Search

Roasting of mustard seeds prior to oil extraction is a well-documented unit operation essential to produce canolol and other lipophilic sinapates. This study investigated the effectiveness of air frying as a seed roasting treatment operation for enhancing the recovery of lipophilic sinapates from various mustard samples and fractions/products. Air frying of seeds, powder, cake, bran, and flour from different mustard varieties was carried out at temperature-time combinations of 160, 170, and 180°C for 5, 10, 15, and 20 min, respectively. Oil was extracted using the Soxtec method. Lipophilic sinapates were extracted from the oil using equal volumes of hexane to methanol 70% (v/v) and quantified by high performance liquid chromatography-diode array detection (HPLC-DAD). The total phenolic content (TPC) and antioxidant activity of the oils were also evaluated. The results showed a time-temperature dependency for the recovery of major oil-soluble sinapates in all mustard samples and fractions. The optimum air frying condition 180°C for 15 min produced the maximum yield of canolol as well as other unidentified oil-soluble sinapates (retention time (RT)-7.7, RT-11.50, RT-14.95, and RT-16.24 min). The oil from lower grade yellow mustard seeds (LGYMS) roasted at 180°C for 20 mins specifically had the highest TPC (3402.22 ± 58.79 mg GAE/g oil), while LGYMS oils generally showed better antioxidant activities (2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric ion reducing antioxidant power (FRAP), and inhibition of linoleic acid oxidation) but were lower in metal ion chelating capacity. This information would be beneficial to the oil industry because air frying generated valuable canolol and other antioxidant lipophilic sinapates from mustard varieties and their fractions. PRACTICAL APPLICATION: A major limitation in the application of natural extracts in vegetable oils is the poor lipophilic nature of phenolic compounds. This study employed a new thermal treatment (air frying) in the recovery of canolol and other lipophilic antioxidants. Such treatments can enrich mustard-based ingredients with canolol and other lipophilic antioxidants for domestic and industrial applications.

The effect of preheating temperature (XThe online version contains supplementary material available at 10.1007/s13197-021-05325-9.

De-oiled canola meals are sources of protein-containing flavor-active phenolic compounds. Conventional canola oil processing utilizes an excess amount of solvents and is associated with the release of high-intensity bitter flavor-active phenolic compounds, limiting the use of the canola meal. Recent advances in the extraction and isolation of the bitter favor-active phenolic compounds from canola by-products produce protein isolates, however, would benefit the industry by producing a side-stream ingredient rich in phenolics. High temperature and pressure-aided processing, namely the accelerated solvent extraction (ASE) was investigated to extract the flavor-active bitter molecules from the canola meal. The extractability of flavor-active phenolic compounds including the major sinapates, kaempferol derivatives, and other thermo-generative compounds including thomasidioc acid (TA) was evaluated. The effects of temperature, solvent extractant and concentration, and the particle size of the meal, were examined on the extraction efficiency of these phenolic compounds. Extraction temperature (180oC) was the primary determinant (p

The majority of the bioactive compounds present in canola seeds are phenolic compounds. They are present as aglycones, glycosides, monomers, polymerized structures, or as free or matrix-bound compounds. Conventional methods of extraction utilize an excessive amount of organic solvents and require high energy input. Current environmental issues associated with organic solvent disposal demand alternative methods for the extraction of phenolic compounds that are environmentally friendly and energy-efficient. Green technology has identified a number of alternative methods suitable for the extraction of phenolic compounds. This chapter will review those alternative green methods suitable for the extraction of phenolic compounds from canola and rapeseed. Such methods include ultrasonic extraction, microwave extraction, accelerated solvent extraction, subcritical water extraction, and supercritical fluid extraction.

Canola meal, a by-product of oil pressing, is a rich source of phenolic antioxidants. However, its use in the food and feed sector is still limited by the need for greener, sustainable, and more cost-effective extraction methods. This study used accelerated solvent extraction (ASE) to enhance the extraction efficiency of the phenolic antioxidants. The high selectivity and short extraction time associated with ASE were ideal for obtaining high yields of these antioxidants. The structure-based activity of phenolic compounds may be influenced by the high pressure and temperature of the greener ASE process. The present study evaluated the effect of temperature (140, 160, and 180 °C) and pressure (1,500 psi) on the extraction and yield of phenolic compounds from canola meal as well as the solvent type (ethanol and methanol) and concentration (30%, 40%, 60%, and 70% v/v). Antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl, ferric reducing/antioxidant power assay, and ion-chelating activity. The highest yield of phenolic compounds was obtained with 70% methanol (20.72 ± 1.47 mg SAE/g DM [milligrams of sinapic acid equivalents per gram of dry matter]) and 70% ethanol (24.71 ± 2.77 mg SAE/g DM) at 180 °C temperature. A similar trend was observed for the antioxidant activity of the extracts and their total flavonoid content. The structure-based antioxidant activity of the extracts examined increased with the increase in the percentage of the extracting solvent (P > 0.05). This study established ASE as an efficient green method for extracting phenolic compounds from canola meal, with potential application for the production of natural bioactive compounds from underutilized agricultural by-products. PRACTICAL APPLICATION: ASE is an efficient eco-friendly method for extracting phenolic compounds from agricultural by-products such canola meal. Under the conditions of high pressure and temperature, ASE significantly improved the yields of phenolic compounds, sinapine, sinapic acid, and canolol. Under these conditions, water, as an extractant, was not effective in extracting sianpine. Moreover, it was much less effective than both 70% ethanol and 70% methanol in extracting sinapine or canolol. These phenolic compounds are of great interest as natural antioxidants for enhancing the shelf life of food products. They also represent new sources of neutraceuticals for improving human health.

Canola by-products have considerable potential as functional ingredients and antioxidants due to the presence of unique phenolic compounds. Thus, extraction of flavor-active phenolics present in canola by-products is important for their co-production and valorization. The quantity and quality of these unique phenolic compounds could affect the sensory and organoleptic properties of any product or ingredients derived post-processing of the canola by-products. This study evaluated, both quantitatively and qualitatively, the formation of these flavor-active compounds under pressurized temperature processing. Particle size, extraction temperature, type of solvent extractants (70%v/v methanol or ethanol), were factors examined for extracting the major flavor-active phenolic compounds including thomasidioic acid (TA), kaempferol 3-O-β-sophoroside (KS), kaempferol 3-O-(2‴-O-sinapoyl-β-sophoroside) (KSS). Two other kaempferol derivatives, kaempferol 3-(2″-hydroxypropionylglucoside)-4′-glucoside (K-4-G) and kaempferol 3-[2″-glucosyl-6″-acetyl-galactoside] 7-glucoside (K-7-G) were also tentatively identified in the extract. The results confirmed that extraction temperature and solvent type had a significant impact (p

Ultrasonic treatment was applied to reduce chlorophyll of cold-pressed hempseed oil in conjunction with various clays. Bleaching clays such as bentonite (activated/non-activated), sepiolite and clay from a canola oil refining industry (industrial clay) were used. Ultrasonic bleaching of hempseed oil for 20 min at 20, 40 and 60% power (expressed as ultrasound amplitude) with bleaching clays (40 g/kg) reduced chlorophyll in decreasing order of effectiveness from industrial clay > activated bentonite > sepiolite > non-activated bentonite together with an increase in ultrasound power to 40%. At 20% ultrasound power, chlorophyll reduction (%) was found to be 99.4% (industrial clay) > 97.8% (activated bentonite) > 82.7% (sepiolite) > 47.1% (non-activated bentonite). The reduction in total phenolic content was 27.3%, 33.4%, 27.9% and 34.7% when treated at 20% ultrasound power with 40 g/kg clay from canola industry, activated bentonite, non-activated bentonite and sepiolite, respectively. The corresponding reduction in the peroxide value for the oil samples, due to the adsorptive nature of the clay, followed the trend of industrial clay > sepiolite > non-activated bentonite. This process proved promising for impacting hempseed oil color through reduction of chlorophyll.

Phenolic compounds in beer are derived from grains and hops during processing and production. Thus, the total phenolic content (TPC) of beer extracts, from selected Canadian and foreign commercial, and laboratory produced beers were examined and ranged from 3.72 ± 0.23 to 13.73 ± 0.49 mg GAE/100 mL beer. The total flavonoid content (TFC) of the same beer extracts varied from 0.82 ± 0.02 to 5.28 ± 0.04 mg CE/100 mL beer. Of particular interest were the hydroxycinnamic acids (HCAs) and derivatives in beer extracts because of their antioxidant properties. Main HCAs and a key derivative of ferulic acid, 4-vinylguaiacol (4-VG), were identified in beer extracts by high performance liquid chromatography (HPLC). Significant variations in TPC, TFC, HCAs and 4-VG content were observed among the beer extracts. Antioxidant activities of beer extracts, determined by radical scavenging and ferric-reducing assays, were positively correlated (p 0.05). The positive correlation of 4-VG with ABTS radical cation scavenging and reducing power assays is reported first time. These findings suggest that phenolic compounds and a key derivative of the hydroxycinnamic acid, 4-VG, may have the protective role in the beer as an antioxidant.

Canolol-enriched extracts obtained from the extraction of fluidized bed treated canola meal with supercritical carbon dioxide were added to high-oleic canola oil in different concentrations (200, 500 and 750 mg/kg). After 30 h of deep-fat frying, oils fortified with canolol-enriched extracts showed a two to three times better frying performance in comparison to the commonly used antioxidants (TBHQ, 200 mg/kg; rosemary extract, 40 and 200 mg/kg) and a control without antioxidants with regards to the formation of di- and polymer triacylglycerols, total polar compounds, secondary degradation products (anisidine value) and the iodine value. The canolol-enriched extracts were also able to slow down the degradation of α- and γ-tocopherol during frying resulting in significant amounts of tocopherols after 30 h of frying in comparison to the other oils. The influence of the canolol-enriched extracts indicated strongly concentration-dependent performance. With increasing concentration of the extract, the thermal stability of the fortified oil was improved. The only disadvantage of the addition of the extracts was an increase in the initial acid value, but within the frying time, only oil fortified with 750 mg canolol-enriched extract/kg reached the limit given in different countries.

Canadian condiment yellow mustard seeds (also called white), oriental and brown mustard seeds and flour extracts and commercially produced Indian mustard oils were examined for bioactive phenolics primarily to identify the antioxidant properties. Phenolic compounds, namely sinapic acid, sinapoyl glucose and canolol, were quantified using high-performance liquid chromatographic (HPLC) coupled with a diode array detector (DAD). Canolol was detected and confirmed in trace amounts for the first time in commercial oils that had not been preheated specific for canolol production, most likely due to heat applied during processing. Sinapic acid, sinapine and canolol derived from unheated/unroasted mustard seeds and canola extracts were confirmed utilizing HPLC-DAD, ultra-performance liquid chromatography-tandem-mass spectrometry (UPLC-tandem-MS) and nuclear magnetic resonance (NMR) spectroscopy. Practical applications: Oilseeds canola and mustard contain significant amounts of phenolic compounds, principally sinapic acid derivatives. The level and functionality of these phenolic is highly influenced by the processing conditions. In the current study, the phenolic composition of some commercial mustard seed, oil, meal and flour samples were profiled with special focus on the occurrence of canolol, the decarboxylation product of sinapic acid. This study suggests that optimizing the crushing, pressing, or extraction steps during processing is crucial to enrich mustard and canola products with benefits associated with these bioactives, especially canolol. The existence of sinapic acid derivatives was confirmed in the 70% aqueous methanolic extracts of commercial mustard products such as deheated mustard flour and oil. Extracts of mustard, in addition to canola, contain significant amounts of phenolics, mainly sinapine. Traditional ghani pressing, cold pressing and/or screw expeller pressing hold potential for enriching mustard and sinapate-rich oil with benefits associated with canolol.

Valuable phenolic antioxidants are lost during oil refining, but evaluation of their occurrence in refining byproducts is lacking. Rapeseed and canola oil are both rich sources of sinapic acid derivatives and tocopherols. The retention and loss of sinapic acid derivatives and tocopherols in commercially produced expeller-pressed canola oils subjected to various refining steps and the respective byproducts were investigated. Loss of canolol (3) and tocopherols were observed during bleaching (84.9%) and deodorization (37.6%), respectively. Sinapic acid (2) (42.9 μg/g), sinapine (1) (199 μg/g), and canolol (344 μg/g) were found in the refining byproducts, namely, soap stock, spent bleaching clay, and wash water, for the first time. Tocopherols (3.75 mg/g) and other nonidentified phenolic compounds (2.7 mg sinapic acid equivalent/g) were found in deodistillates, a byproduct of deodorization. DPPH radical scavenging confirmed the antioxidant potential of the byproducts. This study confirms the value-added potential of byproducts of refining as sources of endogenous phenolics.

Endogenous sinapic acid (SA), sinapine (SP), sinapoyl glucose (SG) and canolol (CAN) of canola and mustard seeds are the potent antioxidants in various lipid-containing systems. The study investigated these phenolic antioxidants using different fractions of canola and mustard seeds. Phenolic compounds were extracted from whole seeds and their fractions: hulls and cotyledons, using 70% methanol by the ultrasonication method and quantified using HPLC-DAD. The major phenolics from both hulls and cotyledons extracts were SP, with small amounts of SG, and SA with a significant difference of phenolic contents between the two seed fractions. Cotyledons showed relatively high content of SP, SA, SG and total phenolics in comparison to hulls (p < 0.001). The concentration of SP in different fractions ranged from 1.15 ± 0.07 to 12.20 ± 1.16 mg/g and followed a decreasing trend- canola cotyledons > mustard cotyledons > mustard seeds > canola seeds > mustard hulls > canola hulls. UPLC-tandem Mass Spectrometry confirmed the presence of sinapates and its fragmentation in these extracts. Further, a high degree of correlation (r = 0.93) was noted between DPPH scavenging activity and total phenolic content.

Crude canolol (CAN) extracted from canola meal by accelerated solvent extraction and phenolic extracts from canola oil deodistillates (DDL) were assessed for their potential to stabilize canola oil during deep-fat frying. Phenolics extracted from DDL with methanol ranged from 0 to 323 μg/g of DDL phenolics. French fries were deep fried in canola oil (3 L) enriched with 200 ppm of BHT, DDL, or CAN at 185 ± 5°C for 5 min. Twelve batches of fries (30 g each) were fried each day, 30 min apart for a total of 6 h of frying for 5 days. Both CAN and DDL extracts exhibited protection against frying oil deterioration compared to BHT with a considerable reduction in the hydroperoxides after the first day of frying. The ability to reduce primary oxidation was highest with CAN followed by DDL compared to BHT and the control (CAN>DD>Control). The total oxidation (TOTOX) and conjugated diene/triene values of oils fried with DDL and CAN were significantly (p

The enzymatic oxidation of sinapic acid catalyzed by horseradish peroxidase (HRP) or tyrosinase was investigated using model systems, which contained the pure compound or canola meal. Spectrophotometric scanning of pure sinapic acid solution in the presence of HRP (0.2 U) or tyrosinase (40.3 U) showed continuous decreases in absorbance at 304 nm over a period of 90 and 60 min, respectively. HPLC analyses of enzymatic end products, obtained by the catalysis with HRP or tyrosinase, indicated the presence of two main compounds (1 and 2). After alkaline hydrolysis of canola meal, sinapic acid that was released from sinapine was also converted to compounds 1 and 2 by HRP or tyrosinase. Enzyme reaction kinetics results indicate that the catalytic efficiency (CE = 0.538), reaction velocity (Vmax = 5.67 ∆A/h), and Michaelis-Menten constant (Km = 926.64 µM) of HRP are significantly higher than those of tyrosinase (CE = 0.041, Vmax = 0.41 ∆A/h, Km = 173.03 µM) at 50-250 μM pure sinapic acid concentrations. PRACTICAL APPLICATIONS: Canola meal contains a large amount of sinapine, which is the choline ester of sinapic acid, a strong antioxidant compound. However, the oxidation or decarboxylation products of sinapic acid could add value by increasing the level of electron-dense carboxylic and carbonyl compounds. In this study, enzymatic treatment of alkaline-hydrolyzed canola meal with horseradish peroxidase (HRP) and tyrosinase was investigated and shown to be suitable for converting sinapic acid into oxidized compounds. Therefore, the enzymatic treatment is a potential application for value-added processing of canola meal.

Canola seeds were subjected to conventional and microwave heat treatments to investigate changes in the phenolic profile of defatted meal and oil obtained from the toasted seeds. Different temperature (120–200 °C) and time (5–20 min) combinations were applied for toasting the seeds in a conventional oven. The seeds were also toasted using a microwave oven at 300 Watt power level with and without steaming. Phenolics were extracted from the defatted meal and oil of raw and toasted seeds. The main phenolic compounds namely sinapine (SP), sinapoyl glucose (SG), sinapic acid (SA) and canolol were identified and quantified by HPLC-DAD. Total phenolics and SA derivatives in the meal were found to decrease in both toasting treatments. Canolol was formed in the oil and subsequently increased with increasing toasting temperature up to 200 °C. The optimum toasting conditions under which the canolol content of the oil showed the highest increment rate (more than 2200 folds) were found to be 200 °C for 15 min in the conventional oven. However, the optimum microwave toasting conditions were 20 min with steam which increased canolol content by more than 1700 folds.

Owing to its high content of omega-6/omega-3 fatty acids and bioactive minor components with antioxidant activities, hemp seed oil is now recognized for its health benefits by a large number of consumers. This paper primarily discusses the profile of minor components in hemp seed oil and their beneficial and adverse effects on oil quality. While tocopherols, polyphenols and phytosterols prevent oxidative deterioration of hemp seed oil, the high amount of chlorophyll can be detrimental to oil quality.

A potent antioxidant, anti-inflammatory and anti-mutagenic agent; 4-vinyl-2,6-dimethoxyphenol (canolol) was obtained from canola meal in a significant yield via alkaline (NaOH)/enzymatic (ferulic acid esterase) hydrolysis followed by microwave-assisted decarboxylation. The hydrolysis was carried out either through using canola meal directly as a substrate or by using the 70 % aqueous methanolic extract filtrates. The hydrolyzed extracts underwent RP-HPLC analysis which showed that 81.0 and 94.8 % of the total phenolics were hydrolyzed to sinapic acid after the alkaline hydrolysis of the meal and the methanolic extracts, respectively. The enzymatic hydrolysis showed lower conversion rates (49.5 and 58.3 %). The hydrolyzed extracts were consequently decarboxylated using 8-diazabicyclo[5.4.0]undec-7-ene under microwave irradiation at different conditions. The HPLC profiling of decarboxylated extracts showed that using microwave at 300 W of microwave power for 12 min brought the highest sinapic acid conversion to canolol (58.3 %) yielding 4.2 mg canolol from each gram of canola meal suggesting that the process could be commercially economical.

The aim of this study was to evaluate the antioxidative effect of phenolics naturally present in canola seeds and meal. Individual phenolics were extracted from ground, defatted canola seeds, and meal. Fractionated extracts rich in sinapic acid, sinapine, or canolol as well as a non-fractionated extract were used. These extracts (100 and 350 µM) were evaluated as antioxidants in stripped canola oil-in-water (o/w) emulsion. For comparison, the antioxidative effect of phenolic standards for sinapic acid and sinapine (as sinapine thiocyanate) and butylated hydroxytoluene (BTH) as a positive control were also evaluated. The concentration of lipid hydroperoxides and selected volatiles measured at different time points was used to evaluate the antioxidative effect. Moreover, the properties of extracts and corresponding phenolic standards were evaluated in three different in vitro antioxidant assays. All extracts and standard antioxidants had radical scavenging activity and reducing power. The antioxidant standards and extracts inhibited lipid oxidation in the emulsions compared to no antioxidant added. At 100 µM the effectiveness of the extracts was as follows: sinapine>whole extract>sinapic acid>canolol>Con2 (no antioxidant). At 350 µM the ranking was as follows: canolol ≥ sinapine ≥ whole extract ≥ sinapic acid > Con2. Sinapine and sinapic acid extracts were more efficient antioxidants than the corresponding pure standards. However, the most efficient antioxidant in this study was BHT. The differences in effectiveness may be ascribed to mainly the different chain attached to the phenolic ring, which results in different polarity and thus different location in the emulsions. Practical applications: The result showed stronger antioxidant activity of canola extracts than phenolic standards. Therefore, these canola extracts can be used for protecting canola oil emulsion or other emulsions against lipid oxidation. However, the results indicate that the antioxidant activity of the extracts rich in sinapine and canolol had a concentration-sensitive effect. In order to get the best antioxidative effect, optimization of the concentration to be used for each specific application is necessary.

The results of ultrasonic bleaching prove effectiveness in reducing chlorophyll content in cold‐pressed hempseed oil and suggest its potential for prolonging the shelf‐life.

Phenolic extracts from Sorbus aucuparia (L.) were lipophilized in the presence of Candida antarctica lipase using octadecanol as the alkyl donor. The antioxidant activity of the lipophilized extract was assessed in refined, bleached and deodorized rapeseed oil during accelerated storage at 65 degrees C and frying at 180 degrees C. Rapeseed oil fortified with lipophilized extract showed significantly higher storage stability with 43% decrease in peroxide value at the end of the 7-day storage compared to rapeseed control sample without extract; however, no significant difference was observed in the performance of lipophilized extract and the native extract. On the contrary, the lipophilized extract exhibited markedly better protection against thermo-oxidative degradation during frying, inhibiting polar component formation and polymerization of triacylglycerol by up to 48%, compared to 30% by the native extract. At the end of the frying, French fries prepared in the presence of lipophilized extract had 7 times more phenolic compounds compared to fries prepared in the native extract indicating better solubilization of the phenolic compounds in the frying medium. Thus, lipophilization of phenolic compounds enhanced their protective activity in frying oil and improved the functionality of the prepared food. (C) 2014 Elsevier Ltd. All rights reserved.