135 research outputs found

    Olive oil

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    Analyses of phytosterol classes of olive and hazelnut oils collected from different countries by TLC, GC and GC-MS revealed considerable quantitative differences. The composition of 4-desmethyl- and 4-monomethylsterols was similar in both oils, but 4,4'-dimethylsterols composition differed. Lupeol and an unknown (lupane skeleton) compound were exclusively present in hazelnut oil 4,4´-dimethylsterols and could be used as markers to detect virgin olive oil adulteration with hazelnut oil at levels below 4%. Conventional TLC to separate phytosterol classes has a low recovery rate and is time-consuming. A new SPE method to separate phytosterol classes was developed with stepwise elution by increasing the polarity of the n-hexane:diethyl ether solvent mixture. Comparison of the results obtained for hazelnut and virgin olive oils with those of TLC revealed that the SPE method was faster and gave higher sterol recovery rates. Free and esterified forms of sterols provide detailed information on the identity and quality of vegetable oils, and therefore 4,4´-dimethylsterols were investigated in hazelnut oil and virgin olive oil. A sample of solvent-extracted hazelnut oil was refined to monitor the effects of processing on 4,4´-dimethylsterol levels and on specific marker compounds. Of the refining processes tested, only neutralisation and bleaching considerably reduced 4,4´-dimethylsterols. In fully-refined hazelnut oil, losses of marker compounds in free form were higher than losses in their esterified form. GC-MS analysis showed that adulteration of olive oil with fully-refined hazelnut oil could be detected at levels of 2% by tracing lupeol in total/esterified forms of 4,4´-dimethylsterols. Olive oil has many applications in the food industry, e.g. blended with oils such as palm stearin to produce margarine or shortening by chemical interesterification. Investigation on lipid and minor lipid components of an olive oil-palm stearin blend during chemical interesterification showed that sterols were esterified with fatty acids at a higher level at 120 °C (7%) than at 90 °C (4%). Despite heat treatment and several steps to produce an interesterified product, there were minor losses in phytosterol and tocopherol contents and no significant increases in phytosterol oxidation

    Amaranth Seed Oil Composition

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    In this chapter, amaranth seed oil composition will be presented. The main component of this oil is triacylglycerols (TAGs). TAGs are composed of fatty acids, which have an important effect on oil stability, application, and nutritional properties. POL, PLL, POO, OLL, and LOO are the predominant TAGs in the amaranth seed oil. Linoleic acid (C18:2), oleic acid (C18:1), and palmitic acid (C16:0) are the predominant fatty acids present in the amaranth oil. Minor components of this oil are squalene, sterols, tocopherols, carotenoids, phospholipids, etc. Growth conditions of amaranth and extraction conditions can influence oil composition, which will be discussed in this chapter as well. Oil stability and quality parameters will be also discussed. The stability of this oil during different conditions of storage will be a part of this chapter

    Plant tonic, a plant-derived bioactive natural product, exhibits antifungal activity against rice blast disease

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    The tendency towards application of natural products and botanical extracts as safer antimicrobial agents against plant pathogens has recently been increased. Plant Tonic9 (EOX-SOV) is an environmentally friendly product and by its application there is no concern of resistance as it is with conventional pesticides. The goal of the present research was to determine the effect of application of this product against Magnaporthe oryzae, the causal agent of rice blast. The efficacy of plant tonic against M. oryzae was evaluated through in vitro and in vivo experiments. Under in vitro conditions, application of plant tonic at all rates (2, 3, and 4 mL/L) could significantly inhibit the mycelial growth and conidial germination of fungus with the highest inhibition (83.63% and 95.15%, respectively) recorded by the rate of 4 mL. Plant tonic treatment (3 and 4 mL) was more effective than fungicide treatment (propiconazole 25% EC (0.1%); 250 ppm) to inhibit mycelial growth and conidial germination of M. oryzae. Under in vivo conditions, plant tonic application (4 mL) was also the most effective treatment and resulted in a significant reduction (57.12%) of the area under the disease progress curve (AUDPC) value as compared with the control. Application of plant tonic also caused increased accumulation of phenolic compounds and higher activity of peroxidase and polyphenol oxidase enzymes than the control. The maximum amount of phenolic compounds (0.49 mg Gallic acid equivalent/g leaf fresh weight) and the highest activity of the enzymes (1.24 and 7.85 Units/mL for peroxidase and polyphenol oxidase, respectively) were observed in plants treated with plant tonic (4 mL) and challenged with M. oryzae as compared with other treatments. No phytotoxicity was observed in plant tonic treated rice plants when compared with the control. Results of the present study confirmed the beneficial effects of plant tonic in controlling rice blast disease. Therefore, its application may help to develop appropriate management strategies and provide with the opportunity to have cleaner and safer environment for agriculture

    Effect of Refined Edible Oils on Neurodegenerative Disorders

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    Neurodegenerative diseases are comprise a prominent class of neurological diseases. Generally, neurodegenerative diseases cannot be cured, and the available treatments can only regulate the symptoms or delay the disease progression. Among the several factors which could clarify the possible pathogenesis of neurodegenerative diseases, next to aging as the main risk, the dietary related diseases are the most important. Vegetable oils, which are composed of triacyclglycerols as the main components and several other components in a trace amount, are the main part of our diet. This review aims to study the effect of refined or unrefined vegetable oil consumption as a preventive or aiding strategy to slow or halt the progression of neurodegenerative diseases. In the refining process, owing to the chemical materials or severe temperatures of the refining process, removal of the desirable minor components is sometimes unavoidable and thus a worrisome issue affecting physical and neurological health

    Influence of acid hydrolysis, saponification and sample clean-up on the measurement of phytosterols in dairy cattle feed using GC–MS and GC with flame ionization detection

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    The fortification of processed foods including dairy products is increasingly commonplace with phytosterols among many compounds used to improve the nutritional value of food products. It is also increasingly common practice for some dairy cattle feeds to be fortified for their potential to increase phytosterol levels in milk. In this study, a combined, streamlined protocol using acid hydrolysis, saponification and sample clean-up was developed to enable the rapid and reliable measurement of phytosterols. The method was developed with focus on streamlining the overall technique to make it suitable for commercial laboratories, to reduce labor and consumable costs, while maintaining accuracy. A total of 12 different feed types commonly used in the dairy industry were analyzed with the highest and lowest sterol contents found in cotton seed oil and tannin with average phytosterol contents of 256 and  0.99, the method was validated for milk to enable feed comparison studies with respect to the total phytosterol content in raw milk

    Some Qualitative and Rheological Properties of Virgin Olive Oil- Apple Vinegar Salad Dressing Stabilized With Xanthan Gum

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    Purpose: Lipid oxidation and rheological properties are the main qualitative parameters determined in food emulsions. Salad dressings are food emulsions important in our daily diet, but conventional salad dressings have high amounts of cholesterol and saturated fatty acids because of egg yolk in their formulations. There are many studies on the modification of salad dressing formulations to replace egg yolk and saturated fats. The present study describes new formulation of salad dressing with olive oil and apple vinegar to produce a functional food product. Methods: This study investigated the qualitative properties, oxidative stability, rheological behavior and microstructure of the salad dressing without egg yolk. Oil-in-water emulsions were prepared with virgin olive oil and apple vinegar stabilized with various percentages of xanthan (T1: 0.25%, T2: 0.5%. T3: 0.75%). Samples were stored at refrigerator for 90 days and experiments were performed at production day and during storage. Results: The obtained results showed that peroxide value was increased for all samples during storage, but it was at an acceptable level. Fatty acid changes were not significant during storage. Droplet size was reduced by increasing xanthan gum. T2 had the best rheological properties during storage. Generally, T2 and T3 had higher scores and were more acceptable in organoleptic assay. Conclusion: Obtained results showed that T2 had suitable qualitative and rheological properties and can be a proper egg yolk free salad dressing to introduce to the market

    Quality properties of sesame and olive oils incorporated with flaxseed oil

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    Purpose: Suitable ratio of essential fatty acids has an important role in maintaining good health. There is no pure oil with an ideal fatty acid composition and oxidative stability. The main goal of the present study was to evaluate the physical, chemical and nutritional properties of oil obtained by blending flaxseed oil as a rich source of ω3 fatty acids with sesame and olive oils. Methods: Three different ratios (65:30:5, 60:30:10 and 55:30:15) were prepared using olive, sesame and flaxseed oils. These mixtures were stored at 4°C and 24°C and their quality and physicochemical properties were determined by measuring the fatty acid composition, phenolic compound, peroxide, anisidine values and schaal tests. Results: Fatty acid composition indicated that adding 10% and 15% flaxseed oil into blends have suitable ratio of essential fatty acids. The sample which contained 5% flaxseed oil had the highest phenolic content among treatments and these compounds showed a significant decrease during storage. A significant increase (p < 0.05) was observed in peroxide values of all samples during storage. Increasing the flaxseed oil content in the blends, lead to an increase of the anisidine value. Conclusion: Blending sesame and olive oils with flaxseed oil produced oil blends with a good balance of essential fatty acids. Although peroxide and anisidine values increased during storage of the oil blends; the blends were of a good quality for home and industrial use
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