Analytical methods for determining the peroxide value of edible oils: A mini-review

Carbon dots-functionalized aerogel sensor for fluorescent and portable monitoring of organic peroxides

Organic peroxides in foodstuffs like lipid hydroperoxides and benzoyl peroxide (BPO) have risks to human health, which need rapid and on-site determination. This study prepared hydrophobic and reductive fluorescent iodine-doping carbon dots (I-CDs) via a solvothermal strategy using oleylammonium iodide as the precursor. The I-CDs can be used as nanoprobes to rapidly and sensitively determine organic peroxides. Organic peroxides can oxidize the I-CDs to produce I2, which can efficiently quench their fluorescence through the inner filter effect. Furthermore, hydrophobic aerogels were prepared to incorporate the I-CDs, constructing a fluorescent sensor. When combined with a smartphone and portable detection equipment, the developed sensor enables rapid on-site testing of peroxide values (PVs) in edible oils, as well as BPO in flour. The fluorescent sensor has a detection limit of 1.2 mmol/kg for PVs and 0.10 mmol/kg for BPO. Our study provides an efficient tool for monitoring organic peroxides in foodstuffs.

Simultaneous determination of vegetable oil frying frequency and peroxide value based on the three-dimensional fluorescence spectroscopy and machine learning

The practice of deep-frying introduces various health concerns. Assessing the quality of frying oil is paramount. This study employs three-dimensional fluorescence spectroscopy to evaluate the peroxide value of vegetable oils after varying frying times. Three feature preprocessing techniques combined with three machine learning methods to predict the frying frequency and the peroxide value. For the prediction of frying frequency, SG-RF model performed the best for soybean oil, while for peanut and corn oils, SG-PLS excelled, with the Rp2 of 0.98, 0.98, and 0.97, respectively. Regarding the quantification of peroxide value, normalize-kNN performs the best for soybean frying oil, for peanut frying oil SG-RF are optimal, and the optimal combination is normalization-RF for corn frying oil, with the Rp2 of 0.87, 0.89, and 0.93, respectively. This rapid assessment method enables early detection of oil safety issues, protecting consumer health by preventing the use of degraded oils.

Physicochemical, rheological, sensory properties and shelf life of processed cheese analogue prepared with oleogel sesame oil and mono- and di-glyceride (E471)

Analog processed cheeses are cheese-like products with diverse compositions and functional properties that are produced by replacing milk components with non-milk components. The aim of the study was to investigate physicochemical, rheological and sensory properties of cheeses and oleogels. The results showed; that increasing the concentration of Mono and di-glyceride increased the oil binding capacity and improved the characteristics of the oleogel texture and stable during storage, especially in terms of oxidative. The concentration of gelator, with attention to increasing the storage modulus (G') and the loss modulus (G'') important role in formation of the network structure. The use of oleogel in the processed cheese analogue formulation increased the oil binding capacity of the samples and decreased the meltability of the samples. The storage time in the refrigerator temperature did not have a significant effect on the measurement parameters. The samples of cheeses prepared with oleogel were more stable in terms of physicochemical than the control sample.

Production of partially hydrogenated soybean oil with low trans-fatty acids using surface dielectric barrier discharge cold plasma

This study examined the feasibility of applying surface dielectric barrier discharge cold plasma (SDBDCP) to partially hydrogenate crude soybean oil. The oil sample was treated for 13 h using SDBDCP at 15 kV with 100% hydrogen gas under room temperature and atmospheric pressure. Fatty acid composition, iodine value, refractive index, carotenoid content, melting point, peroxide value, and free fatty acids content (FFA) were investigated during SDBDCP treatment. Analysis of fatty acid composition demonstrated an increase in the content of saturated and monounsaturated fatty acids (from 41.32% to 55.3%) and a decrease in the content of polyunsaturated fatty acids (from 58.62% to 40.98%), which resulted in a reduction of the iodine value to 98.49 over the treatment time. Also, the fatty acid profile indicated that the total detected level of trans-fatty acids was very low (0.79%). After a 13-h treatment, the samples showed a refractive index of 1.4637, melting point of 10 °C, peroxide value of 4.1 meq/kg, and FFA content of 0.8%. In addition, the results revealed a 71% decline in the carotenoid content of the oil sample due to the saturation of their double bonds. Therefore, these findings suggest that SDBDCP can be effectively used for hydrogenation along with bleaching oil.

Preparation and characterization of Levan composite film incorporating vanillin for use as a potential edible coating for peony seed oil

The study prepared an edible packaging material for peony seed oil by adding natural antioxidant vanillin to a microbial Levan composite film. The presence of highly branched Levan, containing polyhydroxyl groups, significantly enhanced the maximum tension (26.57 N), tensile strength (36.31 MPa), and elongation at break (42.15 %) of the Aga/Lev film. The values were 9.84-fold, 5.74-fold, and 1.11-fold higher than those of Aga films, respectively. Furthermore, SEM and FTIR analysis revealed that Levan increased the intermolecular force of the vanillin composite film (Aga/Lev/Gly/Van), forming a dense gel network with a Schiff base reaction occurring between vanillin and glycine. The addition of vanillin and glycine slightly lowered the transparency of the film but enhanced the ultra violet (UV)-blocking with 100 % UV-region and 91 % visible region light screening. The Aga/Lev/Gly/Van films showed strong antioxidant efficacy with 91.85 % ABTS and 44.33 % DPPH radical scavenging potential. The electrical conductivity, P-anisidine value, thiobarbituric acid value, and fatty acid distribution of peony seed oil samples were analyzed after accelerated storage. The Aga/Lev/Gly/Van group had a significantly higher retention rate (95.65 %) for total conjugated fatty acids compared to the control group (84.17 %). The utilization of Aga/Lev/Gly/Van film packaging effectively extended the shelf life of peony seed oil and retarded the degradation of unsaturated fatty acids in the oil. Therefore, Levan composite films incorporating vanillin can be used as sustainable packaging materials to minimize the oxidation of susceptible foods.

Comprehensive Extraction and Biological Activities of Mycosporine-like Amino Acids and Glyceroglycolipids Extracts from Two Macroalgae Ecklonia kurome and Ulva lactuca

Mycosporine-like amino acids (MAAs) and glyceroglycolipids have promising applications in various fields, but limited research exists on their simultaneous extraction from macroalgae. This study optimized the key parameters (liquid-solid ratio, extraction temperature and extraction time) in the extraction of MAAs and glyceroglycolipids from Ecklonia kurome and Ulva lactuca using single factor and response surface experiments. The yields of MAAs from E. kurome and U. lactuca were 169.71 mg/g and 177.33 mg/g, respectively, while glyceroglycolipids were extracted from the residue with yields of 163.51 mg/g and 213.45 mg/g, respectively. Both extracts showed concentration-dependent antioxidant activities, with the MAAs extracted from U. lactuca demonstrating the strongest effect. The addition of MAA extract to flaxseed oil significantly reduced oxidation rancidity, highlighting its potential as a natural antioxidant for oils. The glyceroglycolipid extract from E. kurome exhibited significant moisture absorption, and a water-retaining agent prepared from this extract showed excellent moisture retention and resistance to high temperatures, freezing, and pressure. A silica gel column chromatography method confirmed the presence of MGDG in the purified glyceroglycolipid extract. These findings suggested that E. kurome and U. lactuca can be converted into high-value-added compounds with potential applications in food, cosmetics, and pharmaceuticals.

Electrochemical Method for the Assay of Organic Peroxides Directly in Acetonitrile

Lipid peroxidation is a major process that determines the quality of various oil samples during their use and storage, in which the primary products are hydroperoxides (HP'S). HP'S are very stable compounds at ambient conditions and are harmful to human health. Therefore, the evaluation of the degree of oil oxidation is an excellent tool for ensuring food safety. The peroxide value (PV) is the main parameter used for quality control in oils. Herein, we propose an alternative electrochemical method to the classical iodometric titration method most widely used for determining the PV. Our approach is based on the electrochemical quantification of hydroperoxides/peroxides in an organic solvent medium (acetonitrile and organic ammonium salt) using a composite electrocatalyst-glassy carbon electrode modified with 2D-nanomaterial graphitic carbon nitride doped with Co3O4. Calibration was made by the method of standard addition using benzoyl peroxide (BPO) as a model peroxide compound, dissolved in chloroform and added to fresh Rivana-branded anti-cellulite oil, used as a model oil sample. Calibration plots showed a linear response and the very good reproducibility of the analytical result (R2 ˃ 0.99). Further, in terms of accuracy, the method showed good results, since the BPO quantitative analysis was close to the theoretical response. In addition, the accuracy of the electrochemical method was compared with that of the standard iodometric titration method for determining the PV of vegetable fats (according to a standard method). Finally, using the electrochemical method, the concentration of peroxides was determined in a real sample-an anti-cellulite oil of the trademark Rivana with an expired shelf life.

An overview of the detection methods to the edible oil oxidation degree: Recent progress, challenges, and perspectives

Oil oxidation, the main quality-deteriorated reaction, would significantly and negatively influence its quality and safety during processing and storage. Evaluating oil oxidation degree is an effective strategy to enable early warning and ensure food safety. Herein, principles, recent progresses, advantages and shortcomings, representative applications, current challenges and promising perspectives, and summary tables of traditional (titration), instrumental (chromatography and spectroscopy), and especially rapid detection methods (chemical colorimetric methods and portable miniaturized devices) for evaluating oil oxidation degree are presented and reviewed. It is believed that rapid detection methods are the most promising practical candidate for detecting oil oxidation. Also, the interaction between advanced data-processing techniques and detection methods, and the systematic integration of whole analytical processes is proposed as next-generation perspectives in the oil oxidation evaluation. We wish to provide the knowledge of oil oxidation degree determination and enlighten novel strategies.

A novel gelatin composite film with melt extrusion for walnut oil packaging

Gelatin have excellent film-forming and barrier properties, but its lack of biological activity limits its application in packaging. In this study, fish gelatin incorporated with apple polyphenol/cumin essential oil composite films were successfully prepared by melt extrusion. The cross-linking existed in gelatin and apple polyphenol improved the thermal stability and oxidation resistance of the film. The synergistic effect of apple polyphenols and cumin essential oil decreased the sensitivity of the film to water, especially the water solubility decreased from 41.60 % to 26.07 %. The plasticization of essential oil nearly doubled the elongation at break while maintaining the tensile strength of the film (11.45 MPa). Furthermore, the FG-CEO-AP film can inhibit peroxide value to extend the shelf life about 20 days in the walnut oil preservation. In summary, the apple polyphenol/cumin essential oil of FG film exhibits excellent comprehensive properties and high preparation efficiency for utilization as an active packaging material.

Assessment of the impact of microwave roasting on nutrient content, lipid profile, and oxidative stability of pomegranate seed oil

The pomegranate, Punica granatum L. (Punicaceae), stands as one of the most widely employed oils in the cosmetic industry. However, due to its higher content of conjugated linoleic acid, its susceptibility to oxidation is a major challenge, with the most prominent being punicic acid. This study aimed to evaluate the effects of traditional roasting in a microwave on the lipid content, nutritional value, and oxidative stability of Moroccan pomegranate seed oil. The findings indicated a rise in the amount of oil after 15 min of roasting at 650 W, the amount of oil rose from 27.03 to 30.10 (g/100 g). However, the protein content, UV absorbance values, iodine, and saponification values were not significantly affected by a longer roasting time. The peroxide value increases with roasting (1.00 to 5.00 M.eq. O2/kg oil). The roasting process under 350 W did not significantly alter the fatty acid composition. The total tocopherol content exhibits a decrease with increasing roasting time and power, ranging from 333.36 mg/100 g for unroasted seeds to 316.84 mg/100 g for seeds roasted under the conditions of 650 W for 15 min. The roasting process has proven to be critical for the immediate and long-term preservation of the nutritional and physico-chemical properties of pomegranate seed oil.

Quality Characteristics and Volatile Components of Chili Oil Prepared from the Combination of Shuanla and Erjingtiao Peppers

This study aimed to investigate the influence of varying weight ratios of Shuanla and Erjingtiao peppers (10:0, 8:2, 6:4, 5:5, 4:6, 2:8, and 0:10, corresponding to samples PA, PB, PC, PD, PE, PF, and PG, respectively) on the sensory attributes, chromatism, acid values (AVs), peroxide values (POVs), capsaicinoids, and volatile organic compounds (VOCs) of seven chili oil samples. GC-IMS was employed to detect the VOCs of the chili oil samples, which were subsequently analyzed using multivariate statistical methods. The results revealed significant differences in pungency among the samples, with the PA sample exhibiting the strongest pungency. The PG sample demonstrated the highest values for a*, b*, and C*, while the PA sample displayed the highest L* and h*. The AVs of seven samples ranged from 0.490 ± 0.005 to 1.727 ± 0.015 mg/g. The POVs of the chili oil samples, ranging from 0.094 ± 0.000 to 0.127 ± 0.002 g/100 g, were significantly lower than those of extra virgin olive oil, 0.183 ± 0.001 g/100 g. The contents of capsaicinoids ranged from 15.26 ± 0.07 g/kg in the PA sample to 0.38 ± 0.00 g/kg in the PG sample (p < 0.05). Additionally, 56 volatile flavor substances were identified, and 10 key flavor compounds (ROAV ≥ 1) were screened among them. Multivariate data analysis via OPLS-DA indicated that 20 VOCs (VIP > 1) could serve as flavor markers in a clustering heat map to differentiate among the seven chili oil varieties. The findings of this study provide a valuable reference for the promotion of Shuanla and Erjingtiao peppers in chili oil production and the development of specific flavor profiles in chili oil to cater to diverse consumer preferences.

In-situ co-immobilization of lipase, lipoxygenase and L-cysteine within a metal-amino acid framework for conversion of soybean oil into higher-value products

We propose a co-immobilized chemo-enzyme cascade system to mitigate random intermediate diffusion from the mixture of individual immobilized catalysts and achieve a one-pot reaction of multi-enzyme and reductant. Catalyzed by lipase and lipoxygenase, unsaturated lipid hydroperoxides (HPOs) were synthesized. 13(S)-hydroperoxy-9Z, 11E-octadecadienoic acid (13-HPODE), one compound of HPOs, was subsequently reduced to 13(S)-hydroxy-9Z, 11E-octadecadienoic acid (13-HODE) by cysteine. Upon the optimized conditions, 75.28 mg of 13-HPODE and 4.01 mg of 13-HODE were produced from per milliliter of oil. The co-immobilized catalysts exhibited improved yield compared to the mixture of individually immobilized catalysts. Moreover, it demonstrated satisfactory durability and recyclability, maintaining a relative HPOs yield of 78.5% after 5 cycles. This work has achieved the co-immobilization of lipase, lipoxygenase and the reductant cysteine for the first time, successfully applying it to the conversion of soybean oil into 13-HODE. It offers a technological platform for transforming various oils into high-value products.

Effect of glycine and Pediococcus pentosaceus R1 combined application on the physicochemical properties, oxidative stability, and taste profile of Harbin dry sausages

This study investigated the effects of the application of glycine (Gly) and Pediococcus pentosaceus R1(Pp), alone or in combination, on the physicochemical properties, oxidative stability, and taste quality of Harbin dry sausages. The results demonstrated that after nine days of fermentation, the Gly + Pp group exhibited significantly (P < 0.05) lower moisture content (19.04%), water activity (0.686), and pH (4.78) values, alongside notably (P < 0.05) higher lactic acid bacteria count (8.11 log CFU/g sausage) and redness value (17.2), compared to the other three groups (P < 0.05). In addition, the dry sausages in the Gly + Pp group exhibited the lowest peroxide value (0.34 meq/kg sausage), thiobarbituric acid reactive substances (0.46 MAD/kg sausage), and protein carbonyl content (1.26 nmol/kg protein) during fermentation, followed by the Gly group, Pp group, and control group. Electronic tongue (e-tongue) and sensory evaluations revealed that the combined treatment with P. pentosaceus R1 and Gly resulted in superior taste characteristics. Besides, partial least squares regression (PLSR) analysis illustrated that the taste qualities characterized using the e-tongue were accordant with the sensory evaluation consequences, and total free amino acids (FAAs) and organic acids contributed to the dry sausages' taste properties. In conclusion, the combined application of Gly and P. pentosaceus R1 enhanced the physicochemical properties, oxidative stability, and taste profile of Harbin dry sausages.

Fluorescent probe to quantify lipid-derived electrophiles in edible oils

In the presence of molecular oxygen, edible oils can be oxidized to form a multitude of α,β-unsaturated carbonyl products collectively called 'lipid-derived electrophiles'. These molecules affect the taste of fat-containing foods but also act as electrophiles by covalently binding to protein amines/thiols and DNA nucleotides. The chemical modification of proteins by lipid-derived electrophiles appears to play an important role in human health, but the quantification of this diverse class of compounds remains a challenge. In this study, we describe a method capable of measuring the relative content of α,β-unsaturated carbonyls in food containing edible oils by using a "turn-on" fluorescent probe. The detection of electrophiles is based on a pre-fluorescent probe, 7-mercapto-4-methyl-coumarin (C-SH). The fluorescence of C-SH increases after nucleophilic addition to electrophilic lipid oxidation products. Since different lipid-derived electrophiles will react at a different rate with our fluorescent probe, we expressed the probe's response against a standard electrophile: trans-2-nonenal. In this assay, electrophiles which react more quickly will have a more dominant weight in the measurements carried out. Using this analytical technique, we can compare electrophilic content in French fries from several restaurants, and find they have lower amounts of lipid-derived electrophiles versus frozen fries baked at home. We also demonstrate that potato chips sealed in a reduced oxygen atmosphere will have a low 'electrophilic content' that increases over time, whereas chips in oxygen-permeable packaging initially have a higher 'electrophilic content' that does not increase as much over time. The relative ease of fluorescence measurements using microplate readers coupled with a simple oil extraction protocol should allow this method to quantify 'electrophilic content' in several food sources.

Comparative Study of an Antioxidant Compound and Ethoxyquin on Feed Oxidative Stability and on Performance, Antioxidant Capacity, and Intestinal Health in Starter Broiler Chickens

Concerns over the safety of ethoxyquin (EQ) highlight the need for safer, more effective feed antioxidants. This study investigated a healthier antioxidant compound (AC) as a potential alternative to EQ in broilers. A total of 351 one-day-old Arbor Acres Plus male broilers were randomly assigned to three treatments for 21 days: control (CON), EQ group (200 g/ton EQ at 60% purity), and AC group (200 g/ton AC containing 18% butylated hydroxytoluene, 3% citric acid, and 1% tertiary butylhydroquinone). AC supplementation reduced the acid value, peroxide value, and malondialdehyde content in stored feed, decreased feed intake and the feed conversion ratio without affecting body weight gain, and enhanced antioxidant capacity (liver total antioxidant capacity and superoxide dismutase; intestinal catalase and glutathione peroxidase 7). It improved intestinal morphology and decreased barrier permeability (lower diamine oxidase and D-lactate), potentially by promoting ZO-1, Occludin, and Mucin2 expression. The AC also upregulated NF-κB p50 and its inhibitor (NF-κB p105), enhancing immune regulation. Additionally, the AC tended to increase beneficial gut microbiota, including Lactobacillus, and reduced Bacteroides, Corprococcus, and Anaeroplasma. Compared to EQ, the AC further enhanced feed oxidative stability, the feed conversion ratio, intestinal morphology and barrier functions, and inflammatory status, suggesting its potential as a superior alternative to EQ for broiler diets.

Detection and quantification of groundnut oil adulteration with machine learning using a comparative approach with NIRS and UV-VIS

Groundnut oil is known as a good source of essential fatty acids which are significant in the physiological development of the human body. It has a distinctive fragrant making it ideal for cooking which contribute to its demand on the market. However, some groundnut oil producers have been suspected to produce groundnut oil by blending it with cheaper oils especially palm olein at different concentrations or by adding groundnut flavor to palm olein. Over the years, there have been several methods to detect adulteration in oils which are time-consuming and expensive. Near infrared (NIR) and ultraviolet-visible (UV-Vis) spectroscopies are cheap and rapid methods for oil adulteration. This present study aimed to apply NIR and UV-Vis in combination with chemometrics to develop models for prediction and quantification of groundnut oil adulteration. Using principal component analysis (PCA) scores, pure and prepared adulterated samples showed overlapping showing similarities between them. Linear discriminant analysis (LDA) models developed from NIR and UV-Vis gave an average cross-validation accuracy of 92.61% and 62.14% respectively for pure groundnut oil and adulterated samples with palm olein at 0, 1, 3, 5, 10, 20, 30, 40 and 50% v/v. With partial least squares regression free fatty acid, color parameters, peroxide and iodine values could be predicted with R2CV's up to 0.8799 and RMSECV's lower than 3 ml/100 ml for NIR spectra and R2CV's up to 0.81 and RMSECV's lower than 4 ml/100 ml for UV-Vis spectra. NIR spectra produced better models as compared to UV-Vis spectra.

Development, Stability, and In Vitro/In Vivo Studies of Volatile Oil Pickering Emulsion Stabilized by Modified Amber

Volatile oil stabilization strategies based on encapsulation with a large number of excipients limit further applications. The primary objective of this study is to improve the stability of volatile oils using Pickering emulsion (PE) stabilized by Chinese medicinal powder based on the principle of "integrating drug and excipient". Modified amber was acquired through surface modification, and a stable oil-in-water PE loaded with Acorus tatarinowii volatile oil (ATVO) was constructed from modified amber. The stability, including the peroxide value (PV), malondialdehyde (MDA) content, and the content and composition of volatile components in modified amber-PE (MAPE) under intense light exposure, was analyzed deeply. In addition, the in vitro release and pharmacokinetics of MAPE and ATVO were investigated. The results demonstrate that the PV and MDA content in MAPE were significantly lower than in free ATVO, and the content and composition of volatile components in MAPE were closer to those in untreated ATVO. The release kinetics of β-asarone and α-asarone in MAPE demonstrated rapid and higher release, and pharmacokinetic studies show that MAPE has better bioavailability. This research provides a distinctive Chinese medicine solution to address the vaporization of volatile oil in solid formulations.

Change in Sunflower Oil Quality and Safety Depending on Number of Deodorisation Cycles Used

Deodorisation remains a beneficial aspect of the processing of edible oils and fats and is required during the first refining and after transportation, storage, and/or further processing, such as interesterification. While there is awareness among the scientific community that repeated deodorisation may negatively impact product quality, according to some technical and processing requirements, oils, fats, and their blends can still be treated with up to 3-4 cycles of deodorisation. However, the precise changes caused by sequential deodorising processes remain unknown. This study analysed fatty acid compositions, peroxide values, anisidine values, volatile profiles, and monochloropropanediol (MCPDEs) and glycidyl (GEs) fatty acid ester contents in pressed and repeatedly deodorised sunflower oils (SFOs). The latter had higher levels of saturated fatty acids (SFAs); monounsaturated fatty acids (MUFAs); and trans fatty acids (TFAs); as well as volatile aldehydes, such as pentanal, hexanal, (E)-2-hexenal, and (E)-2-heptenal, and MCPDE contents with each successive deodorisation. Most of these compounds have the potential to cause harmful health effects. Therefore, it is necessary to limit the number of edible oil deodorisation cycles in order to maintain their quality and safety.

CsPbBr3 NCs Confined and In Situ Grown in ZIF-8: A Stable, Sensitive, Reliable Fluorescent Sensor for Evaluating the Acid Value of Edible Oils

Rapidly and sensitively evaluating the acid value (AV) of edible oils is significant to ensuring food quality and safety. Cesium lead bromide perovskite nanocrystals (CsPbBr3 NCs) are an effective candidate for AV detection; however, their instability restricts wide applications. Herein, CsPbBr3@ZIF-8 was prepared by confining and growing CsPbBr3 NCs in situ into zeolitic imidazolate framework-8 (ZIF-8) to improve the stability, and a fluorescence sensor was established to evaluate the AV of edible oils. The results present that CsPbBr3 NCs (below 5 nm) with excellent optical properties were confined and grown in situ in micropores and mesopores of ZIF-8. Meanwhile, CsPbBr3@ZIF-8 had better long-term storage, ultraviolet-irradiation, and water-exposure stabilities, compared with CsPbBr3 NCs. Given the fact that free fatty acids (the major contributor of AV) decrease the fluorescence of CsPbBr3 NCs, the fluorescence intensities of CsPbBr3@ZIF-8 were negative-linearly related to oil AV (R2 = 0.9902) in 0.04-6.00 mg of KOH/g with a 0.06 mg of KOH/g limit of detection. Besides, the practical AV recovery was 92-101% with an average relative standard deviation of 2%. Furthermore, the detection time was 20 min. The response mechanism revealed that free fatty acids could remove surface ligands and increase surface defects to prompt the aggregation of CsPbBr3 NCs and the formation of lattice fringe dislocations, inducing a decrease in the fluorescence. Thus, a stable, sensitive, reliable sensor was established to evaluate the AV of edible oils.

Lipids from the purple and white açaí (Euterpe oleracea Mart) varieties: nutritional, functional, and physicochemical properties

The Brazilian superfruit called Açaí or Assaí has gained interested from researcher and consumers worldwide, due to its health-related properties. In this context, this pioneering study aimed to compare the physicochemical, nutritional, and thermal properties of vegetable oils obtained from two varieties of açaí (Euterpe oleracea), purple and white. Both açaí oils from white (WAO) and purple (PAO) varieties were obtained by using the conventional solid-liquid extraction, which resulted in oil yields ranging from 52 to 61%. WAO and PAO were analyzed by their edibility quality parameters given the recommendations from Codex Alimentarius; their nutritional functionality indices and their composition of fatty acids and triglycerides content were estimated. Both oils showed low levels of acidity and peroxides, <1.8 mg KOH g-1 and < 1.7 mEq kg-1, respectively, which are good indicators of their preservation status, agreeing with the food regulations. PAO and WAO showed differences among the composition of fatty acids, mainly related to the content of monounsaturated fatty acids (MUFAs), which were 62.5 and 39.5%, respectively, mainly oleic acid. Regarding the polyunsaturated fatty acids (PUFAs), the WAO showed up to 23% of linoleic acid, whereas the PAO exhibited up to 11% of it. These differences reflect on the values of the nutritional functionality indices, atherogenic (AI), thrombogenic (IT), and hypocholesterolemic/hypercholesterolemic ratio (H/H). Both PAO and WAO showed low levels of AI and TI and superior values of H/H than other oilseeds from the literature. These results indicate the nutritional properties of açaí oils regarding a potential cardioprotective effect when included in a regular dietary intake. The thermogravimetric behavior and the evaluation of oxidation status by infrared spectroscopy (FTIR) were also studied. Both açaí oils demonstrated higher thermal stability (with an onset temperature ranging from 344 to 350 °C) and low indications of oxidation status, as no chemical groups related to it were noted in the FTIR spectrum, which agrees with the determined acidity and peroxide content. Moreover, the FTIR analysis unveiled characteristic chemical groups related to fatty acids and triglycerides, agreeing with the literature reports. These findings collectively contribute to a deeper comprehension of the nutritional and functional properties between white and purple açaí oils, offering valuable insights into their potential health, food, and industrial applications.

Characterization of Lipid Extracts from Different Colors of Peach Palm Fruits-Red, Yellow, Green, and White-Obtained through Ultrasound-Assisted Green Extraction

This study represents a pioneering investigation and comparative analysis of lipid extracts from four different colors of peach palm (Bactris gasipaes Kunt) fruits-red, yellow, green, and white-by employing a green method based on ethanolic ultrasound-assisted extraction. This study examined the extraction yield, physico-chemical-quality attributes, chromatographic profiles (GC), color measurements, total carotenoid content, differential thermogravimetry (TG/DTA), and infrared spectroscopy (FTIR). The obtained lipid extracts displayed a high quality, considering the physico-chemical parameters of the Codex Alimentarius, and a fatty acids profile characterized by unsaturated fatty acids, notably omegas (ω-3, ω-6, and ω-9). The indices of atherogenicity (A.I.), thrombogenicity (I.T.), and hypocholesterolemic and hypercholesterolemic ratios revealed superior outcomes for the red peach palm lipid extract (approximately 0.35, 0.52, and 2.75, respectively), along with higher levels of β-carotene (748.36 µg of β-carotene per 100 g-1 of lipid extract) compared to the yellow, green, and white counterparts. Consequently, this research successfully demonstrates the efficacy of using a green extraction method in preserving the lipid's quality, which can display cardiovascular functionality and thermal stability. These findings underscore the considerable potential of peach palm lipid extract as a valuable raw material for diverse industrial applications across various sectors. The results support its utilization in the production of functional food products and nutraceuticals due to its favorable fatty acid composition, potent antioxidant properties exhibited by its high β-carotene content, and notable cardiovascular functionality indices.

Engine Performance of High-Acid Oil-Biodiesel through Supercritical Transesterification

Relatively cheaper high-acid oil was used to make biodiesel through supercritical methanol transesterification, where high FFA contents in feedstock might conversely enhance the reaction extent. A direct-injection diesel engine and a dynamometer were used to analyze the engine characteristics of the high-acid oil-biodiesel. The experimental results show that the biodiesel made in this study had adequate fuel properties. This present biodiesel from high-acid oil was found to bear a lower heating value and equivalence ratio, with higher exhaust gas temperature, brake-specific fuel consumption (bsfc), and excess air ratio, than super-low sulfur diesel (SLSD). The biodiesel appeared to have larger-sized carbon residue left after the burning process in comparison with that of SLSD. The higher engine speed resulted in higher exhaust gas temperature and equivalence ratio, while lower bsfc, excess air ratio, was observed for the biodiesel. Supercritical methanol transesterification has been successfully proven to convert those low-cost feedstocks to renewable biodiesel products which own competitive engine performance in this study.

A low-toxic, robust, and sensitive colorimetric sensor for the peroxide value of edible oils with CsPbBr3 NCs in ethyl acetate

Sensitively, accurately, and rapidly evaluating edible oils' peroxide value (PV) is significant for safeguarding food quality and safety. However, the conventional detection methods are challenging to meet the above demands due to their complex operation, poor reproducibility, and professional personnel. The colorimetric method is an emerging technique to rapidly and on-site determine the PV of edible oils. CsPbBr3 NCs, as a novel fluorescent-sensing material, have been applied in the chemical colorimetric analysis. However, the heavy use of high-toxic solvents (toluene, chloroform) in the CsPbBr3 NCs colorimetric system significant-negatively influences the environment. This study evaluated the performances of CsPbBr3 NCs in nine low-toxic solvents and investigated the potential response mechanism to PV. The results presented that CsPbBr3 NCs in ethyl acetate displayed the highest photoluminescent intensity and the most uniform distribution. The results performed that the micro-morphology and crystal structure of CsPbBr3 NCs in ethyl acetate were similar to that in toluene, demonstrating the potential excellent performance. Under optimum conditions, three methods, including photoluminescence (PL)-decreased, wavelength-shifted, and phone-based colorimetric methods, were established to evaluate PV with the LOD of 0.0034 g/100 g. The PV recovery rates in Soybean oil, Camellia oil, Linseed oil, and Olive oil were from 75.0% to 100.0%, with a relative error below 25%. Furthermore, it was believed that the decreased PL and shifted wavelength originated from the halogen substitution with the crystal-structure destructions and the surface-defect formations. Thus, developing the low-toxic colorimetric CsPbBr3 NCs system with ethyl acetate could reduce the environmental influence and even enlighten the rise of other green detection methods for PV in edible oils.

Gas chromatography ion mobility spectroscopy: A rapid and effective tool for monitoring oil oxidation

Oil autoxidation is an early process of food deterioration, monitoring oil oxidation is therefore of great significance to ensure food quality and safety. In this study, a detection method of the primary and secondary oxidative products was developed by gas chromatography ion mobility spectrometry (GC-IMS).The secondary oxidative products was analyzed by GC-IMS. Then, the relationships between peroxide values and the contents of secondary oxidative products were investigated by constructing a prediction model of peroxide value of rapeseed oil with the help of secondary oxidative products and chemometrics. The coefficient of determination Q2 of the model validation set is 0.96, and the RMSECV is 0.1570 g/100 g. These validation results indicated that secondary oxidative products could also reflect the content of the primary oxidative products. Moreover, 10 characteristic markers related to oxidative rancidity were identified for monitoring edible oil rancidity and oxidative stability.

Design of an Artificial Intelligence of Things-Based Sesame Oil Evaluator for Quality Assessment Using Gas Sensors and Deep Learning Mechanisms

Traditional oil quality measurement is mostly based on chemical indicators such as acid value, peroxide value, and p-anisidine value. This process requires specialized knowledge and involves complex steps. Hence, this study designs and proposes a Sesame Oil Quality Assessment Service Platform, which is composed of an Intelligent Sesame Oil Evaluator (ISO Evaluator) and a Cloud Service Platform. Users can quickly assess the quality of sesame oil using this platform. The ISO Evaluator employs Artificial Intelligence of Things (AIoT) sensors to detect changes in volatile gases and the color of the oil during storage. It utilizes deep learning mechanisms, including Artificial Neural Network (ANN), Convolutional Neural Network (CNN), and Long Short-Term Memory (LSTM) to determine and evaluate the quality of the sesame oil. Evaluation results demonstrate that the linear discriminant analysis (LDA) value is 95.13. The MQ2, MQ3, MQ4, MQ7, and MQ8 sensors have a positive correlation. The CNN combined with an ANN model achieves a Mean Absolute Percentage Error (MAPE) of 8.1820% for predicting oil quality, while the LSTM model predicts future variations in oil quality indicators with a MAPE of 0.44%. Finally, the designed Sesame Oil Quality Assessment Service Platform effectively addresses issues related to digitization, quality measurement, supply quality observation, and scalability.

Gradual Changes of the Protective Effect of Phenols in Virgin Olive Oils Subjected to Storage and Controlled Stress by Mesh Cell Incubation

The oxidation reactions that take place in virgin olive oil under moderate conditions involved the combined effect of antioxidant and prooxidant compounds. Given the complexity of oxidation processes of multicomponent matrices, there is still a need to develop new methods with a dynamic approach to study the persistence of the compounds with healthy properties. This work studied the joint evolution of them, including phenols and pheophytin a, modeling their tendency during a real storage. The regression equations performed with the total phenol concentration showed that around 2% of the concentration was lost every month. Simultaneously, the progress of oxidation was evaluated by mesh cell incubation and Fourier transform infrared analysis. This method pointed out that, in the presence of light, the prooxidant effect of pigments was able to mask the protective effect of phenols, until the pheophytin a concentration was lower than 1 mg/kg. The antioxidant effect of phenols was less remarkable when the concentration loss was 35% or more.

Autoxidation of glycols used in inhalable daily products: implications for the use of artificial fogs and e-cigarettes

The use of glycols is seen in various industries and occupations. In the past few decades, the health implications of inhalable glycols have gained public attention. Inhalable glycols may cause adverse health effects, especially for workers in occupations receiving frequent exposure and consumers of glycol-based daily products. Our previous work highlighted the rapid accumulation of formaldehyde and glycolaldehyde in fog juice, thus proposing the occurrence of glycol autoxidation. However, the fundamentals of glycol autoxidation remained unclear and unexplored. Our goal is to investigate the autoxidation of common glycols during indoor storage. Carbonyls were quantified using liquid chromatography-mass spectrometry (LC-MS), and peroxides from autoxidation were monitored via iodometry and UV-Vis spectrometry. The impact of certain factors such as the water mixing ratio and antioxidants (vitamin C) was also investigated. Formation of aldehydes in many glycols was weekly monitored, such as e-cigarette juice and triethylene glycol (TEG). Occurrence of autoxidation was confirmed by the increase in the total peroxide concentration. Additionally, we highlighted the dependence of the carbonyl formation rate on the TEG-water mixing ratio, demonstrating the complex role of water in glycol autoxidation. We have also tested the effectiveness of vitamin C and made suggestions for minimizing the formation of toxic carbonyls in consumer products.

Green synthesis of gardenia seeds-based carbon dots for bacterial imaging and antioxidant activity in aqueous and oil samples

In this work, luminescent carbon dots with gardenia seeds as carbon precursors (GCDs) were synthesized using a one-step mild pyrolysis process and were then used as probes for imaging of bacterial (Escherichia coli). The GCDs showed a strong emission at 430 nm when excited at 370 nm. The relative fluorescence quantum yield of GCDs was found to be 1.13% in an aqueous medium. Rapid internalization of the GCDs by bacteria was confirmed by three colors (blue, green, and yellow) images that were obtained using confocal fluorescence microscopy. In addition, GCDs were noted to exhibit potent scavenging activities against DPPH˙, ˙OH, and ˙O2- free radicals. GCDs were also assayed as antioxidants in an oil sample by volumetric determination of the peroxide value. Thus, GCDs exhibited good antioxidant properties both in aqueous and oil media. In addition, a free fatty acid quantification kit in the presence of GCDs showed enhanced fluorescence detection of palmitic acid with a remarkably good limit of detection of 0.08 μM, which is lower than that in the absence of GCDs (0.76 μM). The proposed fluorescence method was then successfully used to determine the concentration of palmitic acid spiked in milk powder samples, with spiked recoveries of 82.6-109.6% and relative standard deviations of 0.9-4.6%.

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.

Evening primrose oil: a comprehensive review of its bioactives, extraction, analysis, oil quality, therapeutic merits, and safety

Oil crops have become increasingly farmed worldwide because of their numerous functions in foods and health. In particular, oil derived from the seeds of evening primrose (Oenothera biennis) (EPO) comprises essential fatty acids of the omega-6 (ω-6) series. It is well recognized to promote immune cells with a healthy balance and management of female ailments. The nutrients of interest in this oil are linoleic acid (LA, 70-74%) and γ-linolenic acid (GLA, 8-10%), which are polyunsaturated fatty acids (PUFA) that account for EPO's popularity as a dietary supplement. Various other chemicals in EPO function together to supply the body with PUFA, elevate normal ω-6 essential fatty acid levels, and support general health and well-being. The inclusive EPO biochemical analysis further succeeded in identifying several other components, i.e., triterpenes, phenolic acids, tocopherols, and phytosterols of potential health benefits. This comprehensive review capitalizes on EPO, the superior product of O. biennis, highlighting the interrelationship between various methods of cultivation, extraction, holistic chemical composition, sensory characters, and medicinal value. Besides the literature review, this study restates the numerous health advantages of primrose oil and possible drug-EPO interactions since a wide spectrum of drugs are administered concomitantly with EPO. Modern techniques to evaluate EPO chemical composition are addressed with emphasis on the missing gaps and future perspectives to ensure best oil quality and nutraceutical benefits.

Lipid oxidation in foods and its implications on proteins

Lipids in foods are sensitive to various environmental conditions. Under light or high temperatures, free radicals could be formed due to lipid oxidation, leading to the formation of unstable food system. Proteins are sensitive to free radicals, which could cause protein oxidation and aggregation. Protein aggregation significantly affects protein physicochemical characteristics and biological functions, such as digestibility, foaming characteristics, and bioavailability, further reducing the edible and storage quality of food. This review provided an overview of lipid oxidation in foods; its implications on protein oxidation; and the assessment methods of lipid oxidation, protein oxidation, and protein aggregation. Protein functions before and after aggregation in foods were compared, and a discussion for future research on lipid or protein oxidation in foods was presented.

Determination of oxidative deterioration in edible oils by high-pressure photoionization time-of-flight mass spectrometry

Since lipid oxidation often causes serious food safety issues worldwide, determination of oil's oxidative deterioration becomes quite significant, which still calls for efficient analytical methods. In this work, high-pressure photoionization time-of-flight mass spectrometry (HPPI-TOFMS) was firstly introduced for rapid detection of oxidative deterioration in edible oils. Through non-targeted qualitative analysis, oxidized oils with various oxidation levels were successfully discriminated for the first time by coupling HPPI-TOFMS with the orthogonal partial least squares discriminant analysis (OPLS-DA). Furthermore, by targeted interpretation of the HPPI-TOFMS mass spectra and the subsequent regression analysis (signal intensities vs TOTOX values), good linear correlations were observed for several predominant VOCs. Those specific VOCs were promising oxidation indicators, which would play important roles as TOTOX to judge the oxidation states of tested samples. The proposed HPPI-TOFMS methodology can be used as an innovative tool for accurate and effective assessment of lipid oxidation in edible oils.

Effective Improvement of the Oxidative Stability of Acer truncatum Bunge Seed Oil, a New Woody Oil Food Resource, by Rosemary Extract

Acer truncatum Bunge is a versatile, oil-producing, woody tree natively and widely distributed in northern China. In 2011, The People’s Republic of China’s Ministry of Health certified Acer truncatum seed oil (Aoil) as a new food resource. Unsaturated fatty acids account for up to 92% of the entire Aoil. When Aoil is processed or stored, it can easily oxidize. In this study, the effects of rosemary (Rosmarinus officinalis L.) extract on the oxidation stability of Aoil were analysed from multiple angles. The results of radical scavenging ability, malondialdehyde, and free fatty acid reveal that rosemary crude extract (RCE), rosmarinic acid (RA), and carnosic acid (CA) can significantly inhibit the oxidation of Aoil, and CA has the best oxidative stability for Aoil among the tested components of the crude rosemary. The delayed oxidation ability of CA for Aoil was slightly weaker than that of tert-butylhydroquinone (TBHQ), but stronger than that of butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and α-tocopherol (α-T), which was confirmed by microstructures, kinematic viscosity, Aoil weight change, and functional group. Additionally, CA-enriched Aoil had the smallest content of volatile lipid oxidation products. Moreover, lecithin-CA particles were added to enhance the oxidative stability of Aoil. These findings show that CA is a potent antioxidant, capable of successfully preventing Aoil oxidation.

Integrated the embedding delivery system and targeted oxygen scavenger enhances free radical scavenging capacity

World trends in oil crop growing area, yield, and production over the last 10 years exhibited an increase of 48 %, 82 %, and 240 %, respectively. Concerning reduced shelf-life of oil-containing food products caused by oil oxidation and the demand for sensory quality of oil, the development of methods the improvement oil quality is urgently required. This critical review presented a concise overview of the recent literature related to the inhibition ways of oil oxidation. The mechanism of different antioxidants and nanoparticle delivery systems on oil oxidation was also explored. The current review provides scientific findings on control strategies: (i) design oxidation quality assessment model; (ii) packaging by antioxidant coatings and eco-friendly film nanocomposite: ameliorate physicochemical properties; (iii) molecular investigations on inhibitory effects of selected antioxidants and underlying mechanisms; (iv) explore the interrelationship between the cysteine/citric acid and lipoxygenase pathway in the progression of oxidative/fragmentation degradation of unsaturated fatty acid chains.

Antioxidant effect of yeast on lipid oxidation in salami sausage

Salami is a kind of fermented meat product with rich nutrition and unique flavor. Because it is rich in fat, it is easy to oxidize to produce bad flavor. Compared with the way of adding artificial or natural antioxidants to reduce the degree of sausage oxidation, the antioxidant characteristics of developing the starter itself deserve more attention. In this study, firstly the antioxidant activities of 5 strains of yeast were measured in vitro, and then the mixture of yeast and Lactobacillus rhamnosus YL-1 was applied to fermented sausage model. The effect of the starter in the sausage model was investigated through physicochemical parameters, degree of fat oxidation, free fatty acid content, and though volatile flavor compound analysis, sensory evaluation and various indexes after storage were observed. Metagenomics was used to explore metabolic pathways, functional genes and key enzymes related to lipid oxidizing substances in sausage in yeast. The results showed that Wickerhamomyces anomalus Y12-3 and Y12-4 had strong tolerance to H2O2, and had higher SOD and CAT enzyme activities. The addition of yeast effectively reduced the material value of peroxidation value and active thiobarbiturate in salami. In flavor analysis, the content of flavor compounds associated with lipid oxidation, such as hexanal, heptanal, nonanal and (E)-2-decenal were significantly lower with the use of Debaryomyces hansenii Y4-1 and Y12-3. Meanwhile, the possible pathways of yeast metabolism of flavor substances related to lipid oxidation (mainly aldehydes) were discussed with the help of metagenomic techniques. According to the results of metagenomics, fatty acid degradation (ko00071) metabolic pathway was related to the degradation of aldehydes through aldehyde dehydrogenase, which was the potential key enzyme.

Variations in Antioxidant Capacity, Oxidative Stability, and Physicochemical Quality Parameters of Walnut (Juglans regia) Oil with Roasting and Accelerated Storage Conditions

Walnut oil, like all vegetable oils, is chemically unstable because of the sensitivity of its unsaturated fatty acids to the oxidation phenomenon. This phenomenon is based on a succession of chemical reactions, under the influence of temperature or storage conditions, that always lead to a considerable change in the quality of the oil by promoting the oxidation of unsaturated fatty acids through the degradation of their C-C double bonds, leading to the formation of secondary oxidation products that reduce the nutritional values of the oil. This research examines the oxidative stability of roasted and unroasted cold-pressed walnut oils under accelerated storage conditions. The oxidative stability of both oils was evaluated using physicochemical parameters: chemical composition (fatty acids, phytosterols, and tocopherols), pigment content (chlorophyll and carotenoids), specific extinction coefficients (K₂₃₂ and K₂₇₀), and quality indicators (acid and peroxide value) as well as the evaluation of radical scavenging activity by the DPPH method. The changes in these parameters were evaluated within 60 days at 60 ± 2 °C. The results showed that the levels of total phytosterols, the parameters of the acid and peroxide value, K₂₃₂ and K₂₇₀, increased slightly for both oils as well as the total tocopherol content and the antioxidant activity affected by the roasting process. In contrast, the fatty acid profiles did not change considerably during the 60 days of our study. After two months of oil treatment at 60 °C, the studied oils still showed an excellent physicochemical profile, which allows us to conclude that these oils are stable and can withstand such conditions. This may be due to the considerable content of tocopherols (vitamin E), which acts as an antioxidant.

Characterization of Traditional Chinese Sesame Oil by Using Headspace Solid-Phase Microextraction/Gas Chromatography-Mass Spectrometry, Electronic Nose, Sensory Evaluation, and RapidOxy

Xiao Mo Xiang You (XMXY) is a traditional Chinese sesame oil variety that is obtained through a hot water flotation process. This unique process gives the oil a unique aroma, health benefits, and excellent product stability. Although XMXY is always the most expensive among all the sesame oil varieties, it is usually used as a flavoring in many traditional Chinese daily food products and is increasingly popular. In order to reveal the characteristics of the oil, the volatile components, sensory evaluation, and oxidation stability of five XMXY samples were, respectively, analyzed by using headspace solid-phase microextraction/gas chromatography−mass spectrometry, an electronic nose, sensory evaluation, and RapidOxy. Comparisons and multidimensional statistical analysis were also carried out to distinguish XMXY from roasted sesame oil (RSO) and cold-pressed sesame oil (CSO) samples. In total, 69 volatiles were identified from XMXY, RSO, and CSO samples. Some compounds possessed high odor activity value (OAV > 1) in XMXY, including heterocyclic compounds, phenols, and sulfur-containing compounds. Additionally, they were also the main volatile components that distinguish XMXY from RSO and CSO. Roasted and nutty aromas were the dominant aroma attributes of XMXY. XMXY had better flavor intensity and oxidation stability than the other two sesame oil samples. These results are very valuable for the quality control and product identification of traditional Chinese sesame oil.

Chemical Properties of Peanut Oil from Arachis hypogaea L. 'Tainan 14' and Its Oxidized Volatile Formation

Arachis hypogaea L. ‘Tainan 14’ has purple skin characteristics. This study investigated the effects of different materials (shelled or unshelled peanuts) and temperatures (120 or 140 °C) on the properties of extracted peanut oil. The results show that its antioxidant components (total flavonoid, α−tocopherol, and γ-tocopherol) and oxidative stability were mainly affected by the roasting temperature (p < 0.05). Fifty-eight volatile compounds were identified by peanut oil oxidation and divided into three main groups during the roasting process using principal component analysis. The volatile formation changes of different materials and temperatures were assessed by agglomerative hierarchical clustering analysis. These results provide useful reference information for peanut oil applications in the food industry.

Shelf-Life Prediction and Thermodynamic Properties of No Added Sugar Chocolate Spread Fortified with Multiple Micronutrients

The development of fortified healthy pleasant foods, in which saturated fats are replaced with unsaturated ones, poses a challenge for the food industry due to their susceptibility to oxidative rancidity, which decreases product shelf-life, causes the destruction of health-promoting molecules, and forms potentially toxic compounds. A comparative study applying the Arrhenius model was carried out to investigate the oxidative stability and predict the shelf-life of a newly developed no added sugar chocolate spread formulated with sunflower oil, and fortified with vitamin D, Mg, and Ca checked against two commercially available spreads: No Palm and a well-known commercially available product (RB). The results obtained from the accelerated shelf-life testing for peroxide value (PV) showed relatively higher activation energy (Ea, 14.48 kJ/mol K) for RB, whereas lower Ea (11.31–12.78 kJ/mol K) was obtained for No Palm and all the experimental spread chocolates. Q10 values were comparable (1.202–1.154), indicating a similar catalytic effect of the temperature upon the oxidation rate across all the investigated samples. The positive Gibbs free energies ranged from 75.014 to 83.550 kJ/mol and pointed out that the lipid oxidation reaction in the chocolate spread was an endergonic process. The predicted shelf-life at 293.15 K was 8.57 months (RB), 7 months (No Palm), and 6.8 months for all the experimental spreadable chocolate. However, the higher production of hydroperoxides was observed in chocolate fortified with magnesium-calcium carbonate nanoparticles and stored at 313.15 and 323.15 K, suggesting these particles may enhance lipid oxidation.

Novel insight into the role of processing stages in nutritional components changes and characteristic flavors formation of noble scallop Chlamys nobilis adductors

Processing stages play critical role in the nutrition and flavor changes of marine products. This study investigated the nutrition and flavor profiles in noble scallop Chlamys nobilis adductor during boiling, rinsing, baking and drying processing stages by high performance liquid chromatography, headspace solid-phase microextraction and gas chromatography-tandem mass spectrometry. The results showed that the overall processing stages favorably preserved the essential amino acids. Drying obviously increased the umami and sweet amino acids contents by 72.08%, 67.77%, respectively (P < 0.05), and promoted the production of flavor nucleotides. In addition, the overall processing stages significantly increased the protein and lipid oxidation degree by (1.49-3.01)-fold and (4.25-5.81)-fold, respectively, compared with raw group (P < 0.05). Moreover, alcohols were the major volatiles in raw group, while the aldehydes, alcohols, and hydrocarbons predominated in rinsing, baking and drying stages. In conclusion, the processing maintained the nutrition value and improved the flavor of scallop adductors.

Potential Matrix Effects in Iodometry Determination of Peroxides Induced by Olefins

Peroxides (H₂O₂, ROOR, and ROOH) are an important reaction intermediate involved in a number of natural processes, including atmospheric autoxidation and lipid peroxidation in oils and animal tissues. Iodometry is an established spectroscopic technique that has been widely used to quantify total peroxide concentration in food, indoor, and outdoor samples. Iodometry provides selectivity toward peroxides through a quantitative reaction between I^- and peroxides to form I₃^- via a molecular iodine (I₂) intermediate. However, equilibrium changes caused by a potential interaction between olefinic species and I₂ can suppress I₃^- formation, thereby underestimating peroxide concentration. For the first time in the current study, this unrecognized interference posed by olefins (OEs) is systematically investigated to gauge its effects on the accuracy of iodometry. A number of model molecules were investigated. The interference was observed to be unique to OEs, but universally affecting different peroxide species such as H₂O₂, tert-butyl hydroperoxide, and aerosol-bound peroxides. A simple kinetic box model was built to explain this chemistry. The measured rate constant for 3-octenoic acid was found to be 0.84 ± 0.02 M^-1 s^-1. Overall, our results show matrix effects induced by OEs can underestimate peroxide concentration determined by iodometry for edible oils, indoor environments, and animal fat, but absent in most of the atmospheric samples. Nonetheless, our results point out the importance of this interfering chemistry in matrices enriched with OEs.

Effect of High-Voltage Electrostatic Field Heating on the Oxidative Stability of Duck Oils Containing Diacylglycerol

High-voltage electrostatic field (HVEF) as an emerging green technology is just at the beginning of its use in meat products and by-products processing. In this study, we employed duck oil to produce duck-oil-based diacylglycerol (DAG), termed DDAG. Three different DDAG volume concentrations (0, 20%, and 100%) of hybrid duck oils, named 0%DDAG, 20%DDAG, and 100%DDAG, respectively, were used to investigate their thermal oxidation stability in high-voltage electrostatic field heating and ordinary heating at 180 ± 1 ℃. The results show that the content of saturated fatty acids and trans fatty acids of the three kinds of duck oils increased (p < 0.05), while that of polyunsaturated fatty acids decreased (p < 0.05) from 0 h to 8 h. After heating for 8 h, the low-field nuclear magnetic resonance showed that the transverse relaxation time (T21) of the three oils decreased (p < 0.05), while the peak area ratio (S21) was increased significantly (p < 0.05). The above results indicate that more oxidation products were generated with heating time. The peroxide value, the content of saturated fatty acids, and the S21 increased with more DAG in the duck oil, which suggested that the oxidation stability was likely negatively correlated with the DAG content. Moreover, the peroxide value, the content of saturated fatty acids and trans fatty acids, and the S21 of the three concentrations of duck oils were higher (p < 0.05) under ordinary heating than HVEF heating. It was concluded that HVEF could restrain the speed of the thermal oxidation reaction occurring in the duck oil heating and be applied in heating conditions.