Multivariate model for the prediction of total phenolic acids in crude extracts of polyphenols from canola and rapessed meals: A preliminary study

The feasibility of using UV spectrophotometry to develop multivariate models for prediction of total phenolic acids content in crude polyphenol extracts from defatted canola and rapeseed meals was investigated. The polyphenols were extracted from the meals with methanol/acetone/water (7∶7∶6, by vol). Partial least squares regression was used to correlate the spectral data of the crude polyphenols in methanol between 320 and 355 nm with the total phenolic acid content in canola and rapeseed meals. The Folin-Denis assay was used to provide reference data for creating the model. The predictive ability of the model is good, as indicated by the RPD value (the ratio of the SD of data to the standard error of calibration) of 3.84.     

Antioxidant activity of crude tannins of canola and rapeseed hulls

The antioxidant activity of crude tannins of canola and rapeseed hulls was evaluated by β-carotene-linoleate, α,α-diphenyl-β-picrylhydrazyl (DPPH) radical, and reducing power assays. Crude tannins were extracted from three samples of Cyclone canola (high-tannin) hulls and Kolner, Ligaret, and Leo Polish rapeseed (low-tannin) hulls with 70% (vol/vol) acetone. The total phenolic content in crude tannin extracts ranged between 128 and 296 mg of sinapic acid equivalents per 1 g of extract. The ultraviolet spectra of methanolic solution of canola extracts showed two absorption maxima (282 and 309 nm), whereas those of rapeseed extracts exhibited a single maximum (326 nm). Crude tannins isolated from canola hulls exerted significantly (P<0.025) greater antioxidant activity than those from rapeseed in all three assays. The scavenging effect of all crude tannins, at a dose of 1 mg, on the DPPH radical ranged from 35.2 to 50.5%. The reducing power of Cyclone canola hull extracts on potassium ferricyanide was significantly (P≤0.0025) greater than that of rapeseed hull extracts, and the observed data correlated well (r=0.966; P=0.002) with the total content of phenolics present.     

Radical scavenging activity of canola hull phenolics

Possible use of canola hulls as a source of natural anti-oxidants was explored. Cyclone canola hulls were extracted with methanol (30 to 80%, vol/vol) and acetone (30 to 80%, vol/vol). The free radical-scavenging activity of phenolic extracts so prepared was evaluated using the 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) radical ion (ABTS^o−), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, and chemiluminescence assays. The total content of phenolics in prepared extracts from canola hulls ranged from 15 to 136 mg sinapic acid equivalents per gram of extract. Higher levels of condensed tannins were detected in the acetone extracts than in the corresponding methanolic counterparts. Seventy and 80% (vol/vol) acetone extracts displayed markedly stronger antioxidant activity than any of the other extracts investigated. Statistically significant linear correlations were found between TEAC (Trolox equivalent antioxidant capacity) values (expressed in mM of Trolox equivalents per gram of extract) and total pehnolics, TEAC and total condensed tannins (i.e., determined using the modified vanillin and pronthocyanidin assays), as well as TEAC and protein precipitation activity of phenolic extracts (i.e., measured using the dye-labeled assay). The antioxidant activities of extracts as determined by the ABTS^o− radical ion assay correlated highly with those of the chemiluminescence and DPPH radical assays.     

Protein-precipitating capacity of crude condensed tannins of canola and rapeseed hulls

The protein-precipitating potentials (PPP) of soluble condensed tannins (SCT) were determined in hulls from several samples of canola and rapeseed varieties. The PPP were expressed as slopes of lines (titration curves) reflecting the amount of SCT-protein precipitated vs. the amount of SCT added to the reaction mixture. The slopes (S _p ) of titration curves obtained using the protein-precipitation assay ranged from 2.96 to 10.91 (absorbance units at 510 nm per mg SCT), and those of titration curves, obtained using the dye-labeled bovine serum albumin (BSA) assay (S _d ), ranged from 28.1 to 267 (% precipitated BSA per mg SCT). For both assays, a statistically significant (P≤0.001) semilogarithmic linear correlation existed between the slopes and the SCT contents in the canola and rapeseed hulls. Higher amounts of SCT-protein complexes were precipitated at 40°C than at room temperature. Determination of titration curves under standardized conditions (type and concentration of protein, pH and temperature) afforded meaningful differences in the slopes among the range of SCT extracts from canola and rapeseed hulls used in this study.     

Application of artificial neural network for prediction of 10 crude oil properties

This study aims to develop an industrially reliable and accurate method to estimate crude oil properties from their Fourier transform infrared spectroscopy (FTIR) spectra. We used the complete FTIR spectral data of selected crude oil samples from seven different Canadian oil fields to predict 10 important crude oil properties using artificial neural networks (ANNs). The predicted properties include specific gravity, kinematic viscosity, total acid number, micro carbon content, and production of light and heavy naphtha, Kero, and distillate in oil refineries. The 107 different (65 light oil and 42 heavy/medium oil samples) crude oil samples used in this study came from seven oil fields and reservoirs across Canada. In line with standard practice, we used 80% of the dataset for training the ANN models and used the remaining 20% of the crude oil samples to test the models. In the ANN analysis, the mean squared error (MSE) was used as the loss function in models, and the mean absolute prediction error (MAPE) was used as a reference to compare the performance of different neural networks constructed with different numbers of layers. This work demonstrates that FTIR spectroscopy is a promising technique that provides rapid and accurate estimates for the oil properties of interest to the industry. A comparison of the values predicted by the validated ANN models and their corresponding measured (actual) values showed excellent prediction with the acceptable range of error (below 15%) aimed for by our industry partner for all properties except viscosity, for which building models based on the natural logarithmic values of measured viscosities significantly improved the results.     

A new method for determining gossypol in cottonseed oil by FTIR spectroscopy

A new method was developed to determine the gossypol content in cottonseed oil using FTIR spectroscopy with a NaCl transmission cell. The wavelengths used were selected by spiking clean cottonseed oil to gossypol concentrations of 0–5% and noting the regions of maximal absorbance. Transmittance values from the wavelength regions 3600–2520 and 1900–800 cm⁻¹ and a partial least squares (PLS) method were used to derive FTIR spectroscopic calibration models for crude cottonseed, semirefined cottonseed, and gossypol-spiked cottonseed oils. The coefficients of determination (R ²) for the models were computed by comparing the results from the FTIR spectroscopy against those obtained by AOCS method Ba 8-78. The R ² were 0.9511, 0.9116, and 0.9363 for crude cottonseed, semirefined cottonseed, and gossypol-spiked cottonseed oils, respectively. The SE of calibration were 0.042, 0.009, and 0.060, respectively. The calibration models were cross-validated within the same set of oil samples. The SD of the difference for repeatability and accuracy of the FTIR method were better than those for the chemical method. With its speed (ca. 2 min) and ease of data manipulation, FTIR spectroscopy is a useful alternative to standard wet chemical methods for rapid and routine determination of gossypol in process and/or quality control for cottonseed oil.     

Separation of Heavy Crude Oil Emulsions Using Microwave Radiation for Further Crude Oil Analysis

Microwave radiation in closed vessels was used for the separation of heavy crude oil emulsions for further oil characterization. Operational conditions were studied and the following parameters were evaluated: water content, density, viscosity, N, S, V, Ni, and Cl. Using the proposed procedure it was possible to reduce the water and Cl content in crude oil to values lower than 1% and 300 µg g^?1, respectively. It was possible to determine important crude oil properties without interferences caused by excessive water and salt concentrations. The proposed procedure is relatively fast and it was possible to obtain a suitable condition for water and salt removal from heavy crude oil emulsions without using demulsifiers or toxic reagents.     

Transformer oils prepared from the vacuum distillates of Egyptian crude paraffinic petroleum

Vacuum gas oil and spindle oil obtained from the vacuum distillation of paraffinic crude oil from the Western Desert region of Egypt were utilized for transformer oils production. The vacuum gas oil, spindle oil and blends therefrom containing different percentages of these oils and were subjected to aromatic extraction, dewaxing catalytic hydrogenation processes. The aromatic extraction process used N-methyl-2-pyrrolidone as solvent, for a feed ratio of 0.7:1 (wt/wt) at an extraction temperature of 55 °C, while in the dewaxing process the wax is removed by chilling the raffinate at − 42 °C using MEK-toluene (60:40,vol/vol). The hydrofinishing process was achieved in a pilot plant using NiO–MoO₃/Al₂O₃ catalyst. These refining processes improved the viscosity indices and the pour points of the resulting oils and removed most of the polar impurities. It was found that, the transformer oil formulated from 7:3 b.w. vacuum gas oil:spindle oil respectively meets the IEC 60296-2003 standard specifications requirements. Its sulfur content is very low and non-corrosive. The gassing tendency is also low due to its low aromatic content. Further, the electrical properties which are significant for transformer oils fulfill the standard specifications as a result of the low water content and polar contaminants. Moreover, addition of 2,4-dimethyl-6-tertiary butyl phenol increases the oxidation stability of the produced oil, by acting as a free radical inhibitor.     

水及杂质积累对粗蒽溶剂结晶精制咔唑的影响

考察了粗蒽结晶分离过程在溶剂循环使用时二甲苯中杂质和乙醇中水的积累对精制咔唑的影响。结果表明,随着二甲苯循环次数的增加,原料中的主要杂质萘、菲和芴在回收二甲苯中逐渐积累,其中萘的浓度最高可达0.35 mg·ml^-1,滤饼中咔唑的含量降低2.77%（质量）左右,收率降低高达7.05%（质量）。同时,母液中杂质的积累使溶剂回收困难,二甲苯的损失率随着循环次数增加而增加,由单程实验的44.75%（体积）增加到循环3次时的79.17%（体积）。原料中的水分随着溶剂循环在回收溶剂中逐渐积累,循环使用3次后,乙醇的含水量高达6.65%（体积）。乙醇含水量在0～12%（体积）之间时,咔唑纯度在98%（质量）以上。含水量在0～6%（体积）时,咔唑的相对结晶度随含水量增加从45.67 %降到40.79 %;含水量为9%和12%时,相对结晶度分别为48.85% 和48.52%。     

Specific energy consumption in electrochemical treatment of food industry wastewaters

BACKGROUND: Specific energy consumption (SEC) is an important factor in electrochemical treatment of wastewaters. SEC during electrochemical treatment of food industry wastewaters, specifically deproteinated whey wastewater (DWW), simulated sugar beet factory wastewater (SFW) and fruit juice factory wastewater (FJW), were investigated in this study. The effects of operational parameters applied voltage, and electrolyte and wastewater concentrations on SEC were assessed and optimized. RESULTS: SEC values were found in the range of 0.27–148.65, 0.94–375.76 and 0.20–636.40 kWh (kg COD)^?1 for DWW, SFW and FJW, respectively, after 8 h of reaction. Operational parameters were optimized at 25 °C through response surface methodology (RSM) where applied voltage was kept in the range (2–12 V), wastewater concentration and COD removal percent were maximized electrolyte concentration and SEC were minimized. Optimum conditions were estimated as 7.73 V applied voltage and 100% wastewater concentration in the presence of 27.11 g L^?1 supporting electrolyte concentration to achieve 25.02, 67.74 and 43.10% COD removal for DWW, SFW and FJW with corresponding SEC values of 17.85, 22.79 and 80.47 kWh (kg COD)^?1, respectively. CONCLUSIONS: Providing further research on the reduction of SEC values, application of electrochemical treatment to food industry wastewaters with non‐biodegradable components may become an alternative to conventional methods. Copyright © 2012 Society of Chemical Industry     

Physical–chemical and structural stability of PHBV/wheat straw fibers based biocomposites under food contact conditions

This aricle aims at investigating for the first time the ability of using poly(3-hydroxylbutyrate-co-3-hydroxyvalerate) (PHBV)/wheat straw fibers (WSF) biocomposites as food contact materials for packaging applications. For that purpose, the impact of the filler size and content on overall migration and mechanical properties was assessed under standardized testing conditions using the food simulant liquids (FSL). Very high overall migration values were noticed in the case of hydrophilic FSL, that is, water, acetic acid 3% (wt/vol), ethanol 20% (vol/vol), and ethanol 95% (vol/vol), related to the leaching of water extractable components of WSF. Low migration values were obtained in contact with isooctane and olive oil, demonstrating the possibility of using biocomposites in contact with fatty products. To answer the lack of methodologies to simulate different types of food for which PHBV-based composites could be more specifically dedicated, including food products of low or intermediate water activity such as fruits and vegetable, bread, and cheese, a new range of new solid food models based on agar-agar gels have been developed. Results showed that the water activity (a_w) was the main parameter governing the overall migration of PHBV/WSF materials, suggesting that such composite materials could only be used as food contact materials in the case of food products with an a_w equal or lower than 0.90.     

Modeling of the α-lactalbumin and β-lactoglobulin protein separation

This work used the General Rate Model (GRM) to evaluate the experimental data of α-lactalbumin (α-la) and β-lactoglobulin (β-lg) mass transfer using size exclusion chromatography (SEC). The chromatographic simulation has become necessary in large scale production processes. Mathematical models have been used for the optimization and control of different operating conditions of the process, as well as providing calculations for the process scale-up. For the SEC experiments, the aqueous biphasic system was composed of polyethylene glycol 1500 g/mol, potassium phosphate and whey protein isolate. The polymeric phase was enriched with α-la and the saline phase with β-lg. The experiments were conducted using a glass column packed with the Sephadex G-25^® gel. Both proteins were quantified by reverse phase liquid chromatography. The experimental data were fitted by non-linear regression, using the successive quadratic programming algorithm. The mass transfer model utilized represented adequately the SEC experimental results.     

Optimization of microwave-assisted enzymatic extraction of polyphenols from waste peanut shells and evaluation of its antioxidant and antibacterial activities in vitro

A microwave-assisted enzymatic extraction (MAEE) method was developed and optimized to enhance the polyphenols extraction yield from waste peanut shells. The optimum conditions were as follows: irradiation time 2.6 min, amount of cellulase 0.81 wt.%, a pH of 5.5, and incubation at 66 °C for 2.0 h. Under these conditions, the extraction yield of total polyphenols could reach 1.75 ± 0.06%, which was higher than other extraction methods including heat-refluxing extraction, ultrasonic-assisted extraction and enzyme-assisted extraction. The structural changes of the plant material after different extractions observed by scanning electron microscopy provided visual evidence of the disruption effect. Moreover, the crude extract was then purified by NKA-9 resin, the polyphenols content in the purified extract increased to 62.73%. The antioxidant activities of the crude and purified polyphenols extract were evaluated by DPPH and hydroxyl radicals, reducing power and β-carotene bleaching test. The antibacterial activities of purified extract were also tested using Oxford cup method. The results indicated that the MAEE method was efficient and environment-friendly, and the polyphenols have significant antioxidant and antibacterial activities, which can be used as a source of potential antioxidant and preservative.     

葡萄多酚在化妆品中的应用

介绍了从葡萄籽中提取葡萄多酚的方法,将葡萄多酚制作成面霜。考察面霜的稳定性、安全性与清除自由基能力,比较了粗提葡萄多酚面霜、纯提葡萄多酚面霜和维生素C面霜的清除自由基能力,以及纯提葡萄多酚的含量清除自由基能力的影响。     

Ethanol extraction of polyphenols in an immersion extractor. Effect of pulsing flow

A comparative study on polyphenol extraction from sunflower press cake in a semicontinuous pulsed-flow immersion extractor and in a conventional laboratory immersion extractor was developed. The solvent was 96% (vol/vol) ethanol. No difference in the residual polyphenol content in the cake was observed at short times, but after 10 h, the pulsed extractor showed a higher polyphenol concentration in the outlet miscella. In addition, the effective diffusivity of polyphenols in sunflower press cake was estimated.     

Rapid method for determining moisture content in crude palm oil by Fourier transform infrared spectroscopy

A simple, rapid, and direct Fourier transform infrared (FTIR) spectroscopic method was developed for the determination of moisture content of crude palm oil (CPO). The calibration set was prepared by adding double-distilled water to dried CPO in ratios (w/w) between 0 and 13% moisture. A partial least squares (PLS) regression technique was employed to construct a calibration model followed by cross-validation step. The accuracy of this method was comparable to the accuracy of the American Oil Chemists' Society's vacuum oven method, which is used for determination of moisture and volatile matter, with mean difference (MD_a) of 0.0105, a coefficient of determination (R ²) and a standard error of calibration (SEC) of 0.9781 and 0.91, respectively. It is also comparable to the accuracy of the International Union of Pure and Applied Chemistry's distillation method with MD_a, R ², and SEC of 0.0695, 0.9701, and 0.65, respectively. The study showed that midband FTIR spectroscopy combined with the PLS regression calibration technique is rapid and accurate for determination of moisture content of CPO samples with a total analysis time of less than 2 min and less than 2 mL of sample.     

Formulation and evaluation of the protein quality of a flour mixture of shark fillet by-products and shrimp heads

A flour proposed as a protein source for chick feeding was evaluated. The flour consisted in a 1.00:1.15 dry mixture of by-products from shark filleting (dt) and shrimp by products (cc). It had a crude protein content of 55.66%, a Ca:P ratio of 5.76 and an essential amino acid pattern similar to that of fish meal and/or shark meat. Methionine proved to be the first limiting essential amino acid. The shark meat and the by-products from shark filleting had adequate levels of available lysine (from 337 to 383 mg/g N). The flour had a fineness modulus (F.M.) of 3.95, an average particle diameter of 0.0175 inches (0.444 mm) and a uniformity index of 1:5:4 (coarse:medium:fine parts). The flour was considered suitable for chick feeding. The protein quality of the flour mixture (dt-cc) was evaluated in rats using diets which contained 3, 6, 9 and 12% protein from the product, and determining the PER, NPR and NGI values. Diets containing similar protein levels prepared from dried shark meat flour, mixed with casein, were used as standards. The flour mixture (dt-cc) had a PER of 1.60, an NGIo of 2.46, an NGI of 2.49 and an apparent digestibility of 88.80%. These values proved to be significantly (p less than 0.05) lower than those found for the corresponding shark meat flour-casein standard diets. The above results are partially explained by the high mineral content, high Ca:P ratio and high Na and K of the dt-cc mixture, factors which could interfere with the utilization of the most limiting essential amino acids and other nutrients, as some vitamins, in these diets. The Kruskal-Wallis test of the feed efficiency (EA) data obtained in growing chicks revealed that there was a significant (p less than 0.05) difference between the EA values obtained with the dried shark meat-containing diets and the standard commercial diets (Purina and a diet based on a 1.6:1.0 soybean meal:cottonseed meal mixture). No significant differences were found between the dt-cc mixture-containing diets and the commercial ones used as standard. The diet containing 6% shark meat flour was found to be the best based on the EA data. The diet with 12% of the dt-cc mixture gave similar EA values than all those containing shark meat flour; however, the greater nutritional-economic impact based on the EA data was found for the diets containing 3 and 6% of the dt-cc flour mixture.(ABSTRACT TRUNCATED AT 400 WORDS)     

Estimation of crude fiber in dehulled soybeans

The determination of crude fiber in soybeans is a lengthy and time-consuming procedure which requires extraction, digestion, and incineration and is not suitable as a routine processing-control tool. A short control procedure has been developed, employing photomicroscopy, which is based on the characteristics of soybean hull cellulose to rotate plane-polarized light. The sample is mounted on a microscope slide, treated with trichloro-acetic acid, and placed in a polarizing projection microscope; the image is compared with a series of standard photomicrographs. The amount of hulls present in the sample is measured quantitatively, and an estimation is made on the crude fiber. The crude fiber estimation on de-hulled soybeans can be made in 15 min compared with 8 to 12 hr by using the official crude fiber method.     

Lipid extraction from the microalga Phaeodactylum tricornutum

Ethanol was used for the extraction and purification of lipids from the biomass of the microalga Phaeodactylum tricornutum. This microalga is an oil‐rich substrate with a high proportion of eicosapentaenoic acid (EPA). The process consisted of two steps. First, ethanol (96% vol/vol) was used to extract the lipids from the lyophilized biomass. Second, a biphasic system was formed by adding water and hexane to the extracted crude oil. In this way, most of the lipids were transferred to the hexanic phase while most impurities remained in the hydroalcoholic phase. The first step was carried out by two consecutive extractions at room temperature, each with 5 mL ethanol per gram of biomass, for 10 and 1.25 h, respectively. Under these conditions, over 90% of the saponifiable lipids in the biomass were extracted. In the second step, the percentage of water in the hydroalcoholic phase, the hexane/hydroalcoholic phase ratio and the number of extraction steps were optimized. A water content of 40% vol/vol in the hydroalcoholic phase provided the highest lipid recovery. A recovery yield of 80% was obtained by four consecutive extractions with a hexane/hydroalcoholic phase ratio of 0.2 (vol/vol). Equilibrium distribution data of the lipids between the hydroethanolic and the hexanic phases were also obtained in order to predict the lipid recovery yield of the extraction. This process is an alternative to the traditional methods of lipid extraction, which uses less toxic solvents and reduces the total amount of solvents used.     

Agronomy,modelling and economics of reactive phosphate rocks as slow-release phosphate fertilizers for grasslands

Reactive phosphate rocks (RPRs) from Sechura, Peru (SPR) and North Carolina, USA (NCPR) were compared with triple superphosphate (TSP) as phosphate (P) fertilizers for permanent grass/clover pastures in four field trials in New Zealand. Trial sites ranged in initial pH (in water) from 5.7 to 6.3 and in rainfall from 712 to 1338 mm yr^–1. SPR and NCPR were used in the unground as-received state. Fertilizers were applied annually for six years. Pasture was harvested by frequent mowing, and herbage dry matter (DM) yields were measured at each cut. Herbage P concentrations were measured at each cut in two trials and on most cuts in the other two.For all sites combined, DM production from RPRs was initially significantly less than from TSP but it improved relative to TSP with time. Substitution values of RPR relative to TSP, denoted by S.V. (TSP/RPR) and defined as the ratio of P in TSP to P in RPR required to produce the same plant response during a specified period of time, were estimated by relating yields from RPR treatments to the yield response curve for different application rates of TSP. For the four trials combined, S.V. (TSP/SPR) increased from 0.32 in year 2 to 0.85 in year 6. S.V. values for NCPR were similar. The site which had the lowest S.V. values (average 0.20) for total production over six years was the site with highest pH (6.3) and lowest rainfall (712 mm). Corresponding S.V. values for the other sites were 0.50 to 0.78.Herbage P concentrations showed a similar pattern of RPR performance relative to TSP to that shown by DM production except at the highest application rate where TSP always supported much higher herbage P concentrations than RPR.The pattern of DM production from RPR relative to TSP was explained on the basis of a model involving soil P pools of undissolved fertilizer P and plant-available P respectively, with the hypothesis that P dissolved from RPR entered the plant-available P pool and was used with the same efficiency as P entering by dissolution of TSP. Model predictions of substitution values using directly measured RPR dissolution rates agreed well with observed substitution values.The advantage of RPRs in comparison to soluble P fertilizers for permanent pastures was considered to lie in their lower price and not in greater nutrient efficiency. Economic advantage was calculated in terms of the return on investment from establishing and maintaining a pool of RPR in the soil large enough to release the required annual amount of plant-available P compared with the cost of annual applications of soluble P fertilizer.