Refined Palm Olein Research Articles

A study on the physicochemical characteristics of popular cooking oils in Cambodia

Cooking oils tend to deteriorate in quality through oxidation reactions and microbial degradation, causing nutritional loss, consumer unacceptability, health risks such as cancer and inflammation. This study aims to assess the quality of five popular cooking oils sold in Cambodia, including two sunflower oils, two soybean oils, and a refined palm olein cooking oil. All the samples were collected from supermarkets in Phnom Penh, Cambodia. The peroxide value (PV), acid value (AV), and anisidine value (AnV) of the cooking oils ranged from 1.93 to 5.68 meq O2/kg oil, 0.11 to 0.26 mg KOH/g, and 28.71 to 62.49, respectively. The iodine value (IV) of soybean oil, sunflower oil, and refined palm olein oil is 121.53 to 125.91 g I2/100g, 127.39 to 128.89 g I2/100g, and 68.61 g I2/100g, respectively. The colour of the oils was presented as L, a, and b*, which ranged from 32.64 to 34.42, -1.48 to -0.34, and 1.50 to 5.25, respectively. The PV and AV of the cooking oils are within the acceptable range of the FAO’s Codex Alimentarius Standards which is 10 meq O2/kg and 0.6 mg KOH/g, respectively. According to the research findings, the popular cooking oils sold in Cambodia are in good quality for consumption.

Determining the effect of raw materials moisture and lipid content on the technological properties of the extruded protein-fat system

The way to solve the problem of correcting technological indicators, in particular porosity and moisture content, in extruded protein-fat systems based on soybean, rapeseed, hemp meal, and corn grits is considered. The peculiarity of the work is the substantiation of the rational ratio of the content of moisture and lipids in the raw components of the extrudate, which is an important aspect of rationalizing the composition and improving the texture of innovative extruded products based on the specified raw materials. The object of the research is technological indicators, in particular the porosity and moisture content of the extruded protein-fat system, depending on the moisture and lipid content in the raw components. A rational ratio of moisture content (10.5...12.5 %) and lipids (3.5...5.0 %) in the raw material for the extruded protein-fat system was determined. The use of refined palm olein as an oil product resistant to oxidative deterioration, which should be added to raw components in order to correct the technological properties of the finished product, is substantiated. The developed protein-fat system of reasonable composition has an advantage over a commercial similar product in terms of crude protein content (29.0 % vs. 8.2 %), porosity (130.0 % vs. 105.0 %) and cost ($ 916/t vs. $ 2,798/t). The obtained data are explained by the fact that a complex of components was used, some of which are production waste, with reasonable moisture and lipid content, which improved the technological characteristics of the extrudate. An applied aspect of using this scientific result is the possibility of rationalizing the extrusion process of oilseed meal to achieve the desired texture, porosity and stability of the lipid component of the product

Biofuel upgrading via catalytic deoxygenation in trickle bed reactor: Crucial issue in selection of pressure regulator type

Trickle bed reactors (TBRs) are commonly used in various chemical and associated processes. The selection of a proper back pressure regulator (BPR) is crucial for maintaining the system's upstream pressure. In this study, we investigate the impact of BPR selection on deoxygenation reaction in a TBR with two typical types of BPR, including gas-phase type back pressure regulator (Gas-BPR) and multiphase type back pressure regulator (Multi-BPR). Notably, Gas-BPR introduces interruptions and pressure drops during the sampling step, impacting the hydrogen flow rate, while Multi-BPR ensures more consistent hydrogen flow. To examine the performance of BPR systems, hydrotreating experiments were conducted at 330 °C, 50 bar of hydrogen over Ni/γ-Al2O3 catalyst using crude Pongamia pinnata oil as a feedstock and refined palm olein as a benchmark. Insignificant difference in the reaction performance between Multi-BPR and Gas-BPR systems was observed when using refined palm olein. Interestingly, there was a significant difference between the two systems when feeding with crude Pongamia pinnata oil. The multi-BPR system demonstrated superior performance, achieving 100% conversion of the feedstock over a prolonged period compared to the interrupted hydrogen flow in the Gas-BPR system. Further characterization of fresh and spent catalysts using N2 sorption, XRD, SEM-EDS and TGA-DTG-DSC techniques revealed that a gum and coke formation was a reason for the rapid catalyst deactivation. Furthermore, the interrupted flow in the Gas-BPR system led to substantial gum production, ultimately causing a blockage in the reactor bed. Consequently, for feedstocks with high impurities, a robust continuous flow of hydrogen is essential. Thus, the study strongly recommends selecting Multi-BPR for continuous operation in TBRs to enhance efficiency and avoid catalyst deactivation.

A comparative study of the oxidative stability and the formation of monochloropropanediol esters (MCPDE) and glycidyl esters (GE) between physically and chemically refined palm olein during repeated deep-frying

A comparative study of the oxidative stability and the formation of monochloropropanediol esters (MCPDE) and glycidyl esters (GE) between physically and chemically refined palm olein during repeated deep-frying

Improved hydrogenation process for margarine production with no trans fatty acid formation by non-thermal plasma with needle-in-tube configuration

Non-thermal dielectric barrier discharge (DBD) plasma with needle-in-tube configuration was used to improve hydrogenation reaction for trans -fat free margarine production. Refined palm olein was used as raw material with operating conditions at ambient pressure, room temperature (29 °C) and no catalyst. Effects of hydrogen gas (H 2 ) concentration, input power, gas flow rate, discharge gap size and reaction time on fatty acid compositions and properties of hydrogenated refined palm olein after plasma treatment was evaluated. Lowest iodine value (IV) was achieved with reduction from 60.75 to 23.56 with increase in saturated fatty acid composition from 40.82 ± 0.05 to 68.70 ± 0.07% and decrease in unsaturated fatty acid composition from 59.11 ± 0.12 to 31.39 ± 0.01% under the condition of 0.5 L/min gas flow rate with 100% H 2 , 40 W input power, 0.5 cm gap size and 15 h reaction time. In addition, no trans -fat was detected by GC-MS analysis. Slip melting point (SMP) was increased from 9.33 ± 0.5 to 36.33 ± 0.5 °C. Acid value (AV) was reduced from 0.47 ± 0.02 to 0.32 ± 0.03 mg KOH/g oil. Texture of produced margarine was similar to that of commercial one. Generated hydrogen free radicals were hypothesized to perform hydrogenation by reacting with carbon-carbon double bonds (π-bonds), converting poly- and monounsaturated fatty acids into saturated ones. This highly effective catalyst-free plasma hydrogenation system can be used as alternative, environmentally friendly and economically feasible method to produce trans -fat free margarine. • Production of trans -fat free margarine via non-thermal plasma hydrogenation of palm olein. • Highly environmental-friendly, requiring no catalyst under low temperature and pressure. • Reduced acid value provides increased storage time and longer shelf life.

Impact of Frying Oil Types and Keeping Duration on the Safety, Storability and Acceptability Factors of Chin-Chin (Deep-Fried Snack)

This study investigated the influence of frying oil types and storage duration on the acrylamide concentration, moisture variation pattern, thiobarbituric acid reactive substances (TBARS) content and acceptability factors of commonly consumed snack (chin-chin). A standard processing procedure was used to prepare the snack (chin-chin) using a combination of ingredients such as wheat flour, sugar, salt, margarine, ground nutmeg, egg, and water. Two types of vegetable oil used for deep-frying were soybean oil and refined palm olein oil while commercial chin-chin samples were also purchased to serve as the control. The results showed that during the storage period, the acrylamide contents in chin-chin samples exhibited gradual increase. The commercial chin-chin (CH-COM) contained the highest initial moisture content (13.54%) while all the chin-chin samples exhibited gradual increase in moisture content during the 12-day storage period. The study also revealed that during the storage period, all the chin-chin samples exhibited gradual reduction in the TBARS level. However, the degree of reduction in the TBARS content of commercial chin-chin was the highest as it reduced from the initial 0.33 mg MDA/kg to 0.17 mg MDA/kg during the 12-day storage duration. The fresh chin-chin samples exhibited relatively high level of browning index with significant differences at p<0.05 while there were variations in the oiliness index of the snack samples. The chin-chin samples in this study were generally found to satisfy the requirements for the tolerable levels for both the acrylamide and thiobarbituric acid reactive substances (TBARS) throughout the 12-day storage period.

Preservative Effect of Ginger Root (Zingiber officinale R.) Extract in Refined Palm Olein Subjected to Accelerated Thermal Oxidation

Oils and fats are susceptible to the oxidation of their unsaturated fatty acids during processing, storage, or handling. Oxidation reactions lead to serious damages to oil quality that makes it to be rejected by consumers for health issues and industries that might undergo financial challenges. To limit these damages, chemically synthesized antioxidants have been added to oils and fats as preservatives. However, these were reported not to be healthy and natural substitutes extracted from plant have been the main focus of many researchers and industries these recent years. This study aimed at evaluating the preservative effect of ginger root extracts in inhibiting palm olein alteration during accelerated air-dried oven storage at 180°C. The natural antioxidants were added to palm olein at the concentrations of 200, 600, 1000, 1400, and 1800 ppm and kept in the air-dried oven for six days at 180°C (daily heating was 4 h). Butylated hydroxytoluene (BHT) was used as positive control and oil with no additive functioned as the negative one. Oil samples were collected from the oven after every 2 days for analysis. The quality parameters including the peroxide value (PV), the p-anisidine value (p-AV), the total oxidation value (TOTOX), the acid value (AV), the thiobarbituric acid value (TBA), and the iodine value (IV) were determined. The changes in the fatty acid composition of palm olein were characterized by gas chromatography coupled to a flame ionization detector (GC/FID). The ginger extract was found to be effective in delaying palm olein alteration during processing. Extract efficiency was concentration-dependent and was better than that of the control and the sample supplemented with butylated hydroxytoluene (BHT). Therefore, ginger root extract can be an ideal alternative to synthetic antioxidants used in palm olein.

Catalytic Hydrotreating of Crude Pongamia pinnata Oil to Bio-Hydrogenated Diesel over Sulfided NiMo Catalyst

This work studied the catalytic activity and stability of Ni-MoS2 supported on γ-Al2O3, SiO2, and TiO2 toward deoxygenation of different feedstocks, i.e., crude Pongamia pinnata oil (PPO) and refined palm olein (RPO). PPO was used as a renewable feedstock for bio-hydrogenated diesel production via catalytic hydrotreating under a temperature of 330 °C, H2 pressure of 50 bar, WHSV of 1.5 h−1, and H2/oil (v/v) of 1000 cm3/cm3 under continuous operation. The oil yield from a Soxhlet extraction of PPO was up to 26 wt.% on a dry basis, mainly consisting of C18 fatty acids. The catalytic activity in terms of conversion and diesel yield was in the same trend as increasing in the order of NiMo/γ-Al2O3 > NiMo/TiO2 > NiMo/SiO2. The hydrodeoxygenation (HDO) activity was more favorable over the sulfided NiMo supported on γ-Al2O3 and TiO2, while a high DCO was observed over the sulfided NiMo/SiO2 catalyst, which related to the properties of the support material and the intensity of metal–support interaction. The deactivation of NiMo/SiO2 and NiMo/TiO2 occurred in a short period, due to the phosphorus and alkali impurities in PPO which were not found in the case of RPO. NiMo/γ-Al2O3 exhibited the high resistance of impure feedstock with excellent stability. This indicates that the catalytic performance is influenced by the purity of the feedstock as well as the characteristics of the catalysts.

Stepwise strategy based on 1H-NMR fingerprinting in combination with chemometrics to determine the content of vegetable oils in olive oil mixtures

1H NMR fingerprinting of edible oils and a set of multivariate classification and regression models organised in a decision tree is proposed as a stepwise strategy to assure the authenticity and traceability of olive oils and their declared blends with other vegetable oils (VOs). Oils of the ‘virgin olive oil’ and ‘olive oil’ categories and their mixtures with the most common VOs, i.e. sunflower, high oleic sunflower, hazelnut, avocado, soybean, corn, refined palm olein and desterolized high oleic sunflower oils, were studied. Partial least squares (PLS) discriminant analysis provided stable and robust binary classification models to identify the olive oil type and the VO in the blend. PLS regression afforded models with excellent precisions and acceptable accuracies to determine the percentage of VO in the mixture. The satisfactory performance of this approach, tested with blind samples, confirm its potential to support regulations and control bodies.

Effects of Combining Antioxidants on the Oxidative Stability of Refined, Bleached and Deodorized Palm Olein during Continuous Deep Frying of Potato Chips

In this study, the effect of a novel antioxidants composite system based on a synergetic composite between Tertiary butyl hydroquinone (TBHQ), Ascorbyl palmitate, citric acid, and Dimethicone have been evaluated against the classical common antioxidant system based on TBHQ at the highest permitted dose of 200 ppm during successive deep-frying cycles. Also, the shelf life of fried food and its sensory performance and oil absorption content o fried food were comparatively studied. The Novel antioxidant composite system is a synergetic blend of an artificial antioxidant, TBHQ and vitamin C palmitate( Ascorbyl palmitate) as natural identical antioxidants, an effective sequestrant which is Citric acid and poly dimethyl siloxane as an anti-foaming system to obtain the highest oxidative stability impact during deep frying. The frying processes were carried at 180 ᴼC for sliced potato chips for 8 successive frying cycles.Sensory evaluation of the fried potato has been conducted under accelerated storage conditions to determine the effect of the oil oxidative stability on the shelf life of fried food. The oxidative degradation of the oil was evaluated by measuring different oxidation and degradation parameters for their respective peroxide value ( PV), free fatty acid( FFA %), the content of conjugated dienes, P-anisidine value,( p-A.V), induction period (IP), and Lovibond color. The (%) of oil absorption in the potato chips was also measured. The sensory evaluation has been done for fried foods to evaluate the crunchiness and likability of obtained french fries. Results revealed that the jump in primary & secondary oxidation parameters as PV and p- A.V.of palm olein after 8 successive frying cycles was very limited for the antioxidant composite system I by only 1.842± 0.1 meq O2/ kg in PV and by 6.2315±0.45 for p-A.V. Same for FFA, the jump was limited for the antioxidant composite system I for only 0.084+/-0.005 as well. However, the final PV, FFA after the 8 frying cycles are still within the Codex and local Egyptian regulation limits the edible oil human usage. Same for other quality parameters like color jump was limited to 3.4 Red jumps on Lovi bond scale for composite I. Study proofed that palm olein fortified with 650 ppm of the antioxidant composite (I) consists of TBHQ, Ascorbyl palmitate, citric acid, and polydimethylsiloxane at the specified synergistic ratios gives outstanding stability to refined Palm olein during the successive deep frying up to 8 successive frying cycles. It also achieved less oil absorption for french fries by about 3.5% less than the same oil fortified with 200 ppm TBHQ, which is the highest permitted dose of this strong antioxidant. (P≤0.05). Furthermore, sensory evaluation of the fried potatoes has been improved with the novel antioxidant system compared to theclassical TBHQ system.

High Conversion of Palm Olein to Ethyl Esters Using a Strong Anion Exchange Resin: Study of the Operational Parameters

Biodiesel, known as a mixture of fatty acid ethyl/methyl esters, is seen as an alternative, ecofriendly, biodegradable and renewable non-fossil fuel. The use of heterogeneous catalysts for biodiesel synthesis can solve several problems associated with the homogeneous alkaline catalyzed-transesterification. Therefore, this work reports the evaluation of the commercial resin Amberlyst A26OH, a strong anion exchange resin, as a heterogeneous catalyst for the batch transesterification of refined palm olein with ethanol. It was studied the effects of the main operational parameters, considering the molar ratio of the reaction mixture (MRRM), namely the molar ratio of ethanol to olein taking into account only the ethanol added to the reaction system, and the total molar ratio (TMR), in this case considering also the amount of ethanol carried by the resin after its pretreatment. It was determined an optimal range of operational conditions by response surface methodology, guaranteeing conversion to ethyl esters higher than 96% with a catalyst amount corresponding to a range from 10.4 to 11.4% of the oil quantity, a temperature within the range of 55 to 60 oC and a MRRM within the range from 3.5:1 to 6.0:1.

Quality parameters of sunflower oil and palm olein during multiple frying

The refined sunflower and palm oils are used in the food industry for the production of fried potatoes. Literary data have shown that palm oil had less tendency to degradation than sunflower oil due to its fatty acid composition. However, palm olein is a palm oil fraction and therefore has a different composition of fatty acids. The aim of this study was to investigate the quality of the refined palm olein in relation to the refined linoleic type sunflower oil during the production of fried potatoes. The oil samples were used for multiple frying during the seven days (40 minutes per day at a temperature of 165oC). The peroxide value and free fatty acid content (acid value) were determined by standard analytical methods. The results showed that the peroxide value in sunflower oil and palm olein increased by 75.0% and 77.8%, while the acid value increased by 50.0% and 26.8%, respectively, in relation to their initial values in the fresh oil samples. Based on these results, it can be concluded that the palm olein was more suitable for frying. However, this finding cannot be reported with certainty because the quality of the oil depends on many more parameters, not only on those analysed in this paper.

Effects of different storage conditions on the oxidative stability of crude and refined palm oil, olein and stearin (Elaeis guineensis)

Abstract Crude palm oil (CPO), refined palm oil (RPO), refined palm olein (RPOL) and refined palm stearin (RPS) were stored in three conditions: kept away in dark (at 20-25 °C, acclimatized environment); in a refrigerator (4-8 °C); and at room temperature (26-32 °C), exposed to natural light. Free fatty acids (FFA; %), peroxide value (meq O2/kg), induction period (h), total carotenoids (ppm) and color measurements (CIELab) were analyzed to determine stability of oils every months until 12 months. All of the crude/refined initial oils were of good quality, except for one sample of CPO. Storage at 26-32 °C and exposure to light intensified the oxidative reactions. The estimated shelf life of CPO, RPO, RPOL and RPS, when stored at 20-25 °C and in the dark, would be approximately 6, 9, 9 and 12 months, respectively. The best quality oils was found stored at 4-8 °C when compared to those stored in other storage conditions.

Hypolipidemic and anti‐atherogenic effect of omega‐3 enriched structured lipids from linseed oil (LSO) with refined palm olein oil (RPOO) on rats fed atherogenic diet

The anti‐atherogenic effect of omega‐3 enriched structured lipids prepared by lipase catalyzed enzymatic intersterification with refined palm olein oil (RPOO) and linseed oil (LSO) was studied in rats. LSO is a good source of short chain omega‐3 fatty acid (alpha linolenic acid, ALA, omega‐3 FA) whereas an RPOO contains a higher amount of palmitic acid (SFA) and oleic acid (MUFA). But it is lacking of omega‐3 fatty acids. Based on standardization with different ratios, the ideal combination was selected based on the fatty acid composition and TAG molecular species of oils. The structured lipids (SL) of RPOO with FXO (40:60) has obtained an ideal SFA:MUFA:PUFA ratios near to 1:1:1 and enriched with omega‐3 fatty acids. This redisposition of fatty acids boost the functional properties and beneficial for cholesterol lowering properties. The feeding experiment conducted on rats fed on normal and atherogenic diet containing 10% omega‐3 SL (experimental) and RPOO(control‐native oil) indicated no adverse effects on growth and food intake. Rats fed Omega‐3 enriched structured lipids showed a decrease in cholesterol as compared to RPOO in atherogenic diets. However, the omega‐3 structured lipids potentially lowered plasma, hepatic and aortic lipids, predominantly cholesterol, LDL +VLDL cholesterol and triglycerides. Feeding of an omega‐3 enriched structured lipids resulted in the accretion of long‐chain omega‐3 PUFA and decrease in the long chain omega‐6 PUFA in plasma, hepatic and aortic lipids. The lipid accumulation observed in the aorta of rats fed atherogenic diet with Omega‐3 enriched structured lipids was considerably reduced as compared to natural oil of RPOO. However, the Omega‐3 enriched Structured lipids exhibited better incorporation of omega‐3 fatty acids and beneficial for cardiac function and reduce the risk for cardiovascular diseases.Support or Funding InformationnoneThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Formulation and Characterization of Human Milk Fat Substitutes Made from Blends of Refined Palm Olein, and Soybean, Olive, Fish, and Virgin Coconut Oils

AbstractThe simplest and the most cost‐effective way of human milk fat substitute (HMFS) production is formulating of suitable vegetable oils at proper ratios. To do this, the D‐optimal mixture design was used to optimize the HMFS formulation. The design included 25 formulations made from refined palm olein (35–55%), soybean oil (5–25%), olive oil (5–20%), virgin coconut oil (5–15%), and fish oil (0–10%). Samples were produced in laboratory and characterized in terms of fatty acid and triacylglycerol (TAG) compositions, free fatty acid content, peroxide value, iodine value, and oxidative stability index (OSI). HMFS samples were also compared with Codex Alimentarius (CA) and Iran National Standards Organization (INSO) standards. Each characteristic of HMFS samples was then expressed as a function of ingredient ratio using regression models. Finally, using numerical optimization, four optimized blends (PB1‐PB4) were selected, made in the laboratory (HMFS1‐HMFS4), characterized, and compared with CA and INSO standards. The properties of all the optimized blends (except the palmitic acid content of HMFS2and the monounsaturated fatty acid [MUFA] content of HMFS3) met the standards. HMFS4showed the highest OSI in Rancimat and the lowest oxidation rate in Schaal oven tests. POL (19.53–21.73%), PPO (20.77–21.73%), OOO (9.11–11.16%), and OPO (8.84–9.46%) were the main (totally about 60%) TAG species found in HMFS samples. In conclusion, the HMFS4formula (55% palm olein, 13.5% soybean oil, 16% refined olive oil, 15% virgin coconut oil, and 0.5% fish oil) was suggested as the best formula for HMFS production.

Palm oil spot-futures relation: Evidence from unrefined and refined products

This study examines the palm oil spot-futures relation in terms of mean and volatility spillovers from 2010 to 2018. Based on the cross-correlation function of standardised residuals and its squared residuals, our results show: first, crude palm oil (CPO) futures returns Granger cause refined palm oil, palm stearin and palm olein spot returns. Second, refined palm kernel oil spot returns Granger cause crude palm kernel oil futures returns in mean and variance. Third, CPO spot and refined palm olein futures returns are independent; and fourth, there is volatility spillover from CPO futures market to refined palm oil spot market within longer time. These findings suggest that refiners can use CPO futures returns instead of crude palm kernel oil futures returns for predicting the future spot return of refined palm oil products. To lock in purchasing price of unrefined palm oil products, the producers can rely on the spot volatility to decide the optimal number of crude palm kernel oil futures contracts.

Catalytic activity of trimetallic sulfided Re-Ni-Mo/γ-Al2O3 toward deoxygenation of palm feedstocks

Catalytic activities of trimetallic ReNiMo sulfide supported on γ-Al2O3 toward the deoxygenation of oleic acid, palm fatty acid distillate (PFAD), refined palm stearin (RPS) and refined palm olein (RPO) were studied. Relevant monometallic and bimetallic (i.e. Mo-, W-, Re-, ReMo-, ReW-, NiMo-) sulfides were also tested for comparison. Experiments revealed that, among all catalysts, ReNiMo sulfide catalyst exhibited the highest diesel yield of 76.5% from oleic acid, 72.5% from PFAD, 69.7% from RPS and 69.5% from RPO. Furthermore, the catalyst could maintain constant diesel yield level for at least six consecutive runs, whereas significant deactivation was observed from other catalysts due to high carbon deposition. Importantly, glycerol was also successfully employed as a hydrogen donor for deoxygenation reaction over this catalyst. From the catalyst characterizations, additional of Re increased the NiMo surface area by 20.4%, furthermore, it reduced the metal particle size and promote the metal dispersion on the support.

Minimum quantity of lubricant drilling of stainless steel using refined palm olein: Effect of coating tool on surface roughness and tool wear

Abstract This study investigates the effect of cutting tool coating during minimum quantity of lubricant (MQL) drilling of austenitic stainless steel using refined palm olein (RPO) as lubricant/cutting fluid. Two types of tool coating, TiAlN and TiSiN, on tungsten carbide drill with diameter 4 ± 0.01 mm, point angle of 130° and helix angle of 30° were used in this study to machine AISI 316L stainless steel workpiece with hardness of 179.5 HV. Drilling tests were conducted with cutting speed of 12 m/min and feed rate of 0.025 mm/rev. Tool overhang was set at 30 mm. The MQL system in this trial was with 5.5 bar of air, the spray output was 27 ml/h, adjusted 20° and located 35 mm away from the cutting tool. Tool wear was measured during experiment using tool microscope connected to image analyser. Surface roughness (Ra) was measured with cut–off and sampling lengths of 0.8 mm and 4 mm, respectively. For each hole, the surface roughness was measured parallel to the drilled axis at four radial positions at 0°, 90°, 180° and 270°, repeated three times repeated for each position. Tool life of the drill and surface roughness of the drilled hole were the machining responses investigated. It was found that the MQL-RPO drilling using TiSiN coated carbide tool produced better result in terms of tool life (reaching 7.54 minutes) compared to using TiAlN coated tool (of only 4.19 minutes). Related to surface roughness, the best result was obtained by TiAlN coated tool. Through two-factor analysis of variance (ANOVA) with replication on first hole, it was found that the wear of the tool affects the surface roughness significantly while different types of coating has no significant effect on tool wear and surface roughness. In addition, there is no interaction between types of coating and wear of the tool that influence the surface roughness.

Effects of Use and Re-Use of Selected Vegetable Oils on the Proximate, Minerals, Mineral Ratios and Mineral Safety Index of Raw and Fried Plantain Chips: Note I

Raw and fried plantain chips obtained from the use and re-use of olive, refined palm olein and coconut oils were investigated for the proximate, mineral compositions, computed mineral ratios and the mineral safety index using standard analytical methods. For the selected oils (both use and re-use): first and second re-use and the fresh plantain chips (unprocessed plantain chips; UPC) had the following range results: proximate composition (%) (moisture: 8.20 - 12.3, crude protein: 9.70 - 8.60, fat: 7.40 - 12.9, fibre: 3.50 - 4.90, ash: 2.80 - 3.80 and carbohydrates: 63.5 - 64.8), % energy contributions (PEC: 63.4 - 70.8, PEF: 20.2 - 28.6, PEP: 8.03 - 9.66, UEDP: 4.49 - 5.08). The mineral composition (mg/100g) of the samples had the following greater than 80.0: Ca, Mg, K and P; Fe, Cu, Mn and Zn recorded values ranging between 1.00 and 4.00; Co, Se and Ni had their concentrations between 0.00 and 0.0363 whereas Pb and Cd recorded levels lower than 0.0006. In the mineral ratios, only K/(Ca + Mg) values fell within the acceptable ideal range. No MSI aberration was observed for the minerals from all the samples obtained from the various oils. The chi-square analysis showed that on parameter wise comparisons, there were no significant differences among the levels as treated based on the various oils except gross energy, Mg, K, P, Ca/P, Fe/Pb and K/Co. Also on pairwise comparison from linear correlation and regression, all these parameters were significantly different at r = 0.01 between the unprocessed and fried plantain samples: proximate, percentage energy distribution, mineral and mineral ratios. Generally, the first (day) frying showed fairly high nutrient concentration than the first and second re-use oils products. Therefore, for optimum nutrient preservation from fried plantain chips re-use of oil for frying should be sparingly allowed. However, olive showed highest level of nutrients in terms of proximate and mineral compositions.

Effects of natural antioxidants extracted from Cameroonian ginger roots on the oxidative stability of refined palm olein

The objective of this study was to evaluate the effect of ginger roots methanolic extract on the stability of palm olein during accelerated storage. After analysis of the extract by the measurement of its total phenolic content by colorimetry and detection of some of its phenolic antioxidants by HPLC-DAD (high performance liquid chromatography-diode array detector) and ESI-MS (Electrospray ionization-mass spectrometer), preliminary antioxidants tests have been conducted. After these tests, the extract has been added in refined palm olein at concentration 200–1800 ppm for investigating its effect on it oxidative stability. Butylated hydroxytoluene (BHT) at it legal concentration of 200 ppm served as positive control, while palm olein without additive served as negative control. Induction time, chemical indexes (peroxide, p-Anisidine, total oxidation, thiobarbituric acid and iodine values) and changes in linoleic acid profile (analyzed by gas chromatography coupled to a flame ionization detector) of oil samples were evaluated. Results of these investigations showed ginger roots methanolic extract to be rich in phenolic antioxidants. Ferulic acid and 6-gingerol were the antioxidants detected. The extract was also efficient in reducing palm olein oxidation on Rancimat and Schaal oven test of 30 days at 70 °C. Ginger roots extract might be a viable source of natural antioxidants for stabilization of palm olein.