Acid Value Of Oil Research Articles

Effects of carboxymethyl chitosan adsorption on bioactive components of Antarctic krill oil

High acid value (AV) and fluorine content of Antarctic krill oil (AKO) extracted from frozen krill by ethanol limit its product development. In this study, a method was proposed to reduce the AV and fluorine content of AKO by carboxymethyl chitosan (CMCS) adsorption. The optimal adsorption condition was 12.5% (w/v) of CMCS at 30℃ for 15 min. At this condition, AV and fluorine content decreased by 78.0% and 61.4%, respectively. It is interesting that CMCS adsorption showed specificity to particular substances. Although free fatty acids content showed a significant reduction, free EPA and DHA, phospholipid and astaxanthin remained almost constant. Moreover, CMCS adsorption showed no influence on neuroprotective activity of AKO against H2O2-induced neuro-damage of PC12 cells. The reclaimed CMCS showed an undiminished antimicrobial activity against both Gram-positive and Gram-negative bacteria. The CMCS adsorption shows a potential development for refining AKO and other oils in food industry.

Investigation of sorption isotherms of wheat germ for its effect on lipid oxidation

This research aimed to investigate the oxidation and sorption isotherm properties of wheat germ and to determine monolayer moisture content (m0 ) in particular, because it has a limiting effect on lipid oxidation. This research comprised two stages. The first stage was the determination of sorption properties and m0 at three temperatures (15, 25, and 35°C). The second stage of the research was to investigate lipid oxidation properties of stored wheat germ at two different temperatures (4 and 25°C) and m0 for 28 days. As a result, it was determined that wheat germ has a Type II sorption isotherm, Halsey is the best fitting sorption equation, and the average m0 is 4.25g moisture per 100g dry matter. Furthermore, the free fatty acid and peroxide value of wheat germ oil increased with increasing storage moisture content and temperature, determined as 12.63% and 5.01 mEqO2 /kg on average, respectively. In conclusion, storage of impermeably packaged wheat germ at low temperature and m0 content is an applicable method for decreasing rancidity and prolonging shelf-life.

Effect of lime fertilizer on reducing the larvae harmfulness of the beetles of the Elateridae family and sunflower productivity

The article presents the research results on the effect of lime mud (lime fertilizer from sugar beet waste during processing) in doses of 3.9 and 5.9 t/ha on the yield and infestation of sunflower sowings with the beetle larvae of the Elateridae family. We carried out the research in 2016-2018 at V.S. Pustovoit All-Russian Research Institute of Oil Crops (Krasnodar, Russia). We established that lime mud applied 30 days before crop planting resulted in a significant decrease of wireworm population from 15-21 to 6-10 specimens/m2. Recording of plant density at the stage of full sprouts showed considerable thinning of sowings due to pest damage; in the control variant, it reached up to 80 % whereas plant death under fertilizer application at the doses of 3.9 and 5.9 t/ha was 42 and 32 %, respectively. The application of lime mud at a dose of 3.9 t/ha resulted in the highest increase in yield - 0.58 t/ha. The oil content of sunflower seeds in the experiment was 48.9-52.1 % but we noted the decrease of this indicator in the variant with the lime mud at a dose of 3.9 t/ha. Oil acid value was at the same level in both variants (3.9 and 5.9 t/ha) of lime application and reached 1.5 mg KOH.

Effect of rice bran rancidity on the structure and antioxidant properties of rice bran soluble dietary fiber

The effects of storage time of fresh rice bran on the structure and antioxidant properties of rice bran soluble dietary fiber (RBSDF) were investigated. As the storage time of rice bran prolonged, a significant increase of acid value of rice bran crude oil was accompanied by a significant decrease of RBSDF yield (P < 0.05). The antioxidant properties of RBSDF first increased, and then decreased, which was accompanied by the formation of oxidized aggregates of RBSDF. The results of FT-IR and monosaccharide composition implied that hydroxyl oxidation was accompanied by changes in monosaccharide composition of RBSDF during storage of rice bran. As the storage time of rice bran increased, the content of free phenolics gradually increased, the content of bound and total phenolics first increased, and then decreased. The results of correlation analysis showed that among the factors affecting the antioxidant properties of RBSDF, the content of phenolics and soluble aggregates was more significant than monosaccharide composition. Overall, the structure and antioxidant properties of RBSDF were related to the degree of rice bran rancidity, suggesting that the degree of rice bran rancidity could be one of the potential means to regulate the antioxidant properties of RBSDF.

Applications and Extraction of Watermelon Seed Oil – A Review

Oil content in the seeds is between 35 - 40 % and the unsaturated fatty acid content in oil is 78-86% predominantly linoleic acid (45-73 %). Watermelon seed oil is effective for skin care as it is light, easily absorbable and has humectants properties. Watermelon seed oil also known as Otenga oil or Kalahari oil suitable for cosmeceutical applications. High acid value in oil will produce soap during transesterification process. High acid value of Watermelon oil necessitated acid pretreatment of the oil before transesterification. Free fatty acids (FFA) are produced by the hydrolysis of oils and fats. The free fatty acid value measures extent to which glycerides in the oil have been decomposed by lipase action. Free fatty acids for Watermelon seed oil was 2.5-3 %. The unsaturated fatty acid content of 77.4% and the high content of 63.2% of PUFA. The time of extraction increased yield of oil also increase and up to maximum level. The extraction of date seed oil carried out 2-6 hrs. Ihe optimum time for extraction is 4 hrs. Crushed seed in powdered form gives large surface area for solid-liquid contact. Due to small size particles increase rate as well as yield of extraction of oil from watermelon seed. Extraction carried out at boiling temperature of solvent should be better for rate and yield of extraction. Temperature for extraction with petroleum ether, methanol and hexane up to 40-50 OC.

Strategies for fuel property enhancement for second-generation multi-feedstock biodiesel

Fatty acids from non-edible bioresources are highly sought after as biofuel feedstock and the use of multi-stream feedstock for biodiesel production is of interest. This study explores the potential of using blended feedstock consisting of inedible jatropha oil (JO) and waste cooking oil (WO) for biodiesel production. Prior to blending, the unfavourable high acid value of jatropha oil was esterified under the most optimal conditions of 60 °C, 1% H2SO4 catalyst and alcohol to oil molar ratio of 11:1 to maximise the esterified yield (81.1 %). Based on the acid value measurement, the optimum volumetric blend of WO/EJO was determined to be 90/10 with the lowest acid value of 1.9 mg KOH g−1, which was then utilised as feedstock for base-catalysed transesterification. The KOH catalysed transesterification was optimised at 60 °C, 1 wt% KOH catalyst and alcohol to oil molar ratio of 6:1 to produce biodiesel with low acid value (0.2 mg KOH g−1), high calorific value (38.4 MJ kg−1), high oxidation stability (∼11 h) and favourable viscosity (4.7 mm2 s−1). The results show that the produced biodiesel has acceptable physicochemical properties but its properties can further be improved by blending with petroleum diesel and antioxidant. Among those produced blend derivatives, petroleum diesel and biodiesel blend (80:20) or B20 showed the best improvement with high calorific value (46.6 MJ/kg), high oxidation stability (∼37 h) and low acid value (0.3 mg KOH g−1). Based on the study, in situ feedstock blending of WO/EJO can improve the physicochemical properties of the produced biodiesel and reduce the dependency on single feedstock. Biodiesel blending with commercial diesel can enhance the biodiesel fuel properties and such derivatives can be directly applied in an existing engine.

The Physical and Chemical Characteristics of Seeds Oil of Local Sudanese Pumpkin (Cucurbita moschata Duchesne).

This study aimed to evaluate the physical and chemical properties of pumpkin (Cucurbita moschata Duchesne) seed oil obtained from local Sudanese pumpkins. Three different genotypes of the pumpkin fruits as round, elongated and bell shapes were collected from Elgadarif State, Sudan. The oil's seeds' physical and chemical characteristics were determined by viscosity, specific gravity, refractive index, oil content peroxide value, acid value, saponification, unsaponifiable, pH, iodine value, total polyphenols and fatty acid content. The results revealed that there were significant (p < 0.05) differences in the oil content and chemical characteristics (except acid value and pH) of oil among the different pumpkin fruit genotypes. Linoleic and oleic acids were the primary fatty acids among the different pumpkin fruit genotypes. However, there were no significant (p < 0.05) differences in the fatty acid content and physical properties of the seed's oil. The high oil content, phenolic content and essential fatty acids indicated that the obtained oil from different local Sudanese pumpkins might impart health and nutritional benefit when involved in the food industry as a natural resource.

Biodiesel production from used palm oil using magnetic solid base catalyst

In this research the biodiesel from palm oil were synthesized by using magnetic solid base catalyst. The magnetic solid base catalyst was prepared by using co-precipitation method and followed by modified Stober’s method and wet impregnation method. CaO-ferrite nanometre magnetic solid base catalysts (CaO@Fe3O4/SiO2) were synthesized by loading CaO on the surface of Fe3O4 core-shell using the polymeric binder, TEOS. Under the optimized condition reactions, the catalysts were synthesized by co-precipitation and incipient wetness impregnation followed by calcination at 700 °C for 5 h. The calcined catalyst was fully characterized. The basic strength of the catalysts (H_) was first assessed using Hammett indicators, which are in range 9.8–15.0. The calcined Ca/ferrite-TEOS showed homogenous spherical shape with an apparent thickness of 92 nm. The FT-IR of CaO observed at 520 cm-1 is attributed to the Ca-O vibrations. The EDX analysis confirmed the presence of Fe, Si and Ca on the catalyst. The optimization conditions for biodiesel production have been measured. The catalyst was used 5.0 % wt. The methanol to oil ratio is 5:1, reaction time is 180 minutes and reaction was produced at 80°C. The catalyst achieved a biodiesel conversion of used palm oil (acid value 1.2) above 92 %. The catalytic activity and recovery rate of CaO@Fe3O4/SiO2 are better as compared to CaO catalyst. The properties of synthesized biodiesel have been studied and meet standard the Department of Energy Business.

Effects of fructooligosaccharide and soybean protein isolate in the microencapsulation of walnut oil

The purpose of this study was to evaluate the effects of different proportions of fructooligosaccharide/soy isolate protein as wall materials on the physical properties and structural characterization of walnut oil microcapsules. Different ratios of oligofructose/soy protein isolate microcapsules were prepared to encapsulate walnut oil. The protective effect of microcapsules on walnut oil was evaluated by accelerated oxidation experiment. The microcapsules were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and thermogravimetric analysis. The results show that fructooligosaccharide had no effect on the two-level structure of soy protein isolate, but its encapsulation efficiency could be improved by reducing the particle size of the emulsion and increasing the viscosity of the emulsion. In addition, fructooligosaccharide can improve the encapsulation efficiency by maintaining the structure of the protein during the freeze-drying process. The addition of fructooligosaccharide reduces the water content and hygroscopicity of the microcapsules. The accelerated oxidation results show that microencapsulation can significantly improve the oxidation stability of walnut oil. After accelerated oxidation, the peroxide value and thiobarbituric acid value of walnut oil in the control group were significantly higher than those of microencapsulated walnut oil (p < 0.05). The peroxide value of unencapsulated walnut oil is 2.8 times higher than that of encapsulated walnut oil. The results show that fructooligosaccharide/soy isolate protein could be used as the wall material of microcapsules to embed sensitive, active substances.

PHYSICOCHEMICAL PROPERTIES AND BIOLOGICAL ACTIVITIES OF MANGO (MAGNIFERA INDICA L.) SEED KERNEL AND PEEL OILS

The peel and kernels mango (Mangifera indica L.) processing by products can be used as a source of valuable products. Therefore, the present study was attempted to study physicochemical properties, antioxidant and antimicrobial activities of mango seed kernel and peel wastes. The result of physicochemical properties indicated that significantly higher oil yield (38.75±1.77), specific gravity (0.86±0.04), acid value (2.66±0.20) and free fatty acid value (1.34±0.12); and higher DPPH (16.70±0.70) antioxidant activities were recorded for mango seed oil extract. However, significantly higher hydrogen peroxide scavenging activity (HPSA, 31.10±1.70) and ascorbic acid (43.00±2.73) were recorded for fruit peel oil extract. Stronger antibacterial activity with maximum zone of inhibition (16.50 mm), minimum inhibitory concentration MIC (0.10µl/ml) and corresponding minimum bactericidal concentration MBC (0.20 µl/ml) was recorded for seed oil extract against S. aureus. Stronger antifungal activity with maximum zone of inhibition (16.47 mm), MIC (0.05 µl/ml, the least value) and MFC (0.10 µl/ml) for seed oil extract against C. albicans. It can be concluded from the results of present study that seed oil extract was found to be more effective antioxidant and antimicrobial potential than peel oil extract in mango (M. indica L.)

Nutritive Quality of Walnutdried by Variable Temperature Drum Catalytic Infrared-hot Air

In order to improve the quality of dried walnut, the changes of walnut oil (acid value, iodine value, peroxide value, oleic acid, linoleic acid, linolenic acid and palmitic acid contents), proteinstructure (FTIR, CD, SEM, fluorescence, surface hydrophobicity, amino acid composition) and polyphenols (content, IC50(DPPH), IC50(ABTS) and iron ion reduction ability) were investigated after the variable temperature drum catalytic infrared-hot air drying (VTDCIR-HAD), and compared with those of single hot air drying (HAD) and constant temperature drum catalytic infrared-hot air drying (CTDCIR-HAD). The results showed that compared with HAD, the VTDCIR-HAD and CTDCIR-HAD treatments reduced the oleic acid value by 17.31% and 28.85%, respectively, and decreased the peroxide value by 4% and 20%, respectively, while the iodine value, oleic acid, linoleic acid and linolenic acid contents had no significant changes. Among the three drying methods, the quality of walnut oil treated with VTDCIR-HAD was the best. Compared with HAD, the VTDCIR-HAD and CTDCIR-HAD treated walnut protein structures were more elongated, but there was no significant difference between them. The results showed that the infrared absorption intensity increased, the α-helical contents decreased by 50% and 18.75%, respectively, the fluorescence intensity increased, and the surface hydrophobicity increased by 28.27% and 12.51%, respectively. The proportion of free hydrophobic amino acids decreased by 19.24% and 9.49%, respectively, while the proportion of hydrophilic amino acids increased by 9.84% and 4.85%, respectively, and the apparent structure of protein had no significant change. Compared with HAD, the VTDCIR-HAD and CTDCIR-HAD treatments increased polyphenols contents by 5.23% and 10.92%, respectively, while IC50(DPPH) and IC50(ABTS) decreased by 24.36%, 11.58% and 14.72%, 10.60%, respectively, and iron reduction ability was significantly improved. Among the three drying methods, VTDCIR-HAD treatment had the highest content of polyphenols in walnut. In conclusion, among the three drying methods, VTDCIR-HAD treatment was the best, which can slow down the rate of oil oxidation and rancidity, improve the protein structure, increase the content of polyphenols and antioxidant activity, and was more conducive to protect the quality of dried walnut.

The effect of boiling, germination and roasting on bioactive properties, phenolic compounds, fatty acids and minerals of chia seed (Salvia hispanica L.) and oils

The protein amounts of chia seeds were determined between 27.56% (control) and 28.37% (boiled). Total phenolic and antioxidant activity values of chia seeds treated by several applications changed between 237.70 mgGAE/100g (germinated) and 535 mgGAE/100g (roasted) to 15.27 mmol/kg (roasted) and 15.50 mmol/kg (germinated), respectively. While (+)-catechin amounts of seeds are determined between 15.47 (control) and 60.95 mg/100g (roasted), rutintrihydrate contents of seed extracts were identified between 3.98 mg/100g (control) and 24.92 mg/100g(roasted). While linolenic acid values of oils vary between 62.89% (germinated) and 66.76% (rpasted), linoleic acid amounts of oil samples were identified between 18.55% (control) and 21.04% (roasted). While P contents of chia seeds change between 6103.58 mg/kg(boiled) and 7253.45 mg/kg (control), K amounts of seeds varied between 2534.48 mg/kg (germinated) and 5351.58 mg/kg(roasted). In general, it was observed that the mineral content of boiled chia seeds was low compared to the control and other treated seeds.

Effect of different drying methods on drying characteristics and quality of Camellia oleifera seeds

In order to improve the drying efficiency and product quality, three drying methods of hot air (HA), hybrid infrared-hot air (IR-HA), and hybrid radio frequency-hot air drying (RF-HA) were used to dry fresh Camellia oleifera seeds. The results showed that the shortest drying time was needed, and the minimum shrinkage of C. oleifera seed cells was obtained under hybrid radio frequency-hot air drying than that under hot air drying and hybrid infrared-hot air drying. The oils squeezed from C. oleifera seeds dried by natural air (room temperature), hot air, hybrid infrared-hot air, and hybrid radio frequency-hot air were represented by AO, HAO, IR-HAO, and RF-HAO respectively. The dielectric constant, characteristic peak value of melting heat flux, acid value, and peroxide value of oils squeezed were compared and found that the values of the four indicators of IR-HAO were the highest, but the values of RF-HAO were the lowest. The RF-HAO contains more unsaturated fatty acids, and the quality of RF-HAO was better than that of HAO and IR-HAO. Hybrid radio frequency-hot air drying was the best among the three drying methods of fresh C. oleifera seeds. Practical applications Camellia oleifera seed oil is rich in a large number of fatty acids, of which the content of unsaturated fatty acids can be as high as 93%. The contents of linolenic acid in unsaturated fatty acids were higher than those in sesame oil and soybean oil. Different drying methods on the drying characteristics in this study, microstructure of C. oleifera seeds and the dielectric properties, melting point, acid value, peroxide value of C. oleifera seed oil are analyzed to select the suitable drying technology for C. oleifera seeds. This theory and achievement can provide theoretical guidance for the subsequent processing and storage of C. oleifera seeds.

Assessment of Quality Parameters in Edible Vegetable Oils

Objectives: Edible oils, derived from a plant source, play a vital role in providing nutrition. A quality edible oil has a flavor, range of physicochemical parameters. Several quality parameters like saponification value, acid value, peroxidase value and iodine value will be helpful in estimating the quality of edible vegetable oils. The present study was intended to evaluate the quality difference between cooked and uncooked oils. Materials and Methods: Utilizing various edible oil samples from major brands in india e.g sunflower oil, soybean oil, canola oil, almond oil, coconut oil and, olive oil saponification value and acid value was determined. All the oil samples were thoroughly characterized by calculating their saponification value and acid value using the standard procedure of association of official analytical chemist (AOCS) and American oil chemist society. Results: In comparision to uncooked oils, cooked oils had significantly higher sapnification values. The acid values were also increased in cooked oils compared to uncooked oils. Widely used sunflower oil had a two fold significant increase in saponification value and five fold significant increase in acid value after cooking. Similar changes were not observed in olive oil. Conclusion: Taken together, results of our study indicate that widely used sunflower oil might not be appropraiate for domestic usage. Further, our results also indicate that olive oil might be a better choice for domestic cooking. Further studies are required for a large scale validation of the present results there by brining in regulation/public health policy on usage of cooked oils by various small scale food vendors.

Production of Biodiesel From Croton gratissimus Oil Using Sulfated Zirconia and KOH as Catalysts

Optimization studies for the esterification and transesterification of oil extracted from Croton gratissimus grains were carried out using the response surface methodology (RMS) that utilizes the central composite design (CCD) and the analysis of variance (ANOVA). A 23 full-factorial rotatable CCD for three independent variables at five levels was developed in each case, giving a total of 20 experiments needed per study. The three design factors chosen for study were the catalyst concentration, methanol-to-oil ratio, and the reaction temperature. The values of the acid value of oil (in esterification) and the percentage FAME yield and FAME purity (in transesterification) were taken as the responses of the designed experiments. In the optimization of the esterification and transesterification processes, the ANOVA showed that both quadratic regression models developed were significant. The optimum operating conditions for the esterification process that could give an optimum acid value of 2.693 mg KOH/g of oil were found to be 10.96 mass% SO42–/ZrO2 catalyst concentration, 27.60 methanol-to-oil ratio, and 64°C reaction temperature. In the optimization of the transesterification process, the model revealed that the catalyst concentration and the methanol-to-oil ratio were the terms that had the most influence on the % FAME yield and the % FAME purity of the final biodiesel product. From the combined regression model, it was established that optimum responses of the 84.51% FAME yield and 90.66% FAME purity could be achieved when operating the transesterification process at 1.439 mass% KOH catalyst concentration, 7.472 methanol-to-oil ratio, and at a temperature of 63.50°C. Furthermore, in the two-step biodiesel synthesis, a predominantly monoclinic-phased sulfated zirconia (SO42–/ZrO2) catalyst exhibited high activity in the esterification of high free fatty acid oil extracted from Croton gratissimus grains. A 91% reduction in the acid value of the Croton gratissimus oil from 21.46 mg KOH/g of oil to 2.006 mg KOH/g of oil, well below the 4 mg KOH/g of oil maximum limit, was achieved. This resulted in the high FAME yield and purity of the biodiesel produced in the subsequent catalytic transesterification of oil using KOH.

Zeytinyağı üretim aşamalarının zeytinyağının fizikokimyasal özellikleri ve fenolik bileşenleri üzerine etkisi

Aims: In this study, it was aimed to investigate the effect of industrial-scale continuous extraction process stages (crushing, malaxation and decantation) on physicochemical (oil contents, L*, a*, b*, free acidity, peroxide values) and bioactive properties (total phenolic content, antioxidant activity and phenolic compounds) of olive oil. Methods and Results: The samples of olive, olive paste after crushing and malaxation, and olive oil after decantation, which were obtained from olive oil factory, were used for analyses. The highest oil (56.80%) and the lowest total phenolic (160.70 mg L-1) contents were determined after malaxation process at 35°C for 20 min. The free fatty acid value of olive oil increased from 1.68% to 2.46%, but the peroxide value of oil decreased from 12.5 meq O2 kg-1 to 1.5 meq O2 kg-1 after decanter. The L*, a* and b* values of olive oils were determined between 73.82 and 82.04, -12.60 and -3.71, 14.22 and 45.78, respectively. Moreover, phenolic compounds were not significantly affected from industrial oil extraction process (p&amp;gt; 0.05). The minimum oleic acid (68.58%), and the maximum linoleic acid (11.57%) and palmitic acid (14.66%) concentrations were observed in olive oil obtained from malaxed olive paste. Conclusions: The results of oil yield, fatty acid composition and total phenolic content of samples showed significant differences after the malaxation process. Significance and Impact of the Study: It has been determined that the malaxation process is the extraction stage which significantly affects the quality of olive oil.

Effect of rice bran rancidity on the emulsion stability of rice bran protein and structural characteristics of interface protein

Rice bran protein (RBP) was prepared from rice bran (RB) under different storage periods (0, 1, 5, 7, 10 d), and isolated RBP was used to prepare protein emulsion. The RB crude oil acid value, the RBP oxidation degree, the RBP emulsion stability, and the interface-adsorbed protein and interface-unabsorbed protein structure of RBP emulsion were evaluated. With the RB storage time prolonged, the acid value of RB crude oil and the RBP carbonyl content gradually increased, indicated the occurrence of RB rancidity and RBP oxidation. Furthermore, RBP oxidation led to significant changes in the RBP emulsion stability. Moderate oxidation (RB stored for 1 d) could increase the stability of RBP emulsion, while excessive oxidation (RB stored for 5–10 d) could weaken the emulsion stability. In addition, the increasing RB storage time changed the flexibility and aggregation degree of the adsorbed protein and unabsorbed protein on the emulsion interface. The correlation analysis showed that the stability of the protein emulsion was highly correlated (P < 0.01) with the flexibility of interface-adsorbed protein, but showed little correlation with the flexibility of the unabsorbed protein at the interface. By regulating the oxidation degree of RPB to improve the emulsion stability, this research can provide a theoretical reference for promoting the stability of protein emulsions, and enlarging their applications in food systems.

PHYSICOCHEMICAL ANALYSIS AND CHARACTERIZATION OF BIODIESEL PRODUCTION FROM RICINUS COMMUNIS SEED OIL

The global energy concern with the availability of recoverable fossil fuel reserves and the environmental problems caused by those fossil fuels, considerable attention has been given to biodiesel production as an alternative to petro diesel worldwide. In this research, the seed oil of Ricinus communis (castor bean) was investigated for its viability as a feedstock for biodiesel production. The oil was extracted from the seed using petroleum ether .The oil quality characteristics of the seed oil were; Acid values for both Ricinus communis oil and biodiesel, 4.208 and3.93, and free fatty acids for both Ricinus communis and biodiesel were 1.2408 and 2.508, saponification value (SV) for both Ricinus communis and biodiesel,, 185.0 and 173.16, specific gravity (S.G) for both Ricinus communis and biodiesel, 0.976g/ml and 0.935g/ml. the PH value for both Ricinus communis and biodiesel, 6.67 and 6.8. Refractive index for both Ricinus communis and biodiesel, 1.37 and 1.191, moisture content of seed, 0.052. Colour for both and Ricinus communis oil and biodiesel is brown colour and amber colour, respectively. The oil was transesterified using methanol and concentrated sulphuric acid. And with other investigated oils from the literature and were found to fall within acceptable limits, this implies that Ricinus communis seed oil could be used as diesel in combustion engines in tropical climates like Nigeria.

Process Optimization for Biodiesel Production from Highly Acidic Hibiscus Cannabinus (Deccan Hemp) Oil

In this study, Hibiscus Cannabinus (deccan hemp) oil was used to convert its methyl ester. Methyl ester synthesis process involves of two-steps: esterification of sulfuric acid (Step-1) and alkaline transesterification (Step-2). Deccan hemp oil was found to have an initial acid value of 12.48 mg KOH/g. The acid value of deccan hemp oil was decreased to below 2 mg KOH/g in Step-1 taking consideration to get higher ester yield after alkaline transesterification process. The alkaline transesterification process parameters such as methyl alcohol to deccan hemp oil molar ratio, sulfuric acid catalyst amount, reaction temperature and reaction time were optimised and analysed in detail. This process gives ester yield of about 95.48%. The important properties of the synthesised methyl ester were determined and compared with IS 51607 and ASTM D6751 biodiesel standards.

Ohmic Heating-Aided Mechanical Extraction of Gamma-Oryzanol and Phytosterols in Rice Bran Oil

The price of rice bran oil depends on the amounts of contained bioactive compounds especially oryzanol and phytosterols. The oryzanol content of rice bran oil under ohmic heating optimized at 70 V/cm, 90 °C for 3 min (27,580.75 ± 916.58 mg/kg) was higher than the control (24,908.57 ± 19.87 mg/kg). Ethanol-to-water ratio (p ≤ 0.000), medium-to-rice bran ratio (p ≤ 0.002), and electric field (p ≤ 0.028) all statistically significantly affected oryzanol content. Using water medium at low electric field (70 V/cm) produced the highest oryzanol content, while a high medium-to-rice bran ratio (1:1) resulted in the highest oryzanol content due to rapid temperature increase. Ohmic heating reduced acid value and free fatty acid content of rice bran oil and hence extended its shelf life. Ohmic heating under pressure (1 bar) was applied to elevate the boiling point and prolong the holding time, thereby obtaining higher oryzanol content (24,758.11 ± 48.96 mg/kg) than in non-pressurized rice bran oil (21,170.93 ± 42.72 mg/kg) (p ≤ 0.05). Conductivity of the medium and holding time positively correlated with oryzanol content whereas temperature had a negative correlation. Ohmic heating extraction efficiency increased with more water-soluble bioactive compounds ranking from phenolics, oryzanol, and phytosterols.