Action of phytosterols on thermally induced trans fatty acids in peanut oil

Synthesis of novel resveratrol nervonic acid ester using a solvent-free mechanochemical method: Improved lipophilicity, thermostability, and oxidation stability

Resveratrol (RES), a polyphenol with strong antioxidant properties, has limited applications in the food industry because of its poor lipophilicity and stability. A new, green, simple, effective, and universally applicable approach was presented for synthesizing resveratrol nervonic acid (NA) ester (RNE) using a solvent-free mechanochemical method. The conversion, purity, and yield of RNE reached 95.85 %, 91.28 %, and 80.78 %, respectively. High yields of alcoholic fatty acid esters (94.54-99.48 %) were also achieved. The RNE synthesis mechanism involved the formation of a 4'- monoester, followed by a 4', 5- diester, and ultimately a 3,4',5- triester. RNE was a slightly yellowish solid with a composition of 3,4',5 -triester (87.19 %), 3/5,4'-diester (11.61 %), and 4'-monoester (1.2 %). Compared to RES, RNE exhibited significantly improved lipophilicity (204.08 times), thermostability (148.9 °C), and oxidation stability (1.05-1.60 times). This study provided a novel strategy for the synthesis of alcoholic fatty acid esters, expanding the application of RES in the food industry.

Mechanism of methyl elaidate on the thermal oxidation behavior

The effects of cis-trans isomerization on the oxidation products of oleic acid (composites and structure characterization) were investigated. The reduction of thermal oxidation reaction of methyl elaidate (ME) was 6.72 % lower than that of methyl oleate (MO), and the oxidation products (core aldehydes) first increased and then decreased with the prolongation of thermal oxidation time. ME exhibited better oxidation stability than MO in free radicals, hydroperoxides, double bonds, aldehydes, and glycerides. The oxidation products were mainly 11-oxo-9-undecenoate (initial stage) and methyl 9-oxononanoate (later stage), following the free radical chain reaction mechanism. The H8 in double bond was more easily dehydrogenated in the chain initiation stage than H11, followed by the formation of core aldehyde through three intermediates and two transition states each pathway. ME required a higher energy barrier (1.3-13.6 kJ/mol) than MO reaction, making it more difficult for ME to undergo thermal oxidation reaction. The transition state 4 and 5 were rate determining steps of chain initiation reaction and proliferation reaction, respectively. This study was of great significance to further control the formation of these trans fats and their oxidation products.

The current state of knowledge about thermal processing of edible seeds; a special emphasis on their bioactive constituents and antioxidant activity

Thermal processing can alter the biological activity of seed phytochemicals in various ways, thus improving shelf life, bioavailability, oxidative stability, and oil yield; it can also decrease the content of antinutritional compounds, reduce cytotoxic activity and increase the total phenolic content of the seeds. However, this treatment can also inactivate beneficial compounds, including phenolics. This review describes the effect of different thermal processing methods on the content, activity, and bioavailability of chemical compounds from different edible seeds. The outcome is dependent on the method, temperature, time of processing, and type of seeds. Although thermal processing has many benefits, its precise effect on different species requires further clarification to determine how it influences their phytochemical content and biological activity, and identify the optimal conditions for processing.

Vegetable oils: Classification, quality analysis, nutritional value and lipidomics applications

Lipids are widespread in nature and play a pivotal role as a source of energy and nutrition for the human body. Vegetable oils (VOs) constitute a significant category in the food industry, containing various lipid components that have garnered attention for being natural, environmentally friendly and health-promoting. The review presented the classification of raw materials (RMs) from oil crops and quality analysis techniques of VOs, with the aim of improving comprehension and facilitating in-depth research of VOs. Brief descriptions were provided for four categories of VOs, and quality analysis techniques for both RMs and VOs were generalized. Furthermore, this study discussed the applications of lipidomics technology in component analysis, processing and utilization, quality determination, as well as nutritional function assessment of VOs. Through reviewing RMs and quality analysis techniques of VOs, this study aims to encourage further refinement and development in the processing and utilization of VOs, offering valuable references for theoretical and applied research in food chemistry and food science.

Properties and Characterization of Sunflower Seeds from Different Varieties of Edible and Oil Sunflower Seeds

Sunflower seeds, oil, and protein powder are rich in nutritional value, but the quality of different varieties of sunflower seeds is quite different, and the comprehensive comparative analysis characteristics of edible and oil sunflower seeds are still unclear. The comprehensive analysis and comparison of the raw material indicators, physicochemical properties, and processing characteristics of four edible and four oil sunflower seed varieties were investigated. The results showed that the engineering properties, texture characteristics, single-cell structure, and oil, protein, and starch granule distribution were different between edible and oil sunflower seeds. The composition of fatty acids and amino acids was different among edible, oil sunflower seeds and different varieties. The oleic acid (18.72~79.30%) and linoleic acid (10.11~51.72%) were the main fatty acids in sunflower seed oil, and in amino acid composition, the highest content was glutamic acid (8.88~11.86 g/100 g), followed by aspartic acid (3.92~4.86 g/100 g) and arginine (4.03~4.80 g/100 g). Sunflower meal proteins were dominated by 11S globulin and 2S albumin, and the secondary structure was dominated by β-folding, with -SH and S-S varying greatly among different varieties. Sunflower meal proteins vary widely in terms of functional properties among different varieties, and specialized quality screening was necessary. This study provided a reference and theoretical support for understanding sunflower seeds to further promote the processing and utilization of sunflower seeds.

Green process for the preparation of resveratrol-containing high oleic acid peanut oil

Resveratrol (Res), a polyphenol compound with strong biological activity, is widely used in medicinal and health products. In this study, an innovative resveratrol high oleic peanut oil (Res-HOPO) was prepared utilizing self-developed cold pressing equipment and high oleic peanuts. The peanut roots were pretreated with four different methods, including ultra-fine crushing, ultrasound-treating, microwave-treating, and a combination of microwave-ultrasound-treating peanut roots. Under optimized conditions (microwave power of 15 W, ultrasound time of 28 min, and ultrasound power of 400 W), the Res-HOPO prepared by pretreating with a combination of microwave-ultrasound had the most Res (91.12 mg/kg). Except for the pretreated whole peanut roots, pretreating with microwave (40.49 mg/kg), ultrasound (39.03 mg/kg), and ultra-fine crushing of peanut root powder (22.57 mg/kg) resulted in the high Res content. The Res-HOPO had a satisfactory yield (40%), oleic acid content (74.05% ∼ 75.85%), no trans fatty acids, great physicochemical properties, higher nutritional value (4-fold increase in squalene and almost 10-fold increase in campesterol), an extended oxidation induction time (1.39 ∼ 22 times), and no heavy metals, pesticides, or aflatoxins. The four green pretreatment methods used for the preparation of Res-HOPO in this study were effective, which provided an innovative approach for developing nutritious and healthy edible oil.

Quality Evaluation of Hainan Robusta Coffee Bean Oil Produced by Ultrasound Coupled with Coconut Oil Extraction

This study investigates the treatment of coconut oil using thermosonic treatment in combination with green coffee beans. Under a defined ratio of coconut oil to green coffee beans, the effect of different thermosonic time on the quality parameters, active substance content, antioxidant capacity, and thermal oxidative stability of coconut oil were investigated as a strategy to potentially improve the quality of oil. Results showed that the β-sitosterol content of CCO (coconut coffee oil) treated with the thermal method combined with green coffee bean treatment reached up to 393.80 ± 11.13 mg/kg without affecting the lipid structure. In addition, DPPH clearance equivalents increased from 5.31 ± 1.30 mg EGCG/g to 71.34 ± 0.98 mg EGCG/g, and the ABTS clearance equivalent was 45.38 ± 0.87 mg EGCG/g versus 0 for the untreated sample. The improvement in thermal oxidation stability of treated coconut oil is also significant. The TG (Thermogravimetry) onset temperature was elevated from 277.97 °C to 335.08 °C and the induction time was elevated up to 24.73 ± 0.41 h from 5.17 ± 0.21 h. Thermosonic treatment in combination with green coffee beans is an ideal option to improve the quality of coconut oil. The results of this article provide new ideas for the development of plant-blended oil products and the new utilization of coconut oil and coffee beans.

Inhibition mechanism of trans-resveratrol on thermally induced trans fatty acids in peanut oil

The unanticipated inhibitory effect of trans-resveratrol (trans-Res) on the formation of trans fatty acids (TFAs) by thermal isomerization of peanut oil (PO) and its mechanism were investigated by experiment and density functional theory. Results showed that trans-Res inhibited the amount and formation rate of TFAs. trans-Res first inhibited the formation of C18:2, then C18:1, by the mechanism of proton transfer isomerism. The most active reaction site of trans-Res (4'-OH free radical) preferentially combined with the OOL-L-C11• (di-allyl) and then with OOL-O-C11• (mono-allyl) allyl groups in PO, resulting in the higher reaction energy barrier of speed control steps in OOL-L (transition state 1) and OOL-O (transition state 2), and the lower reaction rate of OOL-L and OOL-O (both decreased by 1-10³ times), to reduce the formation of TFAs. Our study provided a theoretical foundation for the precise regulation of natural hydroxy compound to TFAs in oil.

Green synthesis and structure characterization of resveratrol conjugated linoleate

To improve the stability and broaden the application of resveratrol (Res), the Res conjugated linoleate (RCL) were synthesized successfully using Res and 9c,11t-conjugated linoleic acid (CLA) with N, N'-carbonyldiimidazole (CDI) as catalyst for the first time. The Res conversion and the yield of RCL were achieved at 96.85% and 65.30%, respectively. In comparison with Res, RCL has lower acid value (1.80 mg/g) and peroxide value (3.25 meq/kg) and higher thermal stability (improved by 115.3 ℃). RCL was identified as a novel triester compound with a physical appearance as a light-yellow viscous oil. The 9c,11t-CLA was activated by CDI first, reacted with Res to form 4'-Res-ester preferentially, followed by 5,4'-Res-ester and 3,5,4'-Res-ester. The transition-state quaternary ring structures of monoesters were the key structures determining the formation of RCL. This study provided an efficient and eco-friendly approach for the synthesis of RCL, promoting the development of the synthesis of Res long-chain fatty acid ester.

Biodegradation of Aflatoxin B1 in Peanut Oil by an Amphipathic Laccase-Inorganic Hybrid Nanoflower

Aflatoxin B₁ (AFB₁) contamination is an important issue for the safety of edible oils. Enzymatic degradation is a promising approach for removing mycotoxins in a specific, efficient, and green manner. However, enzymatic degradation of mycotoxins in edible oil is challenging as a result of the low activity and stability of the enzyme. Herein, a novel strategy was proposed to degrade AFB₁ in peanut oil using an amphipathic laccase-inorganic hybrid nanoflower (Lac NF-P) as a biocatalyst. Owing to the improved microenvironment of the enzymatic reaction and the enhanced stability of the enzyme structure, the proposed amphipathic Lac NF-P showed 134- and 3.2-fold increases in the degradation efficiency of AFB₁ in comparison to laccase and Lac NF, respectively. AFB₁ was removed to less than 0.96 μg/kg within 3 h when using Lac NF-P as a catalyst in the peanut oil, with the AFB₁ concentration ranging from 50 to 150 μg/kg. Moreover, the quality of the peanut oil had no obvious change, and no leakage of catalyst was observed after the treatment of Lac NF-P. In other words, our study may open an avenue for the development of a novel biocatalyst for the detoxification of mycotoxins in edible oils.

The preparation of phytosteryl succinyl sucrose esters and improvement of their water solubility and emulsifying properties

Phytosterols have gained much attention due to their outstanding cholesterol-reducing effect, while the insolubility in water limits their application. The aim of this study was to synthesize a novel hydrophilic phytosteryl derivatives-phytosteryl succinyl sucrose esters (PSSEs) and investigated their water solubility and emulsifying properties. PSSEs were synthesized by esterifying phytosterol hemisuccinates with sucrose through a mild chemical reaction. PSSEs were characterized by fourier transform infrared spectroscopy, mass spectroscopy, and nuclear magnetic resonance spectroscopy. The yield of PSSEs exceeded 84% in N,N-dimethylformamide for 36 h of reaction under the selected conditions: 100 mmol/L phytosteryl hemisuccinates, 150 mmol/L sucrose, 110 mmol/L 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide hydrochlide, 10 mmol/L 4-dimethylaminopyridine and 10 mmol/L p-toluenesulfonic acid. The water insolubility of phytosterols was overcome and the water solubility of PSSEs achieved 2.13 mg/mL. The emulsifying activity of PSSEs was 2.5 times that of phytosterols, reaching 0.95 mg/mL. PSSEs with better water solubility and emulsification properties could facilitate the widespread use of phytosterols in foods.

Effects of roasting and deodorisation on 3-monochloropropane-1, 2-diol esters, 3, 4-benzopyrene and trans fatty acids in peanut oil

Hazardous substances are readily produced during roasting and deodorisation in the preparation of peanut oil. The aim of this work was to investigate the variation of 3-monochloropropane-1, 2-diol ester (3-MCPDE), 3, 4-benzopyrene (BaP) and trans fatty acid (TFA) contents in the roasting and deodorisation segments of peanut oil production process. Roasting temperatures and durations significantly affected the contaminants contents in peanut oil; they increased significantly at a roasting temperature >210°C and time >60 min. In the deodorisation segment, the BaP and TFA contents were over the standard limits at a deodorisation temperature >210°C and time >140 min. Analysis showed that 3-MCPDE was significantly correlated with the formation of C18:2T (r = 0.979) and there was a linear relationship between BaP and C18:1T (Y = 0.509 C18:1T). This information will provide guidance for the precise and appropriate processing of peanut oil.

Evaluation of trans fatty acids, carbonyl compounds and bioactive minor components in commercial linseed oils

Trans fatty acids (TFAs), associated with the risks of coronary heart disease and diabetes, are formed by isomerization of unsaturated fatty acids during refining of linseed oils. In this study, TFAs and the chemical characteristics (acid value, peroxide value, carbonyl compounds, bioactive minor components and fatty acids) in 32 commercial linseed oils were investigated, and the correlation among them were further analyzed. Results showed that C18:3 TFAs were predominant TFAs in linseed oils and about 9% of the samples had TFA contents above 2 g/100 g fat, as well as the average level of TFA in the refined samples was higher than that in the unrefined oils. The correlation analyses suggested C18:3 TFAs exhibited significant negative correlations with acid value, levels of acetone, trans-2-nonenal, campesterol and α-linolenic acid. These results provided a comprehensive insight of TFAs in linseed oil and had important implications for consumers and linseed oil industry.

Solubility and physicochemical properties of resveratrol in peanut oil

The solubility and physicochemical properties of resveratrol in peanut oil were systematically studied following ultrasonic and magnetic stirring-assisted dissolution. The highest resveratrol solubility in peanut oil observed was 95.91%. The optimal dissolution process was determined to be the addition of 183.00 mg/kg resveratrol, a magnetic temperature of 40.00℃, and a magnetic duration of 3.50 h, which yielded a resveratrol content of 175.51 mg/kg oil. Under this standardized process, the oil composition remained unchanged. Resveratrol promoted the conversion of saturated triglycerides into unsaturated triglycerides, increased the linolenic acid content, and did not facilitate the formation of trans fatty acids. In addition, resveratrol preservedthe lightcolor, decreased the peroxide and acid values by 30%, prolonged the shelf life by more than 2 folds, and improved the thermal stability. In this sense, peanut oil with resveratrol can serve as anti-isomerism and antioxidant additive.