Low Peroxide Research Articles

Ultrasound-Assisted Alcoholic Extraction of Lesser Mealworm Larvae Oil: Process Optimization, Physicochemical Characteristics, and Energy Consumption.

The ultrasound-assisted extraction (UAE) of oil from lesser mealworm (Alphitobius diaperinus L.) larvae powders (LMLPs) using ethanol/isopropanol as the superior solvent was optimized. The evaluation of time (9.89–35.11 min), solvent-to-LMLPs (2.39–27.61 v/w), and temperature (16.36–83.64 °C) showed that the highest extraction efficiency (EE, 88.08%) and in vitro antioxidant activity (IVAA) of reducing power (0.651), and DPPH free-radical scavenging capacity (70.79%) were achieved at 22.5 v/w solvent-to-LMLPs and 70 °C for 22.64 min. Optimal ultrasound conditions significantly improved the EE than n-hexane extraction (60.09%) by reducing the electric energy consumption by ~18.5 times from 0.637 to 0.035 kWh/g. The oil diffusivity in ethanol-isopropanol during the UAE (0.97 × 10−9 m2/s) was much better than that of n-hexane (5.07 × 10−11 m2/s). The microstructural images confirmed the high efficiency of ethanol-isopropanol in the presence of ultrasounds to remove oil flakes from the internal and external surfaces of LMLPs. The improved IVAA was significantly associated with the total phenolic (4.306 mg GAE/g, r = 0.991) and carotenoid (0.778 mg/g, r = 0.937) contents (p < 0.01). Although there was no significant difference in the fatty acid profile between the two extracted oils, ethanol-isopropanol under sonication acceptably improved oxidative stability with lower peroxides, conjugated dienes and trienes, and free fatty acids.

Iron-based electrocatalysts derived from scrap tires for oxygen reduction reaction: Evolution of synthesis-structure-performance relationship in acidic, neutral and alkaline media

Mass generation of scrap tires presents a major challenge for environmental safety, however, their upcycling into carbon-based nanomaterials by the virtue of pyrolysis treatments can open up new windows for energy conversion and storage technologies in the context of the circular economy. Herein, we report the synthesis of Fe-N-C oxygen reduction reaction (ORR) electrocatalyst for fuel cell (FC) applications using carbonaceous char derived from scrap tires through microwave-assisted pyrolysis (MAP). The char obtained from MAP was activated with potassium hydroxide and then pyrolyzed at a high temperature to fabricate Fe-N-C after mixing with iron and nitrogen precursors. Finally, the developed Fe-N-C was ball-milled and acid-etched for homogenization and leaching of iron oxide nanoparticles. In this study, structural evaluation during each synthesis step was elucidated and correlated with the ORR activity in all three pHs i.e. acidic, neutral, and alkaline. Moreover, the effect of electrocatalyst loading on ORR kinetics was also analyzed using two different loadings (0.2 and 0.6 mg cm−2) on the rotating ring disk electrode (RRDE). The developed Fe-N-C demonstrated encouraging onset potentials of 0.881, 0.822, and 0.936 V vs RHE in acidic, neutral, and alkaline conditions, respectively. Whereas the ORR activity was slightly reduced after the milling-etching step. Lower peroxide yield together with a tetra-electronic reduction of oxygen was witnessed in acidic and neutral conditions, however, peroxide production was increased in the alkaline medium.

EXTRACTION, CHARACTERIZATION AND APPLICATIONS OF CASTOR SEED OIL FROM WILD Ricinus communis

The extraction of Castor oil was accomplished by mechanical cold pressing of the seeds of wild castor plant (Ricinus communis) found in Ini Local Government, Area Akwa Ibom State, Nigeria. Oil yield was 38.69%. The virgin oil (obtained as clear, viscous, pale-yellow liquid) was further purified by filtration through sintered glass (fine mesh screen). This was to eliminate any dust, gum, or other particulates present. Physicochemical characterization of the purified oil revealed low acid value (2.07), low iodine value (84.18), low peroxide value (38.00), but relatively high specific gravity (0.959), hydroxyl (163.64) and saponification (175.31) values. These values compare favourably with ASTM standards and general specifications for industrial grade castor oil (WHC, 2012), suggesting that the oil has good industrial potential. Fourier transform infra-red (FTIR) spectroscopic analysis has confirmed the presence of major functional groups in the oil, notably hydroxyl l (3414.12cm-1), carbonyl (1739.85cm-1), olefinic (1659.80cm- ) and methylenic (2925.15cm-1 ). Determined fatty acid composition of the oil by gas chromatography-mass spectrometry (GC-MS) shows ricinoleic acid (74.10%) as the major constituent fatty acid. Other fatty acids were linoleic (10.32%), oleic (7.55%), stearic (2.81%), palmitic (2.59%), erucic (1.70%) and eicosadienoic (0.93%). The appreciable oil yield (39.43%) from this castor seed variety, the quality, unique physicochemical characteristics of the extracted oil, and the renewable nature of castor oil as a natural resource justify the oil’s commercialization and full exploitation in traditional, as well as novel areas (e.g. biopolymer and biofuel production) of industrial application.

Impact of glucose syrup and antioxidants on properties and oxidative stability of microcapsules loaded with skipjack tuna eyeball oil

Effects of glucose syrup (GS) at different ratios as wall materials on encapsulation efficiency (EE) and properties of micro-encapsulated skipjack tuna eyeball oil (ME-STEO) were determined. Highest EE (90.45-90.61%) was obtained when the mixtures of fish gelatin (FG), sodium caseinate (SC) and GS at ratios of 1:1:1 and 1:1:2 (w/w/w) were used. Moisture content, water activity and lightness (L*) of ME-STEO were declined when the amount of GS was augmented, but redness (a*), yellowness (b*), total difference in color (∆E*) and surface shrinkage of ME-STEO were increased. When α-tocopherol (AT) in combination of ascorbyl palmitate (AP) were incorporated in STEO, lower peroxide and thiobarbituric acid substances were found in ME-STEO than others (P < 0.05). Mixtures of wall material (FG:SC:GS=1:1:2) and the addition of 200 ppm AT in combination with 200 ppm AP yielded STEO as a core with higher oxidative stability during 30 days of storage at room temperature.

Waxy maize starch nanoparticles incorporated tea polyphenols to stabilize Pickering emulsion and inhibit oil oxidation

Waxy maize starch (WMS) and tea polyphenols (TPs) were combined to prepare WMS/TP nanoparticles through precipitation. Physicochemical properties and emulsifying capacity of the WMS/TP nanoparticles were investigated. The results showed that the addition of TPs enhanced the hydrophobicity of the WMS nanoparticles, and the size of the WMS/TP nanoparticles increased with increasing TP addition (from 5 % to 15 %). The emulsions stabilized by the WMS/TP nanoparticles exhibited excellent physical stability. After 15 days of storage, the emulsified phase volume fraction remained at 100 % in the emulsion stabilized by the WMS/TP nanoparticles (15 % of TPs). Moreover, the WMS/TP nanoparticles also enhanced the oxidative stability of the emulsions characterized by a lower peroxide value and thiobarbituric acid reactive substances. The results of this study demonstrate that WMS/TP nanoparticles are potential food-grade Pickering emulsifiers with the capacity not only to stabilize emulsions but also to inhibit oil oxidation of the emulsions.

Quality attributes of chicken nuggets extended with different legume flours

Chicken nugget is a comminuted meat product commonly prepared from spiced chicken meat and other ingredients. The tenderness of chicken meat lowers its firmness and mouth feel which may reduce acceptability of chicken nugget made from it. Thus, acceptability of chicken nugget could be harnessed when legume flour extenders are used along. Therefore, acceptability as well as quality of chicken nugget from different legume flours were evaluated. Soyabean, groundnut and cowpea flours were used as meat extenders for development of raw chicken nuggets and thereafter cooked for consumption. The quality of both raw and cooked legume flour extended chicken nuggets were assessed based on functional properties, sensory properties, proximate composition, amino acid content and shelf stability in terms of lipid peroxidation and microbial load. In their raw state, the legume flour extenders competed favourably with each other. Among all, soyabean flour extender maintained remarkable functional properties that transcend into significant (P < 0.05) yield of 86.93% of chicken nugget in comparison to the control (86.37%), groundnut (84.95%) and cowpea (84.50%). Upon cooking, all the legume flour extended chicken nuggets varied in their quality attributes. Apart from the high level of flavour and low microbial load, cowpea extended chicken nugget was of low quality based on the parameters evaluated in comparison with other legume flour extended chicken nuggets. Of interest, soyabean extended chicken nugget followed by groundnut extended chicken nugget were of good quality based on sensory properties, high crude protein and amino acid levels, low cholesterol content and lipid peroxidation value as well as low microbial load.Graphical abstract

Actinomucor elegans and Podospora bulbillosa Positively Improves Endurance to Water Deficit and Salinity Stresses in Tomato Plants.

Fungal strains isolated from the rhizosphere of healthy Solanum lycopersicum were examined to mitigate symptoms of drought and salinity stresses. The fungal strains were identified as Actinomucor elegans and Podospora bulbillosa based on their DNA sequencing and morphological analysis. Additionally, the fungal strains were assayed for a number of plant growth promoting traits and abiotic stresses on solid media. Moreover, a greenhouse experiment was conducted and tomato seedlings were treated with 25% PEG or 1.5% NaCl for 12 days, and the impact of plant growth promoting fungi (PGPF) on tomato seedling performance under these conditions was examined. PGPF application raised the survival of the stressed tomato plants, which was evidenced by higher physiological and biochemical processes. The PGPF-inoculated plants exhibited higher chlorophyll, carotenoid, protein, amino acid, antioxidant activities, salicylic acid, glucose, fructose, and sucrose contents, and showed lower hydrogen peroxide, and lipid metabolism relative to control plants under stress. Analysis using gene expression showed enhanced expression of SlF3H gene and reduced expression of SlNCED1, SlDEAD31, SlbZIP38, and SlGRAS10 genes following PGPFs application. Overall, the outcomes of this study elucidate the function of these fungal strains and present candidates with potential implementation as biofertilizers and in promoting plant stress endurance.

Chilling injury of tomato fruit was alleviated under low-temperature storage by silencing Sly-miR171e with short tandem target mimic technology.

In this study, the role of Sly-miR171e on post-harvest cold tolerance of tomato fruit was researched. The results showed that overexpression of Sly-miR171e (miR171e-OE) promoted postharvest chilling injury (CI) of tomato fruit at the mature red (MR) and mature green (MG) stage. Contrasted with the wild type (WT) and miR171e-OE fruit, the knockdown of Sly-miR171e (miR171e-STTM) showed a lower CI index, lower hydrogen peroxide (H2O2) content, and higher fruit firmness after harvest. In the fruit of miR171e-STTM, the expression level of GRAS24, CBF1, GA2ox1, and COR, and the GA3 content were ascended, while the expression levels of GA20ox1 and GA3ox1 were descended. The research demonstrated that CI in tomato fruit was alleviated at low temperature storage by silencing Sly-miR171e with short tandem target mimic (STTM) technology. Furthermore, it also provided helpful information for genetic modification of miR171e and control of CI in the postharvest fruit.

The ER protein Creld regulates ER-mitochondria contact dynamics and respiratory complex 1 activity.

Dynamic contacts are formed between endoplasmic reticulum (ER) and mitochondria that enable the exchange of calcium and phospholipids. Disturbed contacts between ER and mitochondria impair mitochondrial dynamics and are a molecular hallmark of Parkinson’s disease, which is also characterized by impaired complex I activity and dopaminergic neuron degeneration. Here, we analyzed the role of cysteine-rich with EGF-like domain (Creld), a poorly characterized risk gene for Parkinson’s disease, in the regulation of mitochondrial dynamics and function. We found that loss of Creld leads to mitochondrial hyperfusion and reduced ROS signaling in Drosophila melanogaster, Xenopus tropicalis, and human cells. Creld fly mutants show differences in ER-mitochondria contacts and reduced respiratory complex I activity. The resulting low–hydrogen peroxide levels are linked to disturbed neuronal activity and lead to impaired locomotion, but not neurodegeneration, in Creld mutants. We conclude that Creld regulates ER-mitochondria communication and thereby hydrogen peroxide formation, which is required for normal neuron function.

Whitening efficacy of low concentration hydrogen peroxide photoactivated with blue or violet LED

BackgroundBleaching protocols using low concentration hydrogen peroxide (HP) photoactivated with LED sources have been widely discussed. Herein, we evaluated the whitening efficacy of 15% HP photoactivated with blue or violet LED compared to 35% HP. MethodsThirty bovine crowns were sectioned into 5 × 5 × 2 mm specimens. After staining in black tea, the specimens were randomized into three groups (n = 10): 35% HP, 15% HP + blue LED and 15% HP + violet LED. Two bleaching sessions were performed and the color assessment (∆L*, ∆a*, ∆b*, ∆Eab [CIELab], ∆E00 [CIEDE2000] and WID) was performed before, 24h after each session, 7 days and 1 month after the last session. Data were evaluated by two-way repeated measures ANOVA and Bonferroni post-test at a significance level of 5%. ResultsAll groups showed effective and similar results over 1 month of follow-up (p > 0.05), with only intragroup differences among the time intervals (p < 0.05). ConclusionsThe use of 15% HP photoactivated with blue or violet LED showed similar whitening efficacy compared to 35% HP. Thus, the association of low concentration bleaching gels with blue or violet LED sources can provide successful and less-aggressive treatment in terms of color change.

Production and characterisation of high-quality silkworm pupal oil for omega-3 fatty acid supplementation

The present work aimed to produce edible oil that is low-cost and rich in ω-3 fatty acids (mainly α-linolenic acid; ALA). Silkworm pupae are industrial wastes which could be a good choice as the raw material for silkworm pupal oil (SPO) is. Solvent extraction (SE), supercritical fluid extraction (SFE), and aqueous enzymatic extraction (AE) were compared (oil yields of 28.34, 26.75, and 23.11%, respectively), and crude SPOs showed similar fatty acid compositions. Crude SPO extracted by SE contained a total tocopherol of 289.56 µg/g, which was higher than that of AE. SE was recommended due to its low cost, high oil yield, and high preservation of bioactive compounds, and a further refinement process was adopted only for crude SPO from SE. The fatty acid composition of the refined SPO was not different from that of the crude SPO, which contained 37.51% ω-3 fatty acids. A low acid value (AV, 0.65 mg KOH/g) and peroxide value (PV, 5.79 meq O2/kg), with almost no detectable toxicants indicated that SPO would be a high-quality edible oil for ω-3 fatty acid supplementation.

Evaluation of the penetration of intracoronal bleaching agents into the cervical region using different intraorifice barriers

BackgroundThe present study aimed to make a comparison between the effects of 35% hydrogen peroxide gel (HP) and sodium perborate with distilled water (SP) bleaching agents on the sealing characteristics of glass ionomer cement (GIC), TheraBase, ProRoot MTA and Biodentine intraorifice barriers.MethodsOne hundred and twelve single-rooted mandibular human premolar teeth extracted from young patients (14–25 years) were chosen. Root cement and cementoenamel junction (CEJ) of teeth were examined under a stereomicroscope at 10 × magnification to ensure there was no cement defect or dentin gap in CEJ. After the endodontic access cavities were opened on the occlusal surfaces of the teeth, the working length was determined. Instrumentation of each root canal was performed with a ProTaper Gold rotary system in the determined working length and filled with gutta-percha + AH Plus with a single cone technique using. Root fillings were removed 3 mm short of the CEJ and sealed with one of the following intraorifice barrier materials (n = 30/group): 1. GIC; 2. TheraBase; 3. ProProot-MTA; 4. Biodentine. In each of the sub-groups, either HP or SP was used to perform intracoronal bleaching on days 1, 4, and 7. All outer surfaces of the specimens except the 3 mm cervical region were covered with nail polish and modeling wax layers. Specimens were immersed in a 5 ml Eppendorf tube that contained 2 mL of distilled water. The penetration of peroxide release was measured using the colorimetric ferric thiocyanate method. Statistical analysis of the data was performed with Three-way ANOVA and Tukey’s test (P = 0.05).ResultsIn the HP groups, GIC showed the greatest peroxide release when compared with other tested groups on day 1 (P < 0.05). Biodentine and ProRoot MTA displayed a significantly lower peroxide leakage when compared to GIC and TheraBase on days 1 and 4 (P < 0.05). While GIC and TheraBase were used, HP observed higher peroxide penetration when compared with SP on days 1 and 4 (P < 0.05).ConclusionsPeroxide diffusion was significantly influenced by the kind of intracoronal bleaching agents and intraorifice barrier materials used.

Does water addition during the industrial milling phase affect the chemical-sensory quality of olive oils? The case of cv. Arbequina oils

At olive oil industrial extraction, water addition is a practice overcoming the formation of thick pastes. The effect of water addition (0 to 6.2%, kgadded water/kgolives), during the industrial milling of cv. Arbequina olives, on the oils’ chemical-sensory quality, was evaluated. Despite the extra virgin olive oil classification, compared with the water incorporation (1.2–6.2%), extraction without water addition resulted into oils that showed less primary oxidation (lower peroxide values and K232), greater total phenolic content (+12–22%) and higher oxidative stability (+22–31%). No water addition increased the oils secoiridoids content (+5–13%), mainly oleacein (+27–79%). Oils extracted without water addition had a more intense ripe fruity sensation (≥ +11%) but lower fruit intensities (at least −4%). Thus, the quality and stability of the cv. Arbequina oils can be favoured if extracted without adding water during the olives industrial milling.

Physicochemical, antioxidant and antimicrobial properties of citrus peel essential oils

Essential oils are produced as secondary metabolites of aromatic plants and can be extracted from leaves, seeds or fruit peel of the plants. Citrus peel is a rich source of limonene which is antimicrobial in nature. The present study aimed to deal with the physicochemical, antioxidant and antimicrobial properties of citrus peel essential oil from Citrus reticulate (mandarin orange), Citrus limetta (mosambi) and Citrus limon (lemon). The lemon peel oil had lower peroxide value (1.6 meq/kg of sample), saponification value (112.2 mg KOH/g of oil) and higher iodine value (116 gI2/100g oil) when compared with orange and mosambi peel essential oil. DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging activity of citrus peel essential oil was measured and the result indicated that the total antioxidant activity of lemon peel oil was 89.2 % Radical Scavenging activity (RSA). The antifungal activity was assessed by agar dilution method, whereas the antibacterial property was assessed by the agar diffusion method. Lemon peel oil recorded better antimicrobial properties with minimum inhibitory concentration of 0.3% against Aspergillus flavus MTCC 277, 0.2% for Penicillium MTCC 1995 and Fusarium oxysporum MTCC 284. Likewise, the minimum inhibitory concentration of lemon peel oil against Staphylococcus aureus MTCC 96 was 0.3%; Salmonella enterica MTCC 733 and Erwinia sp MTCC 2760 was 0.5%; Pseudomonas aeruginosa MTCC 1688 and Escherichia coli MTCC 443 was 0.7%. This comparative study showed that lemon peel oil had better physicochemical and antioxidant property. Lemon peel oil can be used as a preservative in the food system as it exhibited antibacterial and antifungal activity.

The rule of biological and microbial safety in &lt;em&gt;Hyssopus officinalis&lt;/em&gt; extract for influencing mozzarella cheese functionality

Mozzarella was identified as one of the most extensively consumed dairy products. The aim of this study was to investigate the effect of Hyssopus officinalis extract on microbial properties, antioxidant activity, and mozzarella storage. Ultrasound was applied to gain extract and tests, such as total phenolics, antioxidant attributes, and microbial investigation were accomplished. Physicochemical features, peroxide, sensory evaluation and microbial population were assessed on mozzarella including 0, 1.13 and 1.40 μg/ml Hyssopusofficinalis extract during 45 days. The highest phenolic content was observed in rosmarinic acid (60.33 ± 2.31 mg/g) and Listeria monocytogenes was recognized as the most resistant microorganism in Hyssopus officinalis. The physicochemical results were found to be standard and the lowest peroxide was detected in the sample with the highest extract amount (1.40 μg/ml) on the 45th day. The microbial evaluation showed that mentioned extract was effective to minimize survival of Escherichia coli and Listeria monocytogenes during storage. The reduction in contamination hazard of Escherichia coli almost 1 log CFU/mL was detected in treatment samples during storage. The Hyssopus officinalis extract was spotted as the most appropriate agent to improve functional and sensory properties of mozzarella.

Salvianolic Acid Modulates Physiological Responses and Stress-Related Genes That Affect Osmotic Stress Tolerance in Glycine max and Zea mays

Drought is a serious threat worldwide to soybean and maize production. This study was conducted to discern the impact of salvianolic acid treatment on osmotic-stressed soybean (Glycine max L.) and maize (Zea mays L.) seedlings from the perspective of physiochemical and molecular reactions. Examination of varied salvianolic acid concentrations (0, 0.1, 1, 5, 10, and 25 μM) on soybean and maize seedling growth confirmed that the 0.1 and 1 μM concentrations, respectively, showed an improvement in agronomic traits. Likewise, the investigation ascertained how salvianolic acid application could retrieve osmotic-stressed plants. Soybean and maize seedlings were irrigated with water or 25% PEG for 8 days. The results indicated that salvianolic acid application promoted the survival of the 39-day-old osmotic-stressed soybean and maize plants. The salvianolic acid-treated plants retained high photosynthetic pigments, protein, amino acid, fatty acid, sugar, and antioxidant contents, and demonstrated low hydrogen peroxide and lipid contents under osmotic stress conditions. Gene transcription pattern certified that salvianolic acid application led to an increased expression of GmGOGAT, GmUBC2, ZmpsbA, ZmNAGK, ZmVPP1, and ZmSCE1d genes, and a diminished expression of GmMIPS2, GmSOG1, GmACS, GmCKX, ZmPIS, and ZmNAC48 genes. Together, our results indicate the utility of salvianolic acid to enhance the osmotic endurance of soybean and maize plants.

Effect of storage period and relative humidity on the quality of moringa oil

This study investigated the influence of storage period and relative humidity on oil extracted from moringa seed using soxhlet extraction method and stored under controlled relative humidity for 90 days using saturated slurry salt method. Samples were taken after 1, 30, 60 and 90 days and the quality parameters like iodine value (IV), acid value (AV), saponification value (SV) and peroxide value (PV) were obtained and compared to FAO/WHO acceptable standards for edible oil. The obtained results showed that the acid value, peroxide value and saponification value increase as relative humidity increases, ranging from 2.47-3.44mg/g, 1.01-1.21Meq/Kg and 172.13-184.36mg/g, respectively, but still falls within the range stated by FAO/WHO for edible oils (4.00 mg/g, 4.00 Meq/Kg and 181±2.60 mg/g) for acid value, peroxide value and saponification value, respectively. Iodine value decreases as relative humidity increases, ranging from 61.28-71.92 g/100g and falls slightly below the standard given by FAO/WHO for edible oils (80-106 g/100g). It was concluded that moringa oil is stable within a wide range of humidity and will have a longer shelf life due to its very low peroxide level.

Investigation of the in vitro digestion fate and oxidation of protein-based oleogels prepared by pine nut oil

Pine nut oil (PNO) was gelled by solvent exchange and absorption methods through soy protein-tannic acid covalent hydrogel. The current study aimed to compare the in vitro digestion of oleogels prepared by different methods: solvent exchange (network oleogel [SNO] and particulate oleogel [SPO]) and absorption methods (AO), and probe the effect of oleogelation on oxidation. Results showed that the preparation affected the physicochemical properties of oleogels; during in vitro digestion, lipolysis was delayed for the oleogels as compared to that for PNO, and the extent of lipolysis followed the order of AO > SNO > SPO > PNO. The fatty acid profile in the micelle fraction demonstrated enhanced solubilization of unsaturated fatty acids (UFAs), especially pinolenic acid. During storage, oleogels had lower peroxide, thiobarbituric acid, and conjugated diene values than PNO, indicating superior oxidation stability. Thus, this work provides valuable directions for designing a delivery system to facilitate UFAs digestion and improve the oxidation stability of PNO.

Phenolic extracts from colored-walnut pellicles: antioxidant efficiency in walnut oil preservation

ABSTRACT The phenolic extracts of walnut cultivars with a red pellicle (HWE), a purple pellicle (ZWE) and a yellow pellicle (WWE) were compared. The total contents of phenolics, flavonoids and condensed tannins, as well as in vitro antioxidant activities (ABTS and DPPH) of the phenolic extracts were evaluated. The results showed that 25 phenolic compounds were identified in three colored walnuts. The HWE contained the highest contents of total phenolics and condensed tannins, while the ZWE contained the highest content of flavonoids. The DPPH and ABTS assays indicated that the phenolic extracts of colored-walnut pellicles showed a higher free radical scavenging ability than butylated hydroxytoluene (BHT) at the same concentration. Phenolic extracts of colored walnuts were also evaluated as natural antioxidants in walnut oil, substituting for BHT. The efficacy of phenolic extracts in walnut oil preservation was evaluated using accelerated storage (60 °C) for 12 days. After accelerated storage, walnut oil enriched with the phenolic extracts kept better qualities, with significantly lower peroxides, p-anisidine, and TOTOX values. The volatiles were measured and identified using the headspace solid phase micro-extraction gas chromatography to further assess oil quality. Aldehydes such as hexanal and 2-heptenal were identified as representative oxidative volatiles. Hexanal and 2-heptenal content indicated that adding phenolic extracts could prevent flavor deterioration of the oil. This study suggested that phenolic extracts of walnut pellicles could offer an effective alternative to synthetic antioxidants for walnut oil preservation.

The Characteristic of Insect Oil for a Potential Component of Oleogel and Its Application as a Solid Fat Replacer in Cookies.

The larvae of Tenebrio molitor, an edible insect, have recently attracted attention in the food industry as a protein supplement or future food material. However, despite more than 30% of the total weight being fat content, few studies have been conducted on the fat (oil) derived from Tenebrio molitor larvae (TM oil) and its food utilization. In this study, TM oil was extracted and its fatty acid composition and antioxidant activity were investigated. Then, the oleogels were prepared with TM oil and oleogelators (candelilla wax, carnauba wax, and beeswax) and their rheological and thermal properties were evaluated to elucidate their utilization as a solid fat replacer in cookies. In the results, TM oil contained 73.6% unsaturated fatty acids and showed a lower antioxidant activity than olive oil. Although the highest hardness was shown in oleogel with candelilla wax, the highest viscoelasticity above 50 °C was observed for oleogel with carnauba wax. The highest melting point was observed in carnauba oleogel. Lower peroxide values were observed in the oleogel samples than for TM oil, indicating that oleogelation of structuring oil improved the oxidative stability of TM oil. In addition, the shortening replacement with carnauba wax oleogel showed a desirable cookie quality in terms of spreadability and texture properties.