The impact of Senjed (Elaeagnus angustifolia L.) peel aqueous extract on qualitative properties of cold-pressed sesame oil

The Senjed peel aqueous extract was added to sesame cold-pressed oil at different concentration of 0, 100, 200, 500 and 750 mg/kg and compared with TBHQ (200 mg/kg). The Senjed peel aqueous extract showed 9.55 ± 0.35% extraction yield, 58.17 ± 2.33% antioxidant activity, 573.31 ± 3.57 (mg GAE/100 g FW) total phenolic content, and 151.33 ± 2.67 (mg CAE/100 g FW) total flavonoid content. The extract preserved 59.08% of antioxidant activity after heating at 185 ℃ for 80 min. Increasing the concentration of the extract caused a significant (p<0.05) qualitative improvement in the oil samples. At all storage times, the highest FFA%, peroxide and P-anisidine value belonged to oil samples containing 0 ppm of Senjed peel aqueous extract and followed by 100, 200, 500 and 750 ppm, respectively. The highest oxidative stability index was observed in oil samples containing TBHQ and 750 mg/kg concentration of extract (both 15.39 h). Oil samples containing 750 ppm of Senjed peel aqueous extract and TBHQ showed almost similar qualitative characteristics. Results showed that Senjed peel aqueous extract have antioxidant potential for stabilization of oils.

Prediction of Walnut Deterioration Using Kernel Oxidative Stability

Monitoring walnut oxidation is essential to control walnut quality during storage. An accelerated oxidation method for differentiating the oxidative stability index (OSI) of walnut kernels was examined and the effects of instrument operational parameters such as temperature and airflow were evaluated. Four cultivars, Chandler, Solano, Durham, and Howard were analyzed at 110, 120, and 130 °C with 15, 20, and 25 L h−1 airflow. Analysis using 110 °C with 25 L h−1 yielded the lowest coefficients of variance (4.4) than other operational parameters; analysis using the same temperature at lower airflow, 15 L h−1, yield the highest coefficient of variance (10.5). Kernel OSI values were independent of airflow, however, dependence of temperature coefficient and Q10 were demonstrated. The results from selected parameters were correlated with fat and moisture content, peroxide value, UV absorbances, oil oxidative stability, hexanal, and rancidity to establish the relationships between OSI values and quality changes during storage. Using 0.5 g of ground kernels, at 110 °C with 25 L h−1 airflow gave a lower coefficient of variance and higher correlation with kernel quality and oxidative markers comparing to other combinations of operating parameters.

Characterization of Biodiesel from residual friture oil, sunflower, through the ethanolic base transesterification process

The conservation of the environment is becoming a global concern for the use of fuels from fossil waste, and the production of biodiesel from renewable sources is being considered as an eco-friendly alternative since oleaginous organic waste presents potential as Energy condition An important aspect is to minimize the impacts generated by this waste under different conditions, and an operation related to the aspect is the elaboration and comparison of biodiesel obtained from residual frying oils with biodiesel produced with sunflower oil through the transesterification process based on ethanol. The evaluation was carried out on a laboratory scale with parameters and specifications found in the Peruvian Technical Standard for Biodiesel (NTP-321.12-200-2008), with the exception of water content, and the oxidative stability index (IEO). The following results were obtained 739.7 mg / kg and 1.5 hours and these do not meet the standards whose minimum reference corresponds to 500 mg / kg and 3 hours, respectively. The yield of residual oil and sunflower corresponds to 68.5% and 85.2% respectively. The research work establishes that the production of biodiesel from residual frying oil by the ethanol-based transesterification process is significantly less than the process with sunflower oilseeds, showing greater performance and stability.

Preliminary Study: Comparison of Antioxidant Activity of Cannabidiol (CBD) and α-Tocopherol Added to Refined Olive and Sunflower Oils

This study evaluates the antioxidant activity of cannabidiol (CBD), added to model systems of refined olive (ROO) and sunflower (SO) oils, by measuring the peroxide value, oxidative stability index (OSI), electron spin resonance (ESR) forced oxidation, and DPPH• assays. Free acidity, a parameter of hydrolytic rancidity, was also examined. CBD was compared using the same analytical scheme with α-tocopherol. CBD, compared to α-tocopherol, showed a higher scavenging capacity, measured by DPPH• assay, but not better oxidative stability (OSI) of the oily systems considered. In particular, α-tocopherol (0.5%) showed an antioxidant activity only in SO, registered by an increase of more than 30% of the OSI (from 4.15 ± 0.07 to 6.28 ± 0.11 h). By ESR-forced oxidation assay, the concentration of free radicals (μM) in ROO decreased from 83.33 ± 4.56 to 11.23 ± 0.28 and in SO from 19.21 ± 1.39 to 6.90 ± 0.53 by adding 0.5% α-tocopherol. On the contrary, the addition of 0.5% CBD caused a worsening of the oxidative stability of ROO (from 23.58 ± 0.32 to 17.28 ± 0.18 h) and SO (from 4.93 ± 0.04 to 3.98 ± 0.04 h). Furthermore, 0.5% of CBD did not lower dramatically the concentration of free radicals (μM) as for α-tocopherol, which passed from 76.94 ± 9.04 to 72.25 ± 4.13 in ROO and from 17.91 ± 0.95 to 16.84 ± 0.25 in SO.

Selenium in Germinated Chickpea (Cicer arietinum L.) Increases the Stability of Its Oil Fraction

Selenium is an essential mineral in human nutrition. In order to assess its effect on the stability of chickpea oil, seeds were germinated and tested with different amounts of sodium selenite (0.0, 0.5, 1.0 and 2.0 mg/100g seeds) for four days. Oil was extracted from sprouted chickpea and its physical properties, fatty acid profile (FAME), oxidative stability index (OSI), lipase and lipoxygenase (LOX) activities, cellular antioxidant activity (CAA), and phenolics and carotenoids were assessed and compared to chickpea seed oil. The amount of chickpea oil and its acid value (AV) increased during germination. The OSI increased by 28%, 46% and 14% for 0.5, 1.0 and 2.0 mg/100g compared with non-selenium treated sprouts. Phenolics increased up to 36% and carotenoids reduced by half in germinated sprouts with and without selenium compared to seeds. Carotenoids increased by 16% in sprouts treated with 1.0 mg/100 g selenium compared to their counterparts without selenium. FAME was not affected by treatments but samples with the highest selenium concentration increased lipase activity by 19% and decreased lipoxygenase activity by 55% compared with untreated sprouts. The CAA of oils increased by 43% to 66% in all germinated treatments compared with seeds. Results suggest that Se-enriched chickpea sprouts could represent an excellent source of oil with a high OSI and CAA, associated with a reduction in LOX activity and an increase in phenolics, respectively.

The impact of saturated monoacylglycerols on the oxidative stability of Canola oil under various time/temperature conditions

Due to the inconsistency of monoacylglycerols’ (MAGs) impacts and the lack of research concerning the weight of saturated monoacylglycerols on the oxidative stability of oils, the current study was designed. For this purpose, saturated MAGs at 0.5, 3.0 and 5.0% were added to canola oil and subsequently exposed to a Schaall oven test at 60 °C for 31 days (to assimilate moderate thermal conditions and a prolonged treatment time) and a Rancimat test at 110 °C (to assimilate extreme thermal conditions and shorter treatment time). To evaluate the quality and oxidative stability parameters of MAG-containing canola oil, free fatty acids (FFA), peroxide value (PV), and the oxidative stability index (OSI) were determined. The findings indicated that with the increase in MAG levels, the FFA increased from 0.05 up to 0.2%. The PV increased from 2 to 100 meq/L with the increase in MAG concentration. Also, it was shown that OSI increased from 12.20 to 13.10 h, which was proportional to MAG concentration.

Evolution of Frying Oil Quality Using Fourier Transform Near-Infrared (FT-NIR) Spectroscopy

This study assesses the capacity of a Fourier transform near-infrared (FT-NIR) spectrometer operating in the range 4500–12 000 cm−1 (833.33–2222.22 nm) to provide quantitative predictions for the parameters of acidity (AV), p-anisidine (pAV), total polar materials (TPM), peroxide value (PV), and oxidative stability index (OSI). 562 samples of frying oil were analyzed from 14 distinct types of oil. The calibrations obtained accounted for 96%, 95%, 99%, 92%, and 91% of the AV, pAV, TPM, PV, and OSI variations in the study set and the similarity between the standard error of laboratory (RMSEP) values and the reference method errors (RMSEL), enabling the authors to conclude that NIR technology has the capacity to replace traditional methods in thermo-oxidative degradation studies in frying oils.

Potentials of enhancing the physicochemical and functional characteristics of Nigella sativa oil by using the screw pressing technique for extraction

In the current investigation the crude oil of Nigella sativa was extracted from seeds using hydraulic and screw pressing techniques. Different parameters were evaluated in order to find out the appropriate technique to enhance the physicochemical and functional-related characteristics of the extracted crude oil. Results showed that the acid and peroxide values were significantly lower in the screw pressed oil (SPO) than in the hydraulic pressed oil (HPO). The total phenolic content of the SPO was significantly higher than that of HPO. Evaluation of the oxidative stability using the Rancimat test showed that SPO recorded a much higher oxidative stability index (40.07 h) than HPO (0.51 h). The yield of the volatile oil fraction and its contents of thymoquinone isolated from the SPO were higher than that from the HPO. Biological evaluation revealed that the SPO had significantly higher antimicrobial activity than HPO against Listeria monocytogenes and Staphylococcus aureus at 40 μL/well.