Folin Reagent Research Articles

Functional Properties and Sensory Quality of Kombucha Analogs Based on Herbal Infusions.

Traditionally, kombucha is produced by the fermentation of black or green tea infusions with the use of SCOBY (Symbiotic Culture of Bacteria and Yeasts). However, SCOBY exhibits the ability to ferment other substrates as well, which can be used to create novel products with new sensory and health-promoting properties. This paper investigates the antioxidant activity, chemical composition, and sensory properties of mint, nettle, and blackcurrant leaf-based kombucha analogs. It has been demonstrated that the fermentation process with SCOBY significantly influenced (p ≤ 0.05) sugar, organic acids, and mineral contents, with the increase in iron, magnesium, and calcium amounts in all tested herbal kombucha. The study shows that the type of herb infusion has a significant influence on the parameters associated with antioxidant potential. The fermentation with SCOBY resulted in an increase in antioxidant activity as measured by the superoxide anion radical (O2•-) inhibition of all three tested herbal infusions, with the greatest changes observed in nettle kombucha. Herbal kombucha was characterized by significantly increased total phenolic content as determined by Folin's reagent and a changed phenolic compound profile by LC-MS/MS (liquid chromatography with tandem mass spectrometry) in comparison to nonfermented infusions. Very high sensory scores were achieved for fermented mint and blackcurrant-based kombucha.

Self-ratiometric fluorescence approach based on room-temperature instantaneously synthesized carbon dots from Folin's reagent and ethanolamine for determination of nitroxinil in water, milk, and food samples

BackgroundNitroxinil has been used extensively to treat parasitic worms, mainly Fasciola, in food-producing cattle and sheep. The reported methods for nitroxinil analysis included expensive instrumentation, the need for skilled operators, and tedious procedures. Fluorimetry is one of the fastest and simplest methods widely used; hence, we aimed to develop a simple, cost-effective, and convenient fluorometric approach for the estimation of nitroxinil in various matrices. Compared with other detection methods, self-ratiometric fluorescent probes are considered a promising approach for the detection of analytes as their detection accuracy overcomes traditional fluorescence sensing probe in that it is not affected by the probe concentration, solution polarity, instrument parameters, and other factors. In this research, room temperature instantaneously synthesized carbon dots were used as a sensitive and selective self-ratiometric probe for the determination of the veterinary medicine nitroxinil in various matrices. ResultsA room-temperature synthesized quinone-ethanolamine carbon dots (RTQECDs) was fabricated using the instantaneous reaction of sodium 1,2-naphthoquinone-4-sulfonate (Folin's) with ethanolamine, without any energy/catalyzing reagents, for the first time. The prepared carbon dots show green-blue fluorescence at 450 nm upon exposure to UV light at 365 nm with a quantum yield of 26.6 %. Upon interaction with nitroxinil, the fluorescence intensity of RTQECDs at 450 nm is quenched and shifted to a longer wavelength at 475 nm. Meanwhile, the fluorescence of RTQECDs at 400 nm (absorbance maxima of nitroxinil) was more extremely quenched under the same conditions. Taking this in hand, a new RTQECDs self-ratiometric probe was developed for the determination of nitroxinil using the decrease in peaks at 450 nm and 400 nm and the shift of the fluorescence maxima to 475 nm as built-in reference peaks. The probe showed a quantitative increase in signal output of F475/F400 in the range of 0.10–30.0 μg/mL nitroxinil with a limit of detection of 30.0 ppb. The nitroxinil-sensing mechanism using RTQECDs is mainly ascribed to the partial secondary blue-type inner filter effect (IFE). The designed study was applied for the estimation of nitroxinil in veterinary dosage forms (recoveries; 99.78 %–100.35 %), river water (recoveries; 98.55 %–101.53 %), and food products, including meat, liver, kidney, and milk (recoveries; 97.60 %–104.25 %). SignificanceThe novelty of our work includes the immediate synthesis of the sensing probe at room temperature, as well as its use as a self-ratiometric fluorescence probe for the determination of nitroxinil in veterinary samples, river water, and food products with excellent sensitivity down to 30.0 ppb. RTQECDs own the highest response and selectivity to nitroxinil compared with cations, anions, as well as other co-administered drugs, including cefotaxime and ivermectin.

Extraction and Characterization of Natural Antioxidants from Olive Leaves Powder

Olive (Olea europaea L.) leaves, which contain large amounts of phenols, are a common byproduct in the production of olive oil. When improperly processed, the by-products produced by the olive diligence can impairment the environment. Its leaves, which are made when olive trees are pruned and harvested and it is expected that foliage make up twenty five percent of pruning remains overall. These byproducts cost manufacturers money and have serious environmental implications. So, like other agronomical production wastes, partial reuse is something that should be pursued. These leftovers have a high concentration of beneficial chemicals, if isolated, may be used in food, cosmetics and nutraceutical sectors. Objectives: To extract the bioactive compounds polyphenols and flavonoids in 70% ethanol extract and its antioxidant activity was done. Methods: The polyphenols were quantified by Folin reagent and flavonoids by aluminum chloride methods respectively and the natural antioxidants were estimated by using free radical scavenging DPPH assay. Results: It was discovered that the 70% ethanol extract's total polyphenolic content was 65.50 ± 1.42 (mg GAE/g) and its total flavonoids were 11.85 ± 0.60 (mg QE/g). In 70% ethanol extract the % inhibition (DPPH) was 42.82±3.20-88.40±5.18 while BHT has the % inhibition (DPPH) 30.4 ± 2.50-80.50 ± 4.68 at concentration 0.1-0.5 mg/ml. Conclusions: The results indicating a noteworthy antioxidant activity in terms of radical scavenging activity. These results also wrapped up that the olive industry waste may be reutilized as a natural source of antioxidants in various sectors.

Biological potential of polysaccharides extracted from Nostoc colonies for film production - Physical and biological properties.

Cyanobacteria of the Nostoc genus secrete a number of biologically active compounds, including polysaccharides, which may exhibit antioxidant, antimicrobial, anticancer, and anti-inflammatory properties. The aim of the study was to investigate the biological properties of Nostoc polysaccharides (NPs) (antioxidative and antimicrobial) and the possibility of using NPs addition in the production of biofoils. Our results allow to indicate that NPs were compatible with the used biopolymer matrix (furcellaran and chitosan) and showed antioxidant properties. The tested polysaccharide extracts (0.14%) exhibited the ability to neutralize free radicals - 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) at a level of 4.46% and 10.14%, respectively. NP extracts demonstrated reducing properties of 15.35 and 30.07mg Trolox equivalents (FRAP and CUPRAC methods, respectively) and 2.64mg chlorogenic acid equivalents (tested with Folin's reagent). NP extracts showed: a growth-stimulating effect (Escherichia coli, Staphylococcus aureus, and Saccharomyces cerevisiae), no effect (Penicillum sp.), or a slight inhibitory effect (Streptomyces sp.) on the tested microorganisms. The enrichment of the film with NPs influenced the physic-chemical properties of the obtained biofoils. The addition of polysaccharides to furcellaran and chitosan films decreased their water solubility (by approximately 40% and 9%, respectively, compared to the control) and, at the same time increased, their water absorption.

A Comparative Study on Ascorbic Acid Concentration, Total Phenol, and Flavonoid Content in Citrus Species Grown in a Different Region of Western Nepal.

Different genetic and environmental factors like altitude, temperature, light radiation, etc. affect the production of phytoconstituents like ascorbic acid, phenol, flavonoid, tannin, etc. So, it is necessary to evaluate phytoconstituents quantitatively and qualitatively because of their different medicinal values. This study is aimed at evaluating and comparing ascorbic acid concentration, total phenol, and flavonoid content in citrus species grown in different places in Western Nepal. For this, fruit collected from Lamjung and Nawalparasi was peeled, and collected juice was extracted with ethanol. Ascorbic acid was estimated using titration with dichlorophenolindophenol dye, and total phenol was estimated using Folin reagent; whereas, flavonoid content was determined by aluminum chloride colorimetric assay. The result showed the maximum ascorbic acid concentration in the fruit juice of Citrus maxima collected from Lamjung, i.e., 2.98 ± 0.161 mg/100 ml, and the least concentration was recorded on extract of Citrus limon collected from Nawalparasi, i.e., 1.005 ± 0.205 mg/100 ml. The total phenol content was comparatively higher in Citrus maxima and Citrus aurantifolia collected from Lamjung, i.e., 12.48 ± 0.40 mg GAE/gm, respectively. Flavonoid content was comparatively higher in Citrus maxima collected from Nawalparasi, i.e., 484.466 ± 3.055 mg QE/gm. This study showed a variation in the concentration of chemical constituents between different places in Western Nepal. This might be due to differences in climatic conditions, environmental factors, altitude, temperature, etc. This study helps to reflect the best-suited altitude for commercial cultivation of the citrus species as these phytochemicals have different medicinal values. Also, this study can help the food industry to use an alternative source of synthetic antioxidant such as ascorbic acid, phenol, and flavonoid. And local people will economically benefit by the commercial cultivation of citrus fruits.

Total Phenol and Antioxidant Activity of Ethanol Extract and Water Extract from Claw Uncariaa gambir Roxb

Uncaria gambier Roxb is a plant from the Rubiaceae family, belongs to the Bajakah group and has been used empirically in the treatment of various types of diseases in the community. Besides being one of the industrial plants and export commodities produced in Sumatra and Kalimantan, gambier leaves is also used frequently in Indonesia, both for the pharmaceutical and cosmetic industries. As a result, market demand both nationally and internationally have increased. The aim of this research are determination of antioxidant activity of ethanol extract and aqueous extract of gambir claw using 1,1-diphenil-2-picrylhydrazyl (DPPH) and determination of total phenol using Calcetau folin reagent. Gambier plant samples were taken in the forest area around the Tanjungpura University campus, the claws were separated and dried at room temperature, then powdered and extracted by maceration using 70% ethanol pa and aquadest, then the extract was concentrated until it was ready to be tested for antioxidant activity and determination of total phenol. The total phenolic ethanol extract and aqueous extract of gambir claw were 224.66 mg GAE/g extract (GEA : Gallic Acid Eqivalent) and 299.08 mg GAE/g extract, respectively, while the antioxidant potential (IC50) was 39.566 μg/mL and 65.140 μg/mL, and the IC50 for comparison of Vitamin C was 7.02 μg/mL.

English

The use of Grewia tenax and Albizia anthelmintica in treating different ailments is attracting significant attention as a primary health care option in Namibia. This study aims to document their ethnobotanical uses, phytochemical composition, antioxidant, and antibacterial activity against multidrug-resistant Streptococcus pneumonia, Klebsiella pneumonia, and Staphylococcus aureus. The ethnobotanical uses of G. tenax and A. anthelmintica in treating respiratory conditions were documented. Organic (ethyl acetate) and aqueous extracts were screened for phytochemical composition using the thin-layer chromatography method. The total phenol content was determined using the Folin and Ciocalteu reagent method. In vitro antioxidant activity was based on the scavenging activity of the stable 1, 1-diphenyl 2-picrylhyorazyl free radical. Antibacterial activity of extracts (200.0 µg/ml) and antibiotics was determined by the disc diffusion method. G. tenax and A. anthelmintica are commonly used to treat pneumonic symptoms. Steam inhalation and decoction are the most common methods used in preparing remedies. While alkaloid, flavonoid, and coumarins were detected in all extracts, organic extract of A. anthelmintica showed higher total phenol content of 28.5 ± 0. 5 mg GAE/g. G. tenax organic extract showed higher in-vitro antioxidant activity of 83.3±0.1%. The pathogens showed resistance to 10 µg of penicillin G, and Co-Trimoxazol, however, A. anthelmintica organic twig extracts inhibited the growth of the bacteria with average inhibition ranging between 17.5±0.6 - 20.7±0.6, mm and a minimum inhibitory concentration of 50.0 µg/mL. These findings are the first to report on the ethnomedicine of G. tenax and A. anthelmintica in Namibia and their effectiveness in killing pneumonia-causing bacteria. Key words: Phytochemical screening, total phenol content, antioxidant activity, antibacterial activity, pneumonia, antibiotic resistance, G. tenax, A. anthelmintica.

Effect of Lipopolysaccharide Extracted from Enterobacter cloacae on some Pathogenic Bacteria

A 106 different specimen were collected to isolate and diagnose some gram negative and gram-positive bacteria, as it was performed for the period from 15 August to 30 November 2019 from AL-Salam and Al-Khansaa educational hospitals in Mosul. Lipopolysaccharide (LPS) was extracted from Enterobacter cloacae by using the Methanol - Chloroform method. extract was diagnosed, using some biochemical tests such as the Molisch test to detect carbohydrate content and Folin reagent in order to determine proteins concentration, lipid solubility in organic solvent and Bio drop technique as well as to detect nucleic acid concentration. The extraction methods showed its efficiency with low protein and nucleic acids concentration in the extract. Lipopolysaccharide demonstrated its efficiency inhibiting microbial growth on all test isolates at concentrations 1100, 1000 µg ml while its lipopolysaccharide showed its inhibition of Proteus mirabilis at all concentrations used. LPS showed possibility used as inhibitory, antimicrobial growth

Determination of theoretical calculations by DFT method and investigation of antioxidant, antimicrobial properties of olive leaf extracts from different regions.

In this study, we studied samples of mature olive leaves from the districts of Incirli Ova within the province of Aydın and the district of Fethiye in Mugla/Turkey. Several processes were carried out on the olive leaves to use them in this study, including drying under different conditions, determination of moisture, extract output, overall determination of phenols, antioxidant activity determination and anti-microbial assays. The chemicals that were used in the study were Folin's reagent and gallic acid for total phenolic assays, DPPH (1,1-diphenyl-2-picrylhydrazyl) and Trolox for antioxidant activity assays and nutrient broth and nutrient agar for antimicrobial testing. In the theoretical part of the study, the structures of oleuropein and Trolox molecules were examined, and their oxidation properties were aimed to be determined and compared to experimental results. According to the results of total phenolic assays, the phenol contents in the olive leaves from Aydın and Mugla were observed to be very close to each other. In the anti-microbial assay, it was observed that the samples of olive leaves from Mugla were more antioxidant than those from Aydın.

Reverse phase high performance liquid chromatography and UV-Visible method for the simultaneous estimation of gemifloxacin

Reverse phase high performance liquid chromatography and UV-Visible method for the simultaneous estimation of gemifloxacin - IJPP- Print ISSN No: - 2393-9079 Online ISSN No:- 2393-9087 Article DOI No:- 10.18231/j.ijpp.2019.014, Indian Journal of Pharmacy and Pharmacology-Indian J Pharm Pharmacol

Spelt wheat tempe as a value-added whole-grain food product

Spelt wheat (Triticum aestivum) is an eco-friendly low-input crop whose consumption is considered advantageous. In this paper, a procedure for obtaining tempe-type products from whole grains of spelt and green spelt (immature grains) is presented, and the effect of biotreatment on the bioactive and nutritional parameters is described. The soluble antioxidant potential of the cooked grains (antiradical activity, reducing power, the sum of compounds reducing Folin's reagent) was enhanced after fermentation with Rhizopus oligosporus ATCC 64063, on average by 100% (buffer extracts) and 70% (acetone/water 1:1 v/v extracts). Spelt tempe also contained 25% more soluble phenolic acids, including a 300% higher ferulic acid level. As compared to cooked spelt, tempe contained more protein (12.7 g/100 g dry matter, dm) and ash (1.9 g/100 g dm), similar contents of total dietary fibre (11.3 g/100 g dm) and fat (2.7 g/100 g dm) but less starch (63 g/100 g dm). The nutritional parameters of spelt and green spelt were significantly improved by the fermentation. Tempe contained partially hydrolysed protein and total dietary fibre enriched in its soluble fraction (by 40% in green spelt tempe). Spelt grains, especially green spelt, can be considered a valuable substrate for obtaining a convenient value-added fermented food product.

Análisis de la clorofila de spinacia oleracea y cuantificación de albumina de espagueti utilizando espectrofotometría

<p>Basándose en el fenómeno de pigmentación que se percibe en los objetos, el cual puede explicarse por análisis fisicoquímicos, en esta investigación se realiza la espectrofotometría ultravioleta-visible (UV-VIS) para analizar la clorofila extraída de la Spinacia oleracea logrando interpretar y relacionar los conceptos de espectro de luz, absorbancia y pigmentos, mediante la elaboración y análisis de curvas de absorbancia. Por otro lado, se logra cuantificar las proteínas (albumina) extraída de pastas comestibles (espagueti) de diferentes costos, haciendo uso del método de Lowry que utiliza el reactivo de Folin, obteniendo de la evidencia experimental en estos casos, la relación de los términos de absorbancia y las concentraciones de diversas sustancias, mediante la ley de Lambert-Beer la cual se deduce matemáticamente.</p>

PRELIMINARY STUDY OF TOTAL PHENOLIC CONTENT IN TRADITIONAL SHEEP CHEESE (BIENO SIRENJE)

The presence of phenolic compounds in the milk and cheese is a result of their transfer from plant to milk and can affect their antioxidant activity. The objective of this work is to make a survey of the prevalence of the total phenolic compounds (TPC) in certain stages during cheese ripening as well as to determinate their final concentration in mature cheese. The obtained results show differences in the content of TPC between cheese samples from two batches (1 and 2). During the cheese ripening and after the dry salting and brining decreasing in the content of TPC has been noticed in both cheese batches. This is a result of number of chemical and enzymatic reactions as well as the high concentration of NaCl that inhibits the phenolic compounds to react with Folin reagent.

Surface functionalization of bioactive glasses with natural molecules of biological significance, Part I: Gallic acid as model molecule

Gallic acid (3,4,5-trihydroxybenzoic acid, GA) and its derivatives are a group of biomolecules (polyphenols) obtained from plants. They have effects which are potentially beneficial to heath, for example they are antioxidant, anticarcinogenic and antibacterial, as recently investigated in many fields such as medicine, food and plant sciences. The main drawbacks of these molecules are both low stability and bioavailability. In this research work the opportunity to graft GA to bioactive glasses is investigated, in order to deliver the undamaged biological molecule into the body, using the biomaterial surfaces as a localized carrier. GA was considered for functionalization since it is a good model molecule for polyphenols and presents several interesting biological activities, like antibacterial, antioxidant and anticarcinogenic properties. Two different silica based bioactive glasses (SCNA and CEL2), with different reactivity, were employed as substrates. UV photometry combined with the Folin&Ciocalteu reagent was adopted to test the concentration of GA in uptake solution after functionalization. This test verified how much GA consumption occurred with surface modification and it was also used on solid samples to test the presence of GA on functionalized glasses. XPS and SEM-EDS techniques were employed to characterize the modification of material surface properties and functional group composition before and after functionalization.

Effect of Folin Reagent from Different Sources on Protease Determination

Folin reagent was one of the most important reagents in protease determination. The differences between Folin reagent from laboratory and Folin reagent sold were studied. The results showed that there was not significant difference between the absorbance of Folin reagent from lab replaced 30d and Folin reagent sold (p<0.05). The RSD of Folin reagent from lab was between 0.3and 1.67, and Folin reagent sold between 0.63 and 1.49. The precision of them was both higher. The maximum absorption wave length of the chromogenic agent of Folin reagent was with 736-755. And there was no significant difference of the value of the same sample protease between both Folin reagent (p<0.05). Folin reagent from lab based on GB/T23527-2009 was perfect.

Saliva increases the availability of lipophilic polyphenols as antioxidants and enhances their retention in the oral cavity

ObjectiveLipophilic polyphenols in fruit beverages can avidly bind to surfaces of microorganisms and to blood cells and to impart upon them enhanced oxidant scavenging abilities (OSA). However, since many of the polyphenols are actually not fully soluble in water, they are therefore not available to act as effective antioxidant agents. We hypothesized that whole saliva, proteins such as albumin and mucin, human red blood cells and platelets, may all increase the “solubility” and availability of lipophilic antioxidant polyphenols thus increasing the OSA of whole saliva. DesignThe OSA of whole un-stimulated human saliva, obtained from healthy donors and of combinations among saliva, mucin, blood cells, fruit beverages and reagent polyphenols were quantified by chemiluminescence, DPPH radical and tetrazolium reduction assays. Kinetics of the clearance of polyphenols from saliva after holding in the mouth for 30s of an extract from beverages cinnamon was assayed by the Folin Ciocalteu's and the luminescence assays. ResultsOSA of fruit beverages and of reagent polyphenols were markedly increased by whole saliva, mucin and by red blood cells. Polyphenols associated with a cinnamon extract were retained in the oral cavity for several hours as measured by luminescence and Folin reagent techniques. ConclusionsA new approach to explain the additional role of saliva and salivary proteins and of blood cells as enhancers of OSA of lipophilic polyphenols is presented. This might have a significant importance to assess complex interactions among polyphenols from nutrients, salivary antioxidants, salivary proteins and blood cells extravasated from injure capillaries during infection and inflammation.

Antioxidant Properties of Coriandrum Sativum (Coriander)

Antioxidants prevent the damage done to cells by free radical‐molecules that are released during the normal metabolic process of oxidation. Some of these free radicals include reactive oxygen free radicals species (ROS), reactive hydroxyl radicals (OH), the superoxide anion radical (O2), hydrogen peroxides (H2O2) and peroxy (ROO) which generates metabolic products that attack lipids in cell membranes or DNA. These are associated with several types of biological damage, DNA damage; carcinogenesis and cellular degeneration related to aging and also contribute to heart disease and arthritis. Spice coriander reduces fever and promotes a feeling of coolness. It is highly beneficial in the deficiency of vitamin A, B1, B2, C and iron. High concentration of polyphenol and other bio reactive components are reported in this spice. The present study was aimed to determine the antioxidant properties of coriander. The antioxidant activity of polyphenolic extracts of Coriandrum Sativum was evaluated in vitro with the systronic Spectrophotometer at 517nm based on the reduction of the stable DPPH free radical. Total phenolic content extracted from the coriander spice sample was 240.0 mg GAE/g dry weight of the spice as estimated by Folin's reagent and calculated with standard curve prepared with gallic acid by the same procedure. Antioxidant activity measured from coriander as DPPH free radical scavenging activity was dose dependent. Incubation of 10μl of extract in DPPH free radical solution eradicated free radicals and caused decrease in OD of 0.01. Antioxidants present in coriander extract were able to protect DNA damage against hydroxyl ion caused by (ferrous sulphate + H2O2 + ascorbate) Fenton's reaction. The study indicate coriander is one of the most effective spice in terms of antioxidant properties and can serve as natural source to develop the free radical scavengers and antioxidant agents.

A Miniaturized Preconcentration Method Based on Dispersive Liquid–Liquid Microextraction for the Spectrophotometric Determination of Aziridine in Food Simulants

In this work a simple, rapid and sensitive method using dispersive liquid–liquid microextraction (DLLME) combined with UV–Vis spectrophotometry has been developed for the preconcentration and determination of trace amounts of aziridine in food simulants. The method is based on derivatization of aziridine with Folin's reagent (1,2-naphthoquione-4-sulphonic acid) and extraction of color product using DLLME technique. Some important parameters, such as reaction conditions, and type and volume of extraction solvent and disperser solvent were studied and optimized. Under optimum conditions, a linear calibration curve in the range of 2.0–350 ng mL−1 of aziridine was obtained. Detection limit based on 3Sb was 1.0 ng mL−1, and the relative standard deviation for 50 ng mL−1 of aziridine was 2.49c (n = 7). The proposed method was applied for the determination of aziridine in food simulants.

High-Antioxidant Potatoes: Acute in Vivo Antioxidant Source and Hypotensive Agent in Humans after Supplementation to Hypertensive Subjects

Potatoes have the highest daily per capita consumption of all vegetables in the U.S. diet. Pigmented potatoes contain high concentrations of antioxidants, including phenolic acids, anthocyanins, and carotenoids. In a single-dose study six to eight microwaved potatoes with skins or a comparable amount of refined starch as cooked biscuits was given to eight normal fasting subjects; repeated samples of blood were taken over an 8 h period. Plasma antioxidant capacity was measured by ferric reducing antioxidant power (FRAP). A 24 h urine was taken before and after each regimen. Urine antioxidant capacity due to polyphenol was measured by Folin reagent after correction for nonphenolic interferences with a solid phase (Polyclar) procedure. Potato caused an increase in plasma and urine antioxidant capacity, whereas refined potato starch caused a decrease in both; that is, it acted as a pro-oxidant. In a crossover study 18 hypertensive subjects with an average BMI of 29 were given either six to eight small microwaved purple potatoes twice daily or no potatoes for 4 weeks and then given the other regimen for another 4 weeks. There was no significant effect of potato on fasting plasma glucose, lipids, or HbA1c. There was no significant body weight increase. Diastolic blood pressure significantly decreased 4.3%, a 4 mm reduction. Systolic blood pressure decreased 3.5%, a 5 mm reduction. This blood pressure drop occurred despite the fact that 14 of 18 subjects were taking antihypertensive drugs. This is the first study to investigate the effect of potatoes on blood pressure. Thus, purple potatoes are an effective hypotensive agent and lower the risk of heart disease and stroke in hypertensive subjects without weight gain.

Determination of Chemical Composition of Plums During Pre-Treatment and Drying

Determination of Chemical Composition of Plums During Pre-Treatment and DryingThanks to drying, fruits are available on the market throughout the year. Parameters of drying conditions affect eg the content of bioactive compounds in the product. The aim of the study was to investigate the effect of pretreatment conditions and the applied drying method on changes in the chemical composition of plums. Analyses were conducted on plums cv. 'Valor', which were subjected to pre-treatment including blanching, drilling and osmotic dehydration. Next they were dried by the convection method at air temperature of 60°C and flow rate of 1.5 m/s. Dehydration was run in a 61.5% sucrose solution at a temperature of 50°C for 1 or 2 h. Convection-dried plums, with no osmotic dehydration applied, constituted the reference sample. In fresh, dehydrated and dried fruits determinations included dry matter, polyphenols by colorimetry with the Folin reagent and contents of sugars by colorimetry using 3,5-DNS acid. As a result of blanching and dehydration the content of dry matter increased. Water loss after dehydration amounted to as much as 1.45 g H2O/g d.m.0after 2 h in comparison with blanched plums. As a result of dehydration total contents of sugars and polyphenols in plums decreased (mg/100 g d.m.). In convection-dried prunes the content of polyphenols was by 30÷50% higher than in the raw material, but lower than in the reference sample.