Production of phenolic antioxidants by the solid-state bioconversion of pineapple waste mixed with soy flour using Rhizopus oligosporus

The ability of Rhizopus oligosporus to produce enhanced levels of free phenolics from pineapple residue mixed with soy flour as potential nitrogen source was investigated. Concurrently, phenolic-linked β-glucosidase and the antioxidant activity of the extracts were followed. Two treatments were studied: (A) 9 g of pineapple residue and 1 g of soy flour (P9); (B) 5 g of pineapple residue and 5 g of soy flour (P5). The increase of water extractable phenolics was 39.3% for P9 treatment and 79.4% for P5 treatment. During early stages of growth high antioxidant activity, low phenolic content and low β-glucosidase specific activity was observed. High antioxidant activity was likely due to the presence of insoluble polymeric phenolics, know for their high antioxidant activity. A marked decrease of the antioxidant activity of P5 treatment during late stages of growth was observed due to likely formation of free soluble phenolics. The moderate total phenolics content and high β-glucosidase specific activity of P9 treatment in late stages is likely the consequence of low nitrogen content in this treatment. The bioconversion of pineapple residue by R. oligosporus leads to enhanced levels of phenolic compounds, mainly for P5 treatment. This approach offers a novel strategy to enhance the value of pineapple wastes.     

Inhibition of Listeria monocytogenes in fish and meat systems by use of oregano and cranberry phytochemical synergies

Optimized phenolics from oregano and cranberry extracts were evaluated for antimicrobial activity against Listeria monocytogenes in laboratory media and in beef and fish. The antimicrobial activity increased when oregano and cranberry extracts were mixed at a ratio of 75% oregano and 25% cranberry (wt/wt) with 0.1 mg of phenolic per disk or ml, and the efficacy was further enhanced by lactic acid. The inhibition by phytochemical and lactic acid synergies was most effective when beef and fish slices were stored at 4 degrees C.     

Inhibition of Listeria monocytogenes in Fish and Meat Systems by Use of Oregano and Cranberry Phytochemical Synergies

Optimized phenolics from oregano and cranberry extracts were evaluated for antimicrobial activity against Listeria monocytogenes in laboratory media and in beef and fish. The antimicrobial activity increased when oregano and cranberry extracts were mixed at a ratio of 75% oregano and 25% cranberry (wt/wt) with 0.1 mg of phenolic per disk or ml, and the efficacy was further enhanced by lactic acid. The inhibition by phytochemical and lactic acid synergies was most effective when beef and fish slices were stored at 4°C.     

Inhibition of Helicobacter pylori and associated urease by oregano and cranberry phytochemical synergies

Ulcer-associated dyspepsia is caused by infection with Helicobacter pylori. H. pylori is linked to a majority of peptic ulcers. Antibiotic treatment does not always inhibit or kill H. pylori with potential for antibiotic resistance. The objective of this study was to determine the potential for using phenolic phytochemical extracts to inhibit H. pylori in a laboratory medium. Our approach involved the development of a specific phenolic profile with optimization of different ratios of extract mixtures from oregano and cranberry. Subsequently, antimicrobial activity and antimicrobial-linked urease inhibition ability were evaluated. The results indicated that the antimicrobial activity was greater in extract mixtures than in individual extracts of each species. The results also indicate that the synergistic contribution of oregano and cranberry phenolics may be more important for inhibition than any species-specific phenolic concentration. Further, based on plate assay, the likely mode of action may be through urease inhibition and disruption of energy production by inhibition of proline dehydrogenase at the plasma membrane.     

Comparative analysis of solid-state bioprocessing and enzymatic treatment of finger millet for mobilization of bound phenolics

The present work investigates the probable bioprocessing technique to mobilize the bound phenolics naturally found in finger millet cell wall for enriching it with dietary antioxidants. Comparative study was performed between the exogenous enzymatic treatment and solid-state fermentation of grain (SSF) with a food grade organism Rhizopus oryzae. SSF results indicated that at the 6th day of incubation, total phenolic content (18.64 mg gallic acid equivalent/gds) and antioxidant property (DPPH radical scavenging activity of 39.03 %, metal chelating ability of 54 % and better reducing power) of finger millet were drastically enhanced when fermented with GRAS filamentous fungi. During the enzymatic bioprocessing, most of the phenolics released during the hydrolysis, leached out into the liquid portion rather than retaining them within the millet grain, resulting in overall loss of dietary antioxidant. The present study establishes the most effective strategy to enrich the finger millet with phenolic antioxidants.     

蓝莓果渣提取物总酚含量及抗氧化活性研究

研究了蓝莓果渣提取物总酚含量及其抗氧化活性。分别采用水、40%乙醇及纤维素酶辅助乙醇超声提取蓝莓果渣,并用Folin-Ciocalteu试剂对3种提取物的总酚含量进行评估;并采用DPPH清除实验及O2—.清除实验对3种提取物的抗氧化活性进行研究。实验结果表明,纤维素酶辅助超声提取蓝莓果渣的总酚含量最高,可达425.36±15.21 mg GAE.100 g-1DW,远远高于水提物(169.46±9.75 mg GAE.100 g-1DW)及醇提物(218.39±12.54mg GAE.100 g-1DW)中的总酚含量。且纤维素酶辅助乙醇超声提取物对DPPH的清除能力为2.67±0.13 gVc.100 g-1DW,对O—.2的清除能力2.48±0.14 g Vc.100 g-1DW,明显好于醇提物及水提物抗氧化活性。     

Inhibition of Helicobacter pylori and Associated Urease by Oregano and Cranberry Phytochemical Synergies

Ulcer-associated dyspepsia is caused by infection with Helicobacter pylori. H. pylori is linked to a majority of peptic ulcers. Antibiotic treatment does not always inhibit or kill H. pylori with potential for antibiotic resistance. The objective of this study was to determine the potential for using phenolic phytochemical extracts to inhibit H. pylori in a laboratory medium. Our approach involved the development of a specific phenolic profile with optimization of different ratios of extract mixtures from oregano and cranberry. Subsequently, antimicrobial activity and antimicrobial-linked urease inhibition ability were evaluated. The results indicated that the antimicrobial activity was greater in extract mixtures than in individual extracts of each species. The results also indicate that the synergistic contribution of oregano and cranberry phenolics may be more important for inhibition than any species-specific phenolic concentration. Further, based on plate assay, the likely mode of action may be through urease inhibition and disruption of energy production by inhibition of proline dehydrogenase at the plasma membrane.     

Morphological characteristics of sporangiospores of the tempe fungus Rhizopus oligosporus differentiate it from other taxa of the R. microsporus group

The fungus Rhizopus oligosporus (R. microsporus var. oligosporus) is traditionally used to make tempe, a fermented food based on soybeans. Interest in the fungus has steadily increased, as it can also ferment other substrates, produce enzymes, and treat waste material. R. oligosporus belongs to the R. microsporus group consisting of morphologically similar taxa, which are associated with food fermentation, pathogenesis, or unwanted metabolite production (rhizonins and rhizoxins). The ornamentation pattern, shape, and size of sporangiospores of 26 R. microsporus group strains and two R. oryzae strains were studied using low-temperature SEM (LT-SEM) and LM. This study has shown that: (1) LT-SEM generates images from well-conserved sporangiophores, sporangia, and spores. (2) Robust spore ornamentation patterns can be linked to all different taxa of the R. microsporus group, some previously incorrectly characterized as smooth. Ornamentation included valleys and ridges running in parallel, granular plateaus, or smooth polar areas. Distribution of ornamentation patterns was related to spore shape, which either was regular, ranging from globose to ellipsoidal, or irregular. Specific differences in spore shape, size, and ornamentation were observed between Rhizopus taxa, and sometimes between strains. (3) R. oligosporus has a defect in the spore formation process, which may be related to the domesticated nature of this taxon. It had a high proportion, 10–31 %, of large and irregular spores, and was significantly differentiated from other, natural Rhizopus taxa as evaluated with partial least squares discriminant analysis. It is remarkable that the vehicle of distribution, the sporangiospore, is affected in the strains that are distributed by human activity. This provides information about the specificity and speed of changes that occur in fungal strains because of their use in (food) industry.     

Comparative analysis of antioxidant activity,toxicity, and mineral composition of kernel and pomace of apricot (Prunus armeniaca L.) grown in Balochistan,Pakistan

The present study aims to investigate some physical attributes, total phenolics content, total flavonoids content, mineral composition, bioluminescence toxicity assay and antioxidant activity in terms of DPPH, HPS, TAC and FRAP assays in the kernel and pomace samples of six apricot cultivars grown in Balochistan, Pakistan. TFC and TPC determined by the AlCl₃ and Folin-Ciocalteu assays in apricot kernel extracts of six cultivars varied from 1797.5 (Chagali) to 4778.9 (Badoghur) mg QUE/100 g DW and from 1750.0 (Chagali) to 5005.8 (Badoghur) mg GAE/100 g DW. Apricot kernels exhibited higher antioxidant activity than pomace; antioxidant activity in terms of IC₅₀ in kernels ranged from 24.88 to 98.61 μg/ml for DPPH, 334.84 to 516.63 μg/ml for HPS, from 22.02 to 110.80 μg/ml for TAC and from 96.27 to 163.35 μg/ml for FRAP. The apricot kernels showed higher TPC, TFC, bioluminescence toxicity to V. logei and antioxidant activity than the pomace. The correlation analysis demonstrated substantial contributions of polyphenols and flavonoids to antioxidant assays. The sample type was the leading factor affecting the amounts of K, Na, Ca, Fe, and Mn in the tested samples; mineral contents were higher in pomace than kernels. The highest inhibition to V. logei was found in the kernels of Badoghur (IC₅₀ = 1.61 mg/ml). The PCA analysis showed significant contributions of phenolic and flavonoid contents towards antioxidant bioluminescence toxicity assays. Our results suggest Badoghur, Shakarpara and Sardai kernels are rich sources of secondary metabolites and possess remarkable antioxidant and antiluminescence activity and can make a significant contribution to the treatment and prevention of chronic health problems.     

The action of berry phenolics against human intestinal pathogens

Phenolic compounds present in berries selectively inhibit the growth of human gastrointestinal pathogens. Especially cranberry, cloudberry, raspberry, strawberry and bilberry possess clear antimicrobial effects against e.g. salmonella and staphylococcus. Complex phenolic polymers, such as ellagitannins, are strong antibacterial agents present in cloudberry, raspberry and strawberry. Berry phenolics seem to affect the growth of different bacterial species with different mechanisms. Adherence of bacteria to epithelial surfaces is a prerequisite for colonization and infection of many pathogens. Antimicrobial activity of berries may also be related to anti-adherence activity of the berries. Utilization of enzymes in berry processing increases the amount of phenolics and antimicrobial activity of the berry products. Antimicrobial berry compounds are likely to have many important applications in the future as natural antimicrobial agents for food industry as well as for medicine.     

Antioxidant and antimicrobial activities of Spirulina platensis extracts and biogenic selenium nanoparticles against selected pathogenic bacteria and fungi

This study investigated the antimicrobial and antioxidant activity of three Spirulina extracts (methanol, acetone, and hexane) and the biological selenium nanoparticles (SeNPs) fabricated by Bacillus subtilis AL43. The results showed that Spirulina extracts exhibited antimicrobial activity against tested pathogens. Besides, Spirulina extracts significantly scavenged ABTS and DPPH radicals in a dose-dependent manner. The methanolic extract had higher total phenolic content, antimicrobial activity, and antioxidant activity than other extracts. The selenium nanoparticles were synthesized by Bacillus subtilis AL43 under aerobic conditions and were characterized as spherical, crystalline with a size of 65.23 nm and a net negative charge of ?22.7. We evidenced that SeNPs possess considerable antimicrobial activity against three gram-positive, three gram-negative bacteria, and three strains from both Candida sp. and Aspergillus sp. Moreover, SeNPs were able to scavenge ABTS and DPPH radicals in a dose-dependent manner. An association was found between the total phenolic content of Spirulina and SeNPs and their biological activities. Our results indicate that Spirulina and SeNPs with significant antimicrobial and antioxidant activities seem to be successful candidates for safe and reliable medical applications.     

红花桑寄生叶提取物的抗氧化活性及酚类物质分析

采用DPPH法、TEAC法、FRAP法对红花桑寄生叶不同溶剂提取物的抗氧化活性进行体外评价,并测定其总酚、总黄酮含量。结果表明,溶剂种类对红花桑寄生叶提取物的得率、总酚、总黄酮及抗氧化活性影响显著。在3种评价方法中,不同溶剂提取物的抗氧化活性均表现出不同程度的量效依赖关系。3种溶剂提取物的抗氧化活性强弱依次为丙酮提取物 >甲醇提取物 >水提取物,其中80%丙酮提取物(总酚含量最高,达276.83mg/g)抗氧化活性最强,清除DPPH自由基能力EC₅₀值为0.247,FRAP值(FeSO₄ mmol/100g)为115.81,浓度为1.0mg/ml时,TEAC值为2.04。     

野生桑树桑黄和杨树桑黄化学成分及抗氧化活性比较

比较了野生桑树桑黄和杨树桑黄子实体乙醇提取物抗氧化活性和化学成分的差异,探讨其高抗氧化能力的来源。以二苯基三硝基苯肼自由基（DPPH）清除率、超氧阴离子清除率和β-胡萝卜素漂白实验作为抗氧化的指标比较其抗氧化活性差异。结果表明,桑树桑黄和杨树桑黄均具有很强的抗氧化活性,杨树桑黄的抗氧化活性显著强于桑树桑黄;杨树桑黄醇提物的总黄酮和总多酚含量均高于桑树桑黄醇提物。通过超高效液相色谱串联三重四级杆飞行时间质谱法（UPLC-Triple-TOF-MS）比较了桑树桑黄和杨树桑黄乙醇提取物成分差异,桑树桑黄中共鉴定出19种多酚类物质,杨树桑黄中除了与桑树桑黄中相同的19种物质,还另外分析出3种多酚类物质。     

Polyphenols of Rosa L. leaves extracts and their radical scavenging activity

Antioxidant potential of Rosa L. leaves methanolic extracts was evaluated in vitro using a spectrophotometric method based on measuring the radical scavenging effect on 2,2-di-phenyl-1-picrylhydrazyl (DPPH) radicals. The contents of ellagic acid, quercetin and kaempferol in the extracts from leaves of seventeen rose species were determined using SPE-RP-HPLC methods. Additionally, total phenolic content was determined spectrophotometrically according to the Folin-Ciocalteu procedure and calculated as gallic acid equivalents (GAE). Remarkable high antioxidant activity and high total phenolic content (5.7% < GAE < 15.2%), large ellagic acid (EA) content from 9.37 to 19.42 mg/g of dry weight, a quercetin content ranging from 3.68 to 15.81 mg/g of dry weight and kaempferol content from 1.25 to 9.41mg/g of dry weight were found in rose leaves. Significant correlation between EA (r(2) = 0.6131), quercetin (r(2) = 0.5158), total phenolic content (r(2)= 0.8485) and antioxidant activity was observed. Basing on the studies conducted one may assume that the extracts of rose leaves are a rich source of natural antioxidants and could be used to prevent free-radical-induced deleterious effects.     

Antioxidant activity and cytotoxicity of methanol extracts from aerial parts of Korean salad plants

The aim of this investigation was to determine the content of total phenolics, antioxidant activity and cytotoxicity of methanol extracts from the aerial parts of 11 Korean medicinal salad plants. The highest total phenolic content of the methanol extracts was found in Aster scaber (17.1 mg 100 g(-1)), followed by Ixeris dentate (16.4 mg 100 g(-1)), Aster yomena (12.0 mg 100 g(-1)) and Sedum sarmentosum (9.1 mg 100 g(-1)) of FW. Methanol extracts of Ixeris dentate and Aster scaber at 50 microg mL(-1) exhibited the highest DPPH radical scavenging activity by 86.4 and 83.3%, respectively. It was registered a dose-dependent increase of DPPH free radical scavenging activity. Total phenolic content of the studied plant extracts was correlated with the DPPH radical scavenging activity. It was found by means of MTT assay, that cytotoxicity of the methanol extracts was the highest against HCT-116. Methanol extracts from Petasites japonicus (IC(50)<25.0 microg mL(-1)) showed the highest activity against HCT-116, following by Angelica gigas (34.75 microg mL(-1)), Erythronium japonicum (44.06 microg mL(-1)), and Aster scaber (54.87 microg mL(-1)). In conclusion, the studied salad plants have high total phenolics content and high antioxidant activity. These plants dose-dependently increased DPPH free radical scavenging activity. The total phenolics level was highly correlated with the free radical scavenging activity. Most of the studied salad plants have potent cytotoxicity activity. The results of this investigation suggest that the extracts of studied salad plants could be an addition to basic medicine for some diseases.     

Antioxidant activity of wheat extracts as affected by in vitro digestion

Phenolic compounds from soft wheat and its milling fractions were extracted and their in vitro antioxidant activity evaluated. Non-hydrolyzed extracts were prepared by extracting phenolics into distilled deionized water. To make hydrolyzed extracts samples were first subjected to pH adjustments in order to simulate gastrointestinal pH conditions. Total phenolic content (TPC) was determined using Folin-Ciocalteu's procedure. Total antioxidant activity (TAA) was determined using Trolox equivalents antioxidant capacity (TEAC) assay and expressed as Trolox equivalents (TE). Antioxidant activity of wheat extracts was determined using the procedures of inhibition of beta-carotene bleaching, scavenging of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and inhibition of oxidation of human low density lipoprotein (LDL) cholesterol. The TPC and TAA of wheat extracts tested were significantly increased following hydrolysis. Similarly, the antioxidant activity, as determined by different procedures, was considerably increased when the samples were subjected to simulated digestion conditions.     

橄榄果渣乙醇提取物成分分析及抗氧化和抑菌性能研究

橄榄果渣中生物活性成分丰富。本文主要研究橄榄果渣提取物成分及其对灰葡萄孢的抑菌性能。首先以橄榄果渣为原料,采用加热回流法,分别以H₂O、50%乙醇、70%乙醇和90%乙醇为提取剂,得到四种提取物并采用HPLC和GC-MS对提取物进行成分分析。其次测定了提取物的总酚含量、抗氧化性和对灰葡萄孢的抑菌性能。研究表明,90%乙醇提取物的酚类含量较高,抗氧化水平优良,并且对灰葡萄孢有明显的抑制作用。该研究为橄榄果渣活性成分在抑菌性能方面的研究提供了一定的理论依据。     

Bioactive berry compounds—novel tools against human pathogens

Berry fruits are rich sources of bioactive compounds, such as phenolics and organic acids, which have antimicrobial activities against human pathogens. Among different berries and berry phenolics, cranberry, cloudberry, raspberry, strawberry and bilberry especially possess clear antimicrobial effects against, e.g. Salmonella and Staphylococcus. Complex phenolic polymers, like ellagitannins, are strong antibacterial agents present in cloudberry and raspberry. Several mechanisms of action in the growth inhibition of bacteria are involved, such as destabilisation of cytoplasmic membrane, permeabilisation of plasma membrane, inhibition of extracellular microbial enzymes, direct actions on microbial metabolism and deprivation of the substrates required for microbial growth. Antimicrobial activity of berries may also be related to antiadherence of bacteria to epithelial cells, which is a prerequisite for colonisation and infection of many pathogens. Antimicrobial berry compounds may have important applications in the future as natural antimicrobial agents for food industry as well as for medicine. Some of the novel approaches are discussed.     

Extraction of Functional Compounds from Tarragon (Artemisia dracunculus L.) by Deep Eutectic Solvents at Different Properties

In this study, it was aimed to examine the capacity of deep eutectic solvents (DESs) with different contents to extract bioactive compounds from tarragon (Artemisia dracunculus L.) plant. For this reason, the total phenolic-flavonoid content, total proanthocyanidin content and antioxidant/antimicrobial activities of the prepared DES extracts were investigated, as well as the individual phenolic and individual amino acid profiles. According to the results, DES10 had the highest efficiency in terms of its capacity to extract individual phenolics (approximately 59 mg/100 g) and individual amino acids (approximately 2500 mg/kg), and also gave a higher yield compared to ethanol (approximately 44 mg/100 g for individual phenolics and about 19810 mg/kg for individual amino acids) and methanol (approximately 58 mg/100 g for individual phenolics and approximately 21430 mg/kg for individual amino acids). However, the total phenolic content, total flavonoid content and antioxidant activity values of DES extracts were determined between 59.09–77.50 mg GAE/100 g, 28.68–45.55 mg GAE/100 g and 42.96–146.86 mg TE/100 g, respectively. Therefore, it can be recommended to use these green solvents, which are known as environmentally friendly, as an alternative to organic solvents in the process of preparing extracts of this important medicinal plant in different areas.     

Screening of the antioxidative properties and total phenolic contents of three endemic Tanacetum subspecies from Turkish flora

Methanolic extracts of three different Tanacetum subspecies [Tanacetum densum (Lab.) Schultz Bip. subsp. sivasicum Hub-Mor and Grierson, Tanacetum densum (Lab.) Schultz Bip. subsp. eginense Heywood and Tanacetum densum (Lab.) Schultz Bip. subsp. amani Heywood] which are endemic to Turkish flora were screened for their possible antioxidant activities by two complementary test systems namely DPPH free radical scavenging and beta-carotene/linoleic acid. In DPPH system, the most active plant was T. densum subsp. amani with an IC(50) value of 69.30+/-0.37 microg/ml. On the other hand, T. densum subsp. sivasicum exerted greater antioxidant activity than those of other subspecies in beta-carotene/linoleic acid system (79.10%+/-1.83). Antioxidant activities of BHT, curcumine and ascorbic acid were also determined as positive controls in parallel experiments. Total phenolic constituents of the extracts of Tanacetum subspecies were performed employing the literature methods involving Folin-Ciocalteu reagent and gallic acid as standard. The amount of total phenolics was highest in subsp. sivasicum (162.33+/-3.57 microg/mg), followed by subsp. amani (158.44+/-2.17 microg/mg). Especially, a positive correlation was observed between total phenolic content and antioxidant activity of the extracts.