Compositions, antioxidant and antimicrobial activities of Helichrysum (Asteraceae) species collected from Turkey

The methanolic extracts of 16 Helichrysum species were investigated for their in vitro antioxidant, radical scavenging and antimicrobial activities. All the extracts showed strong antioxidant and radical scavenging activity. The highest total antioxidant capacity as ascorbic acid equivalents (AAE) of 194.64 mg/g dry extract was obtained for Helichrysum noeanum in the phosphomolybdenum assay. The highest IC₅₀ value (7.95 μg/ml) was observed for the extract of Helichrysum stoechas subsp. barellieri in the DPPH assay. The total phenolic contents of the extracts ranged from 66.74 to 160.63 mg gallic acid equivalents (GAE)/g dry extract. The major component present in the extracts was identified as chlorogenic acid followed by apigenin-7-glucoside and apigenin by HPLC analysis. All the extracts showed significant antimicrobial activity against microorganisms containing 13 bacteria and two yeasts in the agar diffusion method.     

Characterization and Functional Properties of Macela (<Emphasis Type="Italic">Achyrocline satureioides</Emphasis>) Extracts Obtained by Supercritical Fluid Extraction Using Mixtures of CO<Subscript>2</Subscript> Plus Ethanol

Samples of approximately 30 g of dried and comminuted flowers of Achyrocline satureioides, a species popularly known as macela, were subjected to supercritical fluid extraction (SFE) using CO₂ with ethanol as a modifier or co-solvent (20% v/v). The effects of variations in the pressure (10, 20, or 30 MPa) and temperature (303 or 318 K) on the SFE performance were evaluated. The functional properties of the extracts were assessed by measuring the antioxidant activities and the concentrations of total phenolic compounds and analysis of total flavonoids. The influences of the operational parameters temperature and pressure on these properties were also evaluated. The results indicated that the temperature influence was significant for both the process performance and the functional properties. However, pressure did not appear to exert a great influence over the results obtained at 303 K.     

The antioxidative properties of Holy basil and Galangal in cooked ground pork

The ethanolic extracts from Holy basil and Galangal were examined for their extraction yield, total phenolic content, antioxidant activity against a β-carotene-linoleic acid emulsion system, DPPH scavenging activity and reducing power. Ethanolic extracts of Holy basil exhibited higher extraction yield, total phenolic content, antioxidant activity, DPPH scavenging activity and reducing power than ethanolic extracts of Galangal. Antioxidative efficiency to inhibit lipid oxidation of dried Holy basil and dried Galangal powder, ethanolic extracts of Galangal and Holy basil and commercial antioxidant mixture in cooked ground pork was investigated during refrigerated storage at 5°C for 14 days. The quantitative measurements of thiobarbituric acid reactive substances (TBARS), conjugated diene, peroxide value (POV) and hexanal content were used as indicators of lipid oxidation. Increased levels of TBARS value, POV and hexanal content were noticed in all meat samples during storage, however most marked in cooked ground pork without antioxidants, whereas conjugated diene tended to decrease with increasing storage time. Ranking of the treatment in order of their antioxidant effectiveness showed that commercial antioxidant mixture (0.3% citric acid+0.5% ascorbic acid+0.02% α-tocopherol)>dried Galangal powder>dried Holy basil powder>ethanolic extracts of Galangal>ethanolic extracts of Holy basil>control. Furthermore, in cooked ground pork samples a high correlation between TBARS value and hexanal contents was obtained.     

Supercritical Carbon Dioxide Extraction of Valuable Compounds from Citrus junos Seed

Extraction of Citrus junos seed was carried out at temperatures of 40–70 °C, pressures of 20–50 MPa, and CO₂ flow rate of 3 ml/min with supercritical carbon dioxide to obtain the valuable compounds. Seed oil was also extracted by using Soxhlet extraction with hexane as the solvent during 360 min for comparison with the efficiency of supercritical carbon dioxide extraction. Gas chromatography–mass spectrometry (GC–MS) was used to analyze the components present in the seed oil and Gas chromatography-flame ionization detector (GC-FID) was used to quantify their amounts. Among the conditions studied, the highest extraction yield was obtained at higher pressure and temperature (50 MPa and 70 °C). The extraction yield was about 29.5% of the seed, which was almost comparable to that of hexane Soxhlet extraction (33.8%). The results of the GC–MS analyses showed that the seed oil extracted contained N-methylanthranyl acid methyl, fatty acids (such as palmitic, stearic, oleic, linoleic, and linolenic acid), and physiologically active substances of β-sitosterol and squalene.     

Effect of Extraction Techniques and Solvent Systems on the Extraction of Antioxidant Components from Peanut (Arachis hypogaea L.) Hulls

This research work was carried out to investigate the effect of different extraction techniques on antioxidant potential of peanut (Arachis hypogaea) hulls. The antioxidant extracts of peanut hulls (PH) were prepared using different extraction methods such as soaking, stirring, shaking, and sonicated-assisted stirring with methanol/water (80:20) and ethanol/water (80:20) solvents systems. The antioxidant potential of extracts was measured using different in vitro antioxidant assays like estimation of total phenolic contents (TPC), estimation of total flavonoids contents (TFC), DPPH-scavenging capacity, percentage inhibition of linoleic acid peroxidations, and bleachability of ?-carotene in linoleic acid system. TPC and TFC of different PH extracts were found in range of 1.23–8.43 mg/g of dry plant material, measured as gallic acid equivalent, 0.33–5.06 mg/g of dry plant material, measured as catechin equivelent (CE), respectively. All the PH extracts exhibited good free radical scavenging potential and moderate inhibition of linoleic acid peroxidation. Significant (p ≤ 0.05) variations were observed in the antioxidant potentials of various extraction methods and solvent systems. Among all the extraction methods, sonicated-assisted stirring showed better yield and antioxidant capacity. In view of the present findings, it is reasonable to say that different extracts of peanut hulls exhibited varying degree of antioxidant activity, which might be attributed to various mechanisms involved in extraction procedures.     

Synergy between high-pressure, temperature and ascorbic acid on the inactivation of Bacillus cereus

B. cereus strain (CECF 148) was used as a model system in the study of the behaviour of bacillus under high pressure, at temperatures over and below 0 °C and with ascorbic acid added to the culture. Three different assays were carried out in the present experiment. The first assay was performed to observe how B. cereus reacted to pressure shift freezing (PSF) treatment at different subzero temperatures (−8, −12, −20 and −17 °C) and pressures (120, 150, 210 and 350 MPa) in their vegetative form. In the second assay, we observed how different concentrations of ascorbic acid (1, 2, 5 and 20 mM) added to the growing brought decreased B. cereus on its vegetative form. Finally, we tried to inactivate the vegetative and spore form of B. cereus under pressure of 210 MPa at room (20 °C) (HP) and at subzero (−20 °C) (PSF) temperatures, in presence of ascorbic acid (20 mM), added to the growing culture (TSB). The results confirmed that pressures of 210 and 350 MPa at low temperatures (−20 and −17 °C) in the PSF treatment were not enough to inactivate bacillus and only about 10% of B. cereus at the assayed conditions (350 MPa at −17 °C) lost its growth capacity. The presence of ascorbic acid reduced the amount of B. cereus. The initial amount of B. cereus in the vegetative form was 10⁸ to 10⁹ cfu/mL. After HP (210 MPa at 20 °C) and PSF (210 MPa at −20 °C) treatments, the amount of B. cereus decreased by 4 and 2 logarithmic units, respectively. However, in both treatments, the presence of ascorbic acid (20 mM concentration) reduced the B. cereus growth capacity in about 5 logarithmic units. The presence of ascorbic acid in the spore form decreased the amount of B. cereus only by 2 logarithmic units, but without the antioxidant, the values remained close to control. The present research is a contribution to elicit the safety standards of food treated by high pressure.     

Effect of High Hydrostatic Pressure (HHP) Treatment on Physicochemical Properties of Horse Mackerel (Trachurus trachurus)

The basic objective of this study was to determine the effect of high hydrostatic pressure (HHP; 220, 250 and 330 MPa), holding time (5 and 10 min) and temperature (7, 15 and 25 °C) on some quality parameters of horse mackerel such as colour changes, thiobarbituric acid (TBA-i) and trimethylamine nitrogen (TMA-N), free amino acid content. HHP increased L ^* values of horse mackerel. The a ^* and b ^* of treated horse mackerel did not change significantly after HHP applications. After, HHP, TBA-i and TMA values of all HHP-treated horse mackerel samples remained unchanged than those of untreated samples. The results obtained from this study showed that the quality of high pressure treated horse mackerel is best preserved at 250 MPa, 7–15 °C for 5 min, 220 MPa, 15–25 °C for 5 min, 250 MPa, 15 °C for 10 min and 330 MPa, 25 °C for 10 min.     

Polyphenol input to the antioxidant activity of yerba mate (Ilex paraguariensis) extracts

Industrial processing modified the polyphenol content, composition and antioxidant activity of the yerba mate extracts. Pre-dried leaves were the most appropriate raw material combining maximum activity with high polyphenol content. Chlorogenic acid and its derivatives were the major components of the phenolic fraction but we also identified caffeic, rutin and quercetin.Yerba mate extracts inhibited malonedialdehyde formation in sunflower oil (20 μmol/kg) and conjugated dienes production in oil/water emulsions (60 μmol/kg). Enhancing the dose to 60 μmol/kg reduced 27.8% the extract’s activity in oil.The relationship between polyphenol composition and antioxidant activity of a mixture of caffeic, chlorogenic, kaempferol, quercetin and rutin was satisfactorily predicted with a polynomial model. Results showed that quercetin was the highest contributor to the linear term followed by kaempferol and caffeic acid while rutin and chlorogenic acid inputs were the lowest. The model detected five synergistic and six antagonistic effects.     

Phytochemicals and antioxidant activity of different fruit fractions (peel,pulp, aril and seed) of Thai gac (Momordica cochinchinensis Spreng)

Three fractions (peel, pulp and aril) of gac fruit (Momordica cochinchinensis Spreng) were investigated for their phytochemicals (lycopene, beta-carotene, lutein and phenolic compounds) and their antioxidant activity. The results showed that the aril had the highest contents for both lycopene and beta-carotene, whilst peel (yellow) contained the highest amount of lutein. Two major phenolic acid groups: hydroxybenzoic acids and hydroxycinnamic were identified and quantified. Gallic acid and p-hydroxybenzoic acid were found in all fractions. Ferulic acid and p-hydroxybenzoic acid were most evident in pulp. Myricetin was the only flavonoid found in all fractions. Apigenin was the most predominant flavonoid in pulp (red), whereas rutin and luteolin gave the highest content in aril. The extracts of different fractions exhibited different levels of antioxidant activity in the systems tested. The aril extract showed the highest FRAP value. The greatest antioxidant activities of peel and pulp extracts were at immature stage, whereas those in the seed extracts increased from mature stage to ripe stage. The contents of total phenolic and total flavonoid in peel and pulp decreased during the fruit development stage (immature > ripe fruit) and subsequently displayed lower antioxidant capacity, except for the seed.     

Chicoric acid levels in commercial basil (Ocimum basilicum) and Echinacea purpurea products

Fresh basil (Ocimum basilicum) leaves contain chicoric acid, which is the principal phenolic compound in Echinacea purpurea and purportedly an active ingredient in dietary supplements derived from E. purpurea. Here the concentrations of chicoric acid in dried and fresh basil products available to consumers, and how these concentrations compare to those from E. purpurea are reported. A wide range of chicoric acid concentrations (6.48–242.50 mg/100 g or 100 mL) were found in the dried basil flakes, fresh basil leaves, E. purpurea extracts, and E. purpurea capsules. Fresh basil leaves had higher concentrations of chicoric acid than dried basil flakes. Although E. purpurea extracts and capsules contained higher concentrations of chicoric acid than fresh basil leaves, basil could be an economical and more readily available source for chicoric acid for consumers. Additionally, cultivar selection, dehydration processing improvements, and proper storage methods may improve the final chicoric acid levels of future basil crops and products.     

The application of response surface methodology to the production of phenolic extracts of lemon grass, galangal, holy basil and rosemary

The effects of independent variables (ethanol:water ratio, temperature and time) on the extraction yield and antioxidant properties of phenolic extracts from lemon grass, galangal, holy basil and rosemary were studied. The extraction solvent ratio of ethanol to water was found to have a significant (P < 0.05) influence on extraction yield, reducing power and total phenolic content, but not on the antioxidant activity of all herb and spice samples, while extraction temperature had only minor effects. Extraction time had a significant (P < 0.05) effect only on the reducing power of holy basil extracts. The optimum extraction conditions, i.e. extraction solvent ratio of ethanol to water, extraction temperature and extraction time for maximum total phenolic content, were 3:1 at 25 °C for 30 min for lemon grass, 3:1 at 75 °C for 90 min for galangal and holy basil and 3:1 at 75 °C for 30 min for rosemary.     

Antioxidant capacity and phenolic content of different solvent extracts from banana (Musa paradisiaca) and mustai (Rivea hypocrateriformis)

In the present study, chloroform, acetone, and methanol extracts from stem and flower of banana (Musa paradisiaca) and leaves, stem, and flowers of mustai (Rivea hypocrateriformis) were evaluated for their in vitro antioxidant activity using ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picryl-hydrazyl (DPPH^•), 2,2′azinobis (3-ethylbenzothiozoline-6-sulfonic acid) diammonium salt (ABTS^•+), iron chelation, and antihemolytic activity. Among the solvents used, methanol gave the maximum yield in banana, whereas in night glory acetone was reported to having higher extractive value. The total phenolic content was also higher in these extracts. The antioxidant potential of the extracts was well established with their DPPH^• and ABTS^•+ radical scavenging activities and ferric reducing antioxidant capacity. The potential of multiple antioxidant activity of samples can be further evidenced by inhibition of reactive oxygen mediated erythrocyte cell lysis and metal ion chelating activity. However, this is the first report on the antioxidant property of mustai and this plant is having excellent antioxidant potential over banana. In conclusion, the results implied that the leaves, stem, and flowers of banana, and mustai could be considered as health supplements and nutraceuticals/functional foods.     

Extraction of Bioactive Compounds from Milled Grape Canes (Vitis vinifera) Using a Pressurized Low-Polarity Water Extractor

Trans-resveratrol and trans-ε-viniferin were extracted from milled grape canes using pressurized low-polarity water. The effects of temperature were significant for both compounds (p ≤ 0.05): extraction at 160 °C resulted in a 40% loss of trans-resveratrol compared to 95 °C while reduction of trans-ε-viniferin at both temperatures remained at 30%. Increasing ethanol concentration from 0% to 25% increased the extraction of total phenolics and trans-ε-viniferin by 44% and 489%, respectively. Solvent flow rate also influenced trans-ε-viniferin extraction. Antioxidant activity showed a strong correlation with total phenolic content of the extracts, and the two target phenolic compounds. Except for the modifier concentration, the extraction parameters studied were not statistically significant with respect to the antioxidant activity of extracts (p > 0.05). Effective diffusivities of trans-resveratrol multiplied from 3.3 × 10⁻¹¹ to 10.4 × 10⁻¹¹ m²/s by three times with increasing temperature. The modified Gompertz equation satisfactorily explained the extraction of the stilbenes investigated.     

Effect of gamma irradiation on the extraction yield, total phenolic content and free radical-scavenging activity of Nigella staiva seed

In the present study, the radiation processing of Nigella sativa seed samples was carried out at dose levels of 2, 4, 8, 10, 12 and 16 kGy. The extraction yield, total phenolic content and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging activity of both control and irradiated samples extracted in acetone, methanol and water were assessed. The results showed that the extraction yields increased with an increase in radiation dose for all the test solvents. At 16 kGy the increases were 3.7%, 4.2%, 5.6% and 9.0% for hexane, acetone, water and methanol extracts, respectively. The phenolic content in the acetone extract was found to be increased from 3.7 for the control sample to 3.8 mg/g for the 16 kGy radiation-processed sample. No significant change was observed for the phenolic content of the methanolic extract, while the aqueous extract showed a decrease at dose levels of 12 and 16 kGy. In the control samples, the DPPH radical-scavenging activity was 79.4%, 79.1% and 92.0% for water, acetone and methanol extracts, respectively, at 5 mg/ml concentration. Gamma irradiation enhanced the scavenging activity in acetone and methanol extracts by 10.6% and 5.4%, respectively, at 16 kGy. In summary, gamma irradiation increased the extraction yield and total phenolic content, as well as enhancing the free radical-scavenging activity. In addition, the type of solvent used for extraction also affected the impact of irradiation on antioxidant activity and total phenolic content of N. sativa seed.     

Water extractable phytochemicals from Capsicum pubescens (tree pepper) inhibit lipid peroxidation induced by different pro-oxidant agents in brain: in vitro

This study seeks to determine the antioxidant and neuroprotective properties of aqueous extract of ripe and unripe Capsicum pubescens (tree pepper) on some pro-oxidant induced lipid peroxidation in rat’s brain (in vitro). The total phenol, vitamin C, ferric reducing antioxidant property (FRAP) and Fe (II) chelating ability of the extracts of C. pubescens were determined. Thereafter, the ability of the extracts to inhibit lipid peroxidation (induced by FeSO₄, sodium nitroprusside or quinolinic acid) in rat’s brain homogenates (in vitro) was determined. The results of the study revealed that ripe C. pubescens had a significantly higher (P < 0.05) total phenol content [ripe (113.7 mg/100 g), unripe (70.5 mg/100 g)] and reducing power than the unripe pepper. However, there was no significant difference (P > 0.05) in the vitamin C [ripe (231.5 μg/g), unripe (224.4 μg/g)] content and Fe (II) chelating ability of the extracts. However, both extracts significantly (P < 0.05) inhibited lipid peroxidation induced by the pro-oxidant agents [25 μM Fe(II), 7 μM sodium nitroprusside and 1 mM quinolinic acid] in the rat’s brain homogenates in a dose-dependent manner. Nevertheless, the ripe pepper extracts inhibited MDA (Malondialdehyhide) production in the rat’s brain homogenates than the unripe pepper. Conversely, both extracts did not significantly (P > 0.05) inhibit Fe (II)/H₂O₂ induced decomposition of deoxyribose. It was therefore concluded that ripe and unripe C. pubescens would inhibit lipid peroxidation in rat brain in vitro. However, the ripe pepper was a more potent inhibitor of lipid peroxidation in the rat’s brain; this is probably due to its higher phenol content and reducing power.     

Supercritical CO2 extraction of oil from Arctic charr side streams from filleting processing

Although Arctic charr side streams contain limited amounts of fish flesh, they are a rich fish oil source (46.3 ± 0.6%). The aim of the study was to investigate the potential for valorization of Arctic charr filleting side streams through the extraction of oil by supercritical CO₂ technology. The effect of temperature (40 °C and 80 °C) and pressure (20, 35 and 45 MPa) on the final extract after supercritical fluid extraction (SFE) was evaluated. Temperature increase enhanced the yield but decreased the antioxidant activity at 45 MPa, did not affect the yield and the antioxidant activity at 35 MPa, whereas yield was limited at 20 MPa and 80 °C. Extracts were rich in monounsaturated fatty acids (56.7–58.3%, especially oleic acid 37.2–38.0%), and polyunsaturated fatty acids (20.2–26.1%, especially DHA 7.3–11.4%). The presence of astaxanthin significantly preserved the extracts from oxidation.Industrial relevanceSupercritical carbon dioxide extraction is a green technology appropriate for the recovery of non-polar and heat sensitive compounds. The extracted Arctic charr oils were rich in polyunsaturated fatty acids and astaxanthin which inhibited oxidation in combination with the absence of oxygen and light during the process. This technology could be an excellent alternative for more sustainable valorization of fish processing side streams.     

Antioxidant and antimicrobial activities of the methanol extracts from pummelo (Citrus grandis Osbeck) fruit albedo tissues

The present study was conducted to evaluate the antioxidant and antimicrobial properties of methanol (100 and 80% aqueous) extracts of pummelo fruits albedo (Citrus grandis Osbeck). The antioxidant and antibacterial activity for crude extracts and isolated compounds were evaluated using free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) and Paper disc diffusion method. A 100% Methanol (MeOH) extract was steeped in water at different pH levels and partitioned with ethyl acetate (EtOAc) to give basic, acidic, neutral, and phenolic fractions. The neutral extract was found to possess maximum antioxidant and antibacterial activity. Thereafter, neutral extract was carried out on a silica gel column and eluted with hexane:EtOAc:acetone and preparative TLC (PTLC) to give oil buntan compound, linoleic acid methyl ester, β-sitosterol, sigmasterol, limonin, nomilin and meranzin hydrate were isolated. While, 80% MeOH extract was fractionated also using a silica gel column and PTLC to give isomeranzin hydrate, p-coumaric acid and caffeic acid compound. The extract concentration providing 50% inhibition (IC₅₀) was as follows; oil buntan compound 95 μg/mL, caffeic acid 45 μg/mL, p-coumaric acid 105 μg/mL, limonin + nomilin (mixture) 135 μg/mL was lower than that of synthetic antioxidant butylated hydroxyanisole (BHA) 40 μg/mL. The inhibitory zone (mm) of bacteria tested was 2.9–4.1 mm caffeic acid and 11.6–15.1 mm p-coumaric acid.     

Antioxidant activity and antimicrobial properties of phenolic extracts from acerola (Malpighia emarginata DC) fruit

The antioxidant activity and antimicrobial property of phenolic extracts from acerola (Malpighia emarginata DC) fruit were assessed. The contribution of ascorbic acid and phenolic compounds in the total antioxidant capacity of the extracts was also evaluated. The extracts showed high total phenolic values and possessed high antioxidant activity as expressed by 2,2′‐diphenylpicrylhydrazyl (DPPH) and oxygen radical absorbance capacity assays (ORAC). The ascorbic acid content ranged from 405 to 1744 mg/100 g of fruit on a fresh weight basis. The antioxidant capacity of the phenolic fractions was in the following order: anthocyanins<phenolic acids<flavonoids. The phenolic fractions contributed 7.1–36.5% of the antioxidant activity expressed by ORAC, whereas the contribution of ascorbic accounted for 18–39% of the total activity. Selected extracts from the flavonoids fraction showed some activity against Staphylococcus aureus.     

GLOBAL YIELDS, CHEMICAL COMPOSITIONS AND ANTIOXIDANT ACTIVITIES OF CLOVE BASIL (OCIMUM GRATISSIMUM L.) EXTRACTS OBTAINED BY SUPERCRITICAL FLUID EXTRACTION

Clove basil (Ocimum gratissimum) extracts were obtained with supercritical CO₂. Clove basil was cultivated using 0, 4, 8 and 12 kg/m² of organic fertilizer and was harvested in four seasons: winter, spring, summer and autumn, in the Southern Hemisphere. The extracts' global yields were determined at 40C and 150 bar for samples from all cultivation conditions and harvesting seasons. For selected samples, the extracts' global yields at 40C were determined for pressures of 100, 150, 200, 250 and 300 bar. The extracts were analyzed by gas chromatography–flame ionization detector. Antioxidant activity (AA) was assessed using the coupled reaction of β‐caroteneand linolenic acid. The extracts' global yields varied from 0.91 to 1.79% (dry basis), and the AAs varied from 62 to 84% compared with the control β‐carotene. Eugenol and β‐selinene were the major compounds. The relative proportion of eugenol varied from 35 to 60%, while the content of β‐selinene remained approximately constant (11.5–14.1%, area). The other substances quantified in the extracts were 1,8 cineole, trans‐caryophyllene and α‐selinene.     

Azorean macroalgae (Petalonia binghamiae,Halopteris scoparia and Osmundea pinnatifida) bioprospection: a study of fatty acid profiles and bioactivity

The Azorean macroalgae Petalonia binghamiae, Halopteris scoparia and Osmundea pinnatifida are undervalued and require further study regarding their potential use as food. These three seaweed species had low fat contents, and their fatty acid (FA) profiles were characterised by a high proportion of saturated FA (SFA) in the case of O. pinnatifida and similar weights of SFA and polyunsaturated FA (PUFA) in the other two species. Within the PUFAs, the ω3 PUFAs were the most prominent in O. pinnatifida and P. binghamiae, yielding ω3/ω6 ratios that were higher than one. Eicosapentaenoic acid (EPA, 20:5 ω3) was the most important ω3 PUFA (10–14%). Regarding the other bioactive compounds, the polyphenols were found to reach non-negligible levels (140–220 mg/100 g dw). Significant antioxidant activity was detected. Ethanolic extracts of H. scoparia and aqueous extracts of P. binghamiae showed cyclooxygenase-2 (COX-2) inhibitory capacities between 40% and 79%, indicating anti-inflammatory activity.