Selenium content in selected products of animal origin and estimation of the degree of cover daily Se requirement in Poland

The aim of the study was to determine Se concentration in selected products of animal origin (dairy products, pork, beef, chicken, giblets, fish, eggs) and to estimate the degree to which these products cover daily Se requirement in humans. Selenium concentrations were determined using the spectrofluorometric method. Mean Se concentration in the milk, yoghurt, kefir, and probiotic drinks was 0.020 μg mL⁻¹, 0.010 μg mL⁻¹, 0.012 μg mL⁻¹ and 0.012 μg mL⁻¹, respectively. Selenium concentration in cheese ranged 0.022–0.088 μg g⁻¹ wet weight. The average selenium content of meat ranged from 0.064 (beef) to 0.094 (chicken) μg g⁻¹ w.w. The mean Se content of giblets (liver: 0.307–0.401 μg g⁻¹ w.w.) was significantly ( P  < 0.05) higher than in meat. The concentration of Se depends on fish species and in our study it ranged from 0.136 ± 0.023 (flounder) to 0.282 ± 0.024 μg g⁻¹ w.w. (mackerel). The results obtained show that the analysed food provides 22.8% of the daily selenium requirement. Considering that animal products account for 40–45% of the diet daily selenium intake averages 33–37 μg.     

Anti-elastase and anti-hyaluronidase of phenolic substance from Areca catechu as a new anti-ageing agent

Synopsis We have previously screened 150 medicinal plants for the inhibition of elastase and found significant inhibitory effects of the extracts of Areca catechu L. on the ageing and inflammation of skin tissues . To isolate and identify the compounds having biological activity, they were further purified by each fraction of solvents, silica gel column chromatography, preparative TLC and reversed-phase HPLC. The peak in HPLC, which coincided with the inhibitory activity against elastase, was identified as a phenolic substance by using various colorimetric methods, UV and IR. IC₅₀ values of this phenolic substance were 26.9 μg mL⁻¹ for porcine pancreatic elastase (PPE) and 60.8 μg mL⁻¹ for human neutrophil elastase (HNE). This phenolic substance showed more potent activity than that of reference compounds, oleanolic acid (76.5 μg mL⁻¹ for PPE, 219.2 μg mL⁻¹ for HNE) and ursolic acid (31.0 μg mL⁻¹ for PPE, 118.6 μg mL⁻¹ for HNE). According to the Lineweaver–Burk plots, the inhibition against both PPE and HNE by this phenolic substance was competitive inhibition with the substrate. The phenolic substance from A. catechu effectively inhibited hyaluronidase activity (IC₅₀ : 210 μg mL⁻¹ ).
These results suggest that the phenolic substance purified from A. catechu has an anti-ageing effect by protecting connective tissue proteins.     

Arbutin determination in medicinal plants and creams

A simple flow injection (FI) manifold with spectrophotometric detection was fabricated and tested for arbutin determination. It is based on the measurement of a red-coloured product at 514 nm formed by the complexation reaction between arbutin and 4-aminoantipyrine (4-AP) in the presence of hexacyanoferrate (III) in an alkaline medium. On injecting 300 μL standard solutions at various concentrations of arbutin into the FI system under optimum conditions, a linear calibration graph over the range of 1.0–30.0 μg mL⁻¹ arbutin was established. It is expressed by the regression equation y  = 0.2188 ± 0.0036 x  + 0.1019 ± 0.0366 ( r ²   = 0.9990, n  = 5). The detection limit (3σ) and the limit of quantitation (10σ) were 0.04 μg mL⁻¹ and 0.13 μg mL⁻¹, respectively. The RSD of intraday and interday precisions were found to be 1.2–1.4% and 1.7–2.7%, respectively. The method was successfully applied in the determination of arbutin in four selected fruits and three commercial whitening cream extracts with the mean recoveries of the added arbutin over the range of 96.2–99.0%. No interference effects from some common excipients used in commercial whitening creams were observed. The method is simple, rapid, selective, accurate, reproducible and relatively inexpensive.     

Rapid and sensitive determination of formaldehyde in some beverages and foods by flow-injection fluorimetric analysis

A simple and sensitive flow-injection (FI) method for rapid determination of formaldehyde in beverage and food products has been developed. Adopting stop-flow technique, the proposed method distinctly improved the sensitivity of FI fluorimetric method for the determination of formaldehyde based on Hantzsch reaction with cyclohexane-1,3-dione. The fluorescent intensity was proportional to formaldehyde concentrations ranging 0.1 ng mL⁻¹ to 1.000 μg mL⁻¹, and the detection limit ( S / N  = 3) was 0.04 ng mL⁻¹ of formaldehyde. The relative standard deviations ( n  = 11) for determination of 0.100 and 0.005 μg mL⁻¹ of formaldehyde were 1.3% and 2.1%, respectively. The analytical frequency was 18 samples per hour. This method was applied directly for the determination of formaldehyde in diluted beverages and extraction solutions of foods, and the results obtained correlated well with those obtained by the standard method in which a sample pretreatment of steam distillation was required.     

An evaluation of extracts of five traditional medicinal plants from Iran on the inhibition of mushroom tyrosinase activity and scavenging of free radicals

This study aimed to evaluate the free radical scavenging and inhibition properties of five medicinal plants, including Quercus infectoria Olive., Terminalia chebula Retz. , Lavendula stoechas L., Mentha longifolia L., Rheum palmatum L., toward the activity of mushroom tyrosinase using l -tyrosine and l -3,4-dihydroxyphenylalanine ( l -DOPA) as the substrate. The methanol extracts of Q. infectoria and T. chebula showed strong radical scavenging effect in 2,2'-dipheny l -1-picrylhydrazyl (DPPH) assay (IC₅₀ = 15.3 and 82.2 μg mL⁻¹ respectively). These plants also showed inhibitory effects against the activity of mushroom tyrosinase in hydroxylation of l -tyrosine (85.9% and 82.2% inhibition, respectively). These two plants also inhibited the oxidation of l -DOPA similar to kojic acid as positive control (IC₅₀ = 102.8 and 192.6 μg mL⁻¹ respectively). In general Q. infectoria and T. chebula significantly inhibited tyrosinase activity and DPPH radical. Both activities were concentration-dependant but not in linear manner. It is needed to study the cytotoxicity of these plant extracts in pigment cell culture before further evaluation and moving to in vivo conditions.     

Antioxidant and toxicity tests of roasted noni (Morinda citrifolia) leaf infusion

The antioxidant properties and toxicity profile of roasted noni ( Morinda citrifolia L . ) leaf infusion were evaluated. The 2,2-diphenylpicrylhydrazyl (DPPH) radical scavenging activity was greater than green tea infusion (81.6 ± 0.9% vs. 57.5 ± 1.8%, P  < 0.001). The mean quercetin and kaempferol contents of roasted noni leaf infusion, as prepared by the consumer, were 0.24 ± 0.01 and 0.14 ± 0.01 μg mL⁻¹, respectively. Tannic acid content was 10 ± 1 μg mL⁻¹. The infusion was non-mutagenic in the reverse mutation test in Salmonella typhimurium and did not induce primary DNA damage in E. coli PQ37. Further, no significant primary DNA damage was induced by 5,15-dimethylmorindol, which was the only detectable anthraquinone in noni leaves. The infusion was not cytotoxic in the 24 h brine shrimp toxicity test (LC₅₀ > 1 mg mL⁻¹), nor was there any evidence of acute oral toxicity from the freeze–dried infusion in Sprague–Dawley rats (LD₅₀ > 2000 mg kg⁻¹ b.w.).     

Optimisation of the medium composition for production of protease and soybean peptides by Bacillus subtilis SHZ using response surface methodology

Responses surface methodology was employed to enhance the production of protease and soybean peptides by Bacillus subtilis SHZ. For screening of medium composition significantly influencing protease and soybean peptides yield, the two-level Plackett–Burman design was used. Among thirteen variables tested; KH₂PO₄, glucose and defatted soybean flour (DSF) were selected based on their high significant effect on both protease activity and soybean peptides yield. Then, a three-level Box–Behnken design was employed to optimise the medium composition for the production of the protease and soybean peptides in submerged fermentation. Mathematical models were then developed to show the effect of each medium composition and their interactions on the production of protease and soybean peptides. The model estimated that, the maximal protease activity (320 ± 1 U mL⁻¹) could be obtained when the concentrations of glucose, KH₂PO₄, DSF were set at 8–9 g L⁻¹, 2–3 g L⁻¹, 55–65 g L⁻¹, respectively; while a maximal yield of soybean peptides (8.5 ± 0.1 g L⁻¹) could be achieved when the concentrations of glucose, KH₂PO₄, DSF were set at 7–9 g L⁻¹, 3–4 g L⁻¹ and 55–58 g L⁻¹, respectively. These predicted values were also verified by validation experiments.     

Carotenoid composition and vitamin A value of some native Brazilian green leafy vegetables

The composition of carotenoids in five native Brazilian leafy vegetables was determined. The ranges of total carotenoid contents of Amaranthus viridis, Lepidium pseudodidymum, Xanthosoma spp., Sonchus oleraceus , and Portulaca oleracea were 347–468, 237–280, 225–361, 149–334 and 71–109 μg g⁻¹, with lutein and β-carotene predominating. The mean β-carotene contents (μg⁻¹) and vitamin A values (retinol equivalents RE_g⁻¹) were 110 and 18.4, 84.6 and 14.1, 67.3 and 11.2, 62.9 and 10.5, 29.8 and 4.99, respectively. The leaves contained 54–61% of lutein plus violaxanthin, 24–34% of β-carotene, 10–14% of neoxanthin and traces of zeaxanthin and α-crypto-xanthin. The native leafy vegetables were richer sources of provitamin A than the cultivated leafy vegetables analysed previously, justifying their commercial production.     

Influence of particle size fractions on the physicochemical properties of maize flour and textural characteristics of a maize-based nonfermented food gel

The physicochemical properties of fractionated maize flour and the textural characteristics of a maize-based nonfermented food gel (maize tuwo ) prepared from the respective fractionated flours were evaluated. The maize flour was fractionated into four fractions: <75 μm, 75–150 μm, 150–300 μm, 300–425 μm and whole meal (<425 μm). There were variations in the selected chemical constituents of fractionated maize flour including protein (2.9–4%), ash (0.80–0.97%), crude fibre (0.73–0.91%) and damaged starch (10.1–17.4%). The fractionated maize flour gave variable bulk density (0.80–0.93 g cm⁻³), water absorption capacity (1.9–2.1 g g⁻¹) and oil absorption capacity (1.7–2.1 g g⁻¹). The colour characteristics of the fractionated maize flour and the pasting properties were all affected by the fractionation. The cohesiveness index (strain at peak compressive force) of the food gel from the flour fractions ranged between 15% and 19.5% while the softness index of the food gel ranged between 16.7 and 17.5 mm. The relative high cohesiveness and softness indexes (i.e. 19.5% and 17.4 mm respectively) of maize tuwo prepared from the flour fraction of 75–150 μm can predispose the food gel towards easier hand-mouldability and swallowability respectively; being important quality indicators for its acceptability.     

Phenolic content and profiles of selected wild fruits of Zimbabwe: Ximenia caffra, Artobotrys brachypetalus and Syzygium cordatum

The phenolic compound content and profiles of three wild fruits found in Zimbabwe were tentatively identified using the traditional colorimetric methods and high-performance liquid chromatography (HPLC). The fruits assayed were: Ximenia caffra , Artobotrys brachypetalus and Syzygium cordatum . Ximenia caffra fruit peels contained the highest amounts of total phenolics amounting to 1205 μg g⁻¹ in fresh weight, flavonols amounting to 27 μg g⁻¹ and phenolic acids on HPLC tentative identification showed higher concentrations compared with the profiles of the other fruits. Syzygium cordatum fruit peels contained the least amounts of phenolics amounting to 20 μg g⁻¹, flavonols amounting to 8 μg g⁻¹ and phenolic acids' HPLC profiles showed low concentrations. Comparing the peels and pulps of all the fruits, we detected more total phenolics in the peels of X. caffra as high as 1205 μg g⁻¹ and the pulps had 228 μg g⁻¹, more flavonols and phenolic acids while the peels of S. cordatum fruits contained the least with a total phenolic acid content of 20 μg g⁻¹, and had more flavonols in the pulps than the peels, 11 μg g⁻¹ and 8 μg g⁻¹, respectively. Ximenia caffra contained 1.2% and about 1% dry weight condensed tannins in peels and pulps, respectively. In S. cordatum we detected 0.2% and 0.3% dry weight condensed tannins in the peels and pulps, respectively.     

Storage stability of a stimulant coconut water–acerola fruit juice beverage

The objective of this work was to study the stability of a beverage formulated with acerola fruit juice and green coconut water with added caffeine. The beverage was prepared with 25% acerola pulp, 75% green coconut water and sugar up to 12°Brix, and caffeine (125 mg L⁻¹), heat processed at 90 °C for 30 s and packed in 250-mL glass bottles. Chemical, physicochemical, microbiological and sensory analyses of the beverage were performed just after processing and during 6 months of storage at room temperature (27 °C). The vitamin C content decreased significantly throughout storage, from 399.5 to 189.6 mg 100 mL⁻¹, although it has remained relatively high. The anthocyanins initially present (0.025 mg 100 mL⁻¹) were completely lost during the storage at a mean rate of 4 μg 100 mL⁻¹ month⁻¹. The product was microbiologically stable during storage. Colour changes were also observed with absorbance at 420 nm, with average values ranging from 0.19 to 0.24. However, according to the sensory analyses the product was acceptable during the 6 months of storage, presenting sensory scores (colour, taste and global acceptance) from 6.5 to 5.5, which suggests its potential for market.     

J. Cosmet. Sci., 59, 441–448 (September/October 2008)Simultaneous determination of heavy metals in cosmetic products

An extremely small amount of several heavy metals have been detected in cosmetic products as impurities, which can cause skin allergies through percutaneous adsorption on the skin. We present here a fast, accurate, and highly sensitive method for simultaneous determination of Pb²⁺, Fe²⁺, Cu²⁺, Ni²⁺, Zn²⁺, Co²⁺, Cd²⁺ and Mn²⁺ in coloring agents and cosmetic products, to be evaluated by ion chromatography. All of these metals are well separated through a bifunctional ion-exchange column (IonPac CS5A) and detected by post-column reaction and spectrophotometric detection. The calibration graphs are linear ( r ² > 0.999), in the range 0.1–1000 μg ml^-1. Detection limits for a 200-μl sample solution are at the μg L^-1 level, which is sufficient for judging whether the product is safe or not. The relative standard deviations (RSDs) of the retention time and the peak area are less than 0.21 and 1.24%, respectively. The recovery rates are 97–104%. The result shows that the proposed determination method is more sensitive, more accurate, and faster than current methods such as HPLC, ICP-MS and Flame-AAS. The new method was applied to analyse the amount of heavy metals contained in 22 cosmetic products and 11 coloring agents.     

Methyl anthranilate content in Italian citrus honeys determined by HS-SPME-GC

An headspace solid phase microextraction-gas chromatography (HS-SPME-GC) method, previously developed and validated, was applied to the determination of the methyl anthranilate (MA) content of 75 Italian citrus honeys (11 of lemon, 44 of orange and 20 of Citrus spp.). Twenty-four samples were purchased on the local market and 51 were provided by CRA-API ( Consiglio Nazionale per la Ricerca e Sperimentazione in Agricoltura-Istituto Nazionale di Apicoltura e Bachicoltura ) (Bologna, Italy). All the samples had a MA content above the limit of detection (LOD) (0.149 μg g⁻¹) of the analytical method. The concentration range was between 0.46 and 2.52 μg g⁻¹ and the overall average MA content was 1.19 μg g⁻¹. The honeys with the highest mean MA content were the orange honeys followed by Citrus spp. and lemon (1.29 ± 0.461, 1.12 ± 0.511 and 0.92 ± 0.39 μg g⁻¹, respectively). No significant differences were measured between commercial and authenticated samples.     

Biochemical changes in cut vs. intact lamb's lettuce (Valerianella olitoria) leaves during storage

Consumers are oriented towards fresh-cut vegetables that provide phytonutrients useful for preventing stress-related diseases. The aim of this work was to evaluate the cut operations on the quality changes of lamb's lettuce ( Valerianella olitoria L.) cv. Trofy during storage at 4 °C for 8 days. Results showed that chlorophyll and carotenoids reduction was observed after 8 days of storage. In both treatments, total carotenoids after 8 days decreased from 20 to 16 mg g⁻¹ FW. Free and total phenols increased with storage in both treatments. Total phenols were 23% higher in control (32 μmol g⁻¹ FW) compared to cut leaves (25 μmol g⁻¹ FW) after 8 days of storage. Anthocyanins increased after 8 days and reached 30 mg 100 g⁻¹ FW without significant difference between treatments. Ascorbic acid (AsA) and dehydroascorbic (DHA) acid increased in cut leaves compared to control. After 1 day AsA concentration was 3 300 nmol g⁻¹ FW in cut leaves, while in control leaves was 1 500 nmol g⁻¹ FW. Analogously AsA + DHA was higher in cut leaves, 4 100 nmol g⁻¹ FW, while in control leaves the mean was 3 000 nmol g⁻¹ FW. After 5 days of storage the values of AsA returned to initial values, while AsA + DHA were lower.     

Identification and determination butylmethoxydibenzoylmethane in the presence benzophenone-3 and ethylhexylmethoxycinnamate in suncare preparation

The protection of sun radiation is a problem on global level for all living organisms on Earth. The need of people for the overexposure to the UV radiation led human population towards finding novel ways of protection of this kind of radiation, in form of cosmetic preparations applied on the skin. So far, the high values of protection factors of preparations and total block preparations with sun protection factor of 50+ were achieved. Physical and chemical filters which absorb radiation are constituents of these preparations. European Union has set regulations as which substances and in what amounts could be used as UV absorbers. American FDA (Food and Drug Administration) also gave its list of the most frequently used UV absorbers in the sunscreen products, as well as their declared concentrations. The most frequently used concentrations of UV filters in cosmetics is between 0.1% and 10%. Concentrations of UV filters in sunscreen products have to be monitored in order to ensure that they are not less from the declared levels, on which depends the efficacy and safety of the product.
Butyl methoxydibenzoylmethane (BMDM) is used as a UV-A filter in suncare products. Optimized high performance liquid chromatography method for BMDM determination in the presence of other UV filters in suncare preparations is presented in this paper. Determination was performed on C₈ reversed phase using UV detection at 357 nm and isocratic mobile phase of acetonitrile and 0.5% phosphoric acid (70 : 30 v/v). Proposed method has limit of detection of 0.058 μg mL⁻¹, limit of quantification 0.193 μg mL⁻¹ and linearity correlation coefficient of 0.9989. Commercially available products were analysed using the proposed method. All analysed samples complied with EU directives limit of BMDM content to no more than 5%.     

Chemical composition and antimicrobial activities of essential oil from the peel of bingtang sweet orange (Citrus sinensis Osbeck)

The chemical composition of the essential oil obtained from the peel of Bingtang sweet orange ( Citrus sinensis Osbeck) was analysed by gas chromatography and gas chromatography/mass spectrometry (GC/MS). Twenty-seven components were identified. The monoterpenes and sesquiterpene hydrocarbons with 96.03% (w/w) of the total oil were the principal compound groups. Among which, limonene was observed dominant (77.49%), followed by myrcene (6.27%), α-farnesene (3.64%), γ-terpinene (3.34%), α -pinene (1.49%), sabinene (1.29%) and other minor components. Results by disc diffusion method and minimum inhibitory concentration (MIC) determination method showed that the essential oil had a wide spectrum of antimicrobial activities against Staphylococcus aureus , Penicillium chrysogenum , Bacillus subtilis, Escherichia coli and Saccharomyces cerevisiae , with their inhibition zones ranging from 14.57 mm to 23.37 mm and the MIC ranging from 4.66 μL mL⁻¹ to 18.75 μL mL⁻¹.     

Anthocyanin-rich sweet potato lacto-pickle: production, nutritional and proximate composition

Anthocyanin pigment-rich sweet potato (SP) cubes were pickled by lactic fermentation by brining the cut and blanched cubes in common salt (NaCl, 2–10%) solution. They were then inoculated with a strain of Lactobacillus plantarum (MTCC 1407) and incubated for 28 days. Treatment with 8–10% brine solution was found to be organoleptically most acceptable. The final product with 8% and 10% brine solutions had a pH (2.5–2.8), titratable acidity (TA) (1.5–1.7 g kg⁻¹), lactic acid (LA) (1.0–1.3 g kg⁻¹), starch (56–58 g kg⁻¹) and anthocyanin content (390 mg kg⁻¹) on fresh weight basis. Sensory evaluation rated the anthocyanin-rich SP lacto-pickle acceptable based on texture, taste, aroma, flavour and after taste. Principal component analyses reduced the eleven original analytical and proximate variables (pH, TA, LA, starch, total sugar, anthocyanin, organic mater, ash, fat, protein and calories) to three independent components (factors), which accounted for 91% of the total variations.     

A modified colorimetric method for the estimation of β-cyclodextrin using phenolphthalein

The binding equilibrium between β-cyclodextrin and phenolphthalein has been used to develop a method for the estimation of β-cyclodextrin in solution. From logarithmic plots of amounts of β-cyclodextrin against absorbance at 554 nm, a relation log X  = (log A  − log Y )/ B was found, which gave an estimate of β-cyclodextrin in the concentration range 0.0045 mg mL⁻¹ (3.96 μm) to 4.7 mg mL⁻¹ (4.14 mm), where X =  intercept and B  = slope. This method was found to be highly reproducible and reliable.     

Aflatoxin levels in dried figs, nuts and paprika for export from Turkey

Three hundred and thirteen of 2643 dried fig, two of eighty hazelnut, sixteen of twenty-eight pistachio, five of ten peanut and nineteen of twenty-three paprika samples for export from Turkey were contaminated with total aflatoxins in the range of 0.2–162.76, 5.46–6.55, 2.31–63.11, 0.75–26.36 and 1.79–6.55 μg kg⁻¹, respectively. Samples were collected from January to August 2007 and tested for aflatoxins (B₁, B₂, G₁ and G₂) by immunoaffinity column extraction using RP-HPLC. Fifty-six of the 313 dried fig, all of the contaminated hazelnut and pistachio, two of the sixteen peanut and three of the nineteen paprika samples exceeded the regulatory limits of the European Union. The ratio of the different types of aflatoxin present in each sample exhibited great variability. For example, of 313 contaminated fig samples, 159 contained only aflatoxin B₁, eighty-five contained B₁ (49.7%) + G₁ (50.3%), twenty-two contained only G₁, twenty contained B₁ (89.4%) + B₂ (10.6%), thirteen contained B₁ (73.7%) + B₂ (10.8%) + G₁ (15.5%) and fourteen contained all four types, B₁ (26%) + B₂ (2.5%) + G₁ (66.5%) + G₂ (5%).