Predicting the suitable fertilizer for crop based on soil and environmental factors using various feature selection techniques with classifiers

Agriculture is an essential part of human life. The crop productivity is based on the soil and environmental factors. Different crops are cultivated in different areas. Nowadays, the crop productivity level is affected by the climate change and diseases in the crops. Due to this pest infestation, the crop growth is heavily affected. To overcome this problem, the right fertilizer for a particular crop has to be chosen and fertilizer helps farmers to improve the crop productivity rate. This process can be done by using various machine learning techniques. In this work, various features selection techniques with classifiers used to predict the suitable fertilizer for a crop. The experimental results show that recursive feature elimination along the proposed Heterogeneous Stacked Ensemble classifier gives better prediction rate than other methods

Hyperbaric storage at room temperature for food preservation: A study in strawberry juice

Hyperbaric storage at room temperature was evaluated as a new food preservation method. To do that, strawberry juices maintained at different pressure levels (0.1, 25, 100 or 220 MPa) and 20°C for 15 days were compared to raw and thermally pasteurized samples stored at atmospheric pressure and 5°C for the same period. Hyperbaric storage reduced the initial microbial load of the juices by more than 2 log units to levels below the limit of detection. Moreover, pressure was effective to attenuate viscosity and color losses in the samples stored at 20°C. Stability of the samples after the hyperbaric storage was good and microbial load, viscosity and color remained stable when the samples were kept under refrigeration at atmospheric pressure for 15 additional days. All these results show that hyperbaric storage could represent an interesting technology for short-term preservation of food. Industrial relevance: Effective management of the cold chain to maintain the highest quality of food is nowadays expensive and energy consuming and this can jeopardize the sustainability of the food supply chains. The results obtained in this paper suggest that hyperbaric storage at room temperature could be an interesting technology for short-term preservation of strawberry juice. It could imply important energy savings in different sections of the cold chain. © 2012 Elsevier Ltd. All rights reserved.This work has been supported by the R + D + I National Plan of the Spanish Ministry of Education and Science (MEC), through the projects AGL2007-63314/ALI and CSD2007-00045 MALTA CONSOLIDER-INGENIO 2010, by CSIC through the project 201070I033 and by the Madrid Community through the project QUIMAPRES S2009/PPQ-1551Peer Reviewe

Effect of hyperbaric storage at room temperature on pectin methylesterase activity and serum viscosity of strawberry juice

Hyperbaric storage at room temperature (HS-RT) has been lately proposed as a promising technology for food preservation. In this paper, the effect of HS-RT on pectin methylesterase (PME) activity and viscosity decay was evaluated in strawberry juice. To do so, two complementary studies were performed: one in crude strawberry PME extract and the other in strawberry juice. The results showed that, at the assayed conditions, the catalytic activity of the PME extract was not affected by pressure up to 200 MPa. Moreover, in strawberry juices, no pressure PME inactivation was observed during storage, at 0.1-200 MPa and 20 °C, for 1, 2, 5, 7, 10, and 15 days. HS-RT enhanced viscosity decay, especially at the beginning of storage, although no increase in PME activity was observed in this phase. Therefore, chemical and/or enzymatic reactions, other than PME de-esterification, could be pressure enhanced and affect pectin characteristics and serum viscosity. Industrial relevance Hyperbaric storage at room temperature (HS-RT) can involve substantial energy savings in food preservation. As food is preserved with no temperature control, the only energy consumption is produced at the beginning of storage, during compression. HS-RT could be applied in different sections of the cold chain in industrialized countries but also in developing countries in which the continuous supply of electric energy is difficult. However, before industrial implementation, much more research is needed to clarify the effect of the storage pressure on mechanisms implied in food quality degradation.This work was supported by the R + D + I National Plan of the Spanish Ministry of Education and Science (MEC) through projects AGL2007-63314/ALI (partially financed by FEDER funds) and CSD2007-00045 MALTA CONSOLIDER-INGENIO 2010, by CSIC through project 201070I033, and by the Madrid Community (CAM) through project QUIMAPRES S2009/PPQ-1551.Peer Reviewe

Browning reactions in olives: Mechanism and polyphenols involved

The mechanism of the browning reaction in olives has been disclosed by following the polyphenol changes in healthy and bruised fruits and using “in vitro” models. It was later validated in independent experiments with active and denatured enzymatic extracts, treated or not with ascorbic acid to prevent oxidation. The proposed mechanism would consist of two steps. First, there is an enzymatic release of hydroxytyrosol, due to the action of the fruits’ β-glucosidases and esterases on oleuropein and hydroxytyrosol glucoside; additional hydroxytyrosol can also be produced (in a markedly lower proportion) by the chemical hydrolysis of oleuropein. In a second phase, hydroxytyrosol and verbascoside are oxidized by the fruits’ polyphenoloxidase (mainly) and by a chemical reaction, which occurs to a limited extent due to the olive flesh pH, ≈5.0.The authors express their gratitude to CICYT (of the Spanish Government) for their financial support of this research (AGL2006-3540/ALI), Junta de Andalucía through the group AGL 125 (Biotecnología de Alimentos). Kharla A. Segovia-Bravo also thanks fellowship I3P from MEC (Spanish Government).Peer reviewe

Treatments to inhibit the browning reactions in model solutions of olive fruit extracts

Crude enzymatic and polyphenol extracts from olives were subjected to reaction at diverse buffered pH values. At pH values similar to those found in olive flesh (pH 5.0), the colour of the solution increased with reaction time and, simultaneously, a consumption of phenols and oxygen in the reaction medium was observed, especially under aerated conditions. In alkaline solutions (pH 12.4), a strong initial solutionbrowning was noticed while the phenols from the extract reacted with the oxygen present in the solution and caused a significant decrease in the total phenols and oxygen concentrations. This darkening was due to the appearance of non-enzymatic browningreactions since, at this pH, the polyphenoloxidase is not active. Under acidic conditions (pH 3.0), and in solutions with ascorbic acid added (100 mM), the consumption of oxygen and total phenols was negligible, under both aerated and non-aerated conditions; as a result, no significant changes in the colour of the solutions were observed. So, low pH or ascorbic acid solutions may be useful to prevent browning in the bruised areas of hand- or mechanically-harvested table olives.The authors express their gratitude to CICYT (of the Spanish Government) for the financial support of this research (AGL2006-3540/ALI, partially financed from European regional development funds, ERDF), Junta de Andalucía throughout the group AGL 125 (Biotecnología de Alimentos). Kharla A. Segovia-Bravo also acknowledge fellowships I3P from MEC (Spanish Government).Peer reviewe

Effect of bruising on respiration, superficial color, and phenolic changes in fresh Manzanilla olives (Olea europaea pomiformis): Development of treatments to mitigate browning

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. © 2011 American Chemical Society.The authors express their gratitude to CICYT (Spanish Government) for the financial support of this research (AGL2006-3540/ALI and AGL2009-07436), Junta de Andalucía throughout the group AGL 125 (Biotecnología de Alimentos). Kharla A. Segovia-Bravo also thanks fellowship I3P from MEC (Spanish Government).Peer Reviewe

Activida pectolítica en zumo de fresa durante su almacenamiento hiperbárico a temperatura ambiente

Ponencia presentada en el VII Congreso Español de Ingenieria de Alimentos, Ciudad Real, 7-9 de Noviembree. 2012El almacenamiento hiperbárico a temperatura ambiente podría ser un nuevo método de conservación de alimentos que suponga un ahorro energético frente a la refrigeración tradicional. Experimentos previos han demostrado que es efectivo para evitar el crecimiento microbiano en zumo de fresa fresco almacenado por 15 días y para atenuar las pérdidas de color y viscosidad en el producto. Sin embargo, estas pérdidas de viscosidad no son despreciables. Debido a la importancia de la viscosidad en los zumos de frutas, el objetivo de este trabajo ha sido estudiar la actividad pectolítica en el zumo de fresa durante su almacenamiento hiperbárico a temperatura ambiente. Para ello, se almacenó zumo de fresa fresco bajo diferentes presiones (0.1, 50 y 200 MPa) a 20 ºC y se midió el contenido de metanol y la viscosidad en las muestras después de diferentes períodos de almacenamiento (0, 1, 2, 5 y 10 días). Los resultados obtenidos indican que la presión es un parámetro que afecta significativamente a la actividad pectolítica del zumo de fresa durante su almacenamiento a 20 ºC.Este trabajo ha sido financiado por el Ministerio de Educación y Ciencia de España a través de los proyectos AGL2007-63314/ALI y CSD2007-00045 MALTA CONSOLIDER-INGENIO 2010, por el CSIC a través del proyecto 201070I033 y por la Comunidad de Madrid a través del proyecto QUIMAPRES s2009/PPQ-1551.Peer Reviewe

Almacenamiento de alimentos en alta presión hidrostática

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Formation risk of toxic and other unwanted compounds in pressure-assisted thermally processed foods

Consumers demand, in addition to excellent eating quality, high standards of microbial and chemical safety in shelf-stable foods. This requires improving conventional processing technologies and developing new alternatives such as pressure-assisted thermal processing (PATP). Studies in PATP foods on the kinetics of chemical reactions at temperatures (approximately 100 to 120 °C) inactivating bacterial spores in low-acid foods are severely lacking. This review focuses on a specific chemical safety risk in PATP foods: models predicting if the activation volume value (V a) of a chemical reaction is positive or negative, and indicating if the reaction rate constant will decrease or increase with pressure, respectively, are not available. Therefore, the pressure effect on reactions producing toxic compounds must be determined experimentally. A recent model solution study showed that acrylamide formation, a potential risk in PATP foods, is actually inhibited by pressure (that is, itsV avalue must be positive). This favorable finding was not predictable and still needs to be confirmed in food systems. Similar studies are required for other reactions producing toxic compounds including polycyclic aromatic hydrocarbons, heterocyclic amines, N-nitroso compounds, and hormone like-peptides. Studies on PATP inactivation of prions, and screening methods to detect the presence of other toxicity risks of PATP foods, are also reviewed. © 2011 Institute of Food Technologists ®.Peer Reviewe

Instability profile of fresh packed “seasoned” Manzanilla-Aloreña table olives

The shelf life of cracked “seasoned” Manzanilla-Aloreña table olives is short; containers may swell and the fruits become progressively brownish. Respiration of cracked fruits continued for a period longer than 48 h after picking and the carbon dioxide produced may be an initial cause of spoilage. As processing progressed, the microbial loads in the olives increased due to successive washings and, together with the microbial load from the added ingredients, led to relatively high viable counts of yeasts and LAB at packing. During shelf life, this microflora showed an increase in viable counts which could also eventually lead to swelling spoilage. This behaviour was favoured by the presence of residual fermentable substrates and a decrease in potassium sorbate over time in both brine and flesh. At the same time, colour darkened, titratable acidity increased and pH decreased. The application of two additional washings to the cracked olives before packing was favourable because fermentable material and polyphenols were removed; however, fruits with as low as possible respiration rates, stronger washing treatments, ingredients with low or no microbial viable counts and higher preservative concentrations would be necessary to achieve complete stabilization of the product.This work was supported by the Spanish Government (AGL2003-00779 and AGL2006-03540/ALI, partially financed from European regional development funds, ERDF), Junta de Andalucía (through financial support to group AGR-125), and EU (TDC-Olive, FOOD CP 2004 505524).Peer reviewe