Changes in minor lipid components during interesterification

Fats and oils have limited applications in their natural form due to their specific chemical composition. To widen their application and functionality, they need to be modified. Interesterification is one of the modification processes used for this purpose and has advantages over hydrogenation which generates considerable amounts of undesirable trans fatty acids. Numerous studies describe changes occurring during interesterification in triacylglycerols and in physical and chemical properties of the end‐products. The few literature reports available have shown inconsistent results from a slight to extensive loss of tocopherols during the interesterification process. This paper provides information on the effects of interesterification on minor lipid components such as tocopherols, phytosterols and phytosterol oxidation products.     

Sterol fractions in hazelnut and virgin olive oils and 4,4′-dimethylsterols as possible markers for detection of adulteration of virgin olive oil

Reports on the methylsterol fractions of hazelnut oils are scarce. The objectives of this study were to characterize methylsterols in hazelnut and virgin olive oils and to study the possibility of detection of adulteration of virgin olive oils. In hazelnut oils, 4-desmethylsterols were present in higher proportions (86 to 91%) than in virgin olive oils where this fraction was ca. 50% of the total sterol. In the 4-monomethylsterol fraction, citrostadienol was the major component in both kinds of oils followed by cycloeucalenol and obtusifoliol in virgin olive oils, and obtusifoliol in hazelnut oils. 24-Methylenecycloartanol was predominant in both kinds of oils in the 4,4′-dimethylsterols. For the first time, δ-amyrin was tentatively identified by comparing published mass spectral data in the analyzed samples of both kinds of oils. An unknown compound X (containing a lupane skeleton) and lupeol were detected only in the 4,4′-dimethylsterols fraction of hazelnut oils at a level of 2–8 and 6–10%, respectively. GC-MS analysis showed that adulteration of virgin olive oil by hazelnut oil could be detected at a level less than 4% by using these two compounds as possible potential markers.     

A comprehensive review of the physicochemical,quality and nutritional properties of Nigella sativa oil

Nigella sativa L. is an annual herb of the Ranunculaceae family, with the seeds called black cumin seed or black seed containing 34–39% oil. Its oil has many uses in traditional medicine and food industry. Black seed oil is a significant source of essential fatty acids, tocopherols (91–246 ppm), phytosterols (1993?2182 ppm), polyphenols (245–309 ppm), essential oils and other bioactive compounds. Thymoquinone is one of the important active compounds in the essential oil part of black seed oil with many health beneficial properties. Black seed oil is getting much attention either used alone or in combination with other vegetable oils. Therefore, providing information about the black seeds originating in different parts of the world, their oil composition and the effect of different oil extraction methods can be of great value. Environmental condition, cultivated areas, maturity period and storage conditions have significant effects on its properties. Black seed oil deserves more attention as a potential multi-purpose product. This article reviews the physicochemical properties, quality, and medicinal and nutritional aspects of black seed oil.     

Execution examination of chaotic S-box dependent on improved PSO algorithm

Neural Computing and Applications - Achieving proper nonlinear properties and autocorrelation in the S-box structure is an open challenge in cryptography. Besides, there have been numerous articles...     

Free and Esterified 4,4′-dimethylsterols in Hazelnut Oil and their Retention During Refining Processes

Free and esterified forms of sterols provide detailed information on the identity and the quality of vegetable oils. In this study, 4,4′-dimethylsterols in free and esterified forms were investigated in hazelnut and virgin olive oils. Moreover, a sample of solvent-extracted hazelnut oil was refined at the laboratory to monitor the effects of processing on the levels of 4,4′-dimethylsterols. Generally, the level of total 4,4′-dimethyslterols was higher in the esterified form (49–68%) compared with that in free form (32–51%) of these compounds in the hazelnut oil. In virgin olive oil samples, cycloartenol and 24-methylenecycloartanol were present in higher amounts in free forms (70–80%) than in esterified forms (20–30%). Among the refining processes, degumming, deodorization, neutralization and bleaching, only neutralization and bleaching considerably reduced 4,4′-dimethylsterols. In fully refined hazelnut oil, 18 and 37% of lupeol and an unknown compound X in the esterified form were lost, respectively. The loss of these two compounds in the free form was considerably higher, 26 and 72%, respectively. GC–MS analysis showed that adulteration of olive oil with a sample of fully refined hazelnut oil could be detected at a level as low as 2% by tracing lupeol in total or only in esterified forms of 4,4′-dimethylsterols. Further studies on the levels of free and esterified 4,4′-dimethylsterols and their retention during refining processes are anticipated in hazelnut cultivars from different origins.     

Extraction of Oil from Roman Nettle Seed by Cold Press and Evaluation of its Quality during Storage

Roman nettle (Urtica pilulifera L.) is an annual plant whose seeds are rich in oil and valuable phytochemicals. In this study, oil from Roman nettle seeds is extracted by cold pressing and its quality is evaluated during storage at room temperature for up to 90 days. The seed moisture content is adjusted to 0%, 2.5%, 5%, 7.5%, and 10% (g 100 g⁻¹) to evaluate its effect on oil extraction yield. The highest oil yield (31.5%) is found in the seeds containing 5% moisture. Acid and peroxide values increase with both moisture content increase and during storage. Moreover, an increase in seed moisture content decreases the oxidative stability (from 8.1 to 6.3 h), carotenoids (from 25 to 14 mg kg⁻¹), chlorophylls (from 742 to 486 mg kg⁻¹), and phenolic contents (from 134 to 97 (mg caffeic acid per kg oil)) of the extracted oils. Fatty acid profile and phytosterols are not significantly influenced (p > 0.05) by the moisture content of the seeds and storage. Total phenol contents and γ-tocopherol levels increase during storage, but carotenoids, chlorophylls, and α-tocopherol levels decrease. Based on overall composition and quality parameters, Roman nettle seed oil may have potential food applications.     

Stability of Minor Lipid Components with Emphasis on Phytosterols During Chemical Interesterification of a Blend of Refined Olive Oil and Palm Stearin

Minor compounds such as tocopherols and phytosterols in vegetable oils play an important role in their stability and nutritional value. This study monitored the effects of chemical interesterification on the levels of tocopherols, tocotrienols, phytosterols and phytosterol oxidation products (POPs) in an olive oil and palm stearin blend (50/50 w/w). Tocopherols and tocotrienols were dominated by α-tocopherol (192 ppm) and γ-tocotrienol (70 ppm) and decreased during interesterification. Among the tocopherols, δ-tocotrienol had the highest decrease (35%) at 120 °C. During interesterification at 90 and 120 °C, total sterol content in the oil blend (509 ppm) declined slightly, by 3 and 5%, respectively. Phytosterols were esterified at a higher level at 120 °C (7%) than at 90 °C (4%) during this process. Distribution of fatty acids in the esterified sterols followed the fatty acid composition of the oil blend. Total POP content was 4.3 ppm, and remained generally unchanged during interesterification. Among the nine POPs tentatively identified by their mass spectra, 6-hydroxysitostanol and 6-hydroxycampestanol dominated in the oil blend and in the interesterified product. The formation pathways of these saturated di-hydroxyphytosterols have yet to be identified. Although the interesterification process comprised several treatments, there were only minor losses of tocopherols and phytosterols and virtually no increases in the POPs.