Isolation, identification and dyeing studies of betanin on modified acrylic fabrics

Mature red fruits of Opuntia ficus-indica contain two soluble pigment, betanin and indicaxanthin. The optimal conditions for dye extraction were to mix 50 g of juice from cactus pears with 100 mL of acidified water as solvent for dye extraction. Two main dyes were purified from the pigment extract by chromatography and identified by UV-vis, HPLC and LC-MS techniques as indicaxanthin (15 mg per 100 g) and betanin (280 mg per 100 g). The effect of dye bath pH, salt concentration, dyeing time and temperature was studied. The optimal conditions for dyeing modified acrylic fabrics with betanin dye were carried out at 50 °C for 45 min at pH 5. Un-mordanted samples have good properties of water and washing fastness. Mordant CoSO₄ was found to give good light fastness (rating 5).     

The effect of different extraction techniques on extraction yield, total phenolic, and anti-radical capacity of extracts from Pinus radiata Bark

The performance of four techniques, conventional maceration, Soxhlet extraction, microwave assisted extraction (MAE), and ultrasound assisted extraction (UAE), for extraction of Pinus radiata bark, in one and several stages, were evaluated. For each technique, the mass extracted (g extract/g bark), total phenols (by Folin-Cicalteau), and tannin (by precipitation) concentration and anti-radical capacity (diphenyl-picrylhydrazyl, DPPH) were quantified. In one stage, the extracted mass increased in the following order: maceration < UAE < MAE < Soxhlet (p < 0.05). The total phenols and tannin levels were also higher with the Soxhlet technique. With additional extraction stages, only the samples produced with MAE and UAE techniques improved their parameters. Additionally, MAE extracts presented a higher anti-radical capacity than does Soxhlet and Pycnogenol^® extracts. Therefore, MAE was a simple and rapid method that was useful for extraction of P. radiata bark. Scanning electron micrographs (SEM) provided evidence of the mechanical effects on cell walls, mainly evidenced by cell destruction produced by Soxhlet, MAE, and UAE on the bark. In contrast, maceration only results in slightly ruptured cell pores, which could explain its low extraction yield.     

Supercritical carbon dioxide (SC-CO2) extraction of Nigella sativa L. oil using full factorial design

In this study, Nigella sativa L. oil was extracted using supercritical carbon dioxide with full factorial design to determine the best extraction condition (pressure, temperature and dynamic extraction time) for obtaining an extract with high yield, antioxidant activity and thymoquinone (TQ) quantity. The maximum thymoquinone content in the highest overall yield was achieved through SC-CO₂ extraction condition of 150 bar, 40 °C, 120 min with the value of 4.09 mg/ml. The highest SC-CO₂ extraction yield was 23.20% which obtained through extraction condition of 350 bar, 60 °C and 120 min. The extraction conducted at 350 bar, 50 °C, 60 min showed the lowest IC₅₀ value (highest antioxidant activity) of 2.59 mg/ml using DPPH radical scavenging activity method. Fatty acid composition of the extracted oil with highest radical scavenging activity was obtained by gas chromatographic analysis.     

Dyeing properties and colour fastness of wool dyed with indicaxanthin natural dye

This research work involves the dyeing of wool with indicaxanthin, a natural dye extracted from fruits of Opuntia ficus-indica. The optimal conditions for dye extraction were to mix 50 g of Juice from cactus pears with 100 mL of 80% aqueous ethanol as solvent for dye extraction. Liquid chromatography was applied for the separation. Two main dyes were obtained, which were identified as indicaxanthin (75 mg per 50 g) and betanin (5 mg per 50 g). The effect of dye bath pH, salt concentration, dyeing time and temperature were studied. The optimal conditions for wool dyeing with indicaxanthin dye were carried out at 70 °C for 90 min with the pre-treatment of various metal salts as mordant. The colour yields of the dye on the wool were found to be highly dependent of the pH, optimum results being obtained at pH 4. The K/S of wool increased in the order of the dyeing using KAl (SO₄)₂ > MnSO₄ > CoSO₄ > FeSO₄ > none > ZnSO₄ > CuSO₄. Un-mordanted samples have good properties of water and washing fastness. Mordants KAl (SO₄)₂ and CoSO₄ were found to give good light fastness (rating 5).     

A new microwave-assisted extraction method for melatonin determination in rice grains

A new microwave-assisted extraction (MAE) method has been developed for the extraction of melatonin from rice grains. The stability of melatonin under MAE conditions was studied in order to define the working range. The studied analytical conditions for the MAE were temperature (125−175 °C), microwave power (500−1000 W), time (5−15 min), solvent (10−90% EtOAc in MeOH), and ratio of solvent to sample (10:1–20:1). Extraction variables were optimized by Response Surface Methodology (RSM). Extraction temperature was found to have a highly significant effect on the response value (p < 0.0001) and the solvent and quadratic of time also had significant effects (p < 0.1). The optimized MAE conditions were as follows: extraction temperature 195 °C, microwave power 1000 W, extraction time 20 min, solvent 100% MeOH, and ratio of solvent to sample 10:1. The developed method showed high precision (in terms of CV: 4.97% for repeatability and 4.34% for intermediate precision). Finally, the new method was applied to real samples in order to investigate the presence of melatonin in a wide variety of rice grains.     

Optimization of ultrasonic-assisted extraction for herbicidal activity of chicory root extracts

The present study evaluated the herbicidal potential of extracts from chicory (Cichorium intybus L.) roots on the germination of Echinochloa crusgalli L. Beauv and Amaranthus retroflexus L. Eight ultrasonic assisted-extraction (UAE) conditions were optimized, using an orthogonal matrix design. The extract concentrations that would yield the largest allelopathic effects on the plant species were estimated by a modeling analysis. Our results showed that an alcohol solvent extract of chicory root had significant herbicidal activity which depended on the extract concentrations and the target species. The half-inhibitory concentrations of crude extract of chicory root ranged from 0.5 g l⁻¹ to 40.5 g l⁻¹. At a frequency of 40 kHz, the optimum UAE conditions to produce an extract for use as herbicide against E. crusgalli L. included an ethanol content (Ec) of 50% (v/v), a solvent-to-solid ratio (SR) of 16:1, an ultrasound temperature (UT) of 35 °C, an impregnation time (Imt) of 24 h with two rounds of impregnation (Imr), a sonication period (St) of 120 min with two rounds of sonication (Sr) and an ultrasound input power (P) of 200 W. The optimum conditions to produce an extract for use against A. retroflexus L. included an Ec of 100% (v/v), a SR of 16:1, an UT of 20 °C, an Imt of 48 h with two Imr, a St of 30 min with one Sr and a P of 400 W. The extract had the largest inhibitory effects on the germination index and root growth of both E. crusgalli L. and A. retroflexus L. at concentrations ranging from 30.8 to 33.7 g l⁻¹. At a concentration of 4.2 g l⁻¹, the extract significantly enhanced the shoot growth of A. retroflexus L. Overall, chicory root extract has potential for use as a main ingredient in natural herbicides or for development as a novel plant-derived herbicide.     

Response surface optimization of mechanochemical-assisted extraction of flavonoids and terpene trilactones from Ginkgo leaves

Mechanochemical-assisted extraction (MCAE) method was developed for extraction of flavonoids and terpene trilactones from Ginkgo leaves. The MCAE parameters and the antioxidant activities of Ginkgo biloba extract (GBE) were investigated. Through response surface methodology design experiments, the processing conditions were optimized as follows: amount of solid reagent (NaHCO₃) 21%, milling time 7.5 min, and ratio of solvent to solid 33 mL/g. Under these conditions, the yields of flavonoids and terpene trilactones in GBE were 6.83 mg/g and 1.72 mg/g, respectively. Compared with the heat reflux extraction method, the yields of flavonoids and terpene trilactones are higher, and the extraction time was significantly shortened. What is more, the MCAE method only used water as solvent. GBE of MCAE possessed notable antioxidant activity with IC₅₀ values of 11.7 and 13.8 μg/mL, respectively.     

Comparative growth of spring-planted canola, brown mustard and camelina

With increased emphasis for diesel substitution, production of brown mustard (Brassica juncea), canola (Brassica napus) and camelina (Camelina sativa) used as biodiesels may increase in the High Plains. Since these are new crops to this region, understanding their growth is critical for their acceptance. The objective was to elucidate the growth pattern of these crops when spring-planted in western Nebraska. Field trials were conducted in 2005, 2006 and 2007 with early May planting. Plots were seeded 2 cm deep at 200 plants m⁻². Four plants were destructively sampled at about 28, 40, 53, 61, and 82 days after planting (DAP). Canopy growth was field measured. Canopy heights peaked by 61 DAP at 95, 85 and 70 cm for brown mustard, canola and camelina, respectively. Stem length increased to 82 DAP at the rates of 1.24, 1.22 and 0.85 cm/d for brown mustard, canola and camelina, respectively. Root weight accumulated linearly from 28 to 61 DAP. The Brassica grew roots faster and achieved higher weights than camelina. From 28 to 40 DAP, vine fresh weight accumulated rapidly for these crops, leveled and then gradually declined as leaves desiccated. Vine dry weight increased to 61 DAP and then plateaued. The maximum vine dry weights, reached at 61 DAP, were 4.3, 4.5 and 3.0 g/plant for brown mustard, canola and camelina, respectively. By 61 DAP, pods were present and accumulated dry matter while leaves senesced. Pod fresh weight reached its peak at 61 DAP while its dry weight increased linearly to 82 DAP at rates of 0.36, 0.24 and 0.096 g/d for brown mustard, canola and camelina, respectively. Harvest in 2006 showed no significant (p < 0.05) difference between crops with a mean yield of about 1500 kg ha⁻¹. Fatty acid composition was dramatically different between the crops as previously reported. The growth patterns of these crops indicated that all three would be suitable for production in the northern High Plains.     

Synthesis of Jatropha curcas oil-based biodiesel in a pulsed loop reactor

Jatropha curcas oil (JCO) has a high content of free fatty acids and has been used extensively as a feedstock in biodiesel production. In the present study, the transesterification reaction of JCO to Jatropha curcas methyl ester (biodiesel) was performed in a continuous pulsed loop reactor under atmospheric conditions. The JCO was pre-treated prior to the reaction to reduce the free fatty acid content to below 1% (w/w). The operating parameters of the loop reactor were optimised based on the conversion of the JCO to Jatropha curcas biodiesel and included reaction temperature, molar ratio of oil to MeOH, reaction time and oscillation frequency. The findings show that the highest reaction conversion of 99.7% (w/w) was achieved using KOH catalyst and 98.8% conversion was obtained using NaOCH₃ catalyst. The optimal operating conditions were a molar ratio of 6:1, an oscillation frequency of 6 Hz, temperature of 60 °C, feedstock FFA content of 0.5% (w/w) and only 10 min of reaction time. As a commercial commodity, the physical properties of biodiesel were analysed, and they compared well with the characteristics of fossil-based diesel fuel.     

Optimisation of a solvent for the complete extraction of prolamins from heated foods

Wheat bread was lyophilised, ground, extracted and centrifuged. The supernatants were analysed for gluten content by RP-HPLC and a commercial sandwich ELISA. Prolamin extraction solvents contained tris(2-carboxyethyl)phosphine (TCEP; 1, 2, 5, 10, 20, 50 mmol/L), guanidine hydrochloride (GUA; 0 or 2 mol/L) and a buffered salt solution. A commercial cocktail solution (250 mmol/L mercaptoethanol (ME), 2 mol/L GUA, buffered salt solution) as well as 60% (v/v) ethanol were used as control solvents. Wheat flour was the control for the extractability of the native prolamins. 60% ethanol only extracted 37% of the prolamins from wheat bread (cocktail = 100%). When ME was replaced by TCEP the protein yield increased from 35% at the lowest TCEP-level to 95% when 20–50 mmol/L TCEP were used. The use of GUA was essential to extract prolamins quantitatively. Comparative protein analysis using RP-HPLC and ELISA showed that both methods provided comparable prolamin (gliadin) concentrations of the wheat flour (40.3–45.7 mg/g), when 60% ethanol was used as extraction solvent. The extraction yields from bread were considerably lower (16.7–24.7 mg/g). Cocktail and TCEP extracted almost the same amount of protein from flour and bread with TCEP showing slightly lower yields. Total extractable protein (gliadin + glutenin) as determined by RP-HPLC was 70.5–75.3 mg/g, and total gliadin as determined by ELISA was 42.7–44.2 mg/g. Thus, the study has shown that TCEP in combination with GUA extracts proteins from heated, gluten-containing foods as effective as the commercial cocktail solution.     

Potential of extracts of the tropical plant Balanites aegyptiaca (L) Del. (Balanitaceae) to control the mealy bug, Maconellicoccus hirsutus (Homoptera: Pseudococcidae)

The effects of extracts of different parts of the perennial tropical plant Balanites aegyptiaca (L) Del., including various solvent extracts of roots, methanol extracts from leaves, fruits, flowers and roots, partially purified saponins obtained from its roots and a standard saponin were studied on the life cycle (adult longevity, number of eggs, crawlers, adults, weight of adults and % wax content) of a laboratory-reared parthenogenic line of the mealy bug, Maconellicoccus hirsutus (Homoptera: Pseudococcidae). Extracts derived from various parts of B. aegyptiaca (leaves, fruits, flowers, and roots in methanol) affected the life cycle of M. hirsutus with a methanol root extract being the most effective at a concentration of 500 μg ml⁻¹. Partially purified saponin of B. aegyptiaca and the commercial bark saponin extract (Sigma) from Quillaja saponaria at a concentration of 500 μg ml⁻¹ were effective in reducing the longevity of M. hirsutus. Significant reductions in oviposition by M. hirsutus were found for all the extracts at a concentration of 500 μg ml⁻¹. Extracts also affected the number of emerging crawlers, number of adults as well as the weight and wax content of emerging adults. These studies suggest that B. aegyptiaca plant extracts and saponins can be useful botanical insecticides for the protection of crops from mealy bugs.     

Gorse (Ulex europæus) as a possible source of xylans by hydrothermal treatment

Autocatalytic hydrothermal process conditions were used to study Ulex europæus (Gorse) as a source of xylan compounds. The aim was to study the possibilities for using this unutilised biomass material to produce xylans. Ulex is an evergreen shrub that grows in the northwest of Spain and has no economic value. Therefore, Ulex is considered a promising candidate as a biomass source. Ulex showed a total xylose content of 12%, thus qualifying it as a suitable material to extract xylan-derived compounds. Autohydrolysis was applied to extract xylans from Ulex. To find the best conditions for xylan extraction, samples of Ulex were subjected to different temperatures and time conditions. Results indicate that autohydrolysis is a suitable method to selectively extract xylans at temperatures between 160 and 190 °C for 5-30 min, reaching a maximum xylan recovery of almost 63% of the initial xylan at 180 °C for 30 min, with only small effects on cellulose and lignin contents.     

Fatty acid composition and oxidation stability of hemp (Cannabis sativa L.) seed oil extracted by supercritical carbon dioxide

Supercritical carbon dioxide (SC-CO₂) was employed to extract oil from hemp (Cannabis sativa L.) seeds. For ground seeds, the supercritical extraction was carried out at temperatures of 40, 60 and 80 °C and pressures of 300 and 400 bar. Different solvent-ratios were applied. Supercritical CO₂ extractions were compared with a conventional technique, n-hexane in Soxhlet. The extraction yields, fatty acid composition of the oil and oxidation stability were determined. The seed samples used in this work contained 81% PUFAs, of which 59.6% was linoleic acid (ω-6), 3.4% γ-linolenic (ω-3), and 18% α-linolenic (ω-6). The highest oil yield from seeds was 22%, corresponding to 72% recovery, at 300 bar and 40 °C and at 400 bar and 80 °C. The highest oxidation stability corresponding to 2.16 mM Eq Vit E was obtained at 300 bar and 80 °C.     

Comparative seasonal variation and chemical composition of essential oils from the leaves and stems of Schefflera heptaphylla using microwave-assisted and conventional hydrodistillation

Two different isolation techniques, microwave-assisted hydrodistillation (MAHD) and conventional hydrodistillation (HD), were used to extract the volatile constituents from the leaves and stems of Schefflera heptaphylla (L.) Frodin harvested during four different seasons, which were subsequently analyzed via gas chromatography with flame ionization detection and gas chromatography with mass spectrometry. MAHD is more advantageous than HD in terms of energy savings and extraction time (60 min vs. 180 min for MAHD vs. HD). Large variations in the composition among the different oils were observed. The seasonal changes in the percentages of the main constituents of the oils were irregular; this affected the quantity and composition of the oil. Oil yield was affected by the method of extraction and seasonal changes. It ranged from 0.11% to 0.27%, with the maximum amount of oil extracted from the leaves using MAHD in winter and the minimum from the stem oil extraction using HD in spring. The essential oil content varied significantly with the season. Sesquiterpene hydrocarbons constituted the major portion of the essential oils. Sesquiterpene hydrocarbons were highest in the leaf oil extraction by HD during winter (88.6%) and lowest in the stem oil extraction by HD during spring (56.3%). Microwave irradiation did not adversely affect the composition of the essential oils. MAHD, indeed, is a modern, green, and fast technology.     

Ultrasound-assisted extraction and profile characteristics of seed oil from Isatis indigotica Fort

In order to further exploit the by-products of Isatis indigotica Fort., the seed oil was studied for its extraction and physicochemical properties. Ultrasound-assisted extraction (UAE) was used, and the parameters affecting seed oil recovery were optimized through response surface methodology (RSM). The optimum conditions were as follows: solvent-to-sample, 24:1; particle size, 110 meshes; extraction temperature, 49 °C; and extraction time, 44 min. Which resulted in a maximum oil recovery of 81.20 ± 0.21% (n = 3). Furthermore, the effects of UAE on the yield, fatty acid compositions, physicochemical properties, and microstructure of the seed powder were also investigated by calculating the recovery rate, utilizing a gas chromatograph fitted with a mass spectrometer (GC-MS), and performing scanning electron microscopy, respectively. The results show that UAE was an effective method for the seed oil extraction and the high content of unsaturated fatty acids (93.81%) demonstrates the oil has potential benefits for the cosmetics, edible products, or pharmaceutical industries.     

In vitro regeneration from petiole explants of non-toxic Jatropha curcas

Jatropha curcas, a multipurpose shrub has acquired significant economic potential as biodiesel plant. The seeds or pressed cake is toxic due to the presence of toxic substances and is not useful as food/fodder despite having the best protein composition. A simple, efficient, and reproducible method for plant regeneration through direct organogenesis from petiole explants of non-toxic J. curcas was developed using Murashige and Skoog (MS) medium supplemented with different concentrations of thidiazuron (TDZ). The best induction of shoot buds (57.61%), and number of shoot buds (4.98) per explant were obtained when in vitro petiole explants were placed horizontally on MS medium supplemented with 2.27 μM TDZ. The Induced shoot buds were transferred to MS medium containing 10 μM kinetin (Kn), 4.5 μM 6-benzyl aminopurine (BA), and 5.5 μM α-naphthaleneacetic acid (NAA) for shoot proliferation and subsequent elongation was achieved on MS medium supplemented with 2.25 μM BA and 8.5 μM IAA. The elongated shoots could be rooted on half-strength MS medium with 15 μM IBA, 11.4 μM IAA and 5.5 μM NAA with more than 90% survival rate.     

Extraction of natural dye from <Emphasis Type="Italic">Coreopsis tinctoria</Emphasis> flower petals for leather dyeing − An eco-friendly approach

This study evaluated the extraction of two colors of dye (yellow and brown) from Coreopsis tinctoria flower petals using ultrasound and the dyeing of leather with the extracted dyes as a source of nontoxic and eco-friendly dye. The results showed an increase in the dye extraction values with increasing time at 100 W ultrasonic power at 80 °C for 1 h. Leather dyeing was optimized with the aid of ultrasound and magnetic stirring. The optimum leather dyeing conditions, with respect to the dye uptake, dye penetration and intensity of the color, were determined to be 12 % dye concentration, 100 W power, 1,000 rpm, and pH 7.0 for 60 min at 80 °C. It was shown that sonication improves dye exhaustion from a 90 % to 60 % rating for 1 h of dyeing time. The dyed leather was assessed by reflectance measurements and compared with visual assessment data. The fastness properties of dyed leather samples showed good fastness against washing, light, and dry and wet rubbing. The strength properties were not significantly altered and the bulk properties, such as softness, were found to be improved by the use of Coreopsis tinctoria yellow and brown dyes using an ultrasonic and magnetic stirring dyeing process.     

NaCl plays a key role for in vitro micropropagation of Salicornia brachiata, an extreme halophyte

A simple and rapid method for micropropagation of succulent, salt accumulator and extreme halophyte Salicornia brachiata has been established for the first time using shoot tips and nodes. Individually, BA showed significant response compared to Kn and in combinations, improved shoot proliferation was observed with BA + NAA than BA + 2,4-D, however no significant response was observed with BA + IAA. Percentage of shoot response significantly increased with NaCl treatment in the combination of BA + NAA while BA + 2,4-D + NaCl combination showed reduced shoot proliferation followed by demises of most of cultures. Efficient shoot proliferation was observed with combinations BA (8.9 μM) + NAA (5.37 μM) + NaCl (500 mM) and BA (13.3 μM) + NAA (5.37 μM) + NaCl (250 mM) indicating that NaCl is required for the micropropagation. The developed method will facilitate functional analysis of novel salt responsive gene(s) isolated from S. brachiata and propagation of industrially important elite accessions.     

Antioxidant activity of phenolic compounds obtained by autohydrolysis of corn residues

This study aimed to evaluate the effect of autohydrolysis temperature of corn residues in the antioxidant activity of the phenolic compounds extracted from the liquid phase. The treatments were carried out at 160, 180, 190 and 200 °C for 30 min in a pressurized batch reactor. Two different methods for phenolic compounds extraction from the autohydrolysis liquors were investigated. For that purpose, solvent extraction with ethyl acetate and acidic precipitation were performed for phenolic compounds recovery. These methods have been compared in terms of extraction yield, physicochemical properties of obtained polyphenols (characterization by Fourier Transform Infrared Spectroscopy, Thermogravimetric Analysis and Gel Permeation Chromatography), total phenolic content, total antioxidant capacity and Trolox equivalent antioxidant capacity (TEAC) values, measured in DPPH (2,2-diphenyl-1-picrylhydrazyl) test system. The maximum phenolic contents ranged from 6.04 mg GAE/100 mg extract in acidic precipitated samples to 16.45 mg GAE/100 mg extract in ethyl acetate soluble fractions. The results indicated that the ethyl acetate fractions possessed the highest antioxidant activity, reaching after 30-60 min the same capacity reported for the reference synthetic antioxidants (Trolox).     

Growth and accumulation of caffeic acid derivatives in Echinacea angustifolia DC. var. angustifolia grown in hydroponic culture

In separate experiments conducted in 2007 and 2008, growth and accumulation of selected caffeic acid derivatives (CADs; i.e., caftaric acid, chlorogenic acid, echinacoside, caffeic acid, cynarin, p-coumaric acid, ferulic acid and cichoric acid) were determined in Echinacea angustifolia DC. var. angustifolia seedlings grown in hydroponic culture (floating raft system) at a density of 122 plant m⁻² (at planting). Plants were harvested 11 (2007) or 16 (2008) weeks after transplanting (i.e., 15 or 20 weeks after sowing). In both years, plants grew vigorously and at harvest approximately half of the plants under observation had developed one to three inflorescences. In 2008, the root yield (2940 kg ha⁻¹) harvested in nearly eight months from two consecutive hydroponic cultures was within the yield reported in the literature for field cultivations lasting two to four years. None of the selected CADs was found in the leaves, while the inflorescences (stem and capitulum) contained only caftaric acid and echinacoside at concentrations higher than the detection limits (0.05 mg g⁻¹ dry weight). Echinacoside, cynarin and chlorogenic acid were found in root tissues at concentrations ranging from 0.36 to 5.25 mg g⁻¹ dry weight. In all plant samples, echinacoside, which is the marker compound for E. angustifolia material, did not reach the minimum quality standard (10 mg g⁻¹ dry weight) for the production of standardized extract. We concluded that short-cycle, high-density greenhouse hydroponic culture stimulates plant growth and root production in E. angustifolia, but it does not ensure sufficient CADs accumulation in dried roots.