Total Polar Materials Research Articles

Oleogel-based frying medium: influence of rice bran wax-canola oil oleogel on volatile profile in fried fish fillets

Oleogelation has proven to be a successful strategy for structuring oils. In recent years, the use of oleogels as a deep frying medium has gained popularity as an effective approach to minimise oil uptake and reduce the energy content of fried foods. This study was designed to evaluate an oleogel matrix consisting of rice bran wax and canola oil, prepared by oleogelation technique, as a deep frying medium. Two types of the oleogels (CRBO-3 with 3 g wax/100 g oil; CRBO-6 with 6 g wax/100 g oil) were formulated and these oleogels were tested as a frying medium for fish fillets. The prepared oleogels were compared with refined canola oil (CO, control) and evaluated for both the frying stability of the oils and the volatile profile of the fried fish fillets. In particular, differences were observed in the crystallization and melting profiles of oleogels before and after frying. Lower levels of total polar material, peroxide value and trans fatty acids contents were noticed in fish fillets fried in the oleogels. An increase in wax concentration had an impact on the volatile profile of fish fillets and lead significant increases in p-xylene, pentene-3-ol and nonanoic acid. In general, oleogel-based frying medium contributed to the formation of characteristic fish fillet including aroma notes of pineapple, balsamic and honey when compared to fish fried in refined canola oil. The findings suggest oleogels as an alternative frying medium for fish with reduced calorie value and improved aromatic quality.Graphical

An innovative carbon dots polarity probe based on intramolecular charge-transfer for visual monitoring of the total polar materials in frying oil

The presence of Total Polar Materials (TPM) in edible oils is a crucial indicator for assessing oil quality. It is of paramount importance to develop a rapid and dependable technique for monitoring polarity in frying oil. Sensitive polarity responsive fluorescence carbon dots (F-CDs) were synthesized by using p-phenylenediamine as precursors and 2-formylphenylboronic acid pinacol ester (2-FAPE) as a post-modifier. The construction of the fluorescent probe F-CDs involved a strong intramolecular charge-transfer (ICT) mechanism, with 2-FAPE serving as the electron-withdrawing fluorophore and the π-conjugated structure acting as a potent electron-donating group. A strong linear relationship was observed between the emission wavelength and the TPM value of frying oil within a range of 11% to 30%. Notably, the fluorescence color of the probe transitioned from blue to yellow under UV light at 365 nm as the TMP value increased. This study expands the range of sensing applications for CDs in food safety.

Underutilised palm stearin as hard stock for deep-frying medium and its performance for oil uptake in instant noodles.

As a by-product of the palm oil industry, palm stearin is often overlooked despite having several beneficial properties, such as excellent stability, which is critically essential to meet the demand of the global food trend in producing safer processed food. Specifically, deep frying of food is often associated with the production of toxic compounds that could potentially migrate into the food system when oils are degraded under continuous heating. The incorporation of palm stearin is regarded as a cost-effective and efficient method to modify the fatty acid composition of oils, enhance the frying qualities and lower the degradation rate. This study blended 5% and 10% palm stearin into palm oil to investigate the deep-frying performance and impact on food quality. Increasing the palm stearin content improved the frying oil's oxidative and hydrolytic stability, evidenced by reduction of total polar material, free fatty acid and total oxidation value. Addition of palm stearin increased the slip melting point which improved the oil's oxidative stability but no significant increase in oil content of instant noodles was observed. Scanning electron microscopy and fluorescence microscopy showed the formation of larger pores in the noodle structure that facilitated oil retention. Blending palm stearin into frying oil enhanced the frying stability and minimally affected the oil uptake in instant noodles. This article presents the viability of blending palm stearin into frying oils to develop longer-lasting frying oils. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Rapid quantitative evaluation of total polar materials (TPM) in frying oil based on an “off-on” fluorescence viscosity response probe

The content of total polar material (TPM) is considered as a comprehensive indicator to evaluate the quality of edible oils which should be discarded and no longer be used when TPM content exceeding 27 %. Nevertheless, there is currently a lack of a convenient and efficient TPM detection method, which is a meaningful challenge. With the increase of TPM content, the viscosity of frying oil grows, and the two maintain a satisfactory positive correlation. Consequently, an “off-on” fluorescence probe TCF-PR method based on viscosity-response has been developed. There exists a good linear relationship between the fluorescence intensity of the probe and the TPM content of soybean oil ((R2 = 0.9936) and salad oil (R2 = 0.9878), accompanying with the advantage of fast response (3 s), which means the rapid detection of TPM can be realized to determine the quality of frying oil in the field of food safety.

Effect of heating and Re-heating on physico-chemical properties of rice bran oil and soybean oil

This study investigates the thermal stability and suitability of rice bran oil (RBO) and soybean oil (SBO) during deep-oil frying of French fries, with a specific focus on the 6th time oil usage. The purpose is to determine the impact of repeated heating cycles on the physical, chemical, and fatty acid composition of these oils. Results reveal that RBO is more stable than SBO. Both oils maintain peroxide values below 10 meqO2/kg in the initial four heating cycles, with acceptable acid values (<0.6 mg KOH/100 g) up to the 5th cycle for RBO and the 3rd cycle for SBO. Saponification values exceed recommended levels initially but stabilize subsequently. Free fatty acids (FFA) and total polar materials (TPM) exhibit remarkable stability after repeated heating, showcasing the resilience of both oils. Fatty acid composition analysis demonstrates RBO's enhanced stability, with an increase in total saturated fatty acids and a concurrent decrease in unsaturated fatty acids. This highlights RBO's superior resistance to degradation compared to the more vulnerable SBO, rendering it more suitable for extended usage. In conclusion, the study provides valuable insights into the physical and chemical changes in these oils during prolonged deep-frying, underscoring RBO's greater thermal stability. This research offers a novel perspective on the suitability of cooking oils for enduring high-temperature culinary applications, emphasizing the importance of RBO for extended usage in deep-frying processes.

Study of oleogel based on components &lt;i&gt;Helianthus annuus L.&lt;/i&gt; and &lt;i&gt;Rosmarinus officinalis L.&lt;/i&gt; as frying oil

The aim of this study was to study the oxidation resistance and functional properties of oleogels based on high oleic oil and wax from Helianthus annuus L. with the addition of a natural complex antioxidant — an extract from Rosmarinus officinalis L. and lecithin from Helianthus annuus L. — when used as a frying medium for French-fries. High oleic sunflower oil was structured into an oleogel with sunflower wax at a dosage of 5%. Studies were carried out to determine the possibility of replacing the synthetic antioxidant tert-butylhydroquinone at a dosage of 200 mg/kg with a natural antioxidant based on rosemary extract and sunflower lecithin in an oleogel with a defoamer. It was determined that the introduction of sunflower wax increased the induction period of high-oleic sunflower oil by 1.6 times, and the additional introduction of defoamer and antioxidants increased this figure by 1.8–2 times. The rate of accumulation of oxidation products in oil, which is characterized by the level of total polar materials, decreased when wax and antioxidants were added. The degree of thermal oxidation most quickly reached the limit value in oil without additives; in oleogels, it significantly decreased. The introduction of sunflower wax into oil contributed to a noticeable decrease in the absorption of oil by potatoes: fried in oleogel, it absorbed 34–38% less oil than fried in oil without additives. The addition of 0.07% rosemary extract with sunflower lecithin to the oleogel increased the operating time of frying oil by at least 2 times, approximately the same as that of the oleogel with tert-butylhydroquinone. This makes it possible to replace the synthetic antioxidant in deepfrying oleogel with natural rosemary extract with sunflower lecithin. The developed oleogel is a frying oil that has a longer service life and allows you to get fried products with a lower amount of fat.

Efficacy of Different Sesame Oil Refining Stages in Reduction of Heavy Metals, Antioxidant Activity, and Oxidative Parameters

The efficacy of different refining stages on physicochemical parameters, heavy metal, and mineral contents of sesame oil were investigated. The sesame oil from different refining stages (crude oil, neutralization, bleaching, deodorization, and refining stages) was taken from the local oil factory in Yazd, Iran. The fatty acid composition of oil samples was determined by GC-FID. The oxidation indexes including peroxide value, p-Anisidine, free fatty acid, TOTOX, total polar material, as well as antioxidant activity (FRAP and DPPH), and total phenolic content were measured. The mineral and heavy metal content of oil samples were analyzed by ICP-OES. Linoleic acid (41.1-42.4%), oleic acid (41-41.4%), palmitic acid (8.3-9.1%), and stearic acid (6.1-6.3%) were reported as the most dominant fatty acids in all oil samples. The results illustrated that the refining process had no significant effects on fatty acid composition except for slight changes in palmitic acid. It was shown that all oxidation indexes, antioxidant activity, total phenolic content and mineral, and heavy metals were decreased during oil refining. The highest decrease in oxidative indexes was reported in the deodorization stage. The total phenolic content, DPPH, and FRAP ranged from 4.79 to 56.56 mg GAE/100 g, 6852.64 to 867.89 mg/ml, and 54.74 to 127.4 mM FeSO4.7H2O in RSO and CSO, respectively, which the highest decrease was shown during the neutralizing stage. The order of metals in RSO was shown as P&gt;Ca&gt;K&gt;Fe&gt;Mg&gt;Al&gt;Cr&gt;Pb&gt;Ni&gt;Cd&gt;Cu&gt;Co. Although all metals were decreased by the refining process, the Pb concentration (0.16 mg/kg) of RSO was evaluated as higher than the permissible limit. Considering that the refining process effectively reduces undesirable compounds, the consumption of crude sesame oil is not recommended.

Engineering of polarity-responsive fluorescent probe for real-time measurement and visualization of total polar materials in edible oils

The content of total polar materials (TPM) in edible oils is generally accepted as a reliable indicator of the quality of edible oils. A high TPM value may signify that the flavor has been compromised and its consumption may lead to adverse effects on human health. However, the lack of convenient and user-friendly detection methods for the detection of TPM remains a challenge. To address this, a sensitive polarity-responsive fluorescent probe has been designed. A good linear relationship was observed for the ratio of the intensity of green to red fluorescence signal (I504 nm/I625 nm) and the TPM content over the range 1.1–29.3% for soybean oil and 0.1–27.5% for salad oil, respectively. A portable fluorescence sensor system was constructed, which provided a stable platform for the convenient detection of TPM via naked eye observation. These results indicate that the probe has great potential for TPM detection of edible oils in the food safety industry.

Preserving Soybean Oil for the Frying of Breaded Butterfly Shrimp Using Natural Rosemary Antioxidant.

Fried foods and frying oil are subjects that warrant the attention of researchers because of their high consumption. Indeed, frying conditions make these oils very sensitive to lipid oxidation which deteriorates the quality and nutritional properties of the food. In this study, we examined the effect of rosemary extract (ROE), known for its high antioxidant activity, in soybean oil used to fry breaded butterfly shrimp, by measuring the induction period with OXIPRES, total polar material (TPM), peroxide index (PI), and free fatty acids (FFA). This evaluation was performed in comparison with control oils without antioxidants. The results showed a significant difference between the oils according to the analyzed parameters, especially in the final hours of frying. The treatment of the oil with rosemary extract effectively delayed its oxidation, having lower levels in all the oxidation markers that were analyzed. It was also found that rosemary extract is able to reduce oil consumption by fried foods. Therefore, ROE ensures soybean oil a high stability against oxidation and a longer shelf life, making it a good natural alternative to synthetic antioxidants.

The Effects of Frying Method and Oil Type on the Quality Attributes of Turkey Nuggets and Frying Oils

AbstractThe aim of the study is to determine the effects of frying under standard atmospheric and pressure conditions on some quality characteristics of turkey nuggets. Turkey nuggets are fried under atmospheric and pressure conditions using sunflower or hazelnut oil. Pressure frying decreases the thiobarbituric acid reactive substances (TBARS) value of turkey nuggets while sunflower oil increases this value. Under atmospheric conditions, nuggets fried with hazelnut oils show higher moisture content than hazelnut oil. The pH is affected by the type of oil. The frying under pressure results in a decrease in the internal and external a* value of nuggets. Under pressure conditions, the use of hazelnut oil increases the external a* value. The application of pressure also causes an increase in the external L* value in the presence of sunflower oil. These treatments also show higher hardness, springiness, gumminess, and chewiness values compared to atmospheric condition. The use of sunflower oil causes a decrease in resilience, cohesiveness, springiness, and chewiness values. After frying, hazelnut oil shows lower peroxide and total polar material values than sunflower oil. However, peroxide value and total polar material are not affected by frying method.Practical applications: Color and texture are very important factors for the quality of nuggets. Pressure and atmospheric conditions show different effects on color parameters. Frying under pressure conditions decreases the external L*, which is an important quality parameter. Hazelnut oil shows lower TBARS value than sunflower oil. Moreover, pressure application causes a decrease in TBARS value. Frying process under pressure decreases the hardness and adhesiveness, while it increases the juiciness of product. On the other hand, the use of hazelnut oil as frying oil shows less changes in peroxide and total polar material during frying than sunflower oil, but the frying method and oil type interaction has no significant influence on these parameters.

The Influence of Edible Oils' Composition on the Properties of Beeswax-Based Oleogels.

This study aimed to find relationships between the properties of beeswax-based oleogels and the type of oil used. The influence of linseed, sunflower, olive, and fish oils was studied. For these oils, the fatty acid composition, the content of total polar components, and the iodine value were characterized. Textural and thermodynamic properties were determined for oleogels, the oil-binding capacity was estimated, and the morphology of crystals was studied. The concentration of beeswax in all oleogels was 6.0% w/w. It was shown that the type of oil has a significant influence on all characteristics of the oleogels. The use of different oils at the same technological treatment leads to the formation of crystals of diverse morphology—from platelets to spherulites. At the same time, it was revealed that some characteristics of oils have a varying contribution to the properties of oleogels. The content of total polar materials in oils is associated with a decrease in strength parameters (yield value and elastic modulus) and the oil-binding capacity of oleogels. In its turn, the iodine value of oils has a close positive correlation with the melting and crystallization temperatures of oleogels. The results obtained in this article indicate that the properties of beeswax-based oleogels can be directed by changing the oil composition.

Antioxidant effect of natural rosemary on the oxidation of mid-oleic sunflower frying oil on chicken wings

Fried foods are hugely popular and very much a part of our modern cuisine. Guarding against oxidation is crucial, due to the absorption of oil during the frying process. This paper presents how, the degree of resistance of sunflower oil was evaluated during repeated fries of chicken wings by adding the natural antioxidant extracted from rosemary. It was compared to tocopherol and to a control sample. A preliminary test of accelerated aging demonstrated the effectiveness of rosemary extract by using the Rapidoxy technique on sunflower oil. This proved that the adequate dose of this antioxidant should be 600 ppm. Many physicochemical transformations were inflicted on the oil during its oxidation. The kinetics monitoring of this phenomenon was determined by measuring the total polar materials (TPM), free fatty acids (FFA), and the peroxide index (PI). The obtained results showed that all the parameters analysed tended to increase over time. However, the effect of the rosemary antioxidant was positive on the stability of the oil and the slowing down of its oxidation. Moreover, its efficiency was higher than tocopherol. Rosemary antioxidants could be a safer alternative to synthetic antioxidants which represent toxicological risks, such as buthylated hydroxyanisole BHA, buthylated hydroxytoluene BHT, and tert-butylhydroquinone TBHQ.

Utilization of activated carbons produced from some natural materials in the purification of used frying oil

The activated carbons (ACs) from shells of horse chestnut, chestnut, acorn, pistachio, apricot kernel, and wood shavings were evaluated to recover used oil (UO). The effects of the amount of AC, adsorption time, and temperature on the purification of the UO were investigated using the apricot kernel shells due to the high apricot production of Turkey. The kinetic evaluation was also done. The percentage improvements (PIs) in total polar materials (TPM), free fatty acids (FFA), p-anisidine value (p-AV), conjugated diene content (CD), and color of UO were found as 100, 56, 92, 51, and 90% for the apricot kernel AC in the column treatment. The most effective other ACs in decreasing FFA, p-AV, CD, and color were the horse chestnut (59%), chestnut (74%), chestnut (43%), and pistachio (72%), respectively. Consequently, these ACs can be used for the purification of UO. Practical applications Industrial wastes cause environmental pollution if they are ejected into river, sea, and soil. Therefore, they should be purified or treated for different purposes. In this study, the industrial wastes from the food and forest industries were used for the production of activated carbon to purify the used oil. The results showed that these activated carbons could be utilized for the regeneration of used oils. The most economical treatment is to blend the activated carbon with used frying oil for a certain time and remove it through centrifugation and filtration. The purified oil has the potential to be used in the biodiesel production.

Sunflower Oil–Beeswax Oleogels Are Promising Frying Medium for Potato Strips

AbstractSunflower oil–beeswax oleogels at 3% (BWO‐3) and 8% (BWO‐8) organogelator concentration are prepared to evaluate oleogels as frying medium for potato strip frying against commercial sunflower oil (SO). Rheological and thermal analyses of oleogels prove that the samples are fully solid (20±3 °C) and totally liquid (180 °C), and thermoreversible. Fresh and used (after frying) fat analyses show that free fatty acidity (FFA), peroxide value (PV) and total polar materials (TPM) are enhanced in all samples at the 7th h, but the relative enhancement levels are lower in oleogel samples. Potato strips fried in oleogels absorb significantly less oil (11.97% and 12.07%) than the control sample (15.20%). Potatoes fried in oleogels are also more bright and yellower than the control sample. Textural profile of the fried potatoes indicates that the samples fried in oleogels are harder, springier, and gummier than that of the control sample. Sensory analysis shows that oleogel fried potatoes get higher sensory scores. Also, overall acceptability of potatoes fried in BWO‐8 sample is the highest (8.50) among all. The prepared oleogels are found quite promising frying medium in this study. Further studies with other types of oleogels in extended period frying of various foods are suggested.Practical applications: The development of innovative frying techniques to produce healthier products with lower fat and calorie values are still a remarkable research area. Oleogelation is an emerging strategy used for solid‐like oil designing and based on the formation of 3D networks by the addition of organogelators. Oleogelation is accepted as a healthy strategy to structure liquid oils into solid consistency, and oleogels have great edible applications in processed foods, and can be used as a frying medium. This work can guide the use of sunflower oil–beeswax oleogels as a frying medium and allow the development of more healthy fried snacks.

High-performance fluorescent sensor based on CsPbBr3 quantum dots for rapid analysis of total polar materials in edible oils

Total polar materials (TPM) in edible oils are considered as the most reliable indicator for the quality of oil. However, the lack of suitable methods for TPM analysis has been an issue in the field of food safety. As is well known, all-inorganic perovskite quantum dots (QDs) are promising candidates for optoelectronic applications but severely restricted by their poor stability affected by environmental factors especially materials with high polarities. On the contrary, this instability to the change of polarity makes perovskite quantum dots particularly suitable as polarity sensors. In this work, CsPbBr3 QDs were synthesized and used to sense various solvents with different polarities. Good linear relationships between fluorescence intensity of CsPbBr3 QDs and volume of polar solvents, such as acetone, methanol, and ethanol, were achieved, separately, proving the feasibility of perovskite quantum dots as TPM sensor. The CsPbBr3 QDs were then used for the TPM detection in edible oils. With the increase of the TPM content, the fluorescence intensity of the CsPbBr3 QDs decreased proportionally without any PL peak shifts. The quenching effect was observed for olive oil, soybean oil, and sunflower oil, and the linear relationships were obtained in the TPM range of 17 %–31.5 %, 25 %–31.5 %, and 21.5 %–33 %, respectively. Moreover, a paper-based CsPbBr3 QDs fluorescent sensor was constructed for real-time monitoring of TPM content and exploring the possibility of a more rapid detection method as well. All the results indicate that CsPbBr3 QDs can be used as an innovative fluorescent sensor for rapid TPM detection of edible oils with great practical applications.

Enhancing oxidative stability of frying oils by low‐frequency radio wave treatment

SummaryRadio wave treatment (approximately 50 kHz frequency) on the oxidative stability was evaluated in corn oil at 180 °C and chicken frying oil for 150 cycles. Radio wave treatment decreased moisture content and critical micelle concentration of lecithin in corn oil. Moisture content in frying oil remained higher when radio wave was treated for the first 30 frying cycles. Radio wave treatment prevented lipid oxidation significantly in corn oil heated at 180 °C when moisture was not added (P &lt; 0.05). p‐Anisidine value and total polar material in chicken frying oils treated with radio waves were significantly lower than those of frying oils without radio wave treatment (P &lt; 0.05). Radio wave treatment enhanced the stability of tocopherols in corn oil heated at 180 °C in the absence of moisture, while the reverse result was observed with moisture addition. Overall, radio wave treatment can be a useful tool to enhance the oxidative stability of frying oils by modifying their moisture content and tocopherol stability.

Analysis of Total Polar Material in Selected Indian Snack’s Fried Oil

The study was envisaged to examine the quality of frying oil used by street food vendors for two of the most popular food items viz. Samosa and Jalebi in India. Changes in the quality of frying oil were analysed by analysing the total polar material (TPM) content in the oil using an oil tester and Attenuated total reflectance–Fourier transform infrared (ATR-FTIR) spectroscopy. Total 143 oil samples were collected at different frying times, i.e. 0, 2 and 4 h from five different Samosa and Jalebi vendors. In both the fried food oil samples, TPM content increased with increasing frying time. The TPM content in the 4 h fried oil samples of Jalebi was significantly (p&lt; 0.001) higher than the samosa fried oil. Partial Least Square Regression (PLS) model based on the 1st derivative FTIR spectra exhibited good prediction capability for TPM values with a high regression coefficient (R2 ≥ 0.99) and low root mean square error (RMSE).

Reused Plant Fried Oil: A Case Study with Home-Made Soaps

The study aimed to analyze the possibility of waste frying oil utilization in home-made soap production. Soaps were made from unheated and fried rapeseed, sunflower and palm oils that had total polar material (TPM) values up to 24%. Physicochemical and microbial analyses were performed on produced samples to check their quality. The hardness increased with the degradation level of rapeseed and palm oils, and opposite findings were obtained for sunflower-made soaps. The highest malondialdehyde (MDA) contents were recorded for sunflower oil-made samples, with the maximum of 6.61 µg/g, and the lowest for the palm oil-made samples, with the maximum of 0.94 µg/g. The antimicrobial assessment showed no significant (p &gt; 0.05) differences between control soap samples and soaps made of oils with the highest TPM value. Gram-positive bacteria (methicillin-resistant Staphylococcus aureus: MRSA) were the most sensitive chosen microorganisms, compared to Gram-negative bacteria and yeasts. The obtained results did not show exact differences between experimentally produced soap samples from fried or not fried oils; these findings highlight the potential of home-made soap production from this byproduct.

Determination of the changes in sunflower oil during frying of leavened doughs using response surface methodology.

In this study, the effect of dough salt content, frying temperature and time on the conjugated diene values, polymer triglyceride content, total polar material content, viscosity, and color values of the sunflower oil during frying of leavened doughs was determined using response surface methodology. Fifty repeated frying operations were applied in the same day at 160-200°C for 1-5min and doughs with 0-2% salt content. According to the results of the study, frying temperature, frying time and dough salt content were significantly (p < 0.05) affected total polar material content, polymer triglyceride content, viscosity and a* and b* color values of oil samples, whereas dough salt content did not affect the L* color values and conjugated diene value of oil significantly (p > 0.05). To minimize the oxidation products of frying oil, the frying process can be applied at 160°C for 1min using dough with 1.97% salt content.

Rapid Assessment of Total Polar Material in Used Frying Oils Using Manganese Tetraphenylporphyrin Fluorescent Sensor with Enhanced Sensitivity

Probe-based three-dimensional fluorescence spectroscopy was developed for the rapid assessment of frying oil quality. Tetraphenylporphyrin manganese (MnTPP) was selected due to its sensitivity and selectivity in response to dissolved organic matter, which is typically produced during the frying process of oil analyte. Parallel factor analysis (PARAFAC) was then performed to decompose three-dimensional fluorescence data for model construction. The digital data representing the change of the MnTPP-base fluorescent probe before and after exposure to dissolved organic matter were analyzed using support vector regression (SVR). SVR was then used for the construction of the regression model between the fluorescence data and the total polar material (TPM). The coefficients of determination (R2) in the training set (R2 = 0.9719) and the test set (R2 = 0.9699) were achieved to evaluate the robustness of the best models for TPM. This study demonstrated that the probe-based three-dimensional fluorescence spectroscopy is useful for assessing the quality of frying oil and perhaps could be used for other food products with high oil contents.