Virgin rapeseed oils obtained from different rape varieties by cold pressed method – their characteristics,properties, and differences

The aim of the present study was to compare different rape varieties. For this purpose oil from six different varieties of rapeseeds was cold pressed under laboratory conditions. In the obtained rapeseed oils the fatty acids composition and minor components, characteristic values (acid value; AV and TOTOX), oxidative stability (DSC test), and volatiles were determined and a sensory evaluation was carried out. The highest oxidative stability was found for oil from sample 5 (IP = 158 min), which also has the lowest amount of C18:3 (7.8%), chlorophylls (0.083 mg/kg), and metals (Cu²⁺ 0.02 mg/kg and Fe²⁺ 0.08 mg/kg). This oil has also the lowest AV (0.17 mg KOH/g), which may be related to the lowest moisture content of the seeds prior to extraction. It was characterized by the highest rapeseed flavor intensity. The lowest induction period was observed for samples 3 and 6 (100 min). Although sample 3 had the same low level of metals as sample 5 and the highest concentration of tocopherols (635 mg/kg), PUFA (33.9%), and AV (1.37 mg KOH/g) it also had the lowest intensity of rapeseed flavor among the analyzed oils. Sample 6, despite its low percentage of PUFA (24.7%), conjugated diens and triens, and the lowest content of total volatiles (0.4Vs), had the highest concentration of metals (Cu²⁺ 0.04 mg/kg and Fe²⁺ 0.34 mg/kg).     

A Comparative Study of the Properties of Selected Melon Seed Oils as Potential Candidates for Development into Commercial Edible Vegetable Oils

A comprehensive compositional and characterization study was carried out on five seed oils from varieties of the melons Citrullus lanatus and C. colocynth in order to evaluate their suitability for large-scale exploitation as edible vegetable oils. The oils were extracted by Soxhlet with a 3:1 mixture of n-hexane/2-propanol with yields that ranged from 24.8 to 30.0% (wt/wt). The refractive indices and relative densities of the oils fell within the narrow ranges of 1.465–1.469 and 0.874–0.954 g/cm³, respectively. Saponification values ranged between 182.1 and 193.8 mg KOH/g, whilst iodine values (IV) ranged from 95.8 to 124.0 (Wijs). The ranges of the values for free fatty acid (AV), 1.2–4.0 mg KOH/g, peroxide (PV), 1.1–10.9 meq/kg and p-anisidine (p-AV), 0.2–9.0, indicated that secondary oxidation products were barely present. GC analysis gave total unsaturation contents of 67.93–82.36%, with linoleic acid (18:2) being the dominant fatty acid (55.21–66.85%). The GC results agreed closely with those from proton NMR analysis of the fatty acid classes. The physicochemical and compositional properties determined in this study show that the qualities of the test Cucurbitacea seed oils are highly comparable to those of soybean, sunflower and groundnut seed oils. Therefore, the test melon seed oils could be developed into commercial products to serve as alternate vegetable oils in Southern and West Africa, the regions where these melons grow.     

Physical Properties and Fatty Acid Profiles of Oils from Black,Kidney, Great Northern,and Pinto Beans

Four common beans (black, kidney, great northern, and pinto) were extracted with hexane and found to contain about 2% triacylglycerols. The fatty acids in these bean oils were mainly linolenic (41.7–46 wt%), linoleic (24.1–33.4 wt%), palmitic (10.7–12.7 wt%) and oleic (5.2–9.5 wt%). Because of the high levels of polyunsaturated fatty acids, the bean oils had iodine values between 174 and 177 g/100 g (compared to 130 g/100 g for soybean oil). Yet, the bean oils exhibited high oxidative stability due to the presence of high amounts of tocopherols (2,670–2,970 ppm). The bean oils had lower pour points (−18 to −11 °C) compared to −9 °C for soybean oil. Among the four bean oils, kidney bean oil had the highest acid value (15.4 mg KOH/g) and kinematic viscosities over a wide range of temperatures.     

Characterization and Compositional Studies of Oil from Seeds of Desi Chickpea (Cicer arietinum L.) Cultivars Grown in Pakistan

The physiochemical properties and fatty acid (FA) composition of oil from seeds of four desi chickpea cultivars, grown in Pakistan, were investigated. The oil content was relatively low (5.88–6.87%). The physiochemical parameters determined included refractive indices (RI) at 40 °C (1.48–1.49), relative density (0.95–0.96), iodine value (IV) (111.87–113.69), acid value (AV) (2.55–2.73 mg KOH/g), saponification value (SV) (183.98–185.64 mg KOH/g), unsaponifiable matter (UM) (2.99–3.71%), peroxide value (PV) (3.97–6.37 mequiv/Kg), p-anisidine value (p-AV) (5.39–8.74), and oxidation value (OV) (13.67–22.34). Linoleic acid and oleic acid were the dominant FAs. Results from most of the parameters revealed significant (P < 0.05) differences among the cultivars. The findings reveal Desi chickpea (Cicer arietinum L.), indigenous to Pakistan, to be a potentially valuable legume crop with comparable nutritional quality oil.     

Production of Low Acid Value Edible Oil with Reduced TFAs by Electrochemical Hydrogenation in a Diaphragm Reactor

A new diaphragm electrochemical system was devised and tested for hydrogenation of soybean oil under moderate processing temperature and atmospheric pressure. With proper loading of the catalyst Pd-C, the reactor was operated successfully for 6 h and yielded hydrogenated soybean oil containing 8.62% TFAs with an IV of 88.86 g I₂/100 g oil and an AV of 0.7 mg KOH/g oil. The low AV (acid value) of the hydrogenated oil, indicative of the oxidization tendency of the oil, is highly desirable from the industrial application standpoint. The low specific isomerization index was reached with 0.4 mol/L of formate ions at pH 5.0 under 60 °C using a constant applied current density (10 mA/cm²)_. The extent of hydrogenation was found to increase with increasing current density, formate ion concentration, reaction temperature, catalyst loading, and speed of agitation. It was characterized that the extent of hydrogenation under low pH (2.0–5.0) was controlled by the regeneration of formate ion, whereas under high pH (6.0–10.0) the hydrogenation was influenced strongly by the formate ion stability.     

Influence of Extraction Method on Yield,Physicochemical Properties and Tocopherol Content of Manketti (<Emphasis Type="Italic">Schinziophyton rautanenii</Emphasis>) Nut Oil

The influence of extraction method on yield, physicochemical characteristics and tocopherol content of manketti nut oil extracted by four different methods has been determined. Soxhlet (SE) and supercritical fluid (SFE) extractions yielded 45.3 and 44.8%, respectively, while screw press and mechanical shaking extractions had 39.7 and 27.3%, respectively. SPE and SE extractions gave oils that had lower values of unsaponifiable matter (0.70; 0.74%) indicating lower amounts of minor components such as tocopherols (233.13; 290.68 µg/g oil), a greater extent of lipid peroxidation parameters; peroxide values (6.25; 3.01 mequiv O₂/kg), para‐anisidine values (10.22; 9.94), totox value (22.72; 15.96), flavour score (?0.25; 2.11), and high acid values (1.23; 1.03 mg KOH/g oil), respectively, compared to SFE and MSE oils. This was attributed to the high processing temperatures of SPE and SE extractions compared to SFE and MSE oils. Refractive indices (1.485–1.487), iodine values (127.97–129.07, Wijs) and density (0.908–0.914 g/cm³) were not affected by extraction method indicating that the oils generally had the same double bond content. Saponification values (182.98–192.95 mg KOH/g oil) and ester values (181.95–192.11), were not affected by extraction method except for SE oil which had lower values that were speculated to be due to co‐extraction with colour pigments.     

Determination of the Fatty Acid Composition of Acorn (Quercus), Pistacia lentiscus Seeds Growing in Algeria

The fruits of two plants from Algeria (Quercus and Pistacia lentiscus) were investigated. The paper reports the chemical characteristics and the fatty acid composition of the oil extracts from the fruits. The black fruits of P. lentiscus has the highest crude fat of 32.8%, followed by the red fruits with 11.7%, and the lowest value of 9% in Quercus (acorn). The acid value was highest in red fruits of P. lentiscus oil (24.0 mg KOH/g), followed by the black fruits oil and lowest in acorn oil. The relatively high iodine value in the oils indicates the presence of many unsaturated bonds. Saponification value was highest in the Quercus ilex oil (166.7 mg KOH/g), while the lowest value was in the black fruits of P. lentiscus oil. Gas-liquid chromatography revealed that the three dominant fatty acids found are: palmitic C16:0 (16.3–19.5%), oleic C18:1 (55.3–64.9%), linoleic C18:2 (17.6–28.4%). The oils contain an appreciable amount of unsaturated fatty acids (78.8–83.5%).     

Chemical Properties of Virgin Coconut Oil

A study on the commercial virgin coconut oil (VCO) available in the Malaysian and Indonesian market was conducted. The paper reported the chemical characteristics and fatty acid composition of VCO. There was no significant difference in lauric acid content (46.64–48.03%) among VCO samples. The major triacylglycerols obtained for the oils were LaLaLa, LaLaM, CLaLa, LaMM and CCLa (La, lauric; C, capric; M, myristic). Iodine value ranged from 4.47 to 8.55, indicative of only few unsaturated bond presence. Saponification value ranged from 250.07 to 260.67 mg KOH/g oil. The low peroxide value (0.21–0.57 mequiv oxygen/kg) signified its high oxidative stability, while anisidine value ranged from 0.16 to 0.19. Free fatty acid content of 0.15–0.25 was fairly low, showing that VCO samples were of good quality. All chemical compositions were within the limit of Codex standard for edible coconut oil. Total phenolic contents of VCO samples (7.78–29.18 mg GAE/100 g oil) were significantly higher than refined, bleached and deodorized (RBD) coconut oil (6.14 mg GAE/100 g oil). These results suggest that VCO is as good as RBD coconut oil in chemical properties with the added benefit of being higher in phenolic content.     

Prediction of optimized pretreatment process parameters for biodiesel production using ANN and GA

An artificial neural network (ANN) based program coupled with genetic algorithm (GA) was developed on MATLAB platform for predicting the optimized process parameters required for reducing high free fatty acids (FFA) of any vegetable oils for successful transesterification. The developed ANN was a feed forward back propagation network (4-7-13-1) with one input, two hidden and one output layers. The input parameters for the ANN to generalize the pretreatment process were initial acid value of vegetable oil (IAV), methanol-to-oil ratio (M), catalyst concentration (C) and reaction time (T) and the output parameter was final acid value (FAV) of oil. The developed ANN was trained with the experimental data obtained for jatropha, mahua, simaruoba and rice bran oils with acid value more than 14 mg KOH/g-oil. The trained ANN was tested with separate set of data generated from pretreatment of mahua oil using response surface methodology (RSM) based on central composite rotatable design (CCRD) and found to predict the input pretreatment process parameters with low mean square error (MSE) and relative percent deviation (RPD). The well trained ANN synaptic joint weights and threshold values were used by GA to evaluate the fitness (to get FAV of oil less than 2 after pretreatment) of individuals (combinations of M, C and T) for optimization. The optimized process parameters predicted by the developed ANN-GA technique for sunflower oil with IAV 28 ± 1 mg KOH/g-oil were experimentally verified and the FAV was measured to be 2 ± 0.2 mg KOH/g-oil against the predicted value of 2 mg KOH/g-oil.     

Use of Phagotrophic Microalga Ochromonas danica to Pretreat Waste Cooking Oil for Biodiesel Production

In this study, the feasibility of pretreatment and/or upgrading of waste cooking oil (WCO) using the microalga Ochromonas danica was investigated. Two WCO samples with initial acid values (AV) of 10.7 mg KOH/g (~5.4 % FFA content) and 3.9 mg KOH/g (~2.0 % FFA content) were examined. The algal cells engulfed oil droplets and grew rapidly on both WCO samples. The cell growth rates on WCO were compared with the rates on olive oil, with or without surfactant addition to make the oil droplets smaller and easier for algal ingestion. Comparison was also made with the growth rate in a sugar‐based medium. More importantly, contacting the WCO with the phagotrophic O. danica cells was found to decrease the acid values of the remaining oil by 2.8 and 2.4 mg KOH/g WCO, respectively. The O. danica‐pretreated WCO, with lower acid values, are potentially better feedstock for biodiesel production.     

Physicochemical and Stability Characteristics of Flaxseed Oils During Pan-heating

Flaxseed oils are used in stir-frying in parts of China. In this study, flaxseed oils were heated at approximately 150 °C as a thin film in a frying pan for 3 and 6 min, respectively. Pan-heating caused loss of tocopherols, plastochromanol-8, phenolic acids and chlorophyll pigments. There was a significant decrease in the linolenic acid resulting in a concomitant relative increase in palmitic, stearic, oleic and linoleic acids in the oils after pan heating. Positive CIELAB “b*” color value, which indicates yellowness and levels of β-carotene and lutein in these oils showed a 42–56% and 8–53% decrease, respectively. Peroxide values, p-anisidine values, percentage of conjugated dienoic acid, specific extinction at 232 and 270 nm and food oil sensor readings of these oils showed significant increases to levels exceeding good oil quality indices. Acid values only showed one to twofold increase from fresh oil values of 0.65–2.23 mg KOH/g of sample. These results indicate that significant levels of oxidation products would be present in flaxseed oils after pan heating. The flaxseed oil with a lower amount of PUFA appeared to be more degraded suggesting that the major factor affecting the oxidative stability of the flaxseed oils during pan-heating was not the degree of unsaturation but was dependent on the complex interaction between the fatty acids and minor constituents in the oils. Presented at the American Oil Chemists’ Society 97th Annual Meeting & Expo, St. Louis, MO, 30 April–3 May, 2006.     

A Comparative Study of the Properties of Six Sudanese Cucurbit Seeds and Seed Oils

The proximate analysis of seeds and physicochemical properties of oils extracted from six Sudanese cucurbit seeds Cucumis mello var. agrestis, Cucumis melo var. flexuosus, Cucumis sativus, Citrullus lanatus var. colocynthoides, Cucumis prophetarum, and Luffa echinata were examined by established methods. For each variety, the proximate analysis showed ranges for moisture, protein, and carbohydrates as 3.70–6.87, 14.50–17.50, and 15.62–28.89% on a dry matter basis, respectively. The oils were extracted by Soxhlet using petroleum ether, with yields that ranged from 10.9 to 27.10% (wt/wt). The obtained extracted oils were subjected to phyiscochemical, fatty acid, and tocopherol analysis. The physicochemical characterization of the oil revealed that the refractive indices and relative densities of the oils fell within the narrow ranges of 1.334–1.442 and 0.874–0.920 g/cm³, respectively. Unsaponifiable matters ranged between 0.8 and 1.2 mg KOH/g, whilst peroxide values (PV) ranged from 2.3 to 4.1 meq/kg. The ranges of the values for free fatty acid (FFA %) were 1.2–4.0%. The predominant fatty acids were 16:0, 18:0, 18:1, and 18:2 with ranges of 8.9–14.2, 6.0–9.4, 14.6–32.1, and 43.6–65.5%, respectively. γ-Tocopherol was the predominant tocopherol in all samples ranging from 0.8 to 43.2% of the total tocopherols, followed by δ-tocopherol and α-tocopherol.     

Rapid quantitative determination of free fatty acids in fats and oils by fourier transform infrared spectroscopy

Rapid direct and indirect Fourier transform infrared (FTIR) spectroscopic methods were developed for the determination of free fatty acids (FFA) in fats and oils based on both transmission and attenuated total reflectance approaches, covering an analytical range of 0.2–8% FFA. Calibration curves were prepared by adding oleic acid to the oil chosen for analysis and measuring the C=O band @ 1711 cm^–1 after ratioing the sample spectrum against that of the same oil free of fatty acids. For fats and oils that may have undergone significant thermal stress or extensive oxidation, an indirect method was developed in which 1% KOH/methanol is used to extract the FFAs and convert them to their potassium salts. The carboxylate anion absorbs @ 1570 cm^–1, well away from interfering absorptions of carbonyl-containing oxidation end products that are commonly present in oxidized oils. Both approaches gave results comparable in precision and accuracy to that of the American Oil Chemists’ Society reference titration method. Through macroprogramming, the FFA analysis procedure was completely automated, making it suitable for routine quality control applications. As such, the method requires no knowledge of FTIR spectroscopy on the part of the operator, and an analysis takes less than 2 min.     

Physico-Chemical Characteristics of Citrus Seeds and Seed Oils from Pakistan

The physico-chemical characteristics of the seeds and seed oils of four citrus species, Mitha (Citrus limetta), Grapefruit (Citrus paradisi), Mussami (Citrus sinensis), and Kinnow (Citrus reticulata) were investigated. The hexane-extracted oil content of citrus seeds ranged from 27.0 to 36.5%. The protein, fiber and ash contents were found to be 3.9–9.6%, 5.0–8.5%, and 4.6–5.6%, respectively. The extracted oils exhibited an iodine value of 99.9–110.0; refractive index (40 °C), 1.4639–1.4670; density (24 °C), 0.920–0.941 mg/mL; saponification value, 180.9–198.9; unsaponifiable matter, 0.3–0.5%; acid value (mg KOH/g of oil), 0.5–2.2 and color (1-in. cell) 1.4–3.0R + 15.0–30.0Y. The oils revealed a good oxidative stability as indicated by the determinations of specific extinctions at 232 and 270 nm (2.3–4.4 and 0.6–0.9, respectively), p-anisidine value (2.2–3.2) and peroxide value (1.6–2.4 mequiv/kg of oil). The citrus seed oils mainly consisted of linoleic acid (36.1–39.8%). Other prominent fatty acids were palmitic acid (25.8–32.2%), oleic acid (21.9–24.1%), linolenic acid (3.4–4.4%), and stearic acid (2.8–4.4%). The contents of tocopherols (α, γ, and δ) in the oil were 26.4–557.8, 27.7–84.1, and 9.1–20.0 mg/kg, respectively. The results of the present study demonstrated that the seeds of citrus species investigated are a potential source of valuable oil which might be utilized for edible and other industrial applications.     

Effect of Moisture and Heat Treatment of Corn Germ on Oil Quality

The changes in the quality of crude corn oil caused by moisture and two different thermal pretreatments (oven heating and steam heating) of wet‐milled corn germ were evaluated and compared with those of untreated oil. Increasing the moisture content of the corn germ from 8 to 25% before oil extraction increased the acid value (AV) (3.02–4.01 mg KOH g^?1), peroxide value (PV) (0.52–1.05 meq kg^?1), and the red value (7.3–8.7) and decreased the content of total tocopherols by 37% and that of γ‐tocopherols by 31%. Oven heating tended to decrease the AV and PV while steam heating significantly increased the total and individual tocopherol contents (P < 0.05). The different moisture contents and thermal pretreatments of corn germ caused no significant differences in the fatty acid composition and the contents of total and individual phytosterols of the crude oils. The γ‐tocopherol contents were found to be highly correlated with the red values (the corresponding R² reached 0.9977 and 0.9089 for moisture and heat pretreatments, respectively).     

Characterization of cold-pressed onion, parsley, cardamom, mullein, roasted pumpkin, and milk thistle seed oils

Cold-pressed onion, parsley, cardamom, mullein, roasted pumpkin, and milk thistle seed oils were characterized for their fatty acid (FA) composition, tocopherol content, carotenoid profile, total phenolic content (TPC), oxidative stability index (OSI), color, physical properties, and radical-scavenging capacities against peroxyl (oxygen radical-scavenging capacity) and stable DPPH (diphenylpicrylhydrazyl) radicals. Parsley seed oil had the highest oleic acid content, 81 g/100 g total FA, and the lowest saturated fat among the tested oils. Roasted pumpkin seed oil contained the highest level of total carotenoids, zeaxanthin, β-carotene, cryptoxanthin, and lutein at 71 μmol/kg and 28.5, 6.0, 4.9, and 0.3 mg/kg oil, respectively. Onion seed oil exhibited the highest levels of α- and total tocopherols under the experimental conditions. One of the parsley seed oils exhibited the strongest DPPH scavenging capacity and the highest oxygen radical absorbance capacity (ORAC) value of 1098 μmol Trolox equiv/g oil. However, ORAC values of the tested seed oils were not necessarily correlated to their DPPH scavenging capacities under the experimental conditions. The highest TPC of 3.4 mg gallic acid equiv/g oil was detected in one of the onion seed oils. The OSI values were 13.3, 16.9–31.4, 47.8, and 61.7 h for the milk thistle, onion, mullein, and roasted pumpkin seed oils, respectively. These data suggest that these seed oils may serve as dietary sources of special FA, tocopherols, carotenoids, phenolic compounds, and natural antioxidants. An erratum to this article is available at .     

Characterization of Fatty Oil of <Emphasis Type="Italic">Zizyphi spinosi semen</Emphasis> Obtained by Supercritical Fluid Extraction

Zizyphi spinosi semen (ZSS) has been widely used for treatment of insomnia in oriental countries. The aim of this study is to characterize the fatty oil of ZSS obtained by supercritical fluid extraction in terms of chemical composition and physicochemical properties. The chemical composition, including fatty acids and unsaponifiable constituents, was analyzed by gas chromatography–mass spectrometer (GC–MS). The results revealed that 9-octadecenoic acid (43.38 ± 0.03%) and 9,12-octadecadienoic acid (40.58 ± 0.03%) were the main fatty acids, and β-sitosterol (37.39 ± 0.02%) and squalene (30.79 ± 0.01%) were the key unsaponifiables. Furthermore, four indexes were assayed according to Chinese Pharmacopeia (2005) to reflect the physicochemical properties of ZSS oil, their values being determined as follows: acid value (10.3 ± 0.1 mg KOH/g), peroxide value (0.05 ± 0.01 g/100 g), saponification value (194.4 ± 0.5 mg KOH/g) and iodine value (109.7 ± 0.8 g I/100 g). The basic information obtained provides data support for quality evaluation and efficacy research of ZSS oil, and suggests its prospects for development in pharmaceutical and food industries.     

Quantitative determination of diesel oil in contaminated edible oils using high-performance liquid chromatography

A simple and reliable high-performance liquid chromatography method for the analysis of diesel oil in contaminated edible oils is described. Analysis performed using a diol column with a mobile phase of heptane and isopropanol (94∶6, vol/vol). Although baseline separation between diesel and other background fluorescent components was not achieved, quantitation was still possible using baseline integration. The method is linear over the range of 5–1000 μg/g with a correlation coefficient (r ²) of 0.9984. Average recoveries from spiked edible oils were 94.4–101.3%, with a limit of quantitation (LOQ) of 5 μg/g for sunflower oil, palm olein, and groundnut oil. Corn oil has a higher content of ester components, thus, LOQ was slightly worse (40 μg/g). The applicability of the method was confirmed by gas chromatography-mass spectroscopic detection to show the presence of diesel hydrocarbons in the suspected contaminated crude palm oil. This procedure provides a simple and sensitive method for determining diesel oil concentration in contaminated edible oils without prior sample cleanup or extraction.     

Chemical Composition and Oxidative Stability of Kernel Oils from Two Current Subspecies of Pistacia atlantica in Iran

Pistacia atlantica subsp. mutica (PAM) and kurdica (PAK) kernel oils showed significantly lower unsaturated to saturated fatty acid ratios (6.39, 6.33, respectively) and calculated oxidizability (Cox) values (3.99, 4.13, respectively) than those of the P. vera L. cv. Ohadi (PVO) kernel oil (8.91, 4.41) samples. The highest peroxide value was observed for the PAK oil (4.07 mequiv kg⁻¹) (PAM, 1.94; PVO, 0.37) samples. Iodine values for the PAM, PAK, and PVO oils were 104.26, 104.77, and 110.66, respectively. The saponification number of the PVO oil was significantly greater than the PAM and PAK oils, which were statistically not different. The unsaponifiable contents, which were composed mainly of sterols, ranged from 5.63 to 6.14%. Statistically the total tocopherols contents of the PAM (818.58 mg α-tocopherol kg⁻¹) and PVO (815.90 mg α-tocopherol kg⁻¹) oils were significantly higher than that of the PAK oil (499.91 mg α-tocopherol kg⁻¹). Total phenolics contents differed significantly, the greatest concentration was for the PAM oil (81.12 mg gallic acid kg⁻¹), followed by the PVO (62.84 mg gallic acid kg⁻¹) and PAK (56.51 mg gallic acid kg⁻¹) oil samples. The wax contents of the oil samples were statistically in the same range, namely 5.67–6.48%. Oxidative stability data indicated that the PAM oil is the most resistant to the formation of lipid oxidation products, followed by the PAK and PVO oil samples.     

A Greener Alternative Titration Method for Measuring Acid Values of Fats,Oils, and Grease

A greener alternative method is proposed for measuring acid values (AV) of fats, oils, and grease (FOG) based on visual titration. Compared with Official Method Cd 3d-63 of the American Oil Chemists' Society (AOCS), this greener alternative method can eliminate the use of toluene, which in turn reduces toxicity and cost. A total of 44 samples of yellow and brown grease with AV ranging from 0.13 to 170.37 (mg KOH) g⁻¹ were titrated using both methods. The alternative titration method can provide accurate and reliable results to determine the AV of FOG by various statistical analyses including repeatability, linear regression, f-test, t-test, and method accuracy calibration with AOCS Cd 3d-63. This low-cost method can be recommended for routine titration in research and development, and in biodiesel plants for most FOG samples.