Characterization of antioxidant compounds in aqueous coriander extract (Coriandrum sativum L.)

An aqueous coriander extract obtained through a sequential extraction process, was analysed using chromatography and mass spectrometry in order to identify the phenolic compounds responsible for its antioxidant activity. Four fractions were identified from the crude extract using chromatography in a silica gel column. Their antioxidant activity, according to the β-carotene/linoleic acid model, was similar to one another but inferior to that of the crude extract and of butylated hydroxytoluene. Of the phenols identified through gas chromatography and mass spectrometry, it was noted that caffeic acid was present in high concentration (4.34 μg/ml in fraction I and 2.64 μg/ml in fraction III), whereas protocatechinic acid and glycitin were present in high concentration in fraction II (6.43 μg/ml) and fraction IV (3.27 μg/ml), respectively. These results, when considered with the recognized antioxidant ability of phenolic acids, suggest that they are principal components responsible for the antioxidant activity of the aqueous coriander extract.     

Evaluation of the antioxidant,antiproliferative and antimutagenic potential of araçá-boi fruit (Eugenia stipitata Mc Vaugh — Myrtaceae) of the Brazilian Amazon Forest

Eugenia stipitata is a fruit from Amazonia rich in terpene, volatile compounds, fiber, and vitamin C. The fruit is recognized for its high antioxidant activity and has attracted much attention due to their potential health benefits to humans. The total polyphenols, antioxidant, antiproliferative, antimutagenic and antigenotoxic activities of E. stipitata ethanolic extract were investigated. Total polyphenols were determined by the Folin–Ciocalteu method and showed 184.05 ± 8.25 mg GAE/100 g. The radical scavenging activity was DPPH _IC50 0.69 ± 0.23 μg/mL and TAC-ORAC_FL 371.98 μmol.TE/100 g. The extract was evaluated for its ability to inhibit the growth of tumor cell lines and had not complete cystostatic effect against any of the tested cell lines. Antimutagenic and antigenotoxic activities were investigated by micronucleus test and comet assay in mice, respectively. Ethanolic extract of E. stipitata showed higher antimutagenic and antigenotoxic properties at the highest concentration tested (300 mg/kg of body weight). In conclusion, these results suggest that this fruit could be used as a preventive agent against cancer.     

Evaluation and improvement of antioxidant and antibacterial activities of supercritical extracts from clove buds

For the first time, extracts from clove buds obtained by supercritical carbon dioxide extraction were screened for antioxidant and antibacterial activities. Additionally, antioxidant and antibacterial activities of extracts obtained by the supercritical extraction of the clove bud–oregano leaf mixtures were studied. Supercritical extract of pure clove had the highest eugenol (64%) and total phenolic content (530.56 mg GAE/g_extract). All extracts had antioxidant activity comparable to synthetic antioxidants against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals and formation of peroxides. Presence of 0.6% and 5% of oregano extract in the clove extracts obtained from the clove–oregano plant mixtures improved their antioxidant activity with respect to the extract from pure clove. Clove extract showed moderate antibacterial activities against selected Staphylococcus and Enterococcus bacterial strains. Presence of 50% of the oregano extract improved antibacterial activity of clove extract against all tested strains and resulted in a synergistic antibacterial activity against Methicillin-resistant Staphylococcus haemolyticus strain (MIC ? 1.25 μg/mL). Study demonstrated great potential of supercritical clove extract as natural functional ingredient and the possibility of increasing its antioxidant and antibacterial efficiencies in order to apply lower concentrations and to reduce undesirable flavour notes and toxicological effects in final products.     

Antioxidant properties of hot water extracts from Ganoderma tsugae Murrill

Ganoderma tsugae Murrill (Ganodermataceae) were available in the form of mature and baby Ling chih, mycelia and fermentation filtrate. From these four forms, hot water extracts were prepared and their antioxidant properties were studied. Hot water extracts from mature and baby Ling chih showed high antioxidant activities (78.5% and 78.2%) at 20 mg/ml, and had EC₅₀ values of 7.25 and 5.89 mg extract/ml, respectively. EC₅₀ values in reducing power were 1.12, 1.37, 2.48 and 1.41 mg extract/ml, whereas those in scavenging abilities of 1,1-diphenyl-2-picrylhydrazyl radicals were 0.30, 0.40, 0.72 and 5.00 mg extract/ml for Ling chih, baby Ling chih, mycelia and filtrate, respectively. At 20 mg/ml, scavenging abilities on hydroxyl radicals were in the descending order of Ling chih>baby Ling chih>mycelia>filtrate. Total phenols were the major naturally occurring antioxidant components found in hot water extracts and in the range of 40.86–42.34 mg/g. From EC₅₀ values obtained, fruit bodies of G. tsugae (Ling chih and baby Ling chih) were good in antioxidant properties, except for the chelating ability on ferrous ions.     

Air-dried capsicum annuum var. acuminatum medium and big: Determination of bioactive constituents,antioxidant activity and carbohydrate-hydrolyzing enzymes inhibition

In the present study the total phenols, flavonoids, carotenoids and capsaicinoids content, the in vitro antioxidant and hypoglycemic activities of extracts of air-dried fruits from two Capsicum annuum cultivars were investigated. A different composition between the two cultivars was evidenced. C. annuum var. acuminatum medium extract presented a major content of phenols, carotenoids, capsaicin and dihydrocapsaicin while C. annuum var. acuminatum big extract is characterized by the highest quercetin, luteolin and kaempferol content with 68.0, 87.6 and 29.7 μg/g dried weight, respectively, analyzed by HPLC. Medium pepper showed the highest radical scavenging activity in DPPH assay (IC₅₀ of 85.3 μg/ml) while big pepper have an interesting activity in ABTS assay (IC₅₀ of 16.4 μg/ml) and the highest inhibition of linoleic acid oxidation with an IC₅₀ value of 1.2 μg/ml after 30 min of incubation. A selective inhibitory activity against α-amylase was demonstrated for C. annuum var. acuminatum big lipophilic fraction (IC₅₀ values of 8.7 μg/ml). The obtained results suggest that C. annuum cultivars could be used as valuable flavor with functional properties for foods.     

Retention of Physicochemical and Antioxidant Properties of Dehydrated Bael (Aegle Marmelos) and Palmyra (Borassus Flabellifer) Fruit Powders

Present study was carried out to evaluate the effect of various dehydration techniques such as sun drying, solar drying, drying after freezing (Freeze for one hour followed by mechanical drying at 55 °C), vacuum drying and drying using lab scale air oven on proximate composition and retention of antioxidants in different fruit powder prepared from Bael (Aegle marmelos) and Palmyra (Borassus flabellifer). Moisture content, Total Ash, Crude fiber %, Fat %, Crude protein %, total phenolic content,β –Carotene and antioxidant activity were tested. The antioxidant activity was measured based on the ability of fruit extract to scavenge 1, 1- diphenyl-2-picrylhydrazyl (DPPH). Among different drying treatments the highest fat percentage recorded by the solar dried palmyra fruit powder and there is no significant difference (α= 0.05) between sun drying and vacuumed drying. Higher concentration of β -Carotene and total phenolic content were recorded in vacuum dried samples both in bael and Palmyra fruit powders and it significantly different (α= 0.05) from other treatments. The scavenging activity of bael fruit powder in vacuum drying was ranged from 65.36% to 81.33% of the concentration 200 μg/ml to1000 μg/ml and the palmyra fruit powder was recorded 57.32% to 83.25% of the concentration 200 μg/ml to1000 μg/ml. Vacuum dried fruit powders of palmyra and bael were given highest radical scavenging activity and the scavenging activity of palmyra fruit powder is higher than the bael. Therefore vacuum drying can be recommended as the most effective drying method to protect chemical characteristics and retention of antioxidant properties of fruit powders.     

Citharexylum solanaceum fruit extracts: Profiles of phenolic compounds and carotenoids and their relation with ROS and RNS scavenging capacities

Citharexylum solanaceum is a native fruit from Brazil, which both bioactive compounds and antioxidant potential were not yet investigated. Thus, the freeze-dried extracts of seed and pulp + skin of C. solanaceum fruits were obtained after solid-liquid extraction with ethanol and their bioactive compounds composition, namely phenolic compounds and carotenoids, were determined. The antioxidant capacity of both extracts against physiologically relevant reactive oxygen species (ROS) and reactive nitrogen species (RNS) was further investigated. Both C. solanaceum extracts showed high contents of phenolic compounds; however, pulp + skin extract presented 2.4-times more phenolic compounds (33.54 mg/g) than the seed extract (14.09 mg/g). Verbascoside (phenylpropanoid) was the major compound identified in both extracts (11–25 mg/g). Regarding the carotenoid composition, all-trans-lutein (14–42 μg/g) and all-trans-β-carotene (13–44 μg/g) were the major compounds in both extracts. The high content of phenolic compounds and carotenoids in pulp + skin extract might explain its higher scavenging capacity against all the ROS/RNS as compared to seed extract. In general, both extracts showed better scavenging capacity for the RNS than for the ROS. Our results indicate that C. solanaceum fruits can be explored as an important natural source of antioxidant compounds.     

Pilosocereus arrabidae (Byles & Rowley) of the Grumari sandbank,RJ, Brazil: Physical,chemical characterizations and antioxidant activities correlated to detection of flavonoids

The fruits of Pilosocereus arrabidae (Cactaceae) is found in the Grumari shoal, located in the Rio de Janeiro state, Brazil and, several studies have already highlighted the importance of consuming its fruits. This work aims to investigate the physical, mineral and physicochemical properties of its fruits as well as to establish the knowledge about their chemical constituents and antioxidant properties. The peel (Pe) and pulp (Pu) extracts were obtained by maceration with the following solvents: hexane (HX), dichloromethane (DCL), ethyl acetate (EAC) and ethanol 70% (ET). The extracts were analyzed by Gas Chromatography coupled to Mass Spectrometry (GC–MS) and, by High Performance Liquid Chromatography (HPLC–DAD and HPLC–MS) for its chemical investigation. For the antioxidant activity investigations the ORAC, DPPH and ferrous ion chelating capacity (FICC) tests were performed. As results, we found higher yields for peels (72%) compared to pulps (28%). By the physical–chemical analyses we point out the fruits as a good source of fiber (pulp: 6.01 mg/100 g; peel: 8.02 mg/100 g). The minerals were analyzed by the method of issuing flames and indicated high levels of selenium (DRI for pulp and peel: 147%) and manganese (DRI pulp: 97.69% and DRI peel: 269.56%). The total flavonoid contents of the fruits performed by HPLC–DAD presented 0.45 μg equiv. in quercetin/mL of peel EAC extract and 0.25 μg equiv. in rutin/mL of pulp EAC extract. The antioxidant activities by the ORAC, FICC and DPPH methods indicated that the ET extracts showed antioxidant activities above the standards adopted for the tests. Among these, we highlight the ET extract of the pulp with EC₅₀ of 17.57 ± 0.27 μg/mL, lower than Ginkgo biloba EGB761® (23.40 ± 0.04 mg/mL). By the FICC test the EAC extract of the peel and pulp showed 70.0% and 53.4% activity, respectively, at 500 mg/mL, higher than the standard quercetin (50.0%). By the HPLC–DAD and HPLC–MS methods there were detected, for the first time on this species, the presence of the following flavonoids on the EAC extracts: quercetin, rutin, catechin, dihydrokaempferol, quercetin 3 or 4′-O-glucoside, kaempferol and isorhamnetin. By the GC–MS analysis there were detected on the DCL extracts saturated fatty acids (palmitic and stearic) and, on the HX extracts, methylated sugars (peel) and menthol (pulp). To sum up, the fruits of P. arrabidae display antioxidant potential correlated to flavonoid presence, and, high levels of selenium, manganese and fibers, characteristics that can promote beneficial effects on human health.     

Effect of ultrafine grinding on hydration and antioxidant properties of wheat bran dietary fiber

Wheat bran dietary fiber (DF) powders was prepared by ultrafine grinding, whose effects were investigated on the composition, hydration and antioxidant properties of the wheat bran DF products. The results showed that ultrafine grinding could effectively pulverize the fiber particles to submicron scale. As particle size decrease, the hydration properties (water holding capacity, water retention capacity and swelling capacity) of wheat bran DF were significantly (p < 0.05) decreased and a redistribution of fiber components from insoluble to soluble fractions was observed. The antioxidant activities of wheat bran and DF before and after grinding were in terms of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, ferrous ion-chelating activity, reducing power and total phenolic content (TPC). Compared with DF before and after grinding, micronized insoluble DF showed increased chelating activity, reducing power and TPC yet decreased DPPH˙ radical scavenging activity. Positive correlations were detected between chelating activity, reducing power and TPC.     

Dietary polysaccharide extracts of Agaricus brasiliensis fruiting bodies: chemical characterization and bioactivities at different levels of purification

Polysaccharides of the European strain of A. brasiliensis were obtained by hot water extraction and ethanol precipitation (HWPE I) of fruiting bodies, and further purified by dialysis (HWPE II) and pronase incubation (PPE). These polysaccharides consisted mainly of (1 → 6)-β-d-glucans. PPE was free of proteins and polyphenols as demonstrated by quantitative assays and NMR profiling. They showed a clear IFN-γ inducing activity in human PBMCs, which suggests these polysaccharides to have proinflammatory effects. Treatment by β-glucosidase caused the polysaccharides to be degraded into smaller fragments and at the same time increased their IFN-γ inducing activity in PBMCs fourfold.In vitro, PPE showed a dose-dependent inhibition of the proliferation of the human leukemia Jurkat cell. At 100 μg/mL the cells’ viability was decreased by appr. 51% compared to the control. EPR spin trapping demonstrated a high antioxidative activity against ^•OH and ^•O2⁻ radicals of HWPE I and PPE. Further, the results of the antioxidant assays indicated that antioxidant activity against ^•OH radicals in the Fenton system was achieved through scavenging or through chelating iron mechanisms.The good immunomodulating and antioxidative properties of A. brasiliensis polysaccharide extract obtained by hot water extraction and ethanol precipitation make it suitable for everyday use as an inexpensive dietary supplement.     

Soluble phenolics and antioxidant properties of soybean (Glycine max L.) cultivars with varying seed coat colours

This research was the first to investigate nutritional components, including soluble phenolics (isoflavones and anthocyanins), protein, oil, and fatty acid as well as antioxidant activities in different coloured seed coat soybeans (yellow, black, brown, and green) for two crop years. The soluble phenolics differed significantly with cultivars, crop years, and seed coat colours, while protein, oil, and fatty acid exhibited only slight variations. Especially, malonylgenistin and cyanidin-3-O-glucoside compositions had the most remarkable variations. Green soybeans had the highest average isoflavone content (3079.42 μg/g), followed by yellow (2393.41 μg/g), and black soybeans (2373.97 μg/g), with brown soybeans showing the lowest value (1821.82 μg/g). Anthocyanins showed only in black soybeans, with the average contents of the primary anthocyanins, cyanidin-3-O-glucoside, delphinidine-3-O-glucoside, and petunidin-3-O-glucoside, quantified at 11.046, 1.971, and 0.557 mg/g, respectively. Additionally, Nogchae of green soybean and Geomjeongkong 2 of black soybean may be recommended as potential cultivars owing to the highest average isoflavone (4411.10 μg/g) and anthocyanin (21.537 mg/g) contents. The scavenging activities of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radicals also differed remarkably, depending upon isoflavone and anthocyanin contents, with black soybeans exhibiting the highest antioxidant effects.     

Comparison of different methods for extracting polyphenols from Ipomoea batatas leaves,and identification of antioxidant constituents by HPLC-QTOF-MS2

This study aimed to compare the extraction efficiency of dynamic high pressure microfluidization-assisted extraction (DHPMAE) and other commonly used extraction methods on the antioxidant activities (AAs) of sweet potato leaves (Ipomoea batatas L., SPL), and to identify the antioxidant compounds by HPLC-QTOF-MS². Two highly consumed commercial varieties, orange-fleshed and cream-fleshed sweet potato leaves (OFL and CFL), were taken as materials. OFL was evidenced to be a better antioxidants resource than CFL due to higher polyphenols and AAs. DHPMAE had the best extraction efficiency on total phenolics and total flavonoids, with the values in OFL extract at 16.35 mg GAE/g DM and 16.51 mg RE/g DM, respectively. DHPMAE extract also exhibited the strongest DPPH· and ABTS·⁺ scavenging ability, chelating ability and reducing power. Multiple regression analysis revealed that polyphenols played an important contribution to the AAs of SPL extracts. After successive fractionation of DHPMAE extract by chloroform, ethyl acetate, and n-butanol, the ethyl acetate fraction showed the highest total phenolic (569.38 mg GAE/g Extract) and total flavonoid (43.15 mg RE/g Extract) content, as well as the highest AAs. HPLC-QTOF-MS² analysis of the ethyl acetate fraction resulted in identifying 37 compounds including 20 phenolic acids, 12 flavonoids, 3 organic acids, 1 nucleoside and 1 ester, and 20 of them were firstly detected in SPL. Caffeoylquinic acid derivatives and flavonoids were the most abundant antioxidant compounds. The presented results suggested that DHPM might be a promising assisted technology in extracting polyphenols from plants, and SPL could be utilized for the development of functional food.     

Thermal and light stabilities and antioxidant activity of carotenoids from tomatoes extracted using an ultrasound-assisted completely solvent-free method

The use of petroleum-derived solvents, particularly volatile organic compounds (VOCs), in the chemical industry has increased the contamination and residual effects of these solvents. Ionic liquids (ILs) can potentially replace VOCs, thereby reducing the risks of environmental contamination and toxicity. In this context, the objectives of this study were as follows: 1 — to obtain an ionic liquid for use in extracting carotenoids from tomatoes with ultrasound assistance; and 2 — to determine the stability and antioxidant activity of tomato carotenoid extracts. Ultrasound can also efficiently extract carotenoid compounds with ionic liquids in comparison with conventional VOC solvents (obtained from an all-trans-lycopene 7.5–8.0 μg·g^− 1 tomato sample by IL and 6.2–7.7 μg·g^− 1 by acetone). Similarly, the activation energies (E_a) in aqueous medium were obtained for the IL carotenoid extract (10.8 kJ·mol^− 1) and acetone carotenoid extract (9.4 kJ·mol^− 1). The antioxidant activities of the tomato carotenoid extract were 7.4 and 12.4 relative to α-tocopherol for the ionic liquid extract and acetone extract, respectively. The combination of chromatographic analysis and degradation kinetics provided data for positive assessment similarity of thermal and light stabilities of tomato carotenoids extracted by IL and extracted by acetone.     

Effect of dietary grape seed extract and Cistus ladanifer L. in combination with vegetable oil supplementation on lamb meat quality

Thirty-six Merino Branco lambs were assigned to six dietary treatments: control diet (C) consisting of 90% dehydrated lucerne and 10% wheat bran; C with 6% of oil blend (CO); C with 2.5% of grape seed extract (GS); GS with 6% of oil blend (GSO); C with 25% of Cistus ladanifer (CL), and CL with 6% of oil blend (CLO). Meat lipid and colour stability was then evaluated during 7 days of storage. The effect of inclusion of grape seed extract and C. ladanifer in diets on meat sensory properties was also evaluated. Meat antioxidant potential, determined after oxidation induction by a ferrous/hydrogen peroxide system, decreased with oil supplementation (P < 0.001), but inclusion of grape seed extract and C. ladanifer in diets protected the meat against lipid oxidation (P = 0.036). Meat colour was not affected by diets. Inclusion of grape seed extract and C. ladanifer in diets did not change the sensory properties of meat.     

Antioxidant activity and effective compounds of immature calamondin peel

The antioxidant activity and the flavonoids of mature and immature calamondin (Citrus mitis Blanco) peel were investigated. The hot water extract of immature calamondin peel exhibited the highest oxygen radical absorbance capacity (ORAC), reducing power, and superoxide scavenging effect. 3′,5′-Di-C-β-glucopyranosylphloretin, naringin, hesperidin, nobiletin, and tangeretin are the five major flavonoids found in hot water extract with the levels of 6888 ± 522, 2333 ± 157, 1350 ± 94, 165 ± 13, and 8 ± 4 mg/100 g dry basis, respectively. The contents of nobiletin and tangeretin increased after ripening. The hot water extract of immature calamondin peel was fractionated using a semi-preparative HPLC. Fraction VI showed the highest ORAC value (28.02 ± 2.73 mmol Trolox equivalents (TE)/g fraction) and two compounds, naringin and hesperidin, were identified as the major active components attributed to the antioxidant activity. Fraction V contained 3′,5′-di-C-β-glucopyranosylphloretin, which revealed low ORAC value with 7.43 mmol TE/g fraction. However, it might also contribute to antioxidant activity in immature calamondin peel due to its greatest quantity.     

Chemical composition of wild edible mushrooms and antioxidant properties of their water soluble polysaccharidic and ethanolic fractions

Mushrooms have become attractive as functional foods and as a source of physiologically beneficial bioactive compounds. Herein, we describe and compare the chemical constituents (phenolic compounds, macronutrients, sugars, fatty acids, tocopherols and ascorbic acid) of four wild edible mushrooms widely appreciated in gastronomy: Armillaria mellea (Vahl) P. Kumm., Calocybe gambosa (Fr.) Donk, Clitocybe odora (Fr.) P. Kumm., Coprinus comatus (O.F. Müll.) Pers. Furthermore, the antioxidant activity of their water soluble polysaccharidic and ethanolic fractions was studied by three different in vitro assays. C. comatus revealed the highest concentrations of sugars (43.23/100 g dry weight), PUFA (77.46%), phenolic compounds (45.02 mg/kg), tocopherols (301.03 μg/100 g) and, among all of the fractions tested, its ethanolic fraction showed the highest antioxidant activity (EC₅₀ < 2.6 mg/ml). C. odora revealed one of the highest ascorbic acid (172.65 mg/100 g) contents and its water soluble polysaccharidic fraction showed the best antioxidant properties (EC₅₀ < 3.6 mg/ml) among the polysaccharidic fractions. The studied mushrooms species could potentially be used in well-balanced diets and as a source of bioactive compounds.     

Antioxidant and antimicrobial activity of Kitaibelia vitifolia extract as alternative to the added nitrite in fermented dry sausage

Fermented dry sausages (FDS) without nitrite added, fortified with bioactive phenol and flavonoid compounds originating from the ethanol extract of Kitaibelia vitifolia were food matrix for investigation of its antioxidant and antimicrobial potency. These activities were researched in order to improve the sausages' shelf-life, safety, and provide health benefits to consumers as well. The oxidative stability of the FDS, containing two different levels of natural preservative, was evaluated using five different contemporary methods for antioxidative activity. The activity was tested on the 20th day of the refrigerated storage. Minimum inhibitory concentrations of the sausage extract were determined against six microorganisms, using a micro dilution method. Determined optimal effective concentration of dissolved K. vitifolia extract (12.5 g/kg of meat dough) revealed strong antioxidant activity, and moderate antimicrobial activity against Escherichia coli (minimum inhibitory concentrations = 15.625 μg/mL). The modified sausages had typical chemical–physical characteristics of FDS, controlled on 0, 13, 26 d of ripening and 20, 40 and 60 d of storage.     

Influence of addition of green tea and green coffee extracts on the properties of fine yeast pastry fried products

This study investigated the influence of antioxidants of green tea aqueous extract (GTE) and green coffee aqueous extract (GCE) in concentrations of 0.25, 0.5 and 1 g·100 g^? 1 on the nutritional properties of fine yeast pastry fried products such as donuts. Yeast donuts were made according to the traditional processing technology. In fried donuts physical properties (water activity, pH, hardness and color with the use of instrumental methods) as well as sensory properties were established. Moreover, quality of fat extracted from donuts (composition of fatty acids and peroxide value), content of acrylamide, composition of polyphenols and antioxidant activity were analyzed. Obtained extracts of GTE and GCE contained 26 and 41% of polyphenols, respectively, and the degree of polyphenol degradation during production of donuts was less when the dilution in dough was greater. Both tests indicated that the highest antioxidant activity had donuts with the highest analyzed addition of extract, however depending on the applied test or GTE or GCE had better antioxidant properties. Fatty acid composition was the most beneficial when the addition of GTE and GCE was on a level of 0.25 and 0.5 g·100 g^? 1, respectively. In fried donuts relatively low amounts of acrylamide were obtained, amounting to 18–46 μg·kg^? 1. Only the lowest addition of GTE and the highest addition of GCE caused an increase of acrylamide content in donuts, while all other levels of added extracts caused a decrease in the content of formed acrylamide.     

Role of Melissa officinalis in cholesterol oxidation: Antioxidant effect in model systems and application in beef patties

Cholesterol oxidation products (COPs) constitute a known health risk factor. The antioxidant effect of a lyophilized aqueous Melissa officinalis extract against cholesterol degradation and COPs formation during a heating treatment was evaluated in a model system (180 °C, 0–180 min) at a ratio of 2 mg extract/100 mg cholesterol. Furthermore, the plant extract was subsequently added to beef patties alone or incorporated within an oil-in-water olive oil emulsion to assess its effectiveness during cooking. Melisa extract protected cholesterol from thermal degradation in the model system, yielding higher remaining cholesterol and lower COPs values throughout the whole heating process. Maximum total COPs were achieved after 30 and 120 min of heating for control and melisa-containing samples, respectively. In cooked beef patties, even though the olive oil emulsion was used as flavor-masking approach, melisa extract off-flavor limited the maximum dose which could be added. At these doses (65 μg/g and 150 μg/g without and with the emulsion, respectively), no additional protective effect of melisa over the use of the emulsion was found. Addition of natural extracts into functional foods should definitively take into account sensory aspects.     

Antioxidant and type II diabetes related enzyme inhibition properties of methanolic extract of an underutilized food legume,Canavalia ensiformis (L.) DC: Effect of traditional processing methods

The methanolic extract of Canavalia ensiformis (L.) DC (Jack bean) seed, an underutilized food legume collected from India was analyzed for antioxidant and health relevant functional properties. The raw seeds contained total free phenolic content of 12.98 ± 1.63 g catechin equivalent/100 g extract DM. The raw seed extract exhibited ferric reducing/antioxidant power (FRAP, 1218 mmol Fe[II]/mg extract), inhibition of β-carotene degradation (49.81%), radical scavenging activity against DPPH (56.78%) and superoxide (35.89%). In addition, 77.56% of α-amylase and 75.45% of α-glucosidase enzyme inhibition characteristics were found under in vitro starch digestion bioassay. Sprouting + oil-frying caused an apparent increase on the total free phenolic content with significant improvement on antioxidant and free-radical scavenging capacity, while soaking + cooking as well as open-pan roasting treatments showed diminishing effects. Inhibition of α-amylase and α-glucosidase enzyme activities were declined to 22.69 and 42.69%, respectively during sprouting + oil-frying treatment is more desirable for the dietary management of type II diabetic patients.