COMPARISON OF THE FRYING PERFORMANCE OF REFINED, BLEACHED AND DEODORIZED PALM OLEIN AND COCONUT OIL

From Palm to Plate: Unveiling the Potential of Coconut as a Plant-Based Food Alternative

This review investigates coconut as a sustainable and nutrient-rich plant-based alternative to traditional animal-based food sources. We have explored the nutritional profile, culinary versatility, particularly focusing on the use of coconut meat, milk, cream, and oil in diverse dietary contexts when consumed in balance. Comparative analysis with animal-derived products reveals the high content of medium-chain triglycerides (MCTs), essential vitamins, and minerals in coconut, contrasted with its lower protein content. Researchers have underscored the environmental sustainability of coconut, advocating for its role in eco-friendly food production chains. We have also addressed challenges like potential allergies, nutritional balance, sensory attributes, and consumer motivations for coconut-based products, in terms of understanding the market dynamics. In conclusion, this review positions coconut as a promising candidate within sustainable diet frameworks, advocating for further research to augment its nutritional value, sensory characteristics, and product stability, thereby facilitating its integration into health-conscious and eco-centric dietary practices.

Multivariate modelling analysis for prediction of glycidyl esters and 3-monochloropropane-1,2-diol (3-MCPD) formation in periodically heated palm oil

Palm oil is a vegetable oil that is widely used for cooking and deep-frying because of its affordability. However, repeatedly heated palm oil is also prone to oxidation due to its significant content of unsaturated fatty acids and other chemical toxicants such as glycidyl esters and 3-monochloropropane-1,2-diol (3-MCPD). Initially, the physicochemical properties such as colour, viscosity, peroxide, p-anisidine and total oxidation (TOTOX) of periodically heated palm oil were investigated. Chemical profiling and fingerprinting of six different brands of palm cooking oil during heating cycles between 90 and 360 min were conducted using Fourier transform infrared (FTIR) and 1H Nuclear Magnetic Resonance (NMR) metabolomics. In addition, the multivariate analysis was employed to evaluate the 1H NMR spectroscopic pattern of repeatedly heated palm oil with the corresponding physicochemical properties. The FTIR metabolomics showed significant different of the chemical fingerprinting subjected to heating duration, which in agreement with the result of 1H NMR metabolomics. Partial least squares (PLS) model revealed that most of the physicochemical properties of periodically heated palm oil are positively correlated (R2 values of 0.98-0.99) to their spectroscopic pattern. Based on the findings, the color of the oils darkened with increased heating time. The peroxide value (PV), p-anisidine value (p-AnV), and total oxidation (TOTOX) values increased significantly due to degradation of unsaturated compounds and oxidation products formed. We identified targeted metabolites (probable carcinogens) such as 3-monochloropropane-1,2-diol (3-MCPD) and glycidyl ester (GE), indicating the conversion of 3-MCPD to GE in repeatedly heated oils based on PCA and OPLSDA models. Our correlation analysis of NMR and physicochemical properties has shown that the conversion of 3-MCPD to GE was significantly increased from 180 to 360 min cooking time. The combination spectroscopic techniques with physicochemical properties are a reliable and robust methods to evaluate the characteristics, stability and chemical's structure changes of periodically heated palm oil, which may contribute to probable carcinogens development. This study has proven that combination of NMR and physicochemical analysis may predict the formation of the probable carcinogens of heated cooking oil over time which emphasizing the need to avoid certain heating cycles to mitigate formation of probable carcinogens during cooking process.

Influence of High Temperature and Duration of Heating on the Sunflower Seed Oil Properties for Food Use and Bio-diesel Production

Two important problems for the food industry are oil oxidation and oil waste after frying. Sunflower seed oil is one of the vegetable oils most commonly used in the food industry. Two variables were applied to the low oleic sunflower seed oil in this work i.e. heating temperature (180-210-240°C) and time of heating (15-30-60-120 minutes), to study from the edible point of view the variations of its physico-chemical properties. After 120 minutes heating at 240°C the following was found: refractive index (1.476), free acidity (0.35%), K232 (2.87), K270 (3.71), antiradical activity (45.90% inhibition), total phenols (523 mg kg^-1), peroxide value (17.00 meq kg^-1), p-anisidine value (256.8) and Totox (271.7), all of which showed a constant deterioration. In relation to the use as a feedstock for bio-diesel production, after 120 minutes heating at 240℃ the following was found: acid value 0.70 mg KOH g^-1 oil, iodine value 117.83 g I₂ 100 g^-1 oil, oil stability index 0.67 h, kinematic viscosity (at 40°C) 77.85 mm² s^-1, higher heating value 39.86 MJ kg^-1, density 933.34 kg/m³ and cetane number 67.04. The parameters studied in this work were influenced, in different ways, by the applied variables. Heating temperature between 180 and 210°C and 120 min heating duration were found to be the most appropriate conditions for sunflower seed oil both from the deep frying point of view and from a subsequent use as feedstock for bio-diesel production. In light of the vegetable oils' International standards for an edible use and for a bio-diesel production, findings of this work can be used to set heating temperature and heating duration to preserve as long possible the physico-chemical properties of a low oleic sunflower seed oil for both its edible use as a fat during cooking and for its re-use after frying.

Quality of Lipid Fractions in Deep-Fried Foods from Street Vendors in Chile

Deep-fried foods sold by unlicensed street vendors are a health concern for various reasons, but oil quality is particularly important considering known links between fat consumption and cardiovascular disease. To diagnose the exact gravity of this situation in Chile, a country where street vendors are proliferate, the physicochemical parameters of fat fractions from fried food samples were assessed. Fat quality was assessed through the acidity index, peroxide index, extinction coefficient, TOTOX index, polar compounds percentage, and fatty acid profile. Most food samples (80%) had at least a 10% fat content. Many samples also had high peroxide values (1.7–103.3 meqO2/kg) and extinction coefficients (K232 and K270), findings indicative of advanced oil deterioration. These results were supported by values for para-anisidine (100.2–311.0), TOTOX (>103.6), and polar compounds (14.2–49.7%). All assessed food samples contained saturated, monounsaturated, and polyunsaturated fatty acids, as well as trans-fatty acids (0.6–1.7%). According to national regulations on polar compounds, 50% of the assessed food samples are unfit for human consumption. When applying national limits for C18, all food samples should be discarded. These findings stress the urgent need to strictly control deep-fried foods sold by street vendors.

Physicochemical properties and oxidative stability of frying oils during repeated frying of potato chips

Physicochemical properties and oxidative stability of refined coconut oil (RCO), refined soybean oil (SBO), pure olive oil (POO), and vegetable shortening (VST) during repeated frying of potato chips were determined. Polyunsaturated fatty acids of all the oils significantly decreased after frying. Tocopherols in SBO, POO and VST, and DPPH radical scavenging activities of POO and VST significantly decreased after frying. L* values of the oils significantly decreased, and a* and b* values significantly increased after 80 times repeated frying. Conjugated dienes and p-anisidine value of SBO after 80 times repeated frying were 21.8 mmol/L and 47.7, respectively, the highest among the oils. Levels of total polar compounds of all the oils after 80 times repeated frying were between 8.1 and 9.5%, not exceeding rejection limit after frying. Compositions and contents of alkanals, 2-alkenals, and 2,4-alkadienals in the oils during frying were largely affected by their fatty acid compositions.

Evaluation of antioxidant activity of loquat fruit (Eriobotrya japonica lindl.) skin and the feasibility of their application to improve the oxidative stability of soybean oil

The effects of ultrasound-assisted, supercritical CO2 and solvent extraction techniques on antioxidant activity of loqua (Eriobotrya japonica Lindl.) skin extract in oxidation stability of soybean oil was evaluated. The antioxidant efficacy of extracts was determined using 2, 2-diphenyl-1-picrylhydrazyl (DPPH(•)) radical scavenging capacity, β-carotene/linoleic acid, and Rancimat test system. Results showed that solvent extract of loquat fruit skin at 400 ppm had the highest antioxidant activity compared to ultrasound-assisted and supercritical CO2 extracts. Further, solvent extraction was the most effective method for extraction of phenolic compounds. Protective effects of extracts in stabilization of soybean oil during both frying and storage conditions were tested and compared to tert-butyl hydroquinone (TBHQ) by measuring their peroxide value, free fatty acids, conjugated dienes and trienes value. During frying process solvent extract of skin at 400 ppm (SOEA) exhibited stronger antioxidant activity in oil compared to other oil samples, but this antioxidant potential was lower than TBHQ in storage conditions. Present study showed that loquat fruit skin is a good source of natural antioxidant compounds, and has the potential to be used as a substitute for synthetic antioxidants in vegetable oils.

Epoxidized Esters of Palm Kernel Oil as an Effective Plasticizer for PVC: A Study of Mechanical Properties and Effect of Processing Conditions

One of the most commonly used vegetable oil plasticizer in polyvinyl chloride (PVC) is epoxidized soybean oil (ESBO). On the contrary, epoxidized palm oil is among the least used, because of its low compatibility with PVC. This work reports that epoxidized and esterified palm kernel oil (EEPKO) has the potential to be used as a plasticizer for PVC. In this study, it was found that a maximum of 65 phr of EEPKO could be incorporated within the PVC resin. In addition, subjecting this EEPKO plasticized PVC (p-PVC) at a processing temperature of 200 °C resulted in much reduced plasticizer loss. EEPKO lowers the glass transition temperature of PVC from 79 °C to −23 °C. The optimum mechanical properties, namely tensile strength, elongation at break and hardness, were obtained for p-PVC processed at 200 °C.

A study on monitoring of frying performance and oxidative stability of virgin coconut oil (VCO) during continuous/prolonged deep fat frying process using chemical and FTIR spectroscopy

The performance or quality of the Virgin coconut oil (VCO) during continuous/prolonged deep fat frying of soaked bengal gram dhal was evaluated at 180 °C ± 5 °C for 8 h with the help of physico-chemical and rheological parameters. Chemical changes indicated that the free fatty acid (FFA) content and TBA increased significantly (p ≤ 0.05) from 0.11 to 0.98 % lauric acid and 0.06 to 0.61 malonaldehyde/kg of oil respectively. Initially, the peroxide value (PV) of VCO sample was 3.25 meqO2/kg which increased to 9.12 meqO2/kg after 6 h of frying but at the end of frying the value of PV was again found to decrease (8.01 meqO2/kg). The regression coefficients (R(2)) between CD232, CT270 and frying time were 0.964 and 0.983 respectively. The L*, a* and b* colour values measured on the CIELAB colour scale showed a decrease in L* and increase in a*, b* values after 8 h of continuous frying. The p-AV and total polar compounds were increased significantly (p ≤ 0.05) from 2.41 to 17.93 and 2.77 to 8.14 % respectively. Initially, the viscosity of VCO was 49.87cp which increased to 69.87cp after 8 h of continuous frying. The FTIR spectra justify that VCO samples after 8 h of frying found to be stable and acceptable as there was no change occurred at 1,739 cm(-1) frequency which mainly corresponded to carbonylic compounds resulted from the hydroperoxide decompositions after 8 h of continuous frying.