Differentiation of Medicinal Plants According to Solvents, Processing, Origin, and Season by Means of Multivariate Analysis of Spectroscopic and Liquid Chromatography Data.

Effects of processing and extraction solvents on antioxidant properties and other characteristics were evaluated for ten medicinal plant species originating from two different localities and two production years. A combination of spectroscopic and liquid chromatography techniques possessed data for multivariate statistics. Water, 50% (v/v) ethanol, and dimethyl sulfoxide (DMSO) were compared to select the most suitable solvent for the isolation of functional components from the frozen/dried medicinal plants. DMSO and 50% (v/v) ethanol were evaluated as more efficient for phenolic compounds and colorants extraction, while water was more useful for element extraction. Drying and extraction of herbs with 50% (v/v) ethanol was the most appropriate treatment to ensure a high yield of most compounds. The satisfactory differentiation of herbs (61.8-100%) confirmed the significant effect of the processing, geographical, and seasonal factors on target functional component concentrations. Total phenolic and total flavonoid compounds content, total antioxidant activity expressed as TAA, yellowness, chroma, and browning index were identified as the most important markers for medicinal plant differentiation.

Effects of Different Factors on Concentration of Functional Components of Aronia and Saskatoon Berries.

Effects of different factors on the content of phenolics, anthocyanins, antioxidants and colour parameters in two varieties of Aronia and three varieties of Saskatoon berries were evaluated. The berries were extracted by dynamic solvent extraction using three different solvents (water, 50% ethanol (v/v) and dimethyl sulfoxide) and subsequently analysed by ultraviolet visible near infrared spectroscopy and electron paramagnetic resonance followed by chemometric analysis. The results obtained show that, dimethyl sulfoxide was the most appropriate for berries functional components isolation, and among the studied berries, Aronia exhibited the highest contents of phenolics. Besides that, varieties of Aronia melanocarpa Viking and of Amelanchier lamarckii Ballerina were selected as the cultivars with high contents of functional components. Satisfactory differentiation of berries was achieved according to extraction solvent, fruit type, variety and production years. The results obtained reveal that, phytochemical composition of Aronia and Saskatoon berries may vary depending on genotypic factors, climate, growing conditions as well as on extraction method used for their assessment. Sample processing, genotypic and seasonal factors had significant effect on the concentration of naturally occurring compounds in berries.

Quality Characteristics Analysis and Remaining Shelf Life Prediction of Fresh Tibetan Tricholoma matsutake under Modified Atmosphere Packaging in Cold Chain.

Tricholoma matsutake (T. matsutake) growing in Tibet is very popular for its high economic and medicinal value, but fresh T. matsutake has an extremely short shelf life. The shelf life of T. matsutake is complex, influenced by product characteristics, surrounding environmental conditions, and spoilage development. The objective of this work was to study the quality characteristics of fresh T. matsutake during its shelf life period in modified atmosphere packaging (MAP) conditions and establish its remaining shelf life prediction models in a cold chain. In this study, we measured and analyzed quality indicators of fresh T. matsutake, including hardness (cap, stipe), color, odor of sensory characteristics, pH, soluble solids content (SSC), and moisture content (MC) of physical and chemical characteristics under the temperature condition of 4 °C and relative humidity (RH) of 90%. The sensory evaluation results showed that the odor indicator in sensory characteristics was more sensitive to the freshness of T. matsutake. The changes of pH, SSC, and MC were divided into three periods to analyze the physiological changes of T. matsutake. The cap spread process could affect the changes of pH, SSC, and MC in period S1, and they changed gradually in period S2. In the period S3, they changed complicatedly because of deterioration. The remaining shelf life prediction model of T. matsutake was established by the back propagation (BP) neural network method to quantify the relationship between the quality indicators and the remaining shelf life. The shelf life characteristics are complex, which were optimized by correlation analysis. Significant benefits of this work are anticipated on the transportation and preservation of fresh T. matsutake to the market and the reduction of its losses in the postharvest chain.

Influence of different cultivation systems on bioactivity of asparagus.

Evaluation of functional and bioactive compounds of Asparagus officinalis L. growing in conventional and organic greenhouse and conventional open - field farming was the aim of this research. Polyphenols in cladodes grown conventionally were higher than organic. Flavonoids and carotenoids were the highest in cladodes in open field. Organic spears were richer in total phenolics (+6.9% and +19.1%) and flavonoids (+4.7% and 16.8%) and showed higher in vitro averages of antioxidant activities by three radical scavenging assays (+12.5% and+ 22.2%) than conventional. Partial differentiation of organically and conventionally grown samples was proved by multivariate statistics. The binding properties of polyphenols to HSA were relatively high in comparison with other plants. A strong positive correlation of binding properties and bioactivity of asparagus was estimated. All new found aspects for the first time lead to recommendation of inclusion of all investigated asparagus plants into the human diet in a wider scale.

Impact of Cultivation Conditions, Ethylene Treatment, and Postharvest Storage on Selected Quality and Bioactivity Parameters of Kiwifruit "Hayward" Evaluated by Analytical and Chemometric Methods.

Organic, semiorganic, and conventional "Hayward" kiwifruits, treated with ethylene for 24 h and stored during 10 days, were assessed by UV spectrometry, fluorometry, and chemometrical analysis for changes in selected characteristics of quality (firmness, dry matter and soluble solid contents, pH, and acidity) and bioactivity (concentration of polyphenols via Folin-Ciocalteu and p-hydroxybenzoic acid assays). All of the monitored qualitative parameters and characteristics related to bioactivity were affected either by cultivation practices or by ethylene treatment and storage. Results obtained, supported by statistical evaluation (Friedman two-way ANOVA) and chemometric analysis, clearly proved that the most significant impact on the majority of the evaluated parameters of quality and bioactivity of "Hayward" kiwifruit had the ethylene treatment followed by the cultivation practices and the postharvest storage. Total concentration of polyphenols expressed via p-hydroxybenzoic acid assay exhibited the most significant sensitivity to all three evaluated parameters, reaching a 16.5% increase for fresh organic compared to a conventional control sample. As a result of postharvest storage coupled with ethylene treatment, the difference increased to 26.3%. Three-dimensional fluorescence showed differences in the position of the main peaks and their fluorescence intensity for conventional, semiorganic, and organic kiwifruits in comparison with ethylene nontreated samples.

Structural features of two heteroxylan polysaccharide fractions from wheat bran with anti-complementary and antioxidant activities.

Wheat bran is a rich source of bioactive substances ascribed to its arabinoxylan component. Two water-soluble arabinoxylans were sequentially extracted from wheat bran. WB1, released during enzymatic digestion of starch and protein, contained medium-branched arabinoxylan (A/X=0.88) consisting of 3-O-substituted (22%), di-substituted (19.8%) and 58% unsubstituted Xylp residues. It was slightly contaminated with (1→3,1→4)-ß-glucan and arabinogalactan, and free of protein. WB2 extracted with 0.5% NaOH contained ∼95% arabinoxylan (A/X=1.09). WB2 and two 5% NaOH-extracted arabinoxylans were rich in protein and phenolic compounds. All radical-scavenging assays indicated a relation with the protein and total phenolics contents. The protein-free WB1 displayed the highest hydroxyl radical scavenging effect indicating the distinct role of phenolic acids. The immunomodulatory activity of WB1 was somewhat lower, whereas, that of WB2 higher in comparison to the immunogenic polysaccharide PMII. The arabinoxylans have the potential as immuno-enhancing and antioxidant additives in functional foods.

Antioxidant activity of grape skin aqueous extracts from pressurized hot water extraction combined with electron paramagnetic resonance spectroscopy.

Pressurized hot water extraction (PHWE) was employed to prepare extracts from dried grape skin of two wine grape varieties (St. Laurent and Alibernet) at various temperatures (from 40 up to 120°C) and amounts of sample (0.5, 1.0 and 1.5 g). To assess the antioxidant activity of the extracts, electron paramagnetic resonance (EPR) spectroscopy was applied involving DPPH and ABTS(+) assays. Other extract characteristics including HPLC profile of anthocyanins and total phenolic compound content were obtained as well. PHWE has also been compared with earlier results of extractions of the same grape skin samples with compressed methanol and compressed ethanol under the conditions of pressurized fluid extraction (PFE). From this comparison, PHWE emerges as the more benign and efficient extraction method to recover valuable phenolic antioxidants from grape skins for the prospective use in functional food supplements.

Offline combination of pressurized fluid extraction and electron paramagnetic resonance spectroscopy for antioxidant activity of grape skin extracts assessment.

A comprehensive characterization of grape skin methanolic and ethanolic extracts prepared by pressurized fluid extraction (PFE) at various temperatures within 40 to 120°C from two wine grape varieties, St. Laurent and Alibernet was performed. For the first time, an offline combination of PFE and electron paramagnetic resonance (EPR) spectroscopy together with other experimental methods was employed to assess the effect of extraction conditions on numerous extract characteristics including antioxidant or radical-scavenging ability, HPLC profile of anthocyanins, total phenolic compounds content (TPC), tristimulus color values (CIE Lab), and pH values. The properties of extracts depend on the solvent used, the mass of grape skins as well as on the extraction conditions among which the temperature plays a crucial role. In spite of wide interval of extraction temperatures, all extracts still retain their antioxidant and/or radical-scavenging properties, indicating that the extracts prepared by PFE can serve as potential source of functional food supplements or color enhancers.

Scavenging and antioxidant properties of compounds synthesized by carotenogenic yeasts stressed by heavy metals--EPR spin trapping study.

Free radical scavenging and antioxidant activities of metabolites produced by carotenogenic yeasts of Rhodotorula sp. and Sporobolomyces sp. grown under heavy metal presence were studied using various EPR experiments. The thermally initiated decomposition of K(2)S(2)O(8) coupled with EPR spin trapping was shown to be the best choice to characterize antioxidant properties of yeast's samples. EPR spectroscopy revealed that yeast walls showed higher ability to scavenge free radicals than those from inside the cells. Since carotenogenic yeast differ to each other in resistance against the heavy metals due to their individual protective system, quenching properties and antioxidant activities of carotenogenic yeasts were modulated by Ni(2+) or Zn(2+) ions variously.

Antioxidant properties of tea investigated by EPR spectroscopy.

The antioxidant properties of green, black and mixed (fruit) tea samples of different origin were investigated by means of EPR spectroscopy. A six line EPR spectrum of solid tea samples indicates the presence of Mn(II) ions and it is superimposed with a sharp singlet line attributed to semiquinone radical species (Delta H(pp)=1 mT; g=2.0022). Antioxidant properties of aqueous tea extracts in H(2)O(2)/NaOH/dimethylsulfoxide system generating reactive radicals (*OH, O(2)*-), *CH(3)) were followed by spin trapping technique. In addition, antioxidant capacity of these samples was assessed using stable radicals 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPOL). Typically, the highest antioxidant potential to terminate superoxide radicals was found in green teas, followed by black and fruity teas. The pro-oxidant activity of green teas evidenced by spin traps was promoted in samples with higher Mn(II) and ascorbic acid concentrations. Various sources of free radicals used in the antioxidant tests due to their specific action show different termination rates in the presence of the individual tea samples.

The influence of additives on beer stability investigated by EPR spectroscopy.

In thermally-accelerated aging followed by EPR spectroscopy of beer samples of various stabilities, free radical 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPOL) was shown to be an effective indicator of the breakdown of a sample's stability, comparable to the commonly used spin trapping agent alpha-phenyl-N-tert-butylnitrone (PBN). Both indicators were then employed to investigate the influence of additives on beer stability. The addition of L-ascorbic acid (ASC) to the beer samples accelerated the radical processes and a lower stability was found. DL-alpha-tocopherol (alpha-TOC) did not influence beer stability significantly (probably due to its limited solubility). Na2SO3, described as a very effective stabilizer in experiments with the PBN spin trap, was found not to be effective using the TEMPOL indicator. This is probably due to inhibition in the formation of spin adducts or their degradation by Na2SO3.