Search results for "vegetable"

Use of Nanomaterials as Alternative for Controlling Enzymatic Browning in Fruit Juices

2020

Abstract Polyphenol oxidase (PPO) enzyme, present in most of fruits and vegetables, frequently induces browning in juices and beverages during postharvest and processing. Many efforts have been done to prevent or avoid this reaction. Nevertheless, the development of new methods is still of interest since many of the current methods present important drawbacks. An overview of the exiting techniques to inhibit enzymatic browning has been compiled in this chapter, including physical (i.e., thermal treatments, high pressures, irradiation, ultrasonication, pulsed electric fields, and ultrafiltration) and chemical techniques (acidification, addition of antibrowning agents) but with particular att…

Pyrolysis of vegetable oil soaps—Palm, olive, rapeseed and castor oils

2011

Abstract Saponified, palm, olive, rapeseed and castor oils were pyrolysed (at 750 °C for 20 s) by pyrolysis gas chromatography with mass selective and flame ionisation detection (Py-GC/MSD and FID) to clarify their thermochemical behaviours. The liquefiable compounds recovered from palm, olive and rapeseed oils mainly contained linear alkenes (up to C 19 ) and alkanes (up to C 17 ), both similar to those found in gasoline (C 4 –C 10 ) and diesel fuel (C 11 –C 22 ) boiling range fractions of petroleum, whereas in the case of castor oil a significant amount of undesired oxygen-containing products (e.g., ketones and phenols) were formed. The obtained data on reaction mechanisms can also be uti…

Determination of pyrethroid insecticide residues in vegetable oils by using combined solid-phases extraction and tandem mass spectrometry detection

2005

Abstract A methodology has been developed for the determination of pyrethroid insecticide residues in vegetable oils, based in a solid-phase extraction (SPE) with combined solid supports phases. Several solid phases such as florisil, alumina, C18 and graphitized carbon black were tested in order to minimize fat residues, being a combination of treated alumina and C18 which provided the best results. Oil samples were partitioned with acetonitrile–hexane (1:1) and then eluted through a combined column packed with deactivated basic-alumina and C18, employing the acetonitrile extract as elution solvent. Gas chromatography tandem mass spectrometry was used for determination. Tetramethrin, Bifent…

Capillary electrophoresis for analyzing pesticides in fruits and vegetables using solid-phase extraction and stir-bar sorptive extraction.

2005

Two procedures based on solid-phase extraction (SPE) and stir-bar sorptive extraction (SBSE) in combination with micellar electrokinetic chromatography (MEKC)--diode array detection (DAD) were compared for the simultaneous extraction of acrinathrin, bitertanol, cyproconazole, fludioxonil, flutriafol, myclobutanil, pyriproxyfen, and tebuconazole in lettuce, tomato, grape, and strawberry. Selectivity and resolution of the MEKC procedure were studied changing the pH and the molarity of the buffer, the type and the concentration of surfactant, and the methanol content in the mobile phase. A buffer consisting of 6 mM sodium tetraborate decahydrate with 75 mM of cholic acid sodium solution (pH 9.…

Classification of Extra Virgin Olive Oils Produced at La Comunitat Valenciana According to Their Genetic Variety Using Sterol Profiles Established by…

2009

A method to classify extra virgin olive oils (EVOOs) according to their genetic variety using sterol profiles obtained by high-performance liquid chromatography (HPLC) with mass spectrometry (MS) detection has been developed. Sterol extracts were chromatographed on a dC18 Atlantis column (100x3 mm, 3 microm) with a gradient of acetonitrile/water (0.01% acetic acid) at a flow rate of 1.0 mL min(-1) and positive-ion mode MS detection. Using linear discriminant analysis of the HPLC-MS data (extracted ion chromatograms), EVOO samples belonging to six genetic varieties cultivated at La Comunitat Valenciana, Spain (Arbequina, Borriolenca, Canetera, Farga, Picual, and Serrana), were correctly clas…

Production and characterization of glicosidases from Aspergillus terreus using "pastazzo" as inductor .

2010

Lead, cadmium and chromium content of edible vegetables grown in three different agricultural areas

1990

(1990). Lead, cadmium and chromium content of edible vegetables grown in three different agricultural areas. Food Additives & Contaminants: Vol. 7, No. sup1, pp. S22-S25.

Inactivation and structural changes of polyphenol oxidase in quince ( Cydonia oblonga Miller) juice subjected to ultrasonic treatment

2020

Background Polyphenol oxidase (PPO) is considered a problem in the food industry because it starts browning reactions during fruit and vegetable processing. Ultrasonic treatment is a technology used to inactivate the enzyme; however, the mechanism behind PPO inactivation is still unclear. For this reason, the inactivation, aggregation, and structural changes in PPO from quince juice subjected to ultrasonic treatments were investigated. Different intensities and times of ultrasonic treatment were used. Changes in the activity, aggregation, conformation, and structure of PPO were investigated through different structural analyses. Results Compared to untreated juice, the PPO activity in treat…

Superior Antibacterial Activity of Integral Lemon Pectin Extracted via Hydrodynamic Cavitation

2020

Abstract Pectin extracted via hydrodynamic cavitation in water only from waste lemon peel and further isolated via freeze drying displays significant antibacterial activity against Staphylococcus aureus, a Gram positive pathogen which easily contaminates food. The antibacterial effect of the new IntegroPectin is largely superior to that of commercial citrus pectin, opening the way to advanced applications of a new bioproduct now obtainable in large amounts and at low cost from citrus juice industry's waste.

Bioaccessibility and decomposition of cylindrospermopsin in vegetables matrices after the application of an in vitro digestion model.

2018

Research on the human exposure to Cylindrospermopsin (CYN) via consumption of contaminated food is of great interest for risk assessment purposes. The aim of this work is to evaluate for the first time the CYN bioaccessibility in contaminated vegetables (uncooked lettuce and spinach, and boiled spinach) after an in vitro digestion model, including the salivar, gastric and duodenal phases and, colonic fermentation under lactic acid bacteria. The results obtained showed that the digestion processes are able to diminish CYN levels, mainly in the colonic phase, especially in combination with the boiling treatment, decreasing CYN levels in a significant way. Moreover, the potential decomposition…