Quality enhancement of groundnut oil by addition of rice bran oil extract (original) (raw)
Related papers
Journal of Food Lipids, 2006
Kernel) prepared using a number of solvents (100% methanol, 80% methanol, 100% acetone and 80% acetone) were evaluated in sunflower oil (SFO) under accelerated storage conditions. The crude concentrated extracts of rice bran were added at 600 mg/kg into refined, bleached and deodorized SFO samples and stored under accelerated (65C) conditions for 24 days. Analyses were done every 4 days, and the extent of oxidative deterioration was followed by measurement of activity index, peroxide, p-anisidine, and conjugated diene and triene values. The overall order of antioxidant efficacy of rice bran extracts as determined by various antioxidant assays was 80% methanolic extract, >100% methanolic extract, >80% acetone extract and >100% acetone extract. The antioxidant activity of rice bran extracts might be attributed to the presence of phenolics and high contents of tocopherol. The results of the present comprehensive analysis demonstrated that extracts of the rice bran of Super Kernel, an indigenous cultivar of Pakistan, are a viable source of natural antioxidants and might be exploited for functional foods and nutraceutical applications.
Journal of Food Science and Technology, 2013
Unrefined groundnut oil (GNO) and refined sunflower oil (SFO) were blended with four minor oils including laboratory refined red palmolein (RRPO), physically refined rice bran oil (RBO), unrefined sesame oil (SESO), and unrefined coconut oil (CNO) containing natural antioxidants viz., β-carotene, tocopherols, oryzanol and lignans. The five blends prepared were GNO+RRPO (80:20), GNO+RBO (80:20), GNO+SESO (80:20), SFO +RRPO (50:50) and SFO +CNO (60:40). Prepared blends contained saturated fatty acids (SFA) (16.7-53.3 %); monounsaturated fatty acids (MUFA) (16.0-45.5 %) and polyunsaturated fatty acids (PUFA) (29.2-37.8 %). GNO blends viz., GNO+RRPO, GNO+RBO and GNO+SESO contained βcarotene (10.7 mg/100 g), oryzanol (0.12 g/100 g) and lignans (0.35 g/100 g) respectively as natural antioxidants. SFO was enriched with β-carotene (28.7 mg/100 g) and medium chain fatty acids (34.2 %) by blending with RRPO and CNO respectively. The oil blends (200 ml) were packed and stored at 38°C/90 % relative humidity (RH) and 27°C/65 % RH and samples were withdrawn at fixed intervals for analysis. Freshly prepared blends were also investigated for their frying performance. During storage, GNO+RBO blend showed highest oxidative stability probably due to the presence of oryzanol in the order GNO+RBO>GNO+SESO>GNO+RRPO. During frying, the peroxide value of GNO blends with RBO (rich in oryzanol) and SESO (rich in lignans) was less while the free fatty acid value was less in SFO blends with RRPO and CNO. Hence, blending of natural antioxidants rich minor oils (RRPO, RBO and SESO) with the major vegetable oils (GNO and SFO) may preserve them by lowering their rate of oxidation during storage and frying.
international food research journal, 2014
The present study investigates the effect of exposure at elevated temperature (60°C) on the stability of edible oils i.e. sunflower oil, sesame oil and their blends in various proportions of 20:80, 50:50 & 80:20 v/v, with and without addition of antioxidants on the basis of acid value, peroxide value and thiobarbituric acid reactive substances (TBARS) value changes. Tocotrienol rich fraction (TRF) extracted from crude rice bran oil was used as a source of natural antioxidant. Addition of TRF at the optimum level to edible oils was observed to show better stability compared to oils without TRF. The optimum level of TRF activity was measured to be 5 μl/g oil. Considering the combined beneficial effects of sunflower and sesame oil, the blend of these two oils (50:50 v/v) with TRF has been found to be the best. Hence, the stability of edible oil could be enhanced by blending and addition of natural antioxidant.
International Journal of Molecular Sciences
Tocopherols are natural bioactive compounds with several health benefits. This study evaluated the effect of different ratios of α- and δ- tocopherol homologs to protect sunflower oil (SO) and olive pomace oil (OPO) against oxidation. A synergistic effect was recorded when the two tocopherols were combined at a ratio of 7:1 (α-T/δ-T). The oil samples were exposed to accelerated oxidation conditions using a Rancimat (90 °C and airflow of 15 L/h for 24 h) and protection from tocopherols was compared with that from butylated hydroxytoluene (BHT). Assessment of oil stability was examined using well-known parameters such as peroxide value (PV), thiobarbituric acid reactive substances (TBARS), p-anisidine value (p-AV), conjugated dienes (CD) and trienes (CT), and total oxidation (Totox) value, which were all significantly reduced when tocopherols were added at a ratio of 7:1 α-T/δ-T. Primary oxidative compounds measured according to PV were only reduced in SO samples (6.11%). Off-flavor c...
Oxidative Stability of Selected Edible Oils
Molecules, 2018
The aim of the study was to examine and compare oxidative stability of refined (peanut, corn, rice bran, grapeseed, and rapeseed) oils. The oils were subject a Schaal Oven Test (temperature 63 ± 1 °C) and a Rancimat test (temperature 120 °C) and their stability was compared at the 1st and 12th month of storage. Changes in the peroxide (PV) and anisidine (AnV) values in the thermostat test were the fastest in rapeseed oil and grapeseed oil. The best quality was preserved by peanut and corn oils both in the first and the twelfth month of storage. The induction times for the rice bran, corn, peanut, and rapeseed oils were similar from 4.77 h to 5.02 h in the first month and from 3.22 h to 3.77 h in the twelfth month. The shortest induction times were determined for grapeseed oil: 2.4 h and 1.6 h, respectively. A decrease of oxidative stability of about 30% was found in all the oils after 12 months of storage. The PV of 10, determined in the thermostat and Rancimat tests, were achieved ...
Antioxidant Stability in Palm and Rice Bran Oil Using Simple Parameters
2010
Fats and oils are recognized as essential nutrients in human diets. Nutritionally, they are concentrated source of energy (9 cal/ gram); provide essential fatty acids which are the building blocks for the hormones needed to regulate bodily systems; and are a carrier for the oil soluble vitamins A, D, E and K. Kinematic Viscosity of unheated and heated (270°C) rice bran oil is measured 30o to 90°C. In this paper, the antioxidant stability in palm oil and rice bran oil at different times of heating is investigated using the parameters like density, viscosity, adiabatic compressibility and acoustic impedance of the oils at different times of heating. The antioxidant stability is resolute at every time of heating. Hence, it can be recommended that rice bran oil can be used for frying without adverse effect preventing the incidence of malignancy and coronary heart diseases.
2018
The effect of sunlight on the quality of groundnut oil in comparison with the same oil samples stored in the dark at room temperature was aimed to study. The oil samples were exposed to sunlight (34-40°C) and ambient storage (~24°C in the dark) for 90 days. The samples were collected every 30 days for the analysis of their physicochemical properties including peroxide value (PV), p-anisidine (p-AnV), total oxidation (TOTOX), thiobarbituric acid (TBA), free fatty acid (FFA), color, induction period on Rancimat and fatty acid composition. At the beginning of the experiment, the PV, p-AnV, TOTOX, TBA and FFA values of groundnut oil were 10.31 meq O2/kg, 4.39, 25.01, 0.99 and 1.49% respectively; color 1.40R, 22.00Y and induction time (IT) 5.33 h. After 90 days storage at room temperature, the PV, pAn -V, TOTOX, TBA and FFA values were respectively ranged between 10.31-21.32 meq O2/kg, 4.39-7.36, 25.01-50.12, 0.99-2.42 ppm and 1.49-2.64%; the color in the red and yellow unit 1.40-1.20R and 22.00-19.00Y respectively; and the induction time 5.33-3.77 h. However, the same parameters at the end of exposure to sunlight were ranged in the same order, between 10.31-43.47 meq O2/kg, 4.39-22.24, 25.01-109.18, 0.99-3.25 ppm and 1.49-5.83% respectively; the color in the red and yellow units 1.40-0.50R and 22.00-1.30Y respectively; and the induction time 5.33-0.03 h. Results also showed that the amount of linoleic and gadoleic acids significantly dropped under sunlight compared to dark at room temperature. Sunlight significantly reduced the quality of groundnut oil. This oil should be stored in the dark at room temperature.
Evaluation of Oxidative Stability of Compound Oils under Accelerated Storage Conditions
Brazilian Archives of Biology and Technology
The oxidative stability of linseed (L), cotton (A), and coconut (C) oils, as well as of linseed:cotton (LA), linseed:coconut (LC), and linseed:cotton:coconut (LAC) compound oils was evaluated under accelerated storage at 60°C/20 days. Coconut oil showed to be rather stable, mainly due to low levels of peroxides, conjugated dienes, ρ-anisidine, and long induction period. In addition, along with cotton oil, it improved the stability of linseed oil in the formulation of LAC compound oil. As to fatty acid profile, the compound oils showed to be composed mainly by unsaturated fatty acids. Cotton and coconut oils presented higher retention of total phytosterols, 78.87 and 76.16%, respectively, after 20 days of storage, when compared to linseed oil. The highest retention of total tocopherols at the end of storage was observed in LA (90.81%). In relation to antioxidant activity, by the DPPH method, with the increase in storage time, a reduction in the antioxidant substances of linseed, LC, and LAC oils was observed. Through the FRAP method, oscillations were observed, especially in linseed and compound oils. Although the oils were degraded over time, it was possible to verify that cotton and coconut oils contributed to increase the stability of linseed oil, which, in turn, raised the levels of coconut oil bioactive compounds.
Journal of Oleo Science, 2004
Many lipids are particularly labile when exposed to a combination of heat, air and light. Under conditions of heating or frying, the acceleration of both thermal and oxidative decomposition reactions will occur (1,2). It is well established that the excessive heating of oils or fats can result in the formation of compounds that possess antinutritional properties, such as enzyme inhibitors (3) and accelerated loss of antioxidant vitamins, such as vitamin E (4,5) leading to growth depression and histologic changes in gastrointestinal tissues (6,7). Notwithstanding these potential adverse health effects of thermally oxidized oil, it is important to note that lipid oxidation also influences the acceptability of the fried product (8). Thus, to retard against undesirable changes in oil during storage and frying operations, antioxidants are required (9).
LWT - Food Science and Technology, 2018
A total of 10 corn oil samples, 6 with herbal extracts, 2 with butyl hydroxy toluene (BHT) and ascorbyl palmitate (AP), a refined corn oil and the control, the stripped corn oil, were evaluated for oxidative stability under accelerated oxidation at 60 °C for 6 wk. Oxidation was followed by determining peroxide value, thiobarbituric acid reactive substances (TBARS), conjugated dienes (CD) and trienes (CT). Antioxidant activity of each herbal extract was evaluated. According to the obtained results, sumac extract, α-tocopherol and AP had the highest antioxidant activity, whereas flaxseed and sage showed the lowest. Peroxide, TBARS, CD and CT values increased during storage in all samples. Samples with BHT, sumac and mint showed the highest inhibition of peroxide formation. Sumac and thyme extracts significantly inhibited TBARS formation compared to BHT and AP added samples. It is concluded that the antioxidant activities of sumac, thyme and mint were high and retarded the oxidation and can be utilized in the food industry for commercial purposes in retardation of oil oxidation.