Nutraceutical Potential of Leaf Hydro-Ethanolic Extract of the Edible Halophyte Crithmum maritimum L.

Aromatic halophytes represent an exceptional source of natural bioactive compounds for the food industry. Crithmum maritimum L., also known as sea fennel, is a halophyte plant colonizing cliffs and coastal dunes along Mediterranean and Atlantic coasts. It is well known to produce essential oils and polyphenols endowed with antioxidant and biological effects. The present work reports the phytochemical profile, as well as antioxidant, antimicrobial and antimutagenic properties of C. maritimum leaf hydro-alcoholic extract. From LC-ESI-MS analysis, eighteen phenolic compounds were depicted in sea fennel extract and the amount of total phenolic content exceeds 3% DW. Accordingly, C. maritimum extract showed strong antioxidant activities, as evidenced by in vitro (DPPH, ORAC, FRAP) and ex vivo (CAA-RBC and hemolysis) assays. An important antimicrobial activity against pathogenic strains was found as well as a strong capacity to inhibit Staphylococcus aureus (ATCC 35556) biofilm formation. Sea fennel extracts showed a significant decrease of mutagenesis induced by hydrogen peroxide (H₂O₂) and menadione (ME) in Saccharomyces cerevisiae D7 strain. In conclusion, our results show that C. maritimum is an exceptional source of bioactive components and exert beneficial effects against oxidative or mutagenic mechanisms, and pathogenic bacteria, making it a potential functional food.     

Antioxidant and antimicrobial study of Schefflera vinosa leaves crude extracts against rice pathogens

Plant extracts are one of the best possible sources of bioactive molecules, and are being used globally as an antioxidants and natural antimicrobial compounds. In current study, Schefflera vinosa leaves extract was prepared through Soxhlet extraction procedure using methanol and chloroform as solvents. The extract was investigated for total antioxidant, phenolic and flavonoid contents, free radical scavenging and antimicrobial activities. The free radical scavenging activities were evaluated through 2,2- diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis-3-ethylbenzotiazolin-6-sulfonic acid (ABTS) and Ferric-reducing/ antioxidant power (FRAP) assay. The antimicrobial activity of extract was determined through poisoned food method. The methanolic extract has exhibited high antioxidant, phenolic, and flavonoid activities compared to chloroform extract. Similarly, free radical scavenging activities (ABTS, DPPH and FRAP) were higher in methanolic extract. Further, Fourier-Transform Infrared Spectroscopy (FTIR) used to determine the functional group and Gas chromatography-mass spectrometry (GC–MS) to elucidate volatile composition of the crude extract. Different functional group like N-H, O-H, C-O, C-N, C-H, C=O, C≡C and C-O-H presence indicate the existence of many metabolites in the extracts. GC–MS study identified 61 compounds and subsequently, these molecules were screened virtually using DockThor. Furthermore, antimicrobial study was confirmed against rice pathogens like Magnaporthe oryzae (M. oryzae) and Xanthomonas oryzae pv. oryzae (Xoo). Molecular docking study further suggested that phytomolecules (3-Isopropoxy-1,1,1,7,7,7-hexamethyl-3,5,5-tris (trimethylsiloxy) tetrasiloxane, and 2-Methoxy-5-methylthiophene) targets Histone Deacetylase (HDAC) of M. oryzae and Peptide Deformylase (PDF) of Xoo, which could inhibit their growth. Hence, this study indicated that Schefflera vinosa extracts could be an important ingredient as an antioxidant as well as antimicrobial agent against rice pathogens.     

Effects of Green Tea Powder,Pomegranate Peel Powder,Epicatechin and Punicalagin Additives on Antimicrobial,Antioxidant Potential and Quality Properties of Raw Meatballs

Alternative technologies, which have been developed in order to meet the consumers’ demand for nourishing and healthy meat and meat products, are followed by the food industry. In the present study, it was determined, using the HPLC method, that green tea contains a high level of epicatechin (EP) under optimal conditions and that pomegranate peel contains a high level of punicalagin (PN). Green tea, pomegranate peel, EP and PN were added to meatballs at different concentrations in eight groups. The antioxidant capacities of extracts were measured. The antimicrobial activity was examined for 72 h using three different food pathogens. The highest level of antimicrobial activity was achieved in the 1% punicalagin group, whereas the minimum inhibition concentration (L. monocytogenes, S. typhimurium) was found to be 1.87 mg/mL. A statistically significant decrease was found in FFA, POV and TBARS levels of meatballs on different days of storage (p < 0.05). When compared to the control group, the bioactive compounds preserved the microbiological and chemical properties of meatballs during storage at +4 °C (14 days). It was concluded that the extracts with high EP and PN concentrations can be used as bio-preservative agents for meat and meat products.     

Leptospermum petersonii as a Potential Natural Food Preservative

Leptospermum petersonii (family Myrtaceae) is often cultivated for ornamental purposes but also serves as a rich source of bioactive essential oils. While several studies focused on the activities of the essential oils, this study analysed the potential of spent L. petersonii leaves as a natural food preservative. Method: We investigated the in vitro antioxidant and antimicrobial activities of crude L. petersonii extracts against activities of the purified isolated flavonoid, 6-methyltectochrysin, which was characterized using spectroscopic methods. The antioxidant assays followed ORAC, FRAP and TEAC tests. The antimicrobial activities of the extract and purified flavonoid were analysed against six multi-drug resistant microbial strains in broth dilution assays. Result: The results revealed that both the crude extracts and isolated 6-methyltectochrysin exhibited positive radical ion scavenging antioxidant potential, however the crude extract was about 6-fold more potent antioxidant than the purified 6-methyltectochrysin. The crude extract also showed strong antimicrobial activities against Bacillus cereus, and even more potent antimicrobial agent than the reference ampicillin antibiotic against Klebsiella pneumoniae subsp. pneumoniae. A higher resistance was observed for the tested Gram-negative strains than for the Gram-positive ones. 6-methyltectochrysin was generally inactive in the antimicrobial assays. Conclusion: The crude methanolic extract showed significant bioactivity which validates the medicinal relevance of the plant. The observed biological activities, especially against a notorious strain of B. cereus, suggest that L. petersonii could be a promising natural source of food preservatives.     

Boiling Technique-Based Food Processing Effects on the Bioactive and Antimicrobial Properties of Basil and Rosemary

Rosemary (Rosmarinus officinalis) and basil (Ocimum sanctum Linn) are mostly used as herbal teas, made by steeping whole or ground herbs in boiling water. Hence, it is important to know the effect of boiling time on the bioactivity of these herbs. The effect of different boiling times (5, 10, and 15 min) on the antioxidant and antimicrobial properties, and some selected phenolic compounds of these herbs was examined in this study. Experimental results revealed that basil displayed the highest total polyphenol content (TPC), total flavonoid content (TFC), and antioxidant activity when it was boiled for 5 min, and the lowest TPC was obtained when it was boiled for 15 min. On the other hand, rosemary had the highest TPC, TFC, and antioxidant potential after being boiled for 15 min, while it had the lowest after being boiled for 5 min. There was no growth inhibition of rosemary extracts against gram-negative bacteria, whereas higher growth inhibition was observed against gram-positive bacteria. The MIC and MBC of rosemary ethanolic extract against Listeria monocytogenes were 5 and 5 mg/mL and against B. subtilis were 10 and 10 mg/mL, respectively. While MIC and MBC of methanolic extract against L. monocytogenes were 5 and 5 mg/mL and against Bacillus subtilis were and 5 and 5 mg/mL, respectively. Salicylic acid was the most abundant (324.7 mg/100 g dry weight (dw)) phenolic compound in the rosemary sample boiled for 5 min, and acetyl salicylic acid was the most abundant (122.61 mg/10 g dw) phenolic compound in the basil sample boiled for 15 min.     

Antimicrobial Effects of Basil,Summer Savory and Tarragon Lyophilized Extracts in Cold Storage Sausages

The problem of functional foods with bioactive components of natural origin is current for the food industry. Plant extracts rich in polyphenols with antioxidant and antimicrobial activity are a promising source for use in improving the quality and characteristics of fresh meat and meat products. In this context, the purpose of the present study was to evaluate the physico-chemical, microbiological, sensory properties of sausages prepared with the addition of lyophilized extract of basil, thyme or tarragon. For the beginning, the total amount of polyphenols, the antioxidant and antimicrobial activity of the extracts obtained from three spices were evaluated. In the sausages previously infected with Staphylococcus aureus and Escherichia coli it was observed that there is a much larger number of colonies of microorganisms in the control sample compared to the other samples within 24 and 48 h. Moreover, following the addition of sausage extracts, no changes were found regarding their sensory acceptability.     

Antioxidant and Antimicrobial Evaluation and Chemical Investigation of Rosa gallica var. aegyptiaca Leaf Extracts

Rosa gallica var. aegyptiaca is a species of flowering plant belonging to the Rosaceae family that plays an important role as a therapeutic agent for the treatment of specific types of cancer, microbial infections, and diabetes mellitus. This work presents the first report on the evaluation of the antioxidant and antimicrobial potential along with the phytochemical analysis of Rosa gallica var. aegyptiaca leaves. Five leaf extracts of hexane, chloroform, methanol, hydromethanol 80%, and water were prepared. Assessment of antioxidant activity was carried out via DPPH radical scavenging assay. Antimicrobial activity against five foodborne pathogenic bacteria—including Listeria monocytogenes, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Salmonella enteritidis—and the fungus Candida albicans, was examined using the disc diffusion method. Total phenolic content and total flavonoid content were determined using the Folin–Ciocalteu reagent and aluminum chloride methods, respectively. Isolation, identification, and quantification of phenolic compounds were performed using HPLC-DAD analysis. Amongst the five leaf extracts that were investigated, hydromethanol 80% extract possessed the highest extraction yield, antioxidant activity, total phenolic content, and antimicrobial activity against all tested microbial strains. Moreover, this extract furnished six active phenolic compounds: gallic acid (1), (+) catechin (2), chlorogenic acid (3), (–) epicatechin (4), quercetin-3-O-α-d-(glucopyranoside) (5), and quercetin (6). This study provides an alternative utilization of R. gallica var. aegyptiaca leaves as a readily accessible source of natural antioxidants and antimicrobials in the food and pharmaceutical industries.     

Effect of Extraction Method on Total Flavonoid,Total Phenolic Content,Antioxidant and Anti-bacterial Activity of Zingiberis Officinale Rhizome

This research aims to compare between decocta and maceration method using water and ethanol as a solvent on total flavonoid, total phenolic content, antioxidant and antibacterial activity of Zingiber officinale rhyzome extract. The Rhyzome was dryed by oven method on 50 °C for 24 hours and 48 hours. Total flavonoid, total phenolic content and antioxidant activity were assay by spectrophotometric method. The antibacterial activity was determined by difussion agar method against Bacillus subtilis (Bs) and Escherichia colli InaCC B5 (Ec). Ethanol extract from dried rhyzome processed for 24 hours (R-24) indicated the best result for total flavonoid, total phenolic content and antioxidant activity. The yield of total flavonoid for R-24 was 286 μg/mL. The yield of total phenolic content for R-24 was 504 μg/mL and the yield of IC₅₀ antioxidant activity for R-24 was 5.753 μg/mL. The extract should antibacterial activity againts Bs with inhibition diameter of 10% and 20% of samples concentration are 10 and 11.5 mm respectively. Meanwhile, The inhibition diameter result against Ec for 10% and 20% of samples concentration are 7.5 and 8.5 mm respectively.     

Phenolic Contents,Organic Acids,and the Antioxidant and Bio Activity of Wild Medicinal Berberis Plants- as Sustainable Sources of Functional Food

Wild fruits have increasingly been investigated as part of recent searches for food products with a high antioxidant activity. In this study, wild edible berberis Berberis vulgaris collected from three different provinces (Jilin, Heilongjiang, and Liaoning) were investigated for their phenolic contents, organic acid contents, mineral contents, antioxidant activity as well as their antimicrobial potential against a range of common food borne pathogens. In addition, a physiochemical and mineral analysis of the fruits was also performed. The methanol extracts of berberis fruit collected from Jilin province were highly active against all the studied food borne bacterial pathogens, i.e., S. aureus and L. monocytogenes, E. coli, P. fluorescens, V. parahaemolyticus, and A. caviae while the berberis extracts from Heilongjiang and Liaoning showed activity only against Gram-negative bacteria. The phenolic content and antioxidant activity were determined by the HPLC separation method and β-carotene bleaching methods, respectively. Four organic acids such as malic acid, citric acid, tartaric acid, and succinic acid were identified while a variety of phenolic compounds were detected among which catechin, chlorogenic acid, and gallic acid were found to be the predominant phenolic compounds in all three of berberis fruit samples. The berberis fruit from Jilin was found to be superior to the Heilongjiang and Liaoning fruit regarding desired physiochemical analysis; however, there were no significant differences in the mineral contents among the three samples. Overall, the berberis fruit from Jilin was ranked as the best in term of the nutritional, physiochemical, antimicrobial, and antioxidant properties. This study confirms the various useful characteristics and features of berberis at a molecular level that can be used as a sustainable source for their potential nutritional applications for making functional foods in different food industries.     

Preservation of Mimosa tenuiflora Antiaflatoxigenic Activity Using Microencapsulation by Spray-Drying

Mimosa tenuiflora aqueous extract (MAE) is rich in phenolic compounds. Among them, condensed tannins have been demonstrated to exhibit a strong antioxidant and antiaflatoxin B1 activities in Aspergillus flavus. Since antioxidant capacity can change with time due to environmental interactions, this study aimed to evaluate the ability of encapsulation by spray-drying of Mimosa tenuiflora aqueous extract to preserve their biological activities through storage. A dry formulation may also facilitate transportation and uses. For that, three different wall materials were used and compared for their efficiency. Total phenolic content, antioxidant activity, antifungal and antiaflatoxin activities were measured after the production of the microparticles and after one year of storage at room temperature. These results confirmed that encapsulation by spray-drying using polysaccharide wall materials is able to preserve antiaflatoxin activity of Mimosa tenuiflora extract better than freezing.     

Rose Hips,a Valuable Source of Antioxidants to Improve Gingerbread Characteristics

The present study analyzes the complex of bioactive compounds from rose hips pulp powder (RHP) obtained after separating the seeds from Rosa canina L. in order to obtain the oil. The extract prepared from RHP was characterized in terms of the total content of polyphenols, flavonoids, cinnamic acids, flavonols, carotenoids, but also the content of individual polyphenols and carotenoids, antioxidant activity, and CIELab color parameters. The effects of some salts, potentially present in foods, and pH variations were examined to predict possible interactions that could occur when adding rosehip pulp as a food component. The results turned out to be a high content of polyphenols, carotenoids and antioxidant activity. The main phenolic components are procyanidin B1, chlorogenic acid, epicatechin, procyanidin B2, gallic acid, salicylic acid, and catechin. The carotenoid complex includes all-trans-β-carotene, all-trans-lycopene, zeaxanthin, α-cryptoxanthin, β-cryptoxanthin, rubixanthin, cis-β-carotene, cis-γ-carotene and cis-lycopene. The addition of CaCl₂ and NaCl to the RHP extract reduced the antioxidant activity and the strong acidic environment (pH to 2.5) decreased the antioxidant activity by 29%. The addition of rose hip powder to gingerbread has improved its general characteristics, and increased its antioxidant activity and microbiological stability, the effects of 4% RHP being the most important.     

Phenolic Profile and Antioxidant,Antibacterial, and Antiproliferative Activity of Juglans regia L. Male Flowers

Juglans regia L., walnut, is a large, long-living tree, cultivated in temperate climates around the world. It is highly appreciated for its nutritional kernels and high-quality timber. Its barks, leaves, and husk are used as dyes and in folk medicine as herbal remedies for several diseases. From a biological and chemical standpoint, relatively little is known about the male flowers of the tree. Therefore, the aim of the study was to evaluate the phenolic profile as well as in vitro antioxidant, antimicrobial, and antiproliferative activity of male Juglans regia L. flowers. Phenolic content was determined by UPLC/PDA/MS/MS analyses; antioxidant activity was assessed by five different methods; antimicrobial activity was evaluated against the six most common pathogenic strains of Gram-positive and Gram-negative bacteria, and antiproliferative properties were assessed against six cell lines. Most of the analyses carried out in this study were performed for the first time for this raw material. J. regia flower extract was characterized by a strong ability to scavenge DPPH˙ free radicals, hydroxyl radicals, and chelating metal ions. Among the examined bacterial strains and neoplastic lines, the strongest antimicrobial activity was shown against S. aureus, L. monocytogenes, and B. cereus, and cytotoxic activity against breast cancer, glioblastoma, and astrocytoma cells. Male J. regia flowers have also been found to be a rich source of phenolic compounds. The content of polyphenols in the extract was 4369.73 mg/100 g d.w., and 24 compounds from the group of flavonoids, phenolic acids, and juglunosides were identified. Additionally, a strong correlation between the content of polyphenols and the antioxidant capacity and cytotoxic activity was observed. This is why the tested J. regia flowers are an excellent source of effective natural antioxidant, antibacterial, and chemopreventive compounds that have potential to be used in the pharmaceutical or food industries.     

Antioxidant and antibacterial activity of silver nanoparticles biosynthesized using Chenopodium murale leaf extract

Silver is known for its antimicrobial effects and silver nanoparticles are gaining their importance due to their antimicrobial activities. The aims of the current study were to use plant extract for the biosynthesis of silver nanoparticles and to evaluate their antibacterial and antioxidant activity in vitro. The results indicated that silver nanoparticles (AgNPs) can be synthesized in a simple method using Chenopodium murale leaf extract. The TEM analysis showed that the sizes of the synthesized AgNps ranged from 30 to 50 nm. The essential oil of C. murale leaf extract was formed mainly of α-Terpinene, (Z)-Ascaridole and cis-Ascaridole. The total phenolic compounds and total flavonides were higher in AgNPs-containing plant extract compared to the plant extract. AgNPs-containing leaf extract showed a higher antioxidant and antimicrobial activity compared to C. murale leaf extract alone or silver nitrate. It could be concluded that C. murale leaf extract can be used effectively in the production of potential antioxidant and antimicrobial AgNPs for commercial application.     

The Optimization of Extraction Process,Antioxidant, Whitening and Antibacterial Effects of Fengdan Peony Flavonoids

Flavonoids have important biological activities, such as anti-inflammatory, antibacterial, antioxidant and whitening, which is a potential functional food raw material. However, the biological activity of Fengdan peony flavonoid is not particularly clear. Therefore, in this study, the peony flavonoid was extracted from Fengdan peony seed meal, and the antioxidant, antibacterial and whitening activities of the peony flavonoid were explored. The optimal extraction conditions were methanol concentration of 90%, solid-to-liquid ratio of 1:35 g:mL, temperature of 55 °C and time of 80 min; under these conditions, the yield of Fengdan peony flavonoid could reach 1.205 ± 0.019% (the ratio of the dry mass of rutin to the dry mass of peony seed meal). The clearance of Fengdan peony total flavonoids to 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical, hydroxyl radical and 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical could reach 75%, 70% and 97%, respectively. Fengdan peony flavonoid could inhibit the growth of the Gram-positive bacteria. The minimal inhibitory concentrations (MICs) of Fengdan peony flavonoid on S. aureus, B. anthracis, B. subtilis and C. perfringens were 0.0293 mg/mL, 0.1172 mg/mL, 0.2344 mg/mL and 7.500 mg/mL, respectively. The inhibition rate of Fengdan peony flavonoid on tyrosinase was 8.53–81.08%. This study intensely illustrated that the antioxidant, whitening and antibacterial activity of Fengdan peony total flavonoids were significant. Fengdan peony total flavonoids have a great possibility of being used as functional food materials.     

Phytochemical analysis,UPLC-ESI-Orbitrap-MS analysis,biological activity,and toxicity of extracts from Tripleurospermum limosum (Maxim.) Pobed

Tripleurospermum limosum (TL) has been used in folk medicine to treat gastritis. Toward the further development and use of TL, we report the phytochemical profiling, determination of active components, and antioxidant and enzyme inhibitory activities of TL. Nineteen compounds were identified by ultra-performance liquid chromatography-electrospray ionization-orbitrap-mass spectrometry for the first time in this plant. Phytochemical studies indicated that TL contained 11 types of phytochemicals. The active components [total carbohydrate content (TCC), total protein content (TP_roC), total triterpenoid content (TTC), total phenolic content (TP_heC), total flavonoid content (TFC), total phenolic acid content (TPAC), condensed tannin content (CTC), and gallotannin content (GC)] of eight different solvent extracts were determined by ultraviolet–visible spectrophotometry. Aqueous extract had highest TP_roC, TP_heC, and GC values. Methanol extract exhibited highest TCC and TFC values. Ethanol extract showed highest TPAC and CTC values and dichloromethane extract exhibited highest TTC value. Methanol extract showed strongest ability to scavenge 2,2-diphenyl-1-picrylhydrazyl radicals, 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt cation radicals, and hydroxyl radicals, and also exhibited highest antioxidant activity in ferric-reducing antioxidant power and cupric ion-reducing antioxidant capacity assays. Best iron and copper chelating activity and H₂O₂ scavenging ability were shown by aqueous extract. Ethanol extract showed strongest ability to scavenge superoxide radicals and effectively prevent β-carotene bleaching. Acetone extract had highest inhibitory activity toward α-glucosidase, α-amylase, and xanthine oxidase. Ethyl ether extract had highest inhibitory activity towards urease and angiotensin converting enzyme. Aqueous and ethanol extracts had strongest inhibitory activity toward acetylcholinesterase. Methanol extract showed highest inhibitory activity toward tyrosinase. Methanol extract showed good stability and antioxidant capacity during heating, at different pH values, and after in vitro digestion and had low toxicity. The efficacy of methanol extract in stabilizing olive and sunflower oils was studied, the results suggested that methanol extract had a protective effect on the primary oxidation of the two oils. TL may be useful as a source of active components for application in human nutrition and/or phytomedicine and methanol extract of TL could be used as a natural oil stabiliser.     

Biochemical and Anti-proliferative activities of seven abundant tropical red seaweeds confirm nutraceutical potential of Grateloupia indica

Seaweeds are being used as food items in Asian countries from ancient times. Seaweeds mainly grow in intertidal zone and survive extreme environmental conditions and thus have developed metabolites, which help them survive in such conditions. Red seaweeds have proven to be rich in compounds, which are antioxidant and having many other health benefits. In this study, seven most abundantly grown red seaweeds, Gracilaria corticata (GC), Grateloupia indica (GI), Kappaphycus alvarezii (KA), Solieria robusta (SR), Amphiroa anceps (AA), Halymenia porphyriformis (HP), and Sarconema scinaioides (SS) were collected from Saurashtra coast of Arabian Sea. Harvested seaweeds were subjected to metabolite profiling, flavonoid and phenolic content analysis, different biological activities including radical scavenging, antioxidant, reducing and proliferation inhibition. Overall, GI was found to contain high contents (flavonoid and phenolic), biological activities and proliferation inhibition. Study confirms nutraceutical potential of red seaweed Grateloupia indica to be explored further for the bioactive compound or to be used as functional food.     

Chemical Profile,Antioxidant Properties and Antimicrobial Activities of Malaysian Heterotrigona itama Bee Bread

The aim of the study was to determine the chemical profile, antioxidant properties and antimicrobial activities of Heterotrigona itama bee bread from Malaysia. The pH, presence of phytochemicals, antioxidant properties, total phenolic content (TPC) and total flavonoid content (TFC), as well as antimicrobial activities, were assessed. Results revealed a decrease in the pH of bee bread water extract (BBW) relative to bee bread ethanolic extract (BBE) and bee bread hot water extract (BBH). Further, alkaloids, flavonoids, phenols, tannins, saponins, terpenoids, resins, glycosides and xanthoproteins were detected in BBW, BBH and BBE. Also, significant decreases in TPC, TFC, DPPH activity and FRAP were detected in BBW relative to BBH and BBE. We detected phenolic acids such as gallic acid, caffeic acid, trans-ferulic acid, trans 3-hydroxycinnamic acid and 2-hydroxycinnamic acid, and flavonoids such as quercetin, kaempferol, apigenin and mangiferin in BBE using high-performance liquid chromatography analysis. The strongest antimicrobial activity was observed in Klebsilla pneumonia (MIC₅₀ 1.914 µg/mL), followed by E. coli (MIC₅₀ 1.923 µg/mL), Shigella (MIC₅₀ 1.813 µg/mL) and Salmonella typhi (MIC₅₀ 1.617 µg/mL). Bee bread samples possess antioxidant and antimicrobial properties. Bee bread contains phenolic acids and flavonoids, and could be beneficial in the management and treatment of metabolic diseases.     

Phenolic Profile,Antioxidant Capacity and Antimicrobial Activity of Nettle Leaves Extracts Obtained by Advanced Extraction Techniques

Nettle is a widely known plant whose high biological activity and beneficial medicinal effects are attributed to various bioactive compounds, among which polyphenols play an important role. In order to isolate polyphenols and preserve their properties, advanced extraction techniques have been applied to overcome the drawbacks of conventional ones. Therefore, microwave-assisted extraction (MAE) has been optimized for the isolation of nettle leaves polyphenols and it was compared to pressurized liquid extraction (PLE) and conventional heat-reflux extraction (CE). The obtained extracts were analyzed for their individual phenolic profile by UPLC MS² and for their antioxidant capacity by ORAC assay. MAE proved to be the more specific technique for the isolation of individual phenolic compounds, while PLE produced extracts with higher amount of total phenols and higher antioxidant capacity. Both techniques were more effective compared to CE. PLE nettle extract showed antimicrobial activity against bacteria, especially against Gram-negative Pseudomonas fragi ATCC 4973 and Campylobacter jejuni NCTC 11168 strains. This suggests that PLE is suitable for obtaining a nettle extract with antioxidant and antimicrobial potential, which as such has great potential for use as a value-added ingredient in the food and pharmaceutical industry.     

HPLC-ESI-MS/MS analysis of phenolics and in vitro antioxidant activity of Epilobium angustifolium L.

The aerial parts of Epilobium plants are widely used as folk medicine and food around the world. The present study was aimed to investigate the antioxidant activities and active chemical constituents from Epilobium angustifolium L. The results revealed that the EtOAc extract, rich in phenolic compounds and flavonoids (16.81 ± 0.67 g GAE/100 g extract and 4.95 ± 0.21 g QE/100 g extract, respectively), possessed significantly antioxidant activities in reducing power, DPPH radical scavenging activity, ABTS radical scavenging activity and highly in inhibiting lipid peroxidation activity. Simultaneously, active fractions F to H from EtOAc extracts showing potent in vitro antioxidant activities also contained high content of total phenolic and flavonoid. Twenty-eight compounds were identified as phenolic compounds and flavonoids by LC-MS/MS. The results illustrate that the E. angustifolium L., which is rich in phenolics, could be used as a natural resource of antioxidant ingredient.     

Effects of Fermentation and Storage on Bioactive Activities in Milks and Yoghurts

Fermentation of milk enhances its nutritional value through improved bioavailability of nutrients and production of bioactive substances which have biological functions. The goals of this research were to study the effect of fermentation and storage on antioxidant and antimicrobial activities in buffalo, goat and cow milks and yoghurts. Samples of buffalo, goat, cow milks and their yoghurts during their fermentation and storage were determined for proximate analysis and bioactive activities including antioxidant activities of DPPH, ABTS and reducing power assays, and antimicrobial activities against Staphylococcus aureus, Bacillus cereus, Salmonella typhimurium and Escherichia coli. Results showed that buffalo, cow and goat yoghurts had antioxidant activities in all assays and their activities significantly increased during their fermentation. Pasteurization did not affect the antioxidant activities. The activities of all yoghurts remained unchanged after a storage time of 21 days at 4 °C. For the antimicrobial activities, only yoghurts from buffalo, cow and goat milks had the activities, while all milks did not show any activities. However, buffalo yoghurt could inhibit only Gram positive strains (S. aureus and B. cereus), while goat and cow yoghurt inhibited all tested strains. A chemical responsible for antimicrobial activities in yoghurts was lactic acid formed by lactic acid bacteria. However, bioactive peptides produced by protein digestion during milk fermentation by lactic acid bacteria could not be ruled out for antioxidant and antimicrobial activities present. The antimicrobial activities of all yoghurts remained constant during their storage. It is concluded that all yoghurts would retain milk nutrition and bioactive functions during their storage in a refrigerator and may be served as a functional food with benefits from those activities for consumers.