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This work aimed to investigate the effects of the microwave-assisted extraction (MAE) on the hempseed (Cannabis sativa L.) oil yield, oxidation stability, and antioxidant activity. Power (300, 450, and 600 W) and time (5, 10, and 15 min) were independent variables while oil extraction yield, peroxide value (PV), p-anisidine value (AV), TOTOX value (TV), and DPPH scavenging activity were considered as dependent ones. Optimization was conducted by response surface methodology where the optimum point was 450 W and 7.19 min. In this point, the extraction yield obtained 33.91% w/w and the oil showed acceptable oxidation quality (PV of 2.5 meq/kg, AV of 0.67, and TV of 5.67) and antioxidant activity with the IC50 value of 30.82 mg/mL. The Soxhlet extraction (SE) method was carried out to be compared with MAE. It showed relatively higher oil extraction yield (37.93% w/w) but lower oil oxidation stability with PV of 6.4 meq/kg, AV of 3.69, TV of 16.49, and higher amount of IC50 32.47 mg/mL which showed lower antioxidant activity. Any significant difference between fatty acid compositions was not observed with the dominant amounts of linoleic acid and α-linolenic acid. Also, the tocopherol contents and thermal properties were studied by HPLC and DSC, respectively. MAE showed higher total tocopherol content (929.67 mg/kg) than SE (832.61 mg/kg) and γ-tocopherol was dominant. Moreover, DSC analysis showed that both profiles (crystallization and melting transitions) are likely influenced mostly by the triglyceride compositions and crystals structure.

The antioxidant activities of natural phenolic compounds (thymol, carvacrol, and thymoquinone) were compared with commercial antioxidants (α-tocopherol, BHT, and BHA) using DPPH · , conjugated diene (CD) in the linoleic acid emulsion, and ferric reducing power methods. Commercial antioxidants had higher DPPH · antiradical activity than natural phenolics. Thymoquinone (TQ) at 1000 ppm showed higher inhibition (65.7%) on DPPH · radicals than other natural phenolics at 1000 ppm (25.0% for thymol, and 18.3% for carvacrol). Carvacrol and thymol showed similar antioxidant activities compared with BHT and BHA in linoleic acid emulsion test at different concentrations, while TQ and α-tocopherol exhibited lower activity among analyzed samples. The results from reducing power test showed that natural phenolics were less effective than commercial antioxidants. The impacts of natural phenolics and BHT on the oxidative stabilities of refined and stripped corn oils were investigated using the Rancimat, Schaal oven, peroxide value (PV), CD (K232) and p -anisidine value ( p -AV) methods. The loss in total tocopherols in refined corn oils was recorded during storage under Schaal oven conditions (60 °C). BHT showed a higher induction period (15.01 h) than phenolic compounds added to corn oils (3.88–5.69 h) and a control sample (2.82 h). According to the results of the Schaal oven test, BHT much better protected the refined and stripped corn oils from oxidation than natural phenolic compounds. Among phenolic compounds, TQ at 250 and 500 ppm exhibited high antioxidant potential in refined and stripped corn oils.

Alzheimer’s disease (AD) is a multifactorial neurodegenerative disorder, characterized by the formation, aggregation and accumulation of amyloid beta, perturbed metal (copper, iron and zinc) homeostasis, metal-induced oxidative stress, neuroinflammation, aberrant activity of acetylcholinesterase (AChE) and other pathologies. The aim of this review is to discuss the current therapies based on the “combination-drugs-multitargets” strategy to target multiple pathologies to block the progression of pathogenesis of AD. In addition to cholinergic and amyloid targets, a significant effort is focused on targeting the metal-induced oxidative stress component of the disease. The main focus of research is based on modifications of existing drugs with specific biological activity. Tacrine was the first AChE inhibitor to be introduced into clinical practice and has been frequently used for the design of multitarget-directed ligands. A number of hybrid compounds containing tacrine and structural moieties derived from natural sources such as flavonoids [quercetin, rutin, coumarin, gallamine, resveratrol, scutellarin, anisidine, hesperetin, (−)-epicatechin] and other molecules (melatonin, trolox) have also been applied to function as multitarget-directed ligands. Most of these hybrids are potent inhibitors of AChE and butyrylcholinesterase and also of amyloid-beta aggregation. In addition, the antioxidant functionality, represented by coumarins, melatonin and other antioxidant molecules reduces the level of oxidative stress via ROS-scavenging mechanisms, as well as via chelation of redox-active Cu and Fe, thus suppressing the formation of ROS via the Fenton reaction. Various medicinal plants are under investigation for their ability to ameliorate symptoms of AD. The therapeutic potency of huperzine A and B, ginseng, curcumin and other compounds is manifested predominantly by the inhibitory action toward AChE, antioxidant or radical-scavenging and redox metal-chelating activity, inhibition of amyloid-beta aggregation and tau-protein hyperphosphorylation and antiinflammatory activity. Flavonoids not only function as antioxidants and metal-chelating agents, but also interact with protein kinase and lipid kinase signaling pathways, and others involving mitogen-activated protein kinase, NF-kappaB and tyrosine kinase. Among the most promising group of substances with potential activity against AD are the flavonoids, including myricetin, morin, rutin, quercetin, fisetin, kaempferol, apigenin and glycitein, which have been shown, in vitro, to possess antiamyloidogenic and fibril-destabilization activity, as well as being able to act as metal chelators and to suppressing oxidative stress. In terms of the clinical use of multifunctional hybrids, herbal drugs or flavonoids against AD, some remaining challenges are to establish the ideal dose to develop effective formulations to preserve bioavailability and to determine the stage when they should be administered. If the onset of the disease could be delayed by a decade, the number of AD victims would be significantly reduced.

The present study investigated the lipid oxidation degree of soybean oil during regularly discontinuous 40 h-deep-frying process. Electron spin resonance (ESR) spectroscopy technique was applied to identify and quantify the formed radicals, along with evaluation of physicochemical parameters including acid value (AV), peroxide value (PV), p-anisidine value (p-AnV), polar compounds (PC), fatty acid composition and volatile profile. Results showed the AV, p-AnV, PC and free radical of frying oil samples increased significantly with the increasing frying time. The results of fatty acids showed that unsaturated fatty acid such as C18:1 and C18:2 decreased by 19.98% and 14.58%, respectively, with prolonged frying time, while the content of C16:1, trans C18:1 and C18:2 increased by 20.38%, 425% and 42.86%, respectively, when compared to the fresh oil samples. In contrast, the content of saturated fatty acid had little change. In total, 37 volatile compounds were detected revealing a complex aroma profile of frying soybean oil, composed of 15 aldehydes, 8 alcohols, 4 ketones, 4 acids, 5 alkanes and 1 furan. Principal component analysis and hierarchical clustering analysis indicated that hexanal, heptanal, (E)-2-hexenal, octanal, (E)-2-heptenal, nonanal, (E)-2-octenal, undecanal, (E,E)-2,4-heptadienal, (E)-2-decenal, 2-undecenal, (E,E)-2,4-decadienal, 1-pentanol, 2,2-dimethyl-3-hexanol, (Z)-2-dodecenol, 1-octen-3-ol, pentanoic acid, octanoic acid, nonanoic acid and 2-pentyl-furan may be potential markers for evaluating lipid oxidation of frying soybean oil.

The volatile fraction of three vegetable oils recommended for deep-frying due to their high MUFA:PUFA ratios, namely extra-virgin olive oil, peanut oil and canola oil, was compared before and after frying potatoes, with a particular focus on toxic volatiles. For the purpose, a headspace solid-phase-micro extraction technique coupled with gas chromatography and mass spectrometry was optimized, with semi-quantification achieved using two internal standards. Significant qualitative and quantitative differences were observed, both before and after frying. From a total of 51 compounds, aldehydes were the main group formed after deep-frying, their nature and abundance being highly associated with the initial fatty acid composition, particularly linoleic acid ( r 2  = −0.999, p  ≤ 0.001). Globally, extra-virgin olive oil revealed fewer formations of unsaturated aldehydes, including toxic ones, and correlated with lower amounts of degradation indicators, as polar compounds ( r 2  = 0.998, p  ≤ 0.001) and p -anisidine value ( r 2  = 0.991, p  ≤ 0.001). Despite the similarities in total unsaturation degree between canola and peanut oils, the former presented lower amount of volatiles, including E,E -2,4-decadienal and acrolein, the more toxic ones. These results highlight for the pertinence of volatile analyses to evaluate and compare oil degradation under thermal and oxidative stress, while complementing other degradation indicators. Additionally, the optimized methodology allows a direct comparison of different oil matrices, supporting further developments into more general methods for volatiles quantification, enabling more efficient comparison of results between research teams.

In this study, ensilaging of herring ( Clupea harengus ) filleting co-products was taken from lab-scale to pilot scale (1500 L) while monitoring the protein degree of hydrolysis (DH) and lipid oxidation. Subsequently, the possibility of recovering fish oil and protein hydrolysates using batch centrifugation at different g-forces/times was investigated. Around 38% DH was recorded after 2-day pilot-scale ensilaging of herring co-products at ambient temperature (i.e., ~ 22 °C), which was similar to the DH found in lab-scale (40% after 2 days; 22 °C). The lipid oxidation marker 2-thiobarbituric acid reactive substances (TBARS) reached 20 µmole TBARS/kg silage after 2-day ensilaging. Centrifugation of the silage at 3000–8500 × g for 2–20 min revealed successful separation into fish oil and protein hydrolysates. Heat-treating the silage (85 °C; 30 min) prior to centrifugation resulted in significantly higher oil and hydrolysates recoveries; the same being true for increased g-force. At 8500 × g, the recovery of oil and hydrolysates were 9.7 and 53.0% w / w , respectively, from heat-treated silage, while recoveries were 4.1 and 48.1% w / w , respectively, from non-heat treated silage. At 4500 × g, being a more scalable approach, corresponding numbers were 8.2 and 47.1% ( w / w ) as well as 2.0 and 40.2% ( w / w ). The recovered fish oil contained 8% EPA and 11% DHA of total fatty acids. Free fatty acids (FFA), peroxide value (PV), p-anisidine value (p-AV), and total oxidation (TOTOX) values of oils were in the range of 4–7% (FFA), 3.6–3.7 meq/kg oil (PV), 2.5–4.0 (p-AV), and 9.9–11.1 (TOTOX), respectively, which were within the acceptable limits for human consumption specified by the GOED voluntary monograph. The recovered protein hydrolysates contained peptides in the molecular weight range 0.3–6 kDa (~ 37%) and 11–34 kDa (~ 63%). Also, the remaining solids contained 15–17% ( w / w ) protein, having 44–45% essential amino acids. Overall, the results suggest that herring co-product silage is a valuable source of fish oil and protein hydrolysates, paving the way for ensilaging based-biorefining of herring co-products into multiple products.

Fats play multiple roles in determining the desirable characteristics of foods. However, there are health concerns about saturated and trans fats. Bigels have been proposed as a novel fat replacer in foods. This research evaluated the role of the type of hydrogel in the development of bigels to be used as fat replacers in cookies. Bigels were made with beeswax/canola oil oleogel and sodium alginate and carboxymethylcellulose hydrogels. The results showed that the peroxide value and binding capacity of bigels were affected by the type of hydrogel used. However, their fatty acid profile, p-anisidine value, oxidative stability, and texture remained unchanged. Using bigels as fat replacers, cookies were obtained with a hardness similar to those with original shortening, showing the potential of bigels for use in foods.

Baltic herring (Clupea harengus membras) is one of the most abundant commercially caught fish species from the Baltic Sea. Despite the high content of fat and omega-3 fatty acids, the consumption of Baltic herring has decreased dramatically over the last four decades, mostly due to the small sizes and difficulty in processing. At the same time there is an increasing global demand for fish and fish oil rich in omega-3 fatty acids. This study aimed to investigate enzyme-assisted oil extraction as an environmentally friendly process for valorizing the underutilized fish species and by-products to high quality fish oil for human consumption. Three different commercially available proteolytic enzymes (Alcalase®, Neutrase® and Protamex®) and two treatment times (35 and 70 min) were investigated in the extraction of fish oil from whole fish and by-products from filleting of Baltic herring. The oil quality and stability were studied with peroxide- and p-anisidine value analyses, fatty acid analysis with GC-FID, and volatile compounds with HS-SPME-GC-MS. Overall, longer extraction times led to better oil yields but also increased oxidation of the oil. For whole fish, the highest oil yields were from the 70-min extractions with Neutrase and Protamex. Protamex extraction with 35 min resulted in the best fatty acid composition with the highest content of eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) but also increased oxidation compared to treatment with other enzymes. For by-products, the highest oil yield was obtained from the 70-min extraction with Protamex without significant differences in EPA and DHA contents among the oils extracted with different enzymes. Oxidation was lowest in the oil produced with 35-min treatment using Neutrase and Protamex. This study showed the potential of using proteolytic enzymes in the extraction of crude oil from Baltic herring and its by-products. However, further research is needed to optimize enzymatic processing of Baltic herring and its by-products to improve yield and quality of crude oil.

This experiment aimed to encapsulate Ferulago angulata essential oil (FEO) into the zein nanofibers through an electrospinning approach and evaluate their application in retarding the lipid oxidation of butter oil during accelerated shelf-life storage. The main constituents of FEO were α-pinene (35.08%), followed by limonene (21.85%) and ɣ-terpinene (8.03%), respectively. Based on the results of scanning electron microscopy, the obtained electrospun nanofibers were cylindrical, uniformly disordered network structures with smooth surfaces and good continuity. The study findings showed that zein + FEO 1% and zein + FEO 1.5% nanofiber mats had better inhibitory effects to improve the oxidative stability of butter oil during accelerated storage for 24 days compared to the samples enriched with butylated hydroxytoluene 100 mg/Kg (P < 0.05). At the end of the study period, the peroxide value, thiobarbituric acid-reactive substances, p-anisidine value, and acid value of treated butter oils with zein + FEO 1% and zein + FEO 1.5% nanofiber mats were in the range of 0.79–1.03 meq oxygen/Kg, 0.35–0.45 MDA/Kg, 1.36–1.66, and 0.53–0.65 mg KOH/g, respectively.

The purpose of this work was to re-evaluate the polar paradox theory (PPT) that explains the relationships between the efficacy of antioxidants, their polarity, and their environments. In this study, ascorbic acid (AA), ascorbyl palmitate (AP), gallic acid (GA), gallyl palmitate (GP), Trolox (TR), α -tocopherol (TO), resveratrol (R), and resveratryl palmitate (RP) were employed to assess conjugated dienoic acid (CDA), the p -anisidine value ( p -AV), headspace oxygen content, and hexanal formation in a bulk oil system. TR, TO, R, and RP showed better antioxidant activities in CDA and p -AV and higher headspace oxygen content than AA, AP, GA, and GP. AA showed lower hexanal formation than AP, whereas GP, TO, and RP had better antioxidant activity than their derivatives. These findings suggest that the PPT might be useful to explain the oxidation that occurs at the air-oil interface/association colloids but applying it to other assays might not appropriate.