Oxidative Stability Index Research Articles

Chemical Compositions of Walnut (Juglans regia L.) Oils from Different Cultivated Regions in China

AbstractThis study is a comprehensive report on the quality of Chinese walnut oil, which enriches the research of oil resources. A total of 16 walnut samples from China were selected, and walnut oils were obtained using the pressing process. The lipid compositions and micronutrient contents were analyzed. The fatty acids corresponded to palmitic acid (3.05–8.25%), oleic acid (12.56–26.03%), linoleic acid (51.21–68.97%), and linolenic acid (6.83–15.01%), and the main triacylglycerols were trilinolein (27.87–39.47%), followed by oleoyl‐linoleoyl‐linolenoyl‐glycerol (17.07–24.18%), dilinoleoyl‐oleoyl‐glycerol (9.65–15.46%), palmitoyl‐dilinoleoyl‐glycerol (5.96–14.98%), and dilinoleoyl‐linolenoyl‐glycerol (6.42–12.43%). In addition, high amounts of micronutrients, including phytosterol, squalene, tocopherol, and total phenolic content, were found in walnut oils ranging from 540 to 1594, 17 to 131, 345 to 1280, and 1.04 to 20.39 mg kg−1 among different samples, respectively. The differences in the geographical location and climate caused different regions of cultivation, which resulted in the differences in the chemical composition of walnut oil. Further multiple linear regression analyses between oxidative stability indices, fatty‐acid compositions, and micronutrients revealed that linoleic acid (R = −0.891; P < 0.05), α‐tocopherol (R = 0.713; P < 0.05), and total phenolic content (R = 0.369; P < 0.05) were the main factors that affect the oxidative stability of the walnut oil.

Oxidative stability of flaxseed oil: Effect of hydrophilic, hydrophobic and intermediate polarity antioxidants

Oxidative deterioration is a major issue limiting the utilization of flaxseed oil (FSO). Present study explored the effects of hydrophilic (tannic acid), hydrophobic (alpha-tocopherol), and intermediate polarity (ascorbyl palmitate) natural antioxidants, which displayed highest DPPH radical scavenging and iron chelating abilities among several others, on the oxidative stability of FSO. A synthetic antioxidant (TBHQ) was also used as a control. FSO oxidation was examined by peroxide and p-anisidine values during 30-day storage at 25, 40 and 60 °C, and by accelerated oxidation using a rancimat at 110 °C. On mass concentration basis, all natural antioxidants were less effective than TBHQ. Irrespective of the polarity, all natural antioxidants, except alpha tocopherol, delayed primary and secondary oxidation, and increased the oxidative stability index. The alpha-tocopherol displayed pro-oxidant effect at all concentrations. Rather than polarity, antioxidant capacities, and their ability to replace minor components from the oil-water interface were crucial for the protection of FSO.

Temperature-Controlled Pulsed Light Treatment: Impact on Aflatoxin Level and Quality Parameters of Peanut Oil

Peanuts are an economically significant crop that is commonly used for edible oil production; however, they are prone to contamination by aflatoxin (AFT)-producing fungi. Common methods to treat edible oils for AFTs often utilize high temperatures (> 100 °C) to thermally degrade the toxins. However, high temperatures often negatively impact product quality. In this study, pulsed light (PL) was assessed as a possible method to degrade AFTs in peanut oil. A pilot-scale PL applicator was used to treat 5-mL samples of peanut oil of 10 mm thick. Samples were treated for 1 to 10 min with or without temperature reduction (TR). The sample containers were placed in an ice water bath to mitigate increases in oil temperatures for the TR samples. The physical, color, and chemical quality parameters (peroxide value, free fatty acid, acidity value, and oxidative stability index (OSI)) of the oil were assessed in comparison to controls. Results show that significant AFT destruction was achieved using PL. There was a significant difference between reduction achieved when TR was employed, likely due to the combined effect of photochemical and thermal treatment. TR samples treated for 400 s experienced an AFT reduction of 48.4%, while those treated 600 and 800 s achieved 55.6 and 78%, respectively. The samples treated with TR showed lower quality degradation when compared to peanut oil samples treated without TR for equivalent treatment times. Using TR, PL resulted in a significant reduction of AFT, without losses in quality typically associated with thermal methods. At industrial scale, PL may offer an economical treatment of AFT-contaminated oil.

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.

Evaluation of antioxidant properties of lemon verbena (Lippia citriodora) essential oil and its capacity in sunflower oil stabilization during storage time.

In this study, lemon verbena essential oil as a natural antioxidant was used to increase the stability of sunflower oil, and stabilization effects in terms of storage conditions were compared with synthetic antioxidant (BHT). For this purpose, the antioxidant activity of the essential oil was determined by DPPH assay and β‐carotene bleaching method. Then, lemon verbena essential oil (0, 400, 800, and 1,600 ppm) was added to sunflower oil without synthetic antioxidant and stored at 60°C for 60 days. Results from different parameters (peroxide value, free fatty acid, iodine value, total polar compound, carbonyl value, conjugated dienes, and oxidative stability index) were in agreement with each other, suggesting that lemon verbena essential oil (1,600 ppm) could act better than BHT in inhibition of lipid oxidation in sunflower oil and can be used as predominant alternative of synthetic antioxidants.

Characteristics of Chamaerops humilis L. var. humilis seed oil and study of the oxidative stability by blending with soybean oil.

Herein we examine the characteristics of date seed oil extracted from Chamaerops humilis L. var. humilis seeds (HSO) cultivated in a gardening zone in Tunisia. Its physicochemical properties, fatty acid composition, and thermal and antioxidant properties were evaluated and compared with those of seed oil from another variety of Chamaerops humilis. The results showed that HSO possessed higher contents of oleic (44%) and linoleic (20%) acids than the other seed oil. The total tocopherol and tocotrienol content was 88mg/100g oil, where α-tocotrienol (64%) was the major isomer. The total phenolic (91μg/g oil) and flavonoid contents (18μg/g oil) of the HSO were determined, and its antioxidant capacities, measured in terms of ABTS and DPPH radical-scavenging capacities, were 210µM TEAC/g DW and 4.3mM TEAC/g DW, respectively. The oxidative stability index (OSI) of the oil was 16h at 110°C. Furthermore, the OSI of soybean oil was significantly enhanced upon blending with HSO. HSO exhibited higher thermal stability than the other oils and significantly different thermal behavior. The determination of fatty acid composition, physicochemical properties, bioactive content, oxidative stability, and thermal behavior of HSO demonstrated that this renewable resource can be used for edible purposes.

Sapucaia nut (Lecythis pisonis Cambess) and its by-products: A promising and underutilized source of bioactive compounds. Part I: Nutritional composition and lipid profile

The nutritional composition of the sapucaia nut, cake and shell, the nut and cake minerals content and the lipid profile of the nut oil (fatty acids, tocopherols, phytosterols and triacylglycerols) were determined. The nuts and cake exhibited a high content of lipid (47.9 to 60.8 mg 100 g−1), protein (15.8 to 19.5 mg 100 g−1), dietary fiber (16.5 to 22.6 mg 100 g−1) and provided an excellent source of selenium (26.4 to 46.94 μg g−1). The oil contained a high amount of unsaturated fatty acids (39.7 to 45.4% of oleic and 32.2 to 46.6% of linoleic acids) and presented a high Oxidative Stability Index (8.57–12.95 h) indicating the presence of antioxidant compounds in the oil. The major triacylglycerols in the sapucaia oil were LLO, PLO, LOO, POO, OOO, PLL and LLL. The main bioactive lipids identified in the oil were γ-tocopherol (19.2 to 28.5 mg 100 g−1) and β-sitosterol (92.8 to 194 mg 100 g−1). The results showed that the sapucaia nut and its by-products are a promising natural source of bioactive and nutritional compounds and when present in the diet can contribute to the maintenance of human health. In addition, the nut and by-product represents a promising raw material for the food industry.

Experimental investigation on improvement of storage stability of bio-oil derived from intermediate pyrolysis of Calophyllum inophyllum seed cake

Due to the unstable nature of bio-oil, it becomes mandatory to analyze the changes in physical and chemical properties of the bio-oil during storage to appreciate its chemical instability, for developing stabilization strategies. The present study aims to investigate the oxidative and thermal stability of bio-oil extracted from pyrolyzing Calophyllum inophyllum (CI) deoiled seed cake in a fixed bed reactor at 500 °C under the constant heating rate of 30 °C/min. Each stability analysis method involve an accelerated aging procedure based on standards established by ASTM (D5304 and E2009) and European standard (EN 14112). Fourier Transform Infrared Spectroscopy and Gas Chromatography-Mass Spectrometry were employed to analytically characterize the un-aged and aged bio-oil samples. The results clearly depict that stabilizing Calophyllum inophyllum bio-oil with 10% (w/w) methanol improved its stability than that of the crude sample. Addition of methanol reduced the change in viscosity of bio-oil by 38.55% during accelerated aging process. The oxidation stability index of bio-oil stabilized with methanol was found to be 3.97 h which is in accordance with ASTM D6751. FT-IR and GC-MS results showed an increase in the relative concentration of C-O (carboxylic acids, ethers and esters) and C=O (carbonyl) functional groups in aged bio-oil samples.

Improving Storage Stability of Pistachio Oil Packaged in Different Containers by Using Rosemary (Rosmarinus officinalis L.) and Peppermint (Mentha piperita) Essential Oils

In this study, the antioxidant capacity of rosemary (REO) and peppermint (PEO) essential oils along with butylated hydroxytoluene (BHT) is investigated on oxidative stability of pistachio oil packaged in glass and polyethylene terephthalate (PET). The essential oils (EOs) and their mixture are added at 1500 and 3000 ppm concentrations into the oil stored for 80 days at 60 °C under darkness. In order to evaluate the efficacy of antioxidants, peroxide value (PV), thiobarbituric acid, total phenolic compounds, oxidative stability index (OSI), conjugated dienes and trienes, free fatty acids (FFAs), and iodine value is measured at intervals of 20 days. The results show that natural antioxidants can reduce PV and FFA levels about five‐ and threefolds compared to control, respectively. The OSI in raw pistachio oil (16 h) reduces to 5 h, while in treated sample by REO the reduction is only to 13 h after storage. Generally, the results reveal that in all measured parameters, following order can be observed for antioxidant activity: 3000 ppm REO>3000 ppm PEO>100 ppm BHT >1500 ppm REO >1500 ppm mixed >1500 ppm PEO > control. Moreover, the findings show that glass container is better than PET to retard oxidation process.Practical Application: Pistachio oil is known as a functional and commercial oil that is susceptible to oxidation due to its high level of unsaturated fatty acids. In this work, rosemary and mint essential oils as natural antioxidant are applied for improving oxidation stability of pistachio oil.Antioxidant capacity of rosemary (REO) and peppermint (PEO) essential oils is investigated on oxidative stability of pistachio oil packaged in glass and polyethylene terephthalate (PET). The essential oils are added at 1500 and 3000 ppm concentrations into the oil stored for 80 days at 60 ºC under darkness. The results reveal that in all measured parameters, following order can be observed for antioxidant activity: 3000 ppm REO >3000 ppm PEO >100 ppm BHT >1500 ppm REO >1500 ppm mixed >1500 ppm PEO > control. The findings show that glass container is better than PET to retard oxidation process.

Frying performance of two virgin oils from <em>Cornicabra</em> olives with different ripeness indices

The frying performance of two virgin olive oils (VOO) from Cornicabra olives of different ripeness indices, 2.08 for VOO1 and 4.13 for VOO2, was evaluated. Thermal, oxidative and hydrolytic alterations were determined throughout 40 frying operations with potatoes. The initial oils showed similar fatty acid compositions and oxidative stability indices as determined by Rancimat, but VOO1 presented higher amounts of total polyphenols and tocopherols. The oils showed high and similar frying performance. No significant differences in the levels of polar compounds (PC) were found between the two oils during frying. Therefore, the frying stability of Cornicabra VOOs appears to be unconnected with olive fruit ripeness. The limit of degradation at 25% PC as established in different countries was calculated to occur at 55 frying operations in the two oils. As oil toxicity is related to the levels of compounds formed, the use of Cornicabra VOOs for frying is highly recommended.

Characteristics of palm mid-fractions produced from different fractionation paths and their potential usages

ABSTRACTThree palm mid-fraction (PMF) groups produced from different fractionation paths were analyzed in terms of the fat, triacylglycerol and sn-2 fatty acid compositions, thermal properties (melting and crystallization behaviors, and solid fat contents (SFCs)), micronutrient levels and oxidative stability indexes (OSIs) to achieve their sufficient utilization. PMF-A (iodine value (IV), 48.4 g/100 g) fractionated from palm olein contained 43.8% 1,3-dipalmitoyl-2-oleoyl-glycerol (POP) and 16.7% 1-palmitoyl-2,3-dioleoyl-glycerol, showing soften properties (slip melting point (SMP), 27.6°C; SFC at 30°C, 2.2%) at hot weather. PMF-B (IV, 42.3 g/100g) obtained from palm stearin showed similar fat and triacylglycerol compositions as PMF-A, but the high 1,2,3-tripalmitoyl-glycerol level (6.2%) improves its thermal behaviors (SMP, 34.9°C; SFC at 30°C, 13.8%). The SFC profiles of PMF-A and PMF-B were comparable to those found in frozen and puff margarine shortenings. Furthermore, both of the PMF groups exhibited excellent OSIs (13.2 and 11.2 h, respectively) because of their high micronutrient levels (especially γ-tocopherol and campesterol). In general, γ-tocopherol and campesterol contribute to preventing lipids from oxidation under frying conditions. Therefore, PMF-A and PMF-B are recommended for manufacturing margarine shortenings and frying fasts. PMF-C (IV, 33.0 g/100g) produced from the additional fractionation of PMF-A or PMF-B contained the highest POP percentage (67.1%) and showed heat-resistant property (SMP, 31.8°C; SFC at 30°C, 22.4%). Its steep SFC profile was superior to that of cocoa butter, suggesting the fat is preferred in producing hard chocolate fats.

Quality Characterization and Oxidative Stability of Camellia Seed Oils Produced with Different Roasting Temperatures.

In this study, the effects of roasting camellia (Camellia oleifera Abel.) seed oils at different temperatures (65°C, 100°C, 120°C, and 140°C) on the oxidative stability and composition of the oils were investigated. The results showed that, in terms of the quality of the oils, the roasting temperature influenced the total phenolic content (which ranged from 1.64～2.45 GAE mg/g for the different oils) and total flavonoid content (which ranged from 0.36～0.45 QE mg/g for the different oils), while the fatty acid profile and tocopherol content were not influenced by the roasting temperature. We also investigated the kinetic parameters of camellia seed oil during oxidation via Rancimat (at temperatures ranging from 110~140°C). It turned out that the natural logarithms of the oxidative stability index (OSI) varied linearly with respect to temperature (R2: 0.958～0.997). This was done on the basis of the Arrhenius equation that indicates that the activation energies (Ea) for oxidative stability are 65.7～78.4 KJ/mol. Simultaneously, we found that increasing the roasting temperature could increase the antioxidant stability of Maillard reaction products in camellia seed oil. The effects of roasting include the assurance that the camellia seed oil so produced will comply with the relevant governmental health codes and standards and have a longer shelf life.

Antioxidant recovery from hydrodistillation residues of selected Lamiaceae species by alkaline extraction

Aqueous solution of potassium hydroxide (KOH) was used in order to obtain rich in antioxidant activity extracts from Origanum dictamnus, Origanum hirtum, Origanum onites, Rosmarinus officinalis and Satureja thymbra, after removal of the essential oil via hydrodistillation. The increase of extraction time induced lower values of total phenolic content and DPPH radical scavenging ability of the extracts, while lower alkaline concentrations, i.e. 1% and 3%, proved to be more effective than 5% (v/w) KOH. The antioxidant activity of the extracts in sunflower oil was also measured by the oxidative stability index (OSI) method. OSI values decreased as extraction time increased, while the effect of KOH concentration at short extraction time was not significant. S. thymbra, O. hirtum and R. officinalis extracts showed high total phenolic content and good antiradical and antioxidant activity in just 30 min of extraction with KOH 1% (w/v). LC–MS analysis showed that all extracts were rich in phenolic acids, such as caffeic acid and rosmarinic acid, while R. officinalis was also rich in carnosic acid.

High Power Ultrasound: Impact on Olive Paste Temperature, Malaxation Time, Extraction Efficiency, and Characteristics of Extra Virgin Olive Oil

High power ultrasound (HPU) provides rapid heating of olive paste and disrupts cell walls, helping small oil droplets exit tissue and coalesce. This has been shown to improve oil yield and reduce malaxation time without affecting oil quality. Indirect and direct HPU at different treatment times were examined on Arbequina and Frantoio olive pastes. Olive pastes were mixed at four different malaxation times to evaluate extraction efficiency. Additionally, oil yield and different quality parameters were observed. HPU increased olive paste temperature from 20 ± 0.5 to 25.5 °C, achieving the optimum kneading temperature of 29 ± 1 °C in less mixing time. HPU significantly (P 0.05) in oil yield between 35 and 45 min malaxation time, suggesting the possibility to reduce malaxation by 10 min with HPU. No significant differences (P > 0.05) were observed in any quality parameters observed, except peroxide value, which increased slightly. Significant increases (P < 0.05) in total tocopherol and pigments with increasing HPU treatment time occurred, while a decrease in total polyphenol and oxidative stability index resulted after 8 min treatment. HPU influenced L, a, and b values causing the oil to become darker. Sensory results showed no differences between commercially available and HPU-treated samples. These results suggest the possibility of using HPU treatment to increase oil extraction capacity and yield without loss of product quality.

A preliminary Rancimat-based kinetic approach of detecting olive oil adulteration

Temperature coefficients (TC and Q10 number) and the parameters of Arrhenius equation (frequency factor, A, and activation energy, Ea) and activated complex theory (enthalpy, ΔH++, and entropy, ΔS++) based on the oxidative stability indices (OSI, by Rancimat test at 100–130 °C) were used to detect the adulteration of olive (Zard and Roghani cultivars) oils with 10–30% of palm olein, PO, and sunflower oil, SO. An adulteration index, AI (h2), which encompassed the more pervasive parameters of maximum sensitivity to the presence of adulterating oils, comprised of the OSI at 100 °C and the values of A and Ea was developed. The AI for the unblended Zard and Roghani oils was calculated to be 18.9 and 26.5 h2, respectively. These quantities increased quite remarkably by adding the different levels of PO (Zard: 180–2247%, Roghani: 185–2146%) and SO (Zard: 1229–9343%, Roghani: 542–1401%).

Effects of Different Pretreatments to Fresh Fruit on Chemical and Thermal Characteristics of Crude Palm Oil.

This study selected 5 methods, including boiling, hot air drying, high-pressurized steam, freezing, and microwave radiation to pretreat fresh oil palm fruit before solvent extraction of the oil. Using fresh fruit as a control, the pretreatment methods were compared for the effects on the activity of the 2 main enzymes in the fruit and some physicochemical properties of the crude palm oil. The results indicated, although all the 5 pretreatments could inactivate lipase and peroxidase in the treated flesh significantly (P < 0.05), the high-pressurized steam was the most effective. There were also differences in the unsaturated fatty acid contents of the 6 oils. The crude oil from frozen fruit contained significantly more vitamin E (37829.33 ppm) than previously reported. Microwave radiation was shown to significantly decrease the free fatty acid content and the peroxide value, while increasing the oxidative stability index. Thermal behaviors of the oils were significantly different to each other with the exception a few parameters (P < 0.05).

Quantitative Indices of the Oxidizability of Fatty Acid Compositions

The correlation between a wide range of fatty acid composition indices, resulted from different groups of purified edible oils and their binary blends, and two quantitative criteria of primary (induction period of hydroperoxide formation at 60 °C) and secondary (oxidative stability index, OSI, at 100 °C) oxidations was evaluated. On the basis of highly correlated linear regression models, a corrected form of calculated oxidizability index and the content of saturated fatty acids, SFA, were jointly found to be appropriate indices of primary oxidative stability of all vegetable oils whereas the ratio between palmitic and linoleic acids was mainly considered to show their secondary oxidative stability. As for the oils containing fish oil (FO), a combination of SFA/(C18:4 + C20:4 + C20:5 + C22:6), and monounsaturated fatty acids/(C18:2 + C18:3) ratios was used to represent the primary and secondary oxidative stabilities. Among the oils containing vegetable oils and even fish oil, canola oil, and its blends had the best fatty acid composition from a health point of view. Practical Application: Since edible oils have a vast diversity in fatty acid compositions of very different oxidative stability, prediction of oxidizability based on fatty acid compositions has become too complicated. Considering primary and secondary oxidation products over the course of lipid oxidation, the present study simplifies the prediction of the oxidative stability of fatty acid compositions by introducing four predictive linear regression models for vegetable and fish oils.Oxidative stability of five different edible oils and their binary blends are determined through the induction period (IP) of hydroperoxide formation and the oxidative stability index (OSI) at 60 and 100 °C, respectively. Considering a range of linear regression models between fatty acid composition indices and the oxidative stability quantities, IP and OSI, four linear regression models of highest correlation were obtained to simplify the prediction of oxidizability of diverse fatty acid compositions.

Synergetic effects of essential oils mixture improved egg quality traits, oxidative stability and liver health indices in laying hens fed fish oil

Omega-3 fatty acids are necessary for human health, although products containing higher proportions of these fatty acids make them more susceptible to lipid peroxidation. The current study was conducted to evaluate the synergetic effects of dietary supplementation of herbal essential oils mixture (Thymus vulgaris, Mentha piperita, Rosmarinus officinalis and Anethum graveolens) and dietary fat sources on egg quality traits, oxidative stability and liver health indices of laying hens. A total of 150 laying hens were randomly distributed among 6 experimental treatments with five replicates of five birds each. Dietary treatment consisted of three levels of herbal essential oils mixture (0, 100 and 200mg/kg) and two sources of fat (fish oil and soybean oil containing different ratios of n-6 to n-3 fatty acids) that fed during an 80 d feeding trial. The results showed that administrating fish oil, containing low ratio of n-6 to n-3 fatty acids, enhanced liver (P<0.05) malondialdehyde concentration, egg yolk color (P<0.05), and led to the reductions in liver relative weight, hepatic lipid percentage (P<0.05), serum alkaline phosphatase activity (P<0.01), as well as serum and egg yolk cholesterol contents (P<0.05). Moreover, herbal essential oils mixture resulted in the declines in blood cholesterol and triglyceride concentrations (P<0.01), enzymes activity of alanine aminotransferase and aspartate aminotransferase (P<0.01), as well as hepatic and serum malondialdehyde concentrations (P<0.05). Also, it caused the improvements in eggshell hardness and thickness (P<0.05). In general, the findings indicated that although dietary administration of fish oil increased the susceptibility of serum and liver to lipid peroxidation, feeding 200mg/kg essential oils mixture resulted in the best systemic and hepatic antioxidant responses, the modulated serum lipid profiles, and also the improved eggshell quality.

Improving the frying performance of RBD palm olein oil using NaturFORT™ TRLG 101 liquid as on-top of TBHQ in deep-fat frying of potato chips.

Improvement in the frying performance of palmolein oil with NaturFORT™ TRLG 101 (TRLG 101) liquid in addition to tert-butyl hydroquinone (TBHQ) has been evaluated. Four treatment groups (Negative control, 200ppm TBHQ, 200ppm TBHQ+400ppm TRLG 101 liquid and 200ppm TBHQ+750ppm TRLG 101 liquid) were added to RBD (Refined, Bleached and Deodorized) palm olein oil which was used to produce potato chips. Frying trials were conducted for 120th frying cycles. The oil samples were analyzed for peroxide value, free fatty acid, p-anisidine value, oxidative stability index, %total polar compounds and Chroma (C*) values after every 20 frying cycles. Potato chips were analyzed for Chroma (C*) values after every 20 frying cycles. The results of oxidative stability index, total polar compounds and p-anisidine value showed that the addition of NaturFORT™ TRLG 101 liquid at 750ppm had showed significantly better performance followed by the addition of NaturFORT™ TRLG 101 liquid at 400ppm. Thus, the addition of NaturFORT™ TRLG 101 liquid as on top of TBHQ contributes to the improvement in the frying performance of palm olein oil with subject to their dosage and this could be a better solution for frying industries which would like to get extra frying cycles for their products without encountering the regulatory hurdles posed by the limitations of using such additives.

Influence of Teucrium polium L. essential oil on the oxidative stability of canola oil during storage.

The susceptibility of Teucrium polium essential oil (EO) as an antioxidant for canola oil was studied. Major compounds of the EO were 11-acetoxyeudesman-4-α-ol (26.3%) and α-bisabolol (24.6%). Different concentrations (200, 600 and 1200ppm) of EO and synthetic antioxidant BHA (200ppm) were added to canola oil and incubated for 60days at room temperature. Acid value (AV), peroxide value (PV), carbonyl value (CV), iodine value (IV), total phenolics (TP), total polar compounds (TPC) and oxidative stability index (OSI) of canola oil were determined. Antioxidant capacity of the EO was measured by DPPH and β-carotene-linoleic acid assays. Results exhibited that DPPH and β-carotene-linoleic acid experiment detections on the EO were analogous in high concentrations to those detected on BHA. Moreover, incorporated EO samples had better AV, PV, CV, IV, TP and TPC than control. EO at concentration of 600 ppm indicated higher antioxidant activity in canola oil compared with BHA.