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This research aims to evaluate the antioxidant potential of oregano extract (OE), as well as its isolated and synergistic effect when applied to soybean oil (SO) under thermal oxidation.

In order to determine the antioxidant activity of oregano extract and its synergistic effect with tert‐butylhydroquinone (TBHQ), thermal oxidation was performed using the following treatments: SO, SO with 50 mg/kg of TBHQ, SO with 3,000 mg/kg of OE, and SO with 3,000 mg/kg of oregano extract and 50 mg/kg of TBHQ (mixture). The treatments underwent heating at 180°C for 20 hours, and analyses of oxidative stability, total polar compounds, tocopherols and fatty acids composition were performed. The results obtained were subjected to analysis of variance and Tukey test for averages at 5 percent, using the program ESTAT version 2.0.

Considering the results of antioxidant activity and total phenolic compounds, it was possible to verify that the ethanolic extract of oregano has presented antioxidant potential. Furthermore, considering the results obtained in the analyses of oxidative stability, polar compounds, tocopherols and fatty acids profile, it was possible to observe that the extract has prevented lipid oxidation when added to SO.

The study offers information on the use of natural antioxidants as an alternative to the use of synthetic antioxidants, which can be considered toxic.

Nigella sativa L. (black cumin) has a unique nutritional profile that can be employed in food formulation to improve health of consumers. Black cumin is already used in traditional medicines in Pakistan to treat various maladies like diabetes mellitus, gastrointestinal disorders, and as immune booster. The core objective of the present research study is to explore the role of black cumin fixed oil (BCFO) as a functional ingredient in cereal‐based bakery products.

The BCFO was supplemented in cookies' formulations and impact on nutritive quality, tocopherols and thymoquinone contents was studied.

The results indicated that addition of fixed oil influenced the physical characteristics of cookies significantly. Chemical attributes varied non‐significantly, but oxidative stability of the cookies was improved as indicated from decreased peroxide (POV) and TBA value. Gradual increase in BCFO in cookies formulations increased the amounts of total tocopherols significantly from 9.85 ± 0.392 to 53.19 ± 1.689 mg/kg‐oil. BCFO addition significantly enhanced α‐, β‐, γ‐, δ‐tocopherols i.e. 8.80±0.630 to 32.19±1.410, 0.96±0.035 to 3.47±0.114, 0.09 ± 0.000 to 14.98 ± 0.520, 0.00 ± 0.000 to 2.55 ± 0.127 mg/kg‐oil, respectively. Likewise, thymoquinone contents were recorded highest in cookies containing 5.0 @ BCFO (7.25 ± 0.482 mg/100 g) as compared to control. Moreover, cookies containing fixed oil @ 4% rated better on hedonic scale as compared with control by the trained taste panel during sensory evaluation.

The results of present research paved the way for the commercial applications of BCFO especially in cereal‐based products. Moreover, present intervention heightened the prospects of using black cumin seed oil in different food products that may produce healthy impact on end consumers.

The aim of this work is to synthesize neopentyl glycol oligoesters based on adipic acid and rapeseed oil (NOAR) which may be used as the renewable and environmentally acceptable base fluids to replace mineral oils in the future.

Oligomeric intermediates were synthesized in the first esterification of neopentyl glycol with adipic acid and characterized by Gas Chromatography-Mass Spectrometer (GC-MS) to calculate the average oligomerisation degree. NOAR were synthesized in the second esterification of oligomeric intermediates with rapeseed oil fatty acid. The effects of average oligomerisation degree on the viscosity, viscosity index, pour point, oxidative stability and biodegradability of NOAR were investigated; the tribological properties and thermal stability of NOAR were evaluated by four-ball tribometer and TGA, respectively.

Results show that with the increase of average oligomerisation degree from 2.10 to 4.34, the viscosity of NOAR increased from 101.1 to 182.0 (mm2/s) at 40°C and 18.3 to 30.1 (mm2/s) at 100°, respectively, and their oxidation stability can be improved as well. The yields of NOAR were 83.3-89.4 per cent, and the evaluated properties were as follows: viscosity index of over 200, pour point of below −43°C, biodegradation rate of more than 96 per cent, maximum non-seizure load (PB value) of 784 N, wear scar diameters of 0.40 mm and thermal decomposition temperature of higher than 300°C.

This work provides a method to synthesize rapeseed oil-based oligoesters which can serve as the renewable and environmentally acceptable base fluids with tunable viscosity by controlling the oligomerisation degree of esterification.

The purpose of this paper is to study a novel Mannich adduct of benztriazole-containing diphenylamine (coded as BD) and its anti-oxidation properties as an additive in two typical synthetic ester-based oils.

The anti-oxidation properties in two typical synthetic ester-based oils were evaluated in detail, using rotating pressure vessel oxidation test. The tribological properties of BD in synthetic ester-based oil (A51) were also tested with Optimal SRV-I oscillating friction and wear tester at atmosphere.

The results of tests demonstrated that the novel BD compound is, indeed, a high-performance anti-oxidation additive that was able to remarkably improve the oxidation stability of synthetic ester-based oils, when it was added at only 0.5 per cent concentration and compared with the base oils containing 0.5 per cent of the commercial available antioxidant additives such as 2, 6-di-tert-butyl-4-methylphenol and octyl-butyl diphenylamine. A plausible mechanism of exceptional synergistic anti-oxidation was proposed.

This paper first investigated the anti-oxidation properties and mechanisms of the compound with the structure of BD, which can be very useful and would promote the application of BD antioxidant in the lubricant industry.

This study aims to evaluate the effect of grape seed extract on the thermal oxidation of soybean oil.

Four treatments were used: soybean oil (SO), butylhydroxytoluene (BHT), antioxidant at concentration of 100 mg/kg in soybean oil (BHTSO), grape seed extract at a concentration of 100 mg/kg in soybean oil (Extract), and mixture at a concentration of 50 mg/kg of grape seed extract (Mixture) and 50 mg/kg of BHT in soybean oil subjected to 180°C for 20 h. The total phenolic compounds were quantified by spectrophotometry using the Folin-Ciocalteu reagent. The antioxidant activity was evaluated by the ABTS^•+, DPPH^• and FRAP acid systems. The fatty acid composition and phytosterols were determined by gas chromatography (GC) and tocopherols were determined by high-performance liquid chromatography.

Among the treatments studied, the Extract and the Mixture presented lower losses of total phenolic compounds, DPPH^• and FRAP, while BHTSO had an opposite effect. After 10 h of heating, the Mixture and the Extract were more effective in reducing the formation decomposition products, measured by the amount of total polar compounds. The Mixture resulted in higher retention of essential fatty acids at the end of heating. The Extract and Mixture showed higher retention rates of total tocopherols and the Mixture resulted in 338.71 mg/100 g (P ≤ 0.05) of total phytosterol after 20 h of heating.

Oils undergoing the heating process suffer major changes, requiring the addition of antioxidant compounds. As a result of the questioning on the use of chemical additives, research on natural antioxidants, as substitute to the synthetic ones, is increasing. Among the natural compounds with high antioxidant potential, the grape wastes such as its seeds are highlighted. Studies using grape seed extract are scarce.

Almond oil is a gourmet product with functional food characteristics owing to its high almond oil content and high nutritional quality. One of the primary constraints on its production is the lack of information regarding oil extraction from an industrial perspective, including by-products generation.

The performance, quality and composition characteristics were analyzed, both from the physical-chemical and organoleptic point of view, of the almond oils obtained through two pressure systems: screw press (SP) and hydraulic press (HP). To ensure the success of almond oil production at a commercial scale, in this work, an economic study of the costs of the process was carried out as a complementary part of optimizing the production of virgin almond oil.

Physicochemical analysis showed little difference, just in total sterols (HP 2069, SP 2153) and some quality indexes (K232: HP 1.63, SP 2.13; peroxide index: HP 1.74, SP 0.95), in contrast to sensory analysis. Consumer judges valued roasted almond oil extracted using a HP the best. The production cost of the oil extracted with the SP was €23.05/l. With the HP it was €25.13/l, owing to the lower oil yield in the extraction. The most expensive treatment was for the HP with toasted almonds (€27.76/l), owing to the greater need for processing.

Production costs derived from the method used have received little attention. This paper presents data that allow for the transference between academic and industrial ambit and their economic viability.

As a first example of the application of the cut‐out procedure to fuselage problems and the selection of appropriate cut systems, the elimination of a complete ring is discussed in detail. ‘Minimal’, ‘maximal’ and ‘dismembering’ techniques are all applied to singly and doubly connected rings, and attention is drawn to some inadmissible and critical combinations of cuts in order to guide the most effective choice. The second fuselage example treats similarly the removal of a portion only of the ring.

The effect of the addition of red palm olein (RPO) as a natural antioxidant to sunflower (SF) on chemical properties and deep-frying oxidative stability of resultant oil during storage.

RPO was added to SF at different levels 0, 5, 10, 15, 20, 25, 50, 75 and 100 (w/w), and potato chips were fried in oil blends repeatedly at 180 °C for 2.5 min for five days to evaluate the effect on chemical properties and oxidative stability.

The results revealed that linoleic acid and total polar compound (TPC) contents decreased in all RPO and SF resultant oil after five days of storage. Colour significantly (p = 0.05) decreased, while peroxide and iodine values were significantly lowered during storage. The oxidative stability increased significantly in the resultant oil. However, an increase in free fatty acid (FFA) before frying significantly reduced with repeated frying of resultant oil during storage. RPO (5–75%) therefore retards oxidative rancidity in the resultant oil after repeated deep frying and storage.

SF oil is high in polyunsaturated fatty acids but prone to oxidation upon heating and storage. RPO is an important ingredient used in industrial frying rich in phytonutrients and a better replacement to synthetic antioxidants. This study indicated that supplementing SF oil with RPO may be recommended to improve the oxidative stability of oils during frying.

The purpose of this study is to explore the possibility of utilization of lemon peel extract as a natural antioxidant source in muscle foods. The products incorporated with lemon peel extract were assessed for various oxidative stability and storage quality parameters.

The study was designed to evaluate the effect of lemon peel extract on the oxidative stability and storage quality of Tabak-Maz, a popular traditional meat product. The products were prepared and treated with different concentrations of lemon peel extract (0.5, 1, 1.5 per cent) and were aerobically packaged in low-density polyethylene pouches and assessed for lipid stability and storage quality parameters under refrigerated (4 ± 1°C) conditions.

Lemon peel extract showed a significant (p < 0.05) effect on the lipid stability of the products as the treated products exhibited significantly (p < 0.05) lower thiobarbituric acid-reactive substances (TBARS) (mg malonaldehyde/kg) and free fatty acid (FFA) (per cent oleic acid) values for the entire period of storage. A significant (p < 0.05) effect was also observed on the microbiological characteristics of the products, as lemon peel extract treated products showed significantly (p < 0.05) lower values for total plate count, psychrophillic count and yeast and mould count throughout the period of storage. Coliforms were not detected throughout the period of storage. Significantly (p < 0.05) higher scores were observed for various sensory parameters of the treated products.

Lemon peel extract successfully improved the oxidative stability and storage quality of Tabak-Maz during refrigerated (4 ± 10°C) storage and may be commercially exploited as a natural antioxidant source in muscle foods.