[Show abstract][Hide abstract] ABSTRACT: The inhibitory activity of an angiotensin I-converting enzyme (ACE), a key regulatory enzyme of blood pressure from the fermented anchovy sauce, was evaluated, and ACE inhibitory peptides were purified. The ACE activity significantly increased with an increase in salt concentration. In addition, the ACE inhibitory activity of the fermented anchovy sauce containing high salt content (25 %) significantly increased with an increase in fermentation time. The maximum activity (96 %) was reached after 15 months of fermentation. Four ACE inhibitors [Pro-Lys (PK), Gly-Cys-Lys (GCK), Asn- His-Pro (NHP), and Asp-Gly-Gly-Pro (DGGP)] in the fermented anchovy sauce were purified through various chromatographic techniques and identified by electrospray ionization tandem mass spectrometer analysis. Four newly identified peptides were synthesized and analyzed for ACE inhibitory activity in order to confirm that the purified peptides were actually ACE inhibitors. The IC50 values for ACE inhibitory activities of synthesized peptides DGGP, GCK, NHP, and PK were 164, 178, 1172, and 4092 μM, respectively.
[Show abstract][Hide abstract] ABSTRACT: We investigated the antihypertensive effects of Artemisia scoparia (AS) in spontaneously hypertensive rats (SHR). The rats were fed diets containing 2% (w/w) hot water extracts of AS aerial parts for 6 weeks. The AS group had significantly lower systolic and diastolic blood pressure levels than the control group. The AS group also had lower angiotensin I converting enzyme (ACE) activity and angiotensin II content in serum compared to the control group. The AS group showed higher vascular endothelial growth factor and lower ras homolog gene family member A expression levels in kidney compared to the control group. The AS group had significantly lower levels of plasma lipid oxidation and protein carbonyls than the control group. One new and six known compounds were isolated from AS by guided purification. The new compound was determined to be 4'-O-β-D-glucopyranoyl (E)-4-hydroxy-3-methylbut-2-enyl benzoate, based on its nuclear magnetic resonance and electrospray ionization-mass spectroscopy data.
[Show abstract][Hide abstract] ABSTRACT: Conventionally (CG), semi-organically (low chemical, LCG) and organically grown (OG) kiwi fruit was stored at 0° C for 24 weeks. Firmness gradually decreased with storage time regardless of cultivation type, and the rate of softening was slightly higher in OG fruits than those of CG or LCG fruits. Soluble solids content increased with storage time, while acidity decreased in all fruits. Reducing sugar content considerably increased until 12 weeks after storage, while starch content significantly decreased. Rate of fruit decay abruptly increased at middle stage of storage in OG fruits. In 24 weeks after storage, the rate reached 35 %. Most fruits decayed with infection of Botritis cineria regardless of cultivation type. Respiration and ethylene contents have peaked at middle stage of storage, and those contents were slightly higher in OG than in CG and LCG fruits. Shelf life of kiwi fruit considerably decreased in OG fruits by increasing fruit decay and softening during storage. Fluorescence measurements showed a difference between the investigated samples, especially in their antioxidant status. The used statistical evaluation confirmed the obtained results. The quenching properties of these samples are correlated with their antioxidant properties and the amount of polyphenols and the decrease in fluorescence intensity.
Full-text · Article · Nov 2015 · European Food Research and Technology
[Show abstract][Hide abstract] ABSTRACT: Bioactive compounds (polyphenols and ascorbic acid) and dietary fibers, and related antioxidant activities of commonly consumed apples, bananas, peaches, pears, blond and red grapefruits, pomelos, oranges, lemons, red plums, white grapes, mango, persimmon and strawberries grown in the same geographical and climatic conditions were compared with standard kiwi fruit. The presence of polyphenols was studied by Fourier transform infrared (FT-IR) spectroscopy. The contribution of dietary fibers to antioxidant activity of the fruits was minimal (R2 from 0.3078 to 0.3626), of the ascorbic acid – moderate (R2 from 0.6402 to 0.6734) and of total polyphenols - decisive (R2 from 0.9792 to 0.9827). It was found that strawberries and kiwi fruits have the highest phenolic contents and their antioxidant activities following by red plum > mango > white grapes ≥ persimmon > apples > pears ≥ red grapefruit > lemons = oranges = blond grapefruits ≥ pomelos > bananas > peaches (P < 0.05). FTIR spectroscopy and radical scavenging assays are suitable for bioactivity determination of these fruits. In order to receive best results for human consumption, a combination of these fruits has to be included in the everyday diet. The methods used are applicable for bioactivity determination in food analysis in general.
[Show abstract][Hide abstract] ABSTRACT: Spectrophotometric assays (Folin–Ciocalteu, ferric-reducing/antioxidant power, cupric-reducing antioxidant capacity, and β-carotene linoleate model system) have been used to evaluate the total phenolics and flavonoids in kiwi fruit cultivars in ethanol and water extracts. Fluorescent and infrared measurements were correlated with the obtained spectroscopic data. It was found that the contents of the bioactive compounds and the level of antioxidant activity in different extracts differ significantly (p < 0.05). Bioactive compounds and antioxidant activities were significantly higher in two kiwi fruit cultivars (“Bidan” and “SKK12”) than in other studied samples. To our knowledge this is the first report showing the differences and similarities in new kiwi fruit cultivars, using these spectroscopic data. The ethanol extracts of these cultivars exhibited high binding properties with human serum albumin compared with rutin. In conclusion, the applied analytical methods showed the main compounds in the kiwi fruit cultivars and can be used for determination of these compounds in any plants. The relative knowledge would contribute to the pharmaceutical development and clinical application of extracts of kiwi fruit extracts.
[Show abstract][Hide abstract] ABSTRACT: Many polyphenols bind proteins, therefore our research was focused on the potential of protein binding to polyphenols of investigated fruits and their health-related effects. The contents of polyphenols and related antioxidant activities of traditional, citrus and exotic fruits were compared. The presence of polyphenols (flavonoids and phenolic acids) in the investigated samples and their interaction with human serum albumin (HSA) was studied by HPLC, Fourier Transform Infrared (FT-IR) and three dimensional fluorescence spectroscopy (3D-FL). The highest levels of polyphenols, antioxidant and binding capacities were found in red and blond grapefruits (citrus group), followed by strawberries and apples (traditional group) and mangosteen and kiwi fruit (exotic fruit), which also contained the highest levels of protocatechuic, p-coumaric, ferulic acids and quercetin. In conclusion, for the first time, the interaction of the polyphenols with human serum albumin was evaluated by fluorometry/FTIR. The obtained binding profiles allowed the comparison of three different groups of fruits. A mixture of these fruits can be recommended for consumption.
Full-text · Article · Aug 2015 · Food Research International
[Show abstract][Hide abstract] ABSTRACT: The main aim of this investigation was to characterize new kiwi fruit cultivars after cold storage treatment and to determine the similarities and differences between them, using spectroscopic methods. The chemometric comparison of kiwi fruit cultivars based on physicochemical indices during cold storage was carried out. All kiwi fruit cultivars showed a high level of correlation between the contents of phenolic compounds (polyphenols, tannins and flavonoids) and their antioxidant capacities. The interactions of soluble polyphenols of different kiwi fruit cultivars with human serum albumin (HSA) were investigated by fluorescence. The obtained statistical and fluorescence results allow to classify the investigated kiwi fruit cultivars according to their properties. The antioxidant properties of different cultivars monitored by β-carotene assay showed that the highest percentage of antioxidant activity (%AA) at the end of the cold storage was detected for ‘SKK-12’ (27.61±2.44) %AA with the lowest shelf life (8 weeks) and the lowest was found for ‘Hayward’ variety (8.33±0.74) %AA with the highest shelf life (24 weeks). The averaged amount of polyphenols in ‘Bidan’ and ‘SKK-12’ 13.97±1.95 mg GAE/g was much higher than in other cultivars 3.93±3.26 mg GAE/g, without respect on time of cold storage. The HSA-binding capacities of these cultivars were the highest and correlated with their antioxidant capacities. To our knowledge this is the first report showing differences and similarities in new kiwi fruit cultivars, using spectroscopic techniques. The fact that fluorescence spectral methods are applied as a powerful tool to show the photophysical properties of intrinsic fluorophores in protein molecules in the presence of fruit extracts is important in this study. In conclusion, the obtained knowledge would contribute to the pharmaceutical development and clinical application of kiwi fruit extracts.
Full-text · Article · Apr 2015 · Journal of Luminescence
[Show abstract][Hide abstract] ABSTRACT: Hizikia fusiforme, Capsosiphon fulvescens, Undaria pinnatifida sporophyll, and Undaria pinnatifida blade extracts were evaluated for in vitro antioxidant and antihyperglycemic activities. Seaweed extracts contained high levels of phenolic compounds (12.44 to 39.01 mg of gallic acid equivalents/g of extract) and exhibited multiple antioxidant activities. Extracts showed weak inhibition of α-amylase. However, all extracts showed pronounced inhibition of α-glucosidase with EC50 values from 2.56 to 18.81 mg/mL. U. pinnatifida sporophyll and U. pinnatifida blade extracts both contained protocatechuic and syringic acids. p-Coumaric and ferulic acids were detected only in the H. fusiforme extract. Caffeic acid and epicatechin were the dominant phenoilc acids found in C. fulvescens extracts. A basis for further research is provided to establish the capability of seaweed extracts as hypoglycemic agents or functional food ingredients.
Full-text · Article · Dec 2014 · Food science and biotechnology
[Show abstract][Hide abstract] ABSTRACT: We have investigated discriminating power of the elements in edible sea salts using Laser Induced Breakdown Spectroscopy (LIBS). For ten different sea salts from South Korea, China, Japan, France, Mexico and New Zealand, LIBS spectra were recorded in the spectral range between 190 and 1040 nm, identifying the presence of Na, Cl, K, Ca, Mg, Li, Sr, Al, Si, Ti, Fe, C, O, N, and H. Intensity correlation analysis of the observed emission lines provided a valuable insight into the discriminating power of the different elements in the sea salts. The correlation analysis suggests that the elements with independent discrimination power can be categorized into three groups; those that represent dissolved ions in sea water (K, Li, and Mg), those that are associated with calcified particles (Ca and Sr), and those that present in soils contained in the sea salts (Al, Si, Ti, and Fe). Classification models using a few emission lines selected based on the results from intensity correlation analysis and full broadband LIBS spectra were developed based on Principal Component Analysis (PCA) and Partial Least Squares-Discriminant Analysis (PLS-DA) and their performances were compared. Our results indicate that effective combination of a few emission lines can provide a dependable model for discriminating the edible sea salts and the performance is not much degraded from that based on the full broadband spectra. This can be rationalized by the intensity correlation results.
No preview · Article · Nov 2014 · Spectrochimica Acta Part B Atomic Spectroscopy
[Show abstract][Hide abstract] ABSTRACT: Certain solar sea salts have a high content of essential minerals other than NaCl. The effects of minerals in sea salts on oxidative stress in rats were investigated. Mineral-rich salt (MRS) and mineral-deficient salt (MDS) did not scavenge DPPH radicals. When MRS and MDS (equivalent to 1.8 g NaCl/kg/day) and a saline control were orally administered to rats for 7 weeks, MRS group rats showed lower levels of plasma lipid oxidation than MDS group rats. MRS group rats exhibited significantly lower levels of protein carbonyls and 8-hydroxy-2′-deoxyguanosine in the liver than MDS group rats. MRS group rats showed lower protein expression of NF-κB p65 in adipose tissue than MDS group rats. Intake of MRS may generate less oxidative stress than intake of MDS.
Full-text · Article · Jun 2014 · Food science and biotechnology
[Show abstract][Hide abstract] ABSTRACT: Changes in phenylpropanoic acid [caffeic, dihydrocaffeic, ferulic, and dihydroferulic acids] and flavonol [quercetin, kaempferol, and isorhamnetin] contents at different growth stages of glasswort (Salicornia herbacea L.) were investigated. Phenylpropanoic acids and flavonols in glasswort were liberated by acid and alkaline hydrolyses, respectively, and their contents before and after hydrolysis were determined by simultaneous octadecylsilane-HPLC. Phenylpropanoic acids and flavonols mostly existed as bound forms in glasswort. Among four phenylpropanoic acids, ferulic acid showed the highest content (ether form, 62.1–105.7 mg/100 g dry wt.; ester form, 241.0–456.6 mg/100 g dry wt.). Kaempferol was the dominant etherified flavonol (108.1–247.6 mg/100 g dry wt.). The total contents of phenylpropanoic acids and flavonols were relatively higher at the mature stage (August and September) when compared to those at the early growth stage. These results provide useful information for phenylpropanoic acid and flavonol content in glassworts grown June to September.
Full-text · Article · Jun 2014 · Food science and biotechnology
[Show abstract][Hide abstract] ABSTRACT: We evaluated preventive effects of Suaeda japonica (SJ) and Spergularia marina Griseb (SMG) on the insulin resistance in Otsuka Long-Evans Tokushima Fatty (OLETF) rats. The 10-week old OLETF rats were fed diets containing 3% (w/w) SJ and SMG for 18 weeks. Fasting blood glucose levels in SJ and SMG groups, measured using the oral glucose tolerance test, were lower than that of the control rats. The SMG group showed significantly lower levels of insulin, glycated hemoglobin, triglyceride, and total cholesterol than the control group. In addition, these levels were relatively lower in the SJ group than those in the control rats. The SJ and SMG groups had relatively lower protein levels of nuclear factor-kappa B (NF-) p65 in adipose tissue and serine phosphorylated insulin receptor substrate 1 (IRS-1) in skeletal muscle than the control group. These results suggest that SJ and SMG prevent insulin resistance and SMG in particular reduces blood triglyceride and total cholesterol levels.
Preview · Article · Feb 2014 · Korean Journal of Food Science and Technology
[Show abstract][Hide abstract] ABSTRACT: Various kiwi fruit cultivars, bred in Korea, were kept in cold storage for 8–24 weeks for possible increase of their quality. Firmness significantly decreased at initial time in all cultivars. The rate of softening was the slowest in “Hayward”, followed by “Hort 16A”, “Haenam”, “Daheung”, “Bidan”, “Hwamei”, and “SKK 12”. Sensory value increased with decreasing of firmness. Soluble solids content increased with storage time while acidity gradually decreased. Reducing sugar content significantly increased at early stage of storage with decreasing of starch content. There was no difference of these indices among cultivars. Respiration rate increased with time and then decreased during cold storage. Peaks time was different between cultivars, therefore we represented trend of respiration changes in all cultivars. All kiwi fruit cultivars showed climacteric patterns in respiration. The rate of softening was closely related to the degree and peak time of ethylene production. The highest shelf life was in “Hayward” and “Hort 16 A” (24 weeks) and the lowest in “SKK-12” (8 weeks). All investigated cultivars bred in Korea showed much lower shelf life than “Hayward” and “Hort 16 A”. Radical scavenging assays and chemometrical processing were used for the determination of bioactive kiwi fruits’ compounds. Polyphenols in water extracts were the highest in “SKK-12” and the lowest in “Hayward” [16.34 ± 1.11 and 5.30 ± 0.45 mg gallic acid equivalents (GAE)/g dry weight (DW)]. The values of β-carotene activities (27.61 ± 2.44% and 8.33 ± 0.74%) and Ferric-reducing/antioxidant power [(FRAP, Trolox equivalent (TE)/g DW) 24.55 ± 2.01 and 7.12 ± 0.41] were the highest in “SKK-12”. The lowest results were estimated in “Hayward”. All kiwi fruit cultivars showed a high level of correlation between the contents of phenolic compounds (polyphenols, tannins, and flavonoids) and their antioxidant values. We presented for the first time the results of shelf life of new cultivars bred in Korea and their comparison with the widely studied ones, such as “Hayward” and “Hort 16A”. Cold storage extended shelf life in kiwi fruit without any chilling injury or color change. According to the antioxidant properties of different cultivars, the highest was in “SKK-12” with the lowest shelf life and the lowest was in “Hayward” with the highest shelf life.
Full-text · Article · Feb 2014 · CyTA - Journal of Food
[Show abstract][Hide abstract] ABSTRACT: The ethyl acetate (EtOAc) and chloroform (CHCl3) layers obtained after solvent fractionation of a H2O suspension of powdered Suaeda japonica juice showed higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicalscavenging activity than other layers. Eighteen compounds were purified and isolated from the EtOAc and CHCl3 layers using chromatography following DPPH radicalscavenging assay. These compounds were identified as dihydroferulic acid methyl ester (1), pyrocatechol (2), syringic acid (3), apigenin (4), isorhamnetin (5), kaempferol (6), dihydroferulic acid (7), vanillic acid (8), 4-hydroxybenzoic acid (9), acetophlorglucine (10), homoeriodictyol (11), naringenin (12), quercetin (13), luteolin (14), 9-epiblumenol C (15), scopoletin (16), dihydroisorhamnetin (17), and chrysoeriol (18). The structures of these compounds were determined by mass spectrometry and nuclear magnetic resonance analyses. The isolated compounds were newly identified from this plant. Compounds 13 and 14 exhibited higher DPPH radical-scavenging activity and an inhibition effect against ferric ion-induced lipid oxidation of rat liver when compared to α-tocopherol and other compounds.
Full-text · Article · Dec 2013 · Food science and biotechnology
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to evaluate the antioxidant and binding effects of gooseberry, a less-studied berry, and to compare with blueberry and cranberry in the model of interaction with human serum albumin (HSA). The relationship between the scavenging properties of dietary polyphenols of the selected berries and their affinities for HSA were investigated by fluorescence analysis. In order to perform the extraction and identification of the antioxidants present in the samples, different types of extraction solvents were used, such as water, ethyl acetate, and diethyl ether. The polyphenols, tannins, anthocyanins and ascorbic acid contents, and the total antioxidant capacities (TACs) of the berry extracts were assessed by using ESI–MS, FTIR, and radical scavenging assays. The contents of bioactive compounds and the levels of TACs in water extracts differed significantly and were the highest in water extracts in comparison with other extracts in all the investigated berries (P < 0.05). Gooseberry water extracts contained: polyphenols (mg GAE/g DW)—5.37 ± 0.6, tannins (mg CE/g DW)—0.71 ± 0.2, anthocyanins (mg CGE/g DW)—12.0 ± 1.2, ascorbic acid (mg AA/g DW)—5.15 ± 0.5, and TACs (μMTE/g DW) by ABTS and FRAP assays were 15.53 ± 1.6 and 6.51 ± 0.7, respectively. In conclusion, the bioactivity of gooseberry was lower than blueberries and cranberries. The antioxidant and binding properties of gooseberries in comparison with widely consumed blueberries and cranberries can be used as a new source for food supplementation.
Full-text · Article · Nov 2013 · European Food Research and Technology
[Show abstract][Hide abstract] ABSTRACT: Ethyl acetate (EtOAc) layer obtained after the solvent fractionation of hot water extracts from nutgall tree (Rhus javanica) stem bark showed higher α-glucosidase inhibition activity than other layers. A novel acetophenone glucoside (4) and six known phenolic compounds were isolated from the EtOAc layer. The structure of 4 was determined to be 3,4,5-trihydroxyacetophenone 4-O-β-d-glucopyranoside. The six known compounds were identified as gallic acid (1), 5-methylresorcinol (2), methylgallate (3), 3-hydroxy-5-methylphenol 1-O-β-d-(6′-galloyl)glucopyranoside (5), scopoletin (6), and phlorizin (7). Their chemical structures were determined by electrospray ionization mass spectrometry and nuclear magnetic resonance analyses. Compound 5 was newly identified from this plant. Compounds 6 and 7 showed significantly higher α-glucosidase inhibition activity than other compounds.
Full-text · Article · Oct 2013 · Journal of the Korean Society for Applied Biological Chemistry
[Show abstract][Hide abstract] ABSTRACT: Fluorometry, ESI-MS, FTIR, and radical scavenging assays were used for characterization of bioactive compounds and the levels of their antioxidant activities. Polyphenols, flavonoids, anthocyanins, and ascorbic acid and the level of antioxidant activity of water extracts of “Murtilla-like” [Myrteola nummularia (Poiret) Berg.], and other widely consumed berries were determined and compared. The contents of bioactive compounds and the levels of antioxidant activities in water extracts differed significantly in the investigated samples (P < 0.05). “Murtilla-like” extracts contained polyphenols (mg GAE/g)—19.13 ± 0.9, flavonoids, (mg CE/g)—3.12 ± 0.1, anthocyanins (mg CGE/g)—120.23 ± 5.4, and ascorbic acid (mg/g)—2.20 ± 0.1; and antioxidant activities (μmolTE/g) by ABTS and CUPRAC assays were 200.55 ± 8.7 and CUPRAC 116.76 ± 5.7, respectively. Chemometrical processing was done on the basis of kinetic data of two variables (concentration and reaction time) by DPPH scavenging reaction. Polyphenol content highly correlated with antioxidant capacity (R2 from 0.96 to 0.83). The quenching properties of berries were studied by the interaction of water polyphenol extracts with a small protein such as BSA by 3-D fluorescence and FTIR spectroscopy. These methods were used as additional tools for the characterization of polyphenols. Wild-grown non-investigated berries were compared with widely consumed ones, using their bioactive composition, antioxidant activities, and antiproliferative and fluorescence properties. In conclusion, the antioxidant properties of “Murtilla-like” can be used as a new source for consumption. The bioactivity of “Murtilla-like” is comparable with blueberries and raspberries. 3-D fluorescence and FTIR spectroscopy can be applied as additional analytical tools for rapid estimation of the quality of food products.