1,721,254 research outputs found
Molecular markers in olive tree: Current state and potential applications to olive oils
No full textDNA analysis by means of molecular markers enables, among its possible applications, genome fingerprinting with consequent identification of different individuals. In the matter of agro-food this can have interesting applications enabling identification of both monovarietal row material and processed products. The various categories of molecular markers employed in Olea europaea L. with cultivar identification purposes are described and their potential application to virgin oils is evaluated. This, with the aim of detecting the presence of not declared cultivars in recognised preserved origin (DOP) oils
INVESTIGATION ON THE DEGREE OF OXIDATION AND HYDROLYSIS OF REFINED OLIVE OILS: AN APPROACH FOR BETTER PRODUCT CHARACTERIZATION
No full textEFFORT TO IMPROVE THE QUANTITATIVE DETERMINATION OF OXIDATION AND HYDROLYSIS COMPOUND CLASSES IN EDIBLE VEGERTABLE OILS
No full textThis paper proposes an analytical method to evaluate the classes of products of polymerization, oxidation and hydrolysis
as well as the polar compounds present in refined edible oils in a more reliable fashion. The polar compounds of a marketed
refined peanut oil were analyzed by preparative gel permeation chromatography and the classes of substances corresponding
to single chromatogram peaks were collected by means of a fraction collector, purified and used as standards for
high-performance size-exclusion chromatographic analysis. The linearity of detector response, the precision and accuracy of
the method for each class of compounds and for polar compounds were assessed. Another aim was to verify whether this
method may be applied to other refined peanut oils and to edible vegetable oils in general, even of different botanical origin,
using the standards that had already been prepared for that particular peanut oil. The results obtained showed that this was
possible and the analytical method developed can be extended to the most common edible vegetable oils
Hydrolysis and oxidation of covering extra-virgin olive oil in canned dried tomatoes as affected by pasteurization
No full textA comparison between olive oil and extra-virgin olive oil used as covering liquids in canned dried tomatoes: hydrolytic and oxidative degradation
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POSSIBILITY OF IMPROVING THE QUALITY CHARACTERISTICS OF OLIVE-POMACE OIL AND ENHANCING ITS DIFFERENTIATION FROM REFINED OLIVE-POMACE OIL
No full textUse of recent analytical parameters to evaluate the quality of refined oils as liquid medium in canned fish
No full textInfluence of some packaging materials and of natural tocopherols on the sensory properties of breakfast cereals
No full textThe combined effect of natural antioxidants and packaging materials on the quality decay of breakfast cereals during storage was evaluated. Corn flakes were produced on industrial scale, using different packages and adding natural tocopherols to the ingredients, and stored for 1 year. The samples were then submitted to sensory analysis and HS-solid phase microextraction/gas chromatography/mass spectrometry (SPME/GC/MS) analysis. The packaging had a significant influence on the sensory profile of the aged product: metallized polypropylene gave the highest levels of oxidation compounds and sensory defects. The sensory profile was improved using polypropylene and especially high-density polyethylene. Natural tocopherols reduced the sensory decay of the flakes and the oxidative evolution of the volatile profile. They gave the most remarkable improvement in polypropylene (either metallized or not) packs. Polypropylene showed a barrier effect on the scalping of volatiles outside of the pack. This led to higher levels of oxidation volatiles and faster rates of the further oxidative processes involving the volatiles. © The Author(s) 2013
Effects of conventional and microwave heating on the degradation of edible vegetable oils
No full textA comparative study was performed to evaluate the effects that microwave (12 and 15 min at 1,100 W) and conventional heating (36 and 45 min at 230 degreesC) have on olive oil (refined+virgin). The extent of the oxidative and hydrolytic degradation of the differently heated oils was evaluated by high performance size-exclusion chromatographic analysis of their polar compounds. The experimental results showed a great degradation of the oils with values of polar compounds higher than 26% at the most intense treatment. Significantly higher amounts of polar compounds, of triglyceride oligopolymers - known to have adverse effects on human health - and of oxidised triglycerides were found in microwaved than in conventionally heated oils, indicating a higher extent of oxidative degradation
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