Results Of Chemical Composition Analysis Research Articles

Simple Sequence Repeat Marker-Based Genetic Diversity and Chemical Composition Analysis of Ancient Camellia sinensis in Jiulong County, Sichuan Province, China.

The ancient tea plant germplasm resources are rich in genetic diversity and provide an important basis for the genetic diversity in tea germplasm resources. To explore the genetic diversity of ancient tea plant germplasm resources in Jiulong County, Sichuan Province. 59 ancient tea tree germplasm resources were analyzed using simple sequence repeat (SSR) molecular markers and chemical composition analysis. The results showed that a total of 83 alleles were amplified by 23 pairs of SSR primers, with an average observed allele number (Na) of 3.6 and an effective allele number (Ne) of 2.335. The average Shannon information index (I) and the polymorphic information content (PIC) of the primers were 0.896 and 0.446, respectively. The results of the UPGMA cluster analysis showed that 59 ancient tea tree samples could be classified into five different subgroups. Based on the results of chemical composition analysis, two specific tea germplasm resources with high amino acid content, 10 excellent germplasm resources with tea polyphenol content over 20% and some other tea germplasm resources were identified. This study reveals that Jiulong's ancient tea tree germplasm exhibits significant genetic diversity and includes valuable tea tree planting resources. These findings provide a foundational framework for the conservation, detailed exploration and sustainable utilization of these resources.

Analysis of sediment re-formation factors after ginseng beverage clarification based on XGBoost machine learning algorithm

The aim of this study was to explore the sediment re-formation factors of ginseng beverages subjected to four clarification ways (11 subgroups) including the ethanol precipitation, enzymatic treatment, clarifier clarification, and Hollow Fiber Column (HFC) methods, based on the Extreme Gradient Boosting (XGBoost) model. The results showed that the clarity of the ginseng beverages was significantly improved by all the clarification treatments, but still formed sediment after storage. HFC method exhibited the highest transmittance, the least sediment, and stronger antioxidant activity in the clarification treatment groups. According to the results of chemical composition analyses and partition coefficients, carbohydrates, saponins, proteins and metal elements were involved in varying degrees in the re-formation of the sediments in ginseng beverage after clarification. Based on the above data, the XGBoost model predicted that protein, Rd, Na, K, and total saponins were the five most important chemical components affecting the sediment re-formation in ginseng beverages.

Chemical Profile and Antioxidant and Antimicrobial Activity of Rosa canina L. Dried Fruit Commercially Available in Serbia.

The aim of this work was to give as much information as possible on Rosa canina dried fruit that is commercially available in Serbia. In order to provide the chemical composition, the UHPLC-DAD-ESI-MS method was employed for both polar and non-polar extracts of samples obtained with a solvent mixture consisting of hexane, acetone, and ethanol in a volume ratio of 2:1:1, respectively, and 0.05% (w/v) butylated hydroxytoluene. In addition, the total content levels of lycopene, β-carotene, total polyphenols, and flavonoids were determined by means of UV-vis spectrophotometry. The antioxidant activity was tested by applying four different methods: ABTS, DPPH, FRAP, and CUPRAC. Overall, nine compounds were identified. The results of chemical composition analysis were used as the basis for the interpretation of the calculated results for the antioxidant and antimicrobial activity. The obtained results for R. canina dried fruit extract are as follows: β-carotene-7.25 [mg/100 g fruit weight]; lycopene-2.34 (mg/100 g FW); total polyphenol content (TPC)-2980 [mg GAE/kg FW]; total flavonoid content (TFC)-1454 [mg CE/kg FW]; antioxidant activity-ABTS 12.3 [μmol/100 g FW], DPPH 6.84, FRAP 52.04, and CUPRAC 15,425; and antimicrobial activity-Staphylococcus aureus MIC/MMC 4/0 [mg∙mL-1], Enterococcus faecalis 4/0, Bacillus cereus 4/0, Escherichia coli 4/0, Salmonella enteritidis 4/4, Enteroabacter aerogenes 4/0, Pseudomonas aeruginosa 2/0, and Candida albicans 2/0.

РАЗРАБОТКА ТЕХНОЛОГИИ ПИЩЕВОЙ СМЕСИ БЫСТРОГО ПРИГОТОВЛЕНИЯ ДЛЯ ЛЮДЕЙ С ПРЕДРАСПОЛОЖЕННОСТЬЮ К ЗАБОЛЕВАНИЯМ СИСТЕМЫ КРОВООБРАЩЕНИЯ

Today «fast food» production is developing very rapidly. In some cases, fast food products act as food substitutes. The most important way to create such products is to enrich mass-consumed food products with the missing physiologically functional ingredient. In this case one should take into account individual needs based on the analysis of genetic research data. A food mixture recipe has been developed for nourishing people with predisposition to cardiovascular diseases. The results of chemical composition analysis of the developed product made it possible to establish that the partial replacement of maltodextrin with stevia, isolated soy protein with dry egg yolk, as well as the addition of the fortifying additive «Tsegepal 03-C», a premix (dietary supplement) of polyunsaturated fatty acids ω-3 and ω-6 VitaMeal led to an increase in the content of nutrients needed by people with predisposition to CVD - vitamins A and E, vitamin B1, vitamin B2, niacin, folates, pantothenic acid, choline, ω-3 and ω-6 – by 100%, vitamin B12 – by 50 %.

Reflections on the beginnings of ancient Russian glassmaking

The origin of non-alkaline lead-silica (PbO•SiO2) and lead-potassium-silica(PbO•K2O•SiO2) glass-forming technologies, which many Russian researchers believe to be typical ofancient Russian glassmaking and attesting to independent glassmaking in early 11th c. Rus’, is discussedin this paper, limited to a few selected aspects of the issue. Research has proposed two sources of thesetechnologies adopted in Rus’: Byzantium (Shchapova, Noonan) and, in the case of the first one, theFar East (Brill). The number of discoveries of glasses of these two chemical types, both artifacts andproduction waste, from Europe as well as from the Far East in particular, has grown in the past fewdozen years. New studies presenting the results of chemical composition analyses of glasses of thesetypes have also increased exponentially. The growing body of data substantiates a return to the subjectof the origins of ancient Rus’ glassmaking. The research should be based on a comparative analysisof the results of laboratory tests of remains from workshops of type A (with full production cyclesattested) as well as ready products found in ancient Rus’ and in other regions, especially in the Far East.

Artificial Humic Substances as Biomimetics of Natural Analogues: Production, Characteristics and Preferences Regarding Their Use.

Various processes designed for the humification (HF) of animal husbandry wastes, primarily bird droppings, reduce their volumes, solve environmental problems, and make it possible to obtain products with artificially formed humic substances (HSs) as analogues of natural HSs, usually extracted from fossil sources (coal and peat). This review studies the main characteristics of various biological and physicochemical methods of the HF of animal wastes (composting, anaerobic digestion, pyrolysis, hydrothermal carbonation, acid or alkaline hydrolysis, and subcritical water extraction). A comparative analysis of the HF rates and HS yields in these processes, the characteristics of the resulting artificial HSs (humification index, polymerization index, degree of aromaticity, etc.) was carried out. The main factors (additives, process conditions, waste pretreatment, etc.) that can increase the efficiency of HF and affect the properties of HSs are highlighted. Based on the results of chemical composition analysis, the main trends and preferences with regard to the use of HF products as complex biomimetics are discussed.

Fucoidan extracted by different methods and bound to zein loaded curcumin nanoparticles: Preparation, physicochemical stability, and in vitro functions

In this study, fucoidan (Fuc) extracted from kelp by water (WFu) and acid (AFu) was combined with zein to prepare nanoparticles. Its potential application as a curcumin (Cur) delivery system was also investigated. The results of chemical composition analysis showed that the sulfate content of AFu (26.44%) was significantly higher than that of WFu (19.65%). The molecular weight (Mw) and monosaccharide composition of WFu and AFu were also different. The anti-solvent precipitation method was used to prepare the nanoparticles. The analysis of nanoparticles with different mass ratios showed that the nanoparticles with a mass ratio of Fuc/zein of 1.5:1 had uniform particle distribution, good stability and the best encapsulation effect. Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and fluorescence spectroscopy showed that hydrogen bonds and electrostatic interaction were the main forces responsible for the formation of the nanoparticles. Moreover, Fuc enhanced the thermal and storage stability of zein nanoparticles (ZNP). An in vitro digestion experiment using nanoparticles revealed that Fuc-ZNP had strong tolerance to the gastrointestinal tract and could be used for colon-specific Cur delivery. In addition, antioxidant experiments showed that Fuc significantly increased the antioxidant activity of ZNP (P < 0.05). In conclusion, Fuc-ZNP have potential as a Cur delivery system.

Characteristics and source apportionment of water-soluble inorganic ions in atmospheric particles in Lvliang, China.

Seasonal atmospheric particulate matter samples with different particle sizes (< 2.5μm [PM2.5], 2.5-5μm [PM2.5-5], 5-10μm [PM5-10], and 10-100μm [PM10-100]) were collected to analyze the mass concentration and distribution characteristics of nine water-soluble ions (WSIs; F-, Cl-, NO3-, SO42-, Na+, NH4+, K+, Mg2+, and Ca2+) in Lvliang in China. The results of chemical composition analysis indicated that the average concentration of total WSIs was 29.08µg·m-3 and accounted for 40.45% of PM2.5, 80.99% of which was attributable to SO42-, NH4+, and NO3-; the concentration demonstrated obvious distribution characteristics. NO3- and NH4+ primarily exist as NH4NO3 and (NH4)2SO4, respectively, in fine particles but as NaNO3 and NH4Cl, respectively, in coarse particles. The PM2.5 was alkaline overall, and K+ and NH4+ caused the highest RC/A values in autumn. Stationary sources contribute more to WSIs in particulates than mobile sources. The secondary transformation degree of SO2 was higher than that of NOx, especially in fine particles. The positive matrix factorization (PMF) and potential source contribution function (PSCF) models were combined to determine the sources of WSIs in PM2.5. Through use of the PMF model, five source factors were categorized: secondary aerosols (43.0%), biomass combustion (21.7%), coal combustion (17.6%), dust (10.9%), and vehicular traffic (6.8%). The results of the PSCF model suggested that the transport of pollutants from Shanxi, northwestern Shaanxi, Gansu, Inner Mongolia and Henan, had the greatest effect on air quality in Lvliang.

Effects of different extraction methods on chemical compositions and biological activities of polysaccharides from Lycium barbarum

In this study, five polysaccharides from Lycium barbarum(LBPs)(LBP-1-LBP-5) were selectively extracted by different extraction methods, and the chemical composition, structural characteristics, and biological activities of LBPs were explored. The results of chemical composition analysis showed that alkaloids were not detected in the five LBPs. The total polysaccharide content was(81.95%±1.6%)-(92.96%±0.76%), the uronic acid content was(8.26%±0.46%)-(24.81%±0.46%), and the protein content was(0.06%±0.03%)-(1.35%±0.13%). The monosaccharide compositions of the five LBPs were basically same, mainly including glucose, xylose, and galactose. However, there was significant difference in the content ratio of different monosaccharide. The results of infrared spectra analysis indicated that the five LBPs had typical infrared spectral characteristics of polysaccharides. The results of nuclear magnetic resonance characteristic spectrum analysis revealed that the five LBPs had two configurations of α and β. Meanwhile, there were triple helix structures in LBP-2, LBP-3, and LBP-4, which enhanced the activities of polysaccharides. The results of activities screening suggested that the biological activities of the five LBPs were significantly different. LBP-3 showed the highest lipid oxidation clearance rate, and its antioxidant activity was equivalent to that of the positive control group. The inhibitory rate of LBP-4 on α-amylase and its activation rate of alcohol dehydrogenase were better than those of other fractions, and the inhibitory rate of LBP-4 on α-amylase was slightly higher than that of the positive control group when the mass concentration was 10 g·L~(-1). LBP-2 showed stronger inhibitory activity against α-glucosidase and hyaluronidase. This study provides references for the precise development and utilization of LBPs.

Reaction kinetics of dissolved black carbon with hydroxyl radical, sulfate radical and reactive chlorine radicals

As an important component of dissolved organic matter (DOM), dissolved black carbon (DBC) which is characterized of abundant aromatic and oxygen-containing functional groups, is widely distributed in aquatic environments. Its presence may hinder the oxidation of organic micro-pollutants during advanced oxidation processes (AOPs) via free radicals scavenging effect. However, the second-order reaction rate constants of DBC with different free radicals including hydroxyl radical (OH•), sulfate radical (SO4•-), reactive chlorine radicals (RCR) are unknown and the relationship between the chemical composition of DBC and the second-order reaction rate constants during different AOPs (UV/H2O2, UV/PDS, UV/Chlorine) is also unclear. In this study, a plant-derived DBC was extracted from wheat biochar and fractionated according to molecular weight (i.e., <10 k, <3 k, and < 1 k Da). The second order rate constants of DBC reaction with different free radicals were determined by competitive kinetic method. Besides, the chemical composition of DBC was revealed by ultraviolet-visible (UV–Vis) spectroscopy, fluorescence excitation-emission-matrix (EEM) spectroscopy Fourier Transform Infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) combined with statistical analysis. The results showed that the second-order rate constants decreased as the molecular weight increased. For the <1 k Da DBC, the kDBC-OH•, kDBC-SO4•-−, kDBC-RCR were (1.83 ± 0.06) × 104, (7.60 ± 0.21) × 103, and (1.71 ± 0.13) × 104 L·mgC−1·s−1, which were 1.98, 2.19, 1.43 times of that for the <10 k Da fraction and 1.38, 1.36, 1.24 times of that for the <3 k Da fraction in UV/H2O2, UV/PDS and UV/Chlorine processes. In addition, the results of chemical composition analysis showed that DBC mainly contained humic substances and was rich in O-containing functional groups such as CO. The second order reaction rate constants of DBC with different free radicals decreased with increasing the molecular weight of DBC due to the more aggregated structure of the small molecules that the inner carbon of DBC was not easily exposed to free radicals.

Downhole Lithological Profile Reconstruction Based on Chemical Composition of Core Samples and Drill Cuttings Measured with Portable X-ray Fluorescence Spectrometer

The reconstruction of a lithological profile based on geophysical logs of chemical composition provided by geochemical gamma-gamma well logging probes has been increasingly used for geophysical interpretation. A chemical profile, analogous to the measurements mentioned above, can be determined based on measurements made with a portable X-ray fluorescence spectrometer (pXRF). This paper presents a methodology for determining the mineral composition of drilled, clastic, as well as clay-rich rocks on the basis of both inexpensive and timesaving pXRF measurements as well as models combining the results of chemical composition analysis with results of mineral composition analysis (XRD). The results of chemical composition analysis obtained with a portable XRF spectrometer were calibrated based on a detailed analysis produced with ICP-OES and ICP-MS methods. A significant advantage of the proposed method is the possibility to apply it with regard to drill cuttings as well as archival cores. However, considerable discrepancies in the results obtained were identified while comparing the results of chemical composition analysed directly on the core and milled material. The analysed material comprised Carboniferous rocks derived from three boreholes located in Poland: Kobylin-1 as well as Biesiekierz-1 and -2. It was possible to directly compare the lithological profile obtained based on measurements taken on drill cuttings with the results of the lithological interpretation of a geochemical probe log.

CHEMICAL COMPOSITION AND NUTRITIVE VALUE OF HEDYSARUM FLEXUOSUM L. ACCORDING TO MORPHOLOGICAL PARTS AND PHAENOLOGICAL STAGES

The objective of this work is to evaluate the chemical composition and nutritive value of different parts of the Hedysarum flexuosum plant and their evolution according to the different phaenological stages, in order to retain the most appropriate harvesting stage. The data are based on the results of chemical composition analysis of the three main parts of the plant (whole plant, stems only and leaves only) according to the phaenological stages (Mid-vegetative, vegetative growth, Budding, flowering, seed setting and seed ripening ). At the budding stage, the chemical composition of the whole plant is much better, especially in terms of protein content, which reaches 225 g/kg of dry matter, Hedysarum flexuosum should be harvested or grazed at the bud stage, at the latest at the beginning of flowering.

The structural characteristics of an acid-soluble polysaccharide from Grifola frondosa and its antitumor effects on H22-bearing mice

The edible mushroom G. frondosa has been used as a kind of functional food for the prevention and therapy of various diseases in Asian countries. In the present work, a novel acid-soluble polysaccharide (GFAP) was successfully isolated from G. frondosa under room temperature and hydrochloric acid solution treatment. Results of chemical composition analysis, UV and HPGPC spectra showed that GFAP mainly contained 94.28% of carbohydrate with the average molecular weight of about 644.9 kDa. GC, FT-IR, NMR and methylation analysis further indicated that GFAP was a neutral sugar mainly composed of (1 → 3)-β-D-Glcp and (1 → 3)-α-D-Manp. The in vivo antitumor experiments demonstrated that GFAP could effectively protect thymuses and spleens of tumor-bearing mice and inhibit the growth of H22 solid tumors with the inhibitory rate of 36.72%. Besides, GFAP could significantly improve the activities of NK cells, macrophages, CD19+ B cells and CD4+ T cells, leading to the apoptosis of H22 cells via G0/G1 phase arrested. Our data demonstrated that GFAP holds great application prospect to be a safe and effective antitumor adjuvant in the future.

A novel nanofiltration membrane with [MimAP][Tf2N] ionic liquid for utilization of lithium from brines with high Mg2+/Li+ ratio

In order to utilize lithium from brines with high Mg2+/Li+ ratio, a positively charged nanofiltration (NF) membrane was prepared by grafting amine-functionalized ionic liquid 1-(3-aminopropyl)-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([MimAP][Tf2N]) onto the surface of polyamide (PA) membrane. The effects of [MimAP][Tf2N] contents on the chemical composition, surface morphology, surface charges and separation properties of the modified PA membranes were discussed. The results of chemical composition analyses indicated reaction of the amine group of [MimAP][Tf2N] with the residual acyl chloride groups, which was existed on the surface of the nascent PA membrane. The surfaces of all the modified PA membranes were positively charged at pH = 6.4 due to the quaternary ammonium group of [MimAP][Tf2N]. In the separation process, the resulting membrane presented high water permeance (37.8 L/(m2⋅h)) and mono-/divalent cation selectivity (Li+ and Mg2+) with much higher MgCl2 rejection (83.8%) than LiCl rejection (24.4%). For a simulative brine with a Mg2+/Li+ ratio of 20, the rejections to Mg2+ and Li+ by the optimized membrane (NF-IL-2.0%) were around 81.9% and −45.2%, respectively, where the permeate with the Mg2+/Li+ ratio of 3.5 was obtained and the selectivity (SLi,Mg) was 8.12. Additionally, the optimized membrane exhibited a stable performance for Mg2+/Li+ separation. Therefore, there is a very possibility for utilization of lithium from brine with high Mg2+/Li+ ratio by using the optimized NF membrane.

Comparison of Deep Eutectic Solvents on Pretreatment of Raw Ramie Fibers for Cellulose Nanofibril Production.

Deep eutectic solvents (DESs), featured as promising green solvents, were applied to examine their effectiveness in pretreating raw ramie fibers (RFs) for cellulose nanofibril (CNF) production. The pretreatment performance of three DESs, i.e., choline chloride–urea (CU), choline chloride–oxalic acid dihydrate (CO), and choline chloride–glycerol (CG), was evaluated based on chemical composition analysis and structural and morphological changes. CO attained the most dramatic morphological changes of RFs, followed by CG and CU. Its high structural disruption of RFs during the pretreatment process, shown in the results from scanning electron microscopy and atomic force microscopy, could be due to an outstanding ability to remove amorphous cellulose and noncellulosic components from raw RFs, confirmed by the results of chemical composition analysis, Fourier transform infrared spectroscopy, and X-ray diffractometry. Overall, this study provided an innovative and effective pretreatment process for fractionating raw cellulosic fibers, so as to promote the subsequent preparation of CNFs.

Osteogenic activity of non-genotoxic sulfated polysaccharides from the green seaweed Caulerpa sertularioides

Biocompatibility is a requirement for new molecules with potential applications in bone regeneration. Molecules with such potential applications in regenerative medicine include sulfated polysaccharides (SPs) isolated from seaweed. In this study, we evaluated the cytotoxicity and genotoxicity of SPs extracted from the green seaweed, Caulerpa sertularioides, and demonstrated its osteogenic activity in human mesenchymal stem cells (hMSCs). Seaweed samples were collected along the coast of Rio Grande do Norte, Brazil, and the results of chemical composition analyses of the samples revealed a high sugar and sulfate content. hMSCs treated with seaweed SPs (1–10 μg/mL) did not alter 3-(4,5-methylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction activity, and alkaline phosphatase activity was increased by approximately 30–40% when cells were treated with 5–10 μg/mL SPs. In addition, 21 days of continuous treatment resulted in increased calcium deposition in the extracellular matrix. Comet assay and the cytokinesis-block micronucleus cytome assay did not reveal significant changes in the frequency of nuclear alterations after 24 h of treatment. Together, our results show, for the first time, the osteogenic activity and non-genotoxicity of SPs from C. sertularioides, suggesting their potential in therapeutic applications in bone regeneration.

Study of pyrite oxidation with chlorine dioxide under mild conditions

Pyrite, usually associated with gold deposit, is disadvantageous to gold leaching. In this study, an environmentally friendly oxidizing agent, chlorine dioxide (ClO2), was used for the first time to efficiently oxidize pyrite under mild experimental conditions, so as to remove the adverse effects of pyrite on gold leaching. Firstly, with established content determination method, the prepared pure ClO2 solutions with different concentrations were investigated on their impacts on pyrite oxidation efficiency. Secondly, solid NaClO2 was used to oxidize pyrite under acidic condition, providing a new oxidation approach for practical application. In fact, the key of the approach is the use of solid NaClO2 in acidic environment to generate ClO2 and then oxidize pyrite. For the pyrite pulp with 400 mL volume with an initial concentration of 0.025 M, the oxidation efficiencies of Fe and S in pyrite reached 99.8% and 98% at a NaClO2 concentration of 0.125 M and C4H6O6 concentration of 0.0025 M with magnetic stirring for 1 h at 30 °C in a constant temperature water bath. The addition of C4H6O6 can increase the acidity of the system and form a complex with iron ions, thereby preventing the precipitation of ferrihydrite from acidity changes caused by overdose NaClO2. After redox reaction, the acidity and oxidation–reduction potential (ORP, Eh) of the system were noticeably increased. The results of chemical composition analysis and X ray diffraction (XRD) analysis of pyrite oxidation residue confirmed that pyrite was oxidized to ions by ClO2, and no solid by-products such as Fe2O3 or Fe(OH)3 were formed. The scanning electron microscope (SEM) analysis of residual pyrite indicated that small pyrite particles were oxidized first, and then oxidants eroded the defects of large particles, gradually oxidizing all pyrites. This method is expected to be used as a pretreatment approach for pyrite oxidation before gold leaching process.

Chemical Composition and Antioxidant Activity of Crude Polysaccharide from Citron (Citrus junos Sieb. Ex TANAKA) Seed.

The crude polysaccharide (citron seed crude polysaccharide, CSCP) from citron (Citrus junos Sieb. Ex TANAKA) seed was obtained by water extraction and ethanol precipitation. The results of chemical composition analyses of the CSCP observed that neutral sugar content and uronic acid content were 27.70% and 14.70%, respectively. Monosaccharide composition of the CSCP was as follows in the following order: galacturonic acid+glucuronic acid (14.70 mol%)> arabinose (12.85 mol%)> glucose (4.54 mol%)> galactose (4.32 mol%)> mannose (2.70 mol%)> fucose (1.68 mol%)> rhamnose (1.61 mol%). The total polyphenol contents of the CSCP was 30.42 μg/mL and 86.12 μg/mL at 1 mg/mL and 10 mg/mL, respectively (P<0.001). 2,2′-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity was higher at the concentration of the CSCP 10 mg/mL (47.12%) than that of the CSCP 1 mg/mL (14.02%), (P<0.001). The ABTS radical scavenging activity was higher than 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity (14.33%) at the same concentration of the CSCP 10 mg/mL (P<0.001). Consequently, in this study, the crude polysaccharide from citron seed may be as a novel potential antioxidant.

Classification and compositional characterization of different varieties of cocoa beans by near infrared spectroscopy and multivariate statistical analyses

Effective and fast methods are important for distinguishing cocoa varieties in the field and in the processing industry. This work proposes the application of NIR spectroscopy as a potential analytical method to classify different varieties and predict the chemical composition of cocoa. Chemical composition and colour features were determined by traditional methods and then related with the spectral information by partial least-squares regression. Several mathematical pre-processing methods including first and second derivatives, standard normal variate and multiplicative scatter correction were applied to study the influence of spectral variations. The results of chemical composition analysis and colourimetric measurements show significant differences between varieties. NIR spectra of samples exhibited characteristic profiles for each variety and principal component analysis showed different varieties in according to spectral features.

Extraction and Characterization of Calotropis gigantea Bast Fibers as Novel Reinforcement for Composites Materials

ABSTRACTThe aim of this study is to scrutinize the use of Calotropis gigantea bast fibers as potential reinforcement in polymer composites. The bast fibers were extracted from the Calotropis gigantea plant bark and some of them were treated with alkali (5 wt.%) solution. The chemical composition, physico-chemical structural properties of the untreated and the alkali treated Calotropis bast fibers were studied. The results of chemical composition analysis indicated that alkali treatment removed most of the non-cellulose materials as confirmed by the FTIR analysis. The X-ray diffraction results exhibited that the crystallinity index of the alkali treated fibers increased in comparison with the untreated fibers, which agrees with the results obtained in the mechanical tests. The tensile strength and modulus of the alkali treated fibers were found to be higher whereas the elongation at break was lower than the untreated fibers. Thermal stability of alkali treated fibers was lower than that of the untreated fiber. Scanning electron micrographs showed roughening of the surface of the fiber due to the removal of the surface impurities and non-cellulosic components on alkali treatment.It can be concluded that alkali treatment is an effective method to improve the surface and mechanical properties of Calotropis bast fibers to be used in composite materials.