que el contenido de sólidos solubles y el parámetro a*+b* (color de fondo) aumentaron. Después de 5 meses de almacenamiento en ULO, las manzanas presentaron una mayor producción aromática tras 1 día a 20 ºC; los frutos cosechados a los J 95 DDPF presentaron mayores concentraciones en aromas. Además, durante el almacenamiento, las manzanas presentaron una buena retención de la calidad físico-quúnica (en frutos cosechados a los 185 DDPF), si bien se observaron ligeras pérdidas de flfOleza y acidez durante el período de pennanencia a 20 ºC posterior a los 5 meses de almacenamie nto; el color de las manzanas se vió también influenciado por dicho período a 20 ºC.
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Relationships between volatile production, fruit quality and sensory evaluation of Fuji apples stored in different atmospheres by means of multivariate analysis
(Wiley, 2003) Echeverría Cortada, Gemma; Fuentes, M. T.; Graell i Sarle, Jordi; López Fructuoso, Mª Luisa
Aroma compounds, quality parameters and sensory characteristics of Fuji apples were analysed after 3, 5 and 7months of storage at 1 ◦C in normal air (AIR; 210 l m−3 O2/0.3 l m−3 CO2) and in controlled atmospheres with O2/CO2 ratios of 10 lm−3/10 l m−3 (ULO1), 10 l m−3/20 l m−3 (ULO2) and 30 l m−3/20 lm−3 (SCA). After storage the apples were kept at 20 ◦C for 1, 5 and 10 days. The components that contributed most to the characteristic aroma of Fuji apples were ethyl 2-methylbutanoate, 2-methylbutyl acetate and hexyl acetate. The highest aroma compound production was found in ULO1 fruits after 5 months of cold storage and 1 day of shelf-life. After 3 and 5months of storage, ULO1 fruits showed the highest firmness after both 1 day and 10 days at 20 ◦C. After 7 months of storage plus 1 day at 20 ◦C, ULO2 fruits showed higher titratable acidity and soluble solid content; fruit firmness was also maintained throughout the shelf-life period. Generally, background and superficial colour were not influenced by storage conditions. A statistically significant correlation was found between aroma compounds, quality parameters and sensory evaluation.
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Aroma volatile compounds of ‘Fuji’ apples in relation to harvest date and cold storage technology: A comparison of two seasons
(Elsevier, 2004) Echeverría Cortada, Gemma; Fuentes, T.; Graell i Sarle, Jordi; Lara Ayala, Isabel; López Fructuoso, Mª Luisa
‘Fuji’ apples were harvested at two different dates, over two consecutive years (1999 and 2000), and stored under different atmosphere conditions: AIR (21 kPa O2 + 0.03 kPa CO2), SCA (3 kPa O2 + 2 kPa CO2) or ULO (1 kPa O2 + 2 kPa CO2). After 3, 5 or 7 months of storage plus 1 or 10 days of ripening at 20 ◦C, aroma volatile emission and quality parameters were measured. Generally, the highest total aroma emission was obtained after 5-months storage and 1 day of ripening at 20 ◦C regardless of atmosphere conditions, for early-harvested fruit. After 7-months storage, the ULO atmosphere depressed total aroma volatile emission. The compounds contributing mostly to the characteristic aroma of ‘Fuji’ apples were ethyl 2-methylbutanoate, 2-methylbutyl acetate and hexyl acetate, and their concentrations were higher the first day after removal from storage at 5, 3 and 7 months, respectively. Storage conditions and season had a significant effect on aroma volatile compounds.
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Volatile production, quality and aroma-related enzyme activities during maturation of ‘Fuji’ apples
(Elsevier, 2004) Echeverría Cortada, Gemma; Graell i Sarle, Jordi; López Fructuoso, Mª Luisa; Lara Ayala, Isabel
Production of volatile aroma compounds, and quality parameters, were monitored in relation to the activity of lipoxygenase, pyruvate decarboxylase, alcohol dehydrogenase and alcohol o-acyltransferase during maturation of ‘Fuji’ apples. Acetate esters increased during maturation and were quantitatively the most significant compounds contributing to ‘Fuji’ aroma. Increase in acetate ester production was associated with the availability of the necessary alcohol precursors. Principal component analysis revealed a clear separation according to sampling date, which accounted for up to 67% of total variance, and allowed ‘Fuji’ apples used in this study to be classified into three ripeness stages. Overall the results suggest that precursor availability for the related enzymes is a more significant factor than enzyme activity for the development of aroma during on-tree maturation of ‘Fuji’ apples.
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Characterization of Fuji apples from different harvest dates and storage conditions from measurements of volatiles by gas chromatography and electronic nose
(American Chemical Society, 2004) Echeverría Cortada, Gemma; Correa, Eva; Ruiz-Altisent, Margarita; Graell i Sarle, Jordi; Puy Llorens, Jaume; López Fructuoso, Mª Luisa
Volatile compounds in Fuji apples harvested at two different maturities were measured at harvest and after 5 and 7 months of cold storage (1 °C) in four different atmospheres. When the samples were characterized by both chromatographic measurements of volatiles and responses of an electronic nose, the analyses showed a clear separation between fruits from different storage conditions (a normal cold atmosphere and three controlled atmospheres). During poststorage, the apples were left to ripen for 1, 5, and 10 days at 20 °C before analytical measurements were done involving headspace-gas chromatography methods and electronic nose type quartz crystal microbalances. Electronic nose responses registered by seven different sensors were used to classify the apples using principal component analysis. It was possible to identify the samples from different storage periods, days of shelf life, and harvest dates, but it was not possible to differentiate the fruits corresponding to different cold storage atmospheres.
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An attempt to optimize potassium sorbate use to preserve low pH (4.5–5.5) intermediate moisture bakery products by modelling Eurotium spp., Aspergillus spp. and Penicillium corylophilum growth
(Elsevier, 2005) Guynot, M. Elena; Marín Sillué, Sònia; Sanchís Almenar, Vicente; Ramos Girona, Antonio J.
Mould growth was modelled on fermented bakery product analogues (FBPA) of two different pH (4.5 and 5.5), different water activity (aw) levels (0.80–0.90) and potassium sorbate concentrations (0–0.3%) by using seven moulds commonly causing spoilage of bakery products (Eurotium spp., Aspergillus spp. and Penicillium corylophilum). For the description of fungal growth (growth rates) as a function of aw, potassium sorbate concentration and pH, 10-terms polynomial models were developed. Modelling enables prediction of spoilage during storage as a function of the factors affecting fungal growth. At pH 4.5 the concentration of potassium sorbate could be reduced to some extent only at low levels of aw, whereas at pH 5.5 fungal growth was observed even by adding 0.3% of potassium sorbate. However, this preservative could be a valuable alternative as antifungal in such bakery product, of slightly acidic pH, if a long shelf life has not to be achieved.
Open Access
Evaluation of an electronic nose to assess fruit ripeness
(Institute of Electrical and Electronics Engineers (IEEE), 2005) Brezmes Llecha, Jesús; López Fructuoso, Mª Luisa; Llobet Valero, Eduard; Recasens Guinjuan, Inmaculada; Orts Latorre, Jorge; Saiz Laudo, Guillermo; Correig i Blanchar, Xavier; Vilanova Salas, Xavier
The main goal of our study was to see whether an artificial olfactory system can be used as a nondestructive instrument to measure fruit maturity. In order to make an objective comparison, samples measured with our electronic nose prototype were later characterized using fruit quality techniques. The cultivars chosen for the study were peaches, nectarines, apples, and pears. With peaches and nectarines, a PCA analysis on the electronic nose measurements helped to guess optimal harvest dates that were in good agreement with the ones obtained with fruit quality techniques. A good correlation between sensor signals and some fruit quality indicators was also found. With pears, the study addressed the possibility of classifying samples regarding their ripeness state after different cold storage and shelf-life periods. A PCA analysis showed good separation between samples measured after a shelf-life period of seven days and samples with four or less days. Finally, the electronic nose monitored the shelf-life ripening of apples. A good correlation between electronic nose signals and firmness, starch index, and acidity parameters was found. These results prove that electronic noses have the potential of becoming a reliable instrument to assess fruit ripeness.
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Effect of antioxidants and proteins on the quality of Israeli Jaffa red and blond grapefruit
(Springer-Verlag, 2005-07) Gorinstein, Shela; Drzewiecki, Jerzy; Sivan, Ami; Trakhtenberg, Simon; Katrich, Elena; Giner, Joaquim; Soliva-Fortuny, Robert; Elez Martínez, Pedro; Martín Belloso, Olga
Some biochemical characteristics of Israeli Jaffa Star Ruby ( red) and blond grapefruits were defined using atomic absorption spectrometry, antioxidant tests and the protein electrophoretic technique. It was found that the contents of dietary fibers, major and minor minerals, phenolic and ascorbic acids in both grapefruits were without significant differences. The contents of total polyphenols, anthocyanins and flavonoids were higher in red grapefruits, but also these differences were not significant. The antioxidant capacity was determined by two modified antioxidant methods, 2,2'-azinobis(3-ethylbenzothiazoline-6- sulfonate) radical cation (ABTS(+)) and scavenging activity against nitric oxide, and was compared with the Folin-Ciocalteu assay. The two antioxidant assays used have shown that the antioxidant potential of the Star Ruby ( red) grapefruit is higher than of the blond (P < 0.05) grapefruit. Proteins were extracted and separated. Some small differences were found in the sodium dodecyl sulfate-protein bands in the region of 36 kDa. Antioxidants and proteins can be used for characterization of the quality of grapefruits as a fruit diet