Mechanical behavior of sheets prepared from sugar beet cellulose microfibrils

The mechanical behavior of films cast from sugar beet cellulose microfibrils was investigated through tensile tests. The obtaining of these microfibrils by chemical and mechanical treatments from the raw beet pulp is described. Depending on their purification level, individualization state, and moisture content, differences in tensile modulus are observed. It is found that pectins act as a binder between the cellulose microfibrils, which tends to increase the Young's modulus in dry atmosphere and to decrease it in moist conditions. The extraction of the cellulose microfibrils from the sugar beet cell wall and the obtainment of microfibril suspensions with partial individualization of the microfibrils by a mechanical treatment lead to the formation of a network of cellulose microfibrils within the film, which in turn increases the tensile modulus. Furthermore, the effect of the remaining pectins is compared with the effect of pectins previously removed and added to completely purified cellulosic microfibrils. As expected, once removed and so partly degraded, those pectins have nearly no influence on the mechanical properties. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 1185–1194, 1997     

Cocoa (Theobroma cacao L.) hulls: a posible commercial source of pectins

Commercial exploitation of cocoa (Theobroma cacao L.) generates a volume of hulls that could be used in the production of pectins on an industrial scale. Therefore, pectins from cocoa hulls were extracted at different pH and temperature conditions, and their main chemical characteristics were evaluated. EDTA at 0.5% was used for the extraction at pHs 3, 4 and 5 and temperatures of 60, 75 and 90 degrees C, under a 3 2 factorial design. The response variables were yield, content of anhydrous galacturonic acid (AGA), content of metoxil, degree of esterification and equivalent weight of the pectins extracted. The strength of the pectic gel was determined with a TA-XT2 texturometer. Strawberry jam was made with the pectin extracted, and its acceptability was determined using a 7-point hedonic scale. The results obtained were as follows: an extraction yield from 2.64 to 4.69 g/100 g; an AGA content between 49.8 and 64.06 g/100 g; a content of metoxil between 4.72 and 7.18 g/100 g; a degree of esterification between 37.94 and 52.20%; an equivalent weight from 385.47 to 464.61 g/equivalent of H+, and a degree of gelation between 28.64 and 806.03 g force. The pectin extracted at pH 4 and 90 degrees C showed a gelation power of 422.16 g force, purity 62.26 g/100 g of AGA, and a yield of extraction of 3.89 g/100 g and allowed to prepare ajam with an average level of liking of "like moderately". Pectins from cocoa hulls show potential application in the food industry, but it is necessary to optimize the extraction parameters to increase its yield.     

Effect of Enzyme Pre-treatments on Bioactive Compounds in Extracted Tiger Nut Oil and Sugars in Residual Meals

Tiger nut oil is a novel oil that requires more research data on its characteristics. In this study, the oil was extracted using both enzyme‐aided pressing (EAP) and aqueous enzymatic extraction (AEE) methods. Using enzymes as a pre‐treatment prior to mechanical pressing increased the concentration of some phenolic acids and tocopherols present in extracted oils compared to controls. High pressure processing as a pre‐treatment before aqueous enzymatic extraction also enhanced tocopherols and total polyphenolic content in oils. The percentage free fatty acid and peroxide values indicated that under the initial extraction parameters, the oils were stable and they all met the standards for virgin olive oil set by the International Olive Oil Council. Residual meals from both extraction processes contained low protein contents ranging from 2.4 to 4.6 %. Additionally, EAP and AEE meals contained low DP (degree of polymerisation) sugars that appeared as 1‐kestose (DP3) and nystose (DP4). EAP had the highest total DP3 and DP4 sugar content of 82.5 mg/g. These sugars would need further assessment to verify their identity and determine their suitability as a potential food.     

Crop resides as lon-exchange materials. Treatment of soybean hull and sugar beet fiber (pulp) with epichlorohydrin to improve cation-exchange capacity and physical stability

Ion exchange systems for the treatment of process water or wastewater may benefit by the use of inexpensive, disposable exchange materials before, or in place of, conventional regenerable exchange resins. Various agricultural by-products have been proposed as suitable exchangers for this role, but they generally fail to have adequate capacity and physical stability for most applications. Two by-products, soybean hull and sugar beet fiber, were found to have enhanced cation-exchange capacity and stability upon treatment with epichlorophydrin and base. Exchange capacity was determined by measuring calcium binding. Physical stability was judged by three different aqueous extraction regimens. The most efficacious and economical reaction conditions found were: soybean hull and sugar beet fiber hydrated with water at a water-to-solids ratio of 6.4 : 1 and 8 : 1 (v/w), respectively, and epichlorohydrin applied at a 0.3 : 1 (v/w) ratio, for 6 h at room temperature. The resultant cross-linked materials had cation-exchange capacities of approximately 0.9 (soybean hull) and 1.3 (sugar beet fiber) meq/g dry weight. These epichlorohydrin-treated agricultural by-products may serve as cost-effective, multivalent-cation exchanges. © 1994 John Wiley & Sons, Inc.     

Optimization of Phenolic Antioxidant Extraction from Wuweizi (Schisandra chinensis) Pulp Using Random-Centroid Optimazation Methodology

The extraction optimization and composition analysis of polyphenols in the fresh pulp of Wuweizi (Schisandra chinensis) have been investigated in this study. The extraction process of polyphenols from Wuweizi pulp was optimized using Random-Centroid Optimization (RCO) methodology. Six factors including liquid and solid ratio, ethanol concentration, pH, temperature, heating time and extraction times, and three extraction targets of polyphenol content, antioxidant activity and extract yield were considered in the RCO program. Three sets of optimum proposed factor values were obtained corresponding to three extraction targets respectively. The set of optimum proposed factor values for polyphenol extraction given was chosen in further experiments as following: liquid and solid ratio (v/w) 8, ethanol 67.3% (v/v), initial pH 1.75, temperature 55 °C for 4 h and extraction repeated for 4 times. The Wuweizi polyphenol extract (WPE) was obtained with a yield of 16.37 mg/g and composition of polyphenols 1.847 mg/g, anthocyanins 0.179 mg/g, sugar 9.573 mg/g and protein 0.327 mg/g. The WPE demonstrated high scavenging activities against DPPH radicals.     

溶剂脱毒汽爆玉米秸秆对酶解以及发酵的影响

以脱毒对酶解及发酵的影响为研究对象,以酶解还原糖得率及发酵乙醇质量浓度为指标,采用溶剂萃取的方法对无催化汽爆玉米秸秆进行萃取脱毒。结果表明,酶解还原糖得率随着萃取剂及萃取方式介于34.85%和89.7%,酶解还原糖得率和发酵乙醇质量浓度与脱毒有机溶剂的沸点高度负相关,表明有机溶剂的残留是导致酶失活的主要原因。而对于所考察的溶剂,乙醇产率为0.47～0.49 g乙醇/g还原糖,表明有机溶剂残留对乙醇发酵并无显著影响。采用乙醚和丙酮的组合萃取,乙醇最高产率可以达到理论值的96.1%。     

Preparation and functional properties of soy hull pectin

Soy hulls (400 g), a co-product of the soybean processing industry, were used as a source of pectin which was extracted by0.05 N hydrochloric acid and precipitated with alcohol. The effect of various ratios of hull to extraction solvent (1∶10, 1∶15, 1∶20, and 1∶25) on the yield and purity of soy hull pectin was measured. The soy hull pectin extracts contained 63.07 to 68.72% galacturonic acid at various hull/solvent ratios. The pectin yield increased from 7.68 to 13.73% as the hull/solvent ratio increased from 1∶10 to 1∶15. Changes in pectin yield for higher hull/solvent ratio were insignificant (16.31–13.28% for 1∶20–1∶25 ratio, respectively). The hull/extraction solvent ratio did not significantly affect the pectin content and degree of esterification. Diffuse reflectance Fourier transform infrared spectroscopy of soy hull pectin revealed a similar surface structure to commercial-and analytical-grade pectins. The solubility of soy hull pectins was independent of solvent extraction ratios and pH. Rheology studies showed that pectin solution viscosity increased as the ratio of extraction solvent to hull decreased.     

Effect of ultrasound- and pulsed electric field-assisted enzymatic treatment on the recovery and quality of sunflower oil

The aim of this study was to evaluate the effect of cavitation and electroporation on enzymolysis extraction of sunflower oil. The optimum extraction conditions during 2 h under enzyme-assisted extraction (EAE) with a maximum oil yield of ≈23.70 ± 0.11% were as follows: cellulase/pectinase ratio 2:1, enzyme concentration 2%, pH 4.5, liquid/solid ratio 6:1 ml/g, and extraction temperature 40°C. Under the optimized enzymatic conditions, the application of ultrasound- (250 W) and pulsed electric field- (1.2 kV/cm; 52.4 kJ/kg) assisted enzymatic extraction for 30 min significantly increased the oil extraction yield by 91.1% and 18.6%, respectively, as compared with EAE.     

Verbesserung der Löslichkeit von Pektinsäure durch Schwingmahlabbau

Vibration grinding of high-molecular pectic acid results in preparations of nearly constant composition and decreased average molecular weight in dependence of grinding time. By using this favourable procedure it is generally possible to produce standardized pectic acid preparations with better and more reproducible solubility properties. Such preparations are required, e.g., for comparative enzymatic investigations. For evaluating polygalacturonase activity it is proposed to use pectic acid preparations with the following properties: viscosity number [η] (intrinsic viscosity) in the range of 50–100 ml/g, mineral content lower than 1 %, and anhydrogalacturonic acid content in the ash-free dry substance minimum 80 %.     

Surfactant-assisted enzymatic extraction of the flavor compounds from Zanthoxylum bungeanum

ABSTRACT

Surfactant-assisted enzymatic hydrolysis, which has been rarely involved in food industry, was used to extract the flavor compounds from Zanthoxylum bungeanum. The extraction conditions optimized through orthogonal and single-factor experiments were as follows: the amount of cellulase, neutral protease and surfactant (calcium stearyl lactylate) addition was 0.5%, 0.3% and 0.7% (w/w), respectively, the solid–liquid ratio was 1:6 (g/mL), the enzymolysis temperature was 45°C, the enzymolysis time was 3 h and the granularity was less than 60 mesh. Under these conditions, the yield of limonene, linalool and alkylamide increased from 1.02% to 7.51%, from 16.50% to 48.39%, and from 27.40% to 37.74%, respectively. The mechanism of surfactant-assisted enzymatic hydrolysis to extract the flavor compounds were also investigated. The study provides a scientific basis for the refinement and comprehensive utilization of Zanthoxylum bungeanum.     

Pectinesterase and polygalacturonase in changes of pectic matter in olives (cv. Hojiblanca) intended for milling

Virgin olive oil is a highly valued product, and it is important to optimize extraction yield. The pectic composition and the related enzymatic activities, present in the raw material, are variables that may affect that process. The pectinolytic activities producing modifications in the pectic matter of olive fruits (variety Hojiblanca) during ripening and the associated changes in texture were studied. Pectinesterase (PE) activity increased with ripeness until reaching a peak when anthocyanin synthesis in the fruit became marked (turning color stage). From then on, it decreased. In contrast, polygalacturonase (PG) activity in the ripe-green fruit decreased sharply when anthocyanin formation began (small reddish spots stage) and then increased, reaching a maximum in the ripe-black fruit. Parallel changes were noted in the texture and pectic content of the olives, related to endo- and exo-PG enzymatic activities, together with a decrease in the degree of esterification of the pectic matter, which could be associated with PE action. The distribution of the pectic fractions in the raw material and the changes in them during the olive oil extraction process showed the role of PE and PG in the fruits that was related to the yield of extracted oil.     

Immunodetection of Pectic Epitopes,Arabinogalactan Proteins,and Extensins in Mucilage Cells from the Ovules of Pilosella officinarum Vaill. and Taraxacum officinale Agg. (Asteraceae)

The main aim of this study was to compare the cytological difference between ovular mucilage cells in two Asteraceae species—Pilosella officinarum and Taraxacum officinale—in order to determine whether pectic epitopes, arabinogalactan proteins, or extensins are present. The immunocytochemical technique was used. Both the Taracacum and Pilosella genera have been used recently as models for understanding the mechanisms of apomixis. Knowledge of the presence of signal molecules (pectic epitopes, arabinogalactan proteins, and extensins) can help better understand the developmental processes in these plants during seed growth. The results showed that in Pilosella officinarum, there was an accumulation of pectins in the mucilage, including both weakly and highly esterified pectins, which was in contrast to the mucilage of Taraxacum officinale, which had low amounts of these pectins. However, Taraxacum protoplasts of mucilage cells were rich in weakly methyl-esterified pectins. While the mucilage contained arabinogalactan proteins in both of the studied species, the types of arabinogalactan proteins were different. In both of the studied species, extensins were recorded in the transmitting tissues. Arabinogalactan proteins as well as weakly and highly esterified pectins and extensins occurred in close proximity to calcium oxalate crystals in both Taraxacum and Pilosella cells.     

Mercury Removal by Adsorption on Pectin Extracted from Sugar Beet Pulp: Optimization by Response Surface Methodology

Considering the rich sugar beet resource in Xinjiang, China, the possibilities for Hg(II) removal by pectin extracted from sugar beet pulp and optimization of the extraction process using response surface methodology (RSM) were studied. The experiments were proposed by Box‐Behnken design (BBD) and a second‐order regression model was developed for regression analysis and analysis of variance. Optimized conditions in terms of temperature, concentration, and solid‐liquid ratio were determined. The effects of different parameters like pH, time, temperature, and initial Hg(II) concentration on adsorption capacity were investigated. The isotherm adsorption experiments were fitted with the Langmuir model which indicated monolayer adsorption.     

Enzymatic Extraction of Wheat Germ Oil

In this study enzymatic extraction of oil from wheat germ (WG) was investigated. Four enzymes (Viscozyme L, Multifect CX 13L, Multifect CX GC and Alcalase 2.4L FG) were screened for their efficacy to release oil from WG. Alcalase 2.4L FG treatment of WG improved oil extraction yield as compared to a control (aqueous extraction without enzyme). Alcalase 2.4L FG, which resulted in significantly higher oil yield than the other three enzymes, was chosen for optimization of the enzymatic oil extraction process by using Response Surface Methodology (RSM). Three processing parameters, liquid/solid ratio, extraction time and enzyme concentration, were investigated as the independent variables. Based on the experimental results, the highest oil yield, 66.5% (w/w), was obtained under the following conditions; liquid/solid ratio 16.5, enzyme concentration 1.1% and extraction time 19.25 h. A cubic model with R ² of 0.91 was developed to describe the enzymatic extraction process. Although the cubic model predicted WG oil extraction yields well within the processing conditions studied in this study it was not effective beyond the experimental range. Further research focusing on high liquid/solid ratio, 16–20, and extraction time in 18–24 h and 0.5–5 h ranges is necessary to improve the model developed in this study.     

Pigment removal from canola oil using chlorophyllase

Frost-damaged or prematurely harvested canola seed (rapeseed) may yield oil with a high chlorophyll content (50–60 μg/ml). Enzymatic hydrolysis of chlorophyll, added to buffer/surfactant, buffer/acetone or buffer/acetone/canola oil, to produce water-soluble chlorophyllide (green pigment) was studied using a crude chlorophyllase preparation (acetone-dried chloroplasts) from 15 to 20-day-old sugar beet seedlings. In buffer/surfactant, the optimum pH for enzyme activity was temperature dependent. At 30 C and 0.24% Triton X-100 (or 30% acetone), chlorophyllase showed maximum activity toward a crude chlorophyll preparation over the range of pH 8–10. At 60 C, the activity was more than twofold higher, with a sharp maximum at ∼pH 8. Mg²⁺ enhanced the activity with an optimal concentration of 50 mM. At pH 7.5, 50 C and in the presence of only 6% acetone, the enzyme showed high affinity for chlorophyll (Km=15μM or 13.5 μg/ml), suggesting that the natural chlorophyll concentrations found in green canola oils might facilitate high enzymatic efficiencies. The crude enzyme was stable in buffer/acetone at pH 7.5 and 50 C for at least two hr. With acetone concentrations as low as 6%, maximum enzyme activities in buffer and buffer/canola oil required intensive mixing (homogenization) of the various substrate, enzyme and liquid phases. In general, the rate and extent of chlorophyll hydrolysis were greater in buffer than in buffer/oil. In both reaction systems, chlorophyll hydrolysis slowed down with time due to accumulation of phytol, which proved to be a competitive inhibitor (K_i=11 μM or 3.3 μg/ml). The other hydrolysis product, chlorophyllide, did not affect enzymatic activity. Crude canola oil used in the reconstitution of green oil did not support enzymatic chlorophyll hydrolysis without prior degumming and desoaping. The optimum buffer/oil ratio of the reaction mixtures was above 2/1 (v/v).     

响应面法优化水/醇处理后汽爆玉米秸秆酶解

为了提高水/醇处理后汽爆玉米秸秆的酶解还原糖产率,对其酶解条件进行了优化。通过响应面优化法确定了底物质量浓度为53.28 g/L,纤维素酶用量为53.32 FPU/g,酶解时间为60.45 h时,还原糖产率可达672.36mg/g,与秸秆物料及汽爆后物料相比,酶解还原糖产率分别提高了170.46%和28.97%。化学组分及结构形貌分析表明,汽爆水/醇处理后物料纤维素含量显著增加,物料相对结晶度增高,其结构更有利于纤维素酶分子的吸附。     

The combined application of extrusion and enzymatic technology for extraction of soybean oil

This paper describes a new technological process for soybean oil extraction. The process deals with the combined effect of thermoplastic extrusion of beans and the subsequent action of hydrolytic and proteolytic enzymes in aqueous medium to recover the oil, thus, avoiding solvent application. The thermoplastic extrusion is fundamental for the process, because it facilitates the action of enzymes in oil containing cells, reduces the non-hydratable phosphatides and promotes protein denaturation by reducing the emulsion stability and thus enhancing the oil extraction. The main parameters affecting the oil yield are: the temperature and diameter of the die in the extrusion process, the dilution, the concentration of enzymes and the incubation time of the enzymatic treatment. The highest yield was obtained under the following conditions: extrusion of beans at 90°C and exit die of 6 mm, enzymatic incubation time of 6 h, extruded soy/water dilution ratio 1:10 and concentration of enzyme 6%. With these conditions 88% of the oil were obtained after centrifugation. Moreover, the aqueous enzymatic extraction is easier than solvent extraction, and leads to high value products: a solvent-free meal more suitable for human consumption, a protein hydrolysate that can be used as ingredient for liquid foods and an oil of better quality. The non-hydrolyzed meal contains ca 25% of original soybean protein and the residual oil. The protein hydrolysate in the liquid phase contains ca 75% of the total protein in the original grain with a molecular weight below 20 kDa.     

Enzymatic production of pectic oligosaccharides from polygalacturonic acid with commercial pectinase preparations

The present study investigates the individual efficiency of six commercial pectinase preparations (Endopolygalacturonase M2, Pectinase, Viscozyme L, Pectinex Ultra SP-L, Pectinase 62L and Macer8 FJ) in catalyzing the liberation of pectic oligosaccharides (POS) from polygalacturonic acid. On the basis of high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) analysis of the enzymatic hydrolysates, products release kinetics revealed a random cleavage pattern and an exo mode of cleavage for all the enzymes except for Endopolygalacturonase M2.All six enzymes generated oligoGalA with different degree of polymerization (DP); the quantitative composition of oligoGalA depended on the enzyme specificity and the time of enzymatic reaction. Endopolygalacturonase M2 was the best enzyme preparation for production of oligoGalA, with 18% (wt) of digalacturonic acid and 58% (wt) of trigalacturonic acid after 2 h of reaction. Concerning galacturonic acid production, Pectinase 62L was superior to the other enzyme preparations with 47% (wt) after 1 h of reaction.     

仙人掌粉水提工艺优化及其化妆品功效评价

对仙人掌粉水提工艺进行了优化。分别进行酶的添加、酶的筛选、酶解时间的确定和离子交换工艺的优化,确定了最终的提取工艺流程。并对仙人掌冻干粉酶提液和水提液的化妆品功效（抗敏舒敏性、保湿性）进行了评价和对纤维素酶提仙人掌粉提取液进行了稳定性测试。结果确定采用纤维素酶,提取的工艺条件为温度50℃,pH为5,g／s为1％,固液比为1：20,酶解时间为1h,离子交换上样比例为1：6。酶提法提取的仙人掌粉提取液在抗敏舒敏性、保湿性上均优于水提法提取的仙人掌粉提取液。纤维素酶提仙人掌粉提取液的稳定性良好。     

Recovery of15N-labelled fertilizer by sugar beet—spring wheat and winter rye—sugar beet cropping sequences

The recovery of¹⁵N labelled ammonium fertilizer was studied during two cropping sequences: sugar beet—spring wheat and winter rye—sugar beet with the labelled N applied to the first crop of each sequence. The difference between fall and spring application was also investigated. For the first cropping sequence 100 kg N ha^–1 labelled with 11.4%¹⁵N atom excess (a.e.) was applied to the sugar beets. This labelled N was followed in the sugar beets, in the soil profile at harvesting time as well as in the spring wheat of the following year. The first crop of sugar beet recovered 43–46% of the applied N, with 26–29% remaining in the soil at harvesting time and 25–31% could not be accounted for. Of the residual N, less than 1% could be recovered by the next crop of spring wheat. For the second cropping sequence 50 kg N ha^–1 labelled with 11.5%¹⁵N a.e. was applied to the winter rye and followed in the winter rye and in the sugar beets of the following year. The recovery of the labelled fertilizer N applied to the winter rye of the second sequence was 20–27% and the sugar beets of the next year could only recover 2%. With respect to time of application, no difference in fertilizer N recovery was found between fall or spring application for the two sequences.