Extraction Of Pectic Substances Research Articles

Extração de substâncias pécticas do mesocarpo de Passiflora nitida Kunth. Passiforaceae

Passiflora nitida Kunth. (maracujá-do-mato) é uma espécie nativa do Brasil com ocorrência nas regiões norte, nordeste e centro-oeste. O seu fruto é consumido principalmente in natura, sendo pouco explorado quanto as suas propriedades funcionais. O objetivo deste estudo, foi extrair substâncias pécticas do mesocarpo de Passiflora nitida Kunth. O mesocarpo foi desidratado, triturado e obtido um pó de fina granulação (farinha), o qual, foi caracterizado quanto a granulometria, índice de intumescência, acidez titulável, cinzas e teor de umidade. Para a extração de substâncias pécticas foi utilizado 4g da farinha, em meio ácido. Foi usado o ácido cítrico comercial e suco de limão a 5% a 60ºC e 80ºC por 60 minutos e 120 minutos. Os experimentos foram realizados em triplicata e submetidos à análise de variância. O rendimento de substâncias pécticas com suco de limão por 60 minutos a 80ºC e 120 minutos a 60ºC foi de 17,9% e 14,3%, respectivamente. Para o ácido cítrico comercial, por 60 min a 80ºC e 120 minutos a 60ºC foi de 12,9% e 12,2%, respectivamente. O mesocarpo de Passiflora nitida poderá ser uma fonte para obtenção de substâncias pécticas.

Discovery of latent reserves of fruit and vegetable raw materials during the production of healthful food products for the world culinary specialists

Latent forms of pectic substances and biologically active substances (BAS) in nanocomplexes with biopolymers and minerals in fruits and vegetables are discovered. It is shown that in the latent form they are found in fruits and vegetables 2.5 ... 5 times more than determined by traditional chemical research methods. As an innovation, the complex effect of steam thermal treatment, cryoprocessing and mechanolysis during fine grinding on biopolymers and BAS is used. It is established that under the influence of these processes, a more complete extraction of pectic substances and BAS from the raw material (4.5 ... 7.3 times) from the latent form and transformation into a soluble form occurs

Study of the new method to intensify the process of extraction of beet pulp

We report results of experimental research into the process of acidic extraction of pectin-containing raw material (beet pulp) using the new model of the stirring element compared with the conventional grid stirrer. We have designed the experimental installation and devised a procedure for processing the results of studying the extraction process of pectin substances from pectin-containing raw materials (beet pulp), using the new combined stirring element. Mathematical models were constructed in the form of nonlinear regression equations based on the multifactor experiment planning method that employed input parameters of temperature, duration, and hydromodule. It was established that the principal influence on a change in the output parameters is exerted by the input variables of temperature and duration of the process. We show graphical dependences for quantitative and qualitative characteristics of pectin extracts (pectic substances concentration, molecular weight, complex- and gel-forming capability) depending on the input parameters of temperature and duration of the process for extraction of pectic substances. An analysis of these characteristics allowed us to determine the rational input parameters for the process of extraction of pectin substances. The rational working parameters of the process of acidic extraction of pectin substances from sugar beet pulp with the application of the new method for intensifying the process, are: temperature is 60...70 °C, duration is 1…1.1 hours, and hydromodule is 8...10. The purpose of this study was to intensify the extraction of pectic substances from pectin-containing raw materials, to improve technical level of the extraction process and to implement the developed method under industrial conditions. Based on the research results, the feasibility of the new method for intensification was established. Further implementation of these results in the food and processing industries would make it possible to produce a wide assortment of pectin-products (extracts, liquid and dry pectin concentrates).

Enzymatic hydrolysis of pretreated sugar beet shreds: Statistical modeling of the experimental results

In this work sugar beet shreds were subjected to pretreatment and enzymatic hydrolysis in order to convert lignocellulosic material to suitable source for bioethanol production, while response surface methodology and analysis of variance were used to fit the responses and determine significance of the models. Applied acidic extraction of pectic substances as pretreatment procedure gave 65% increase in reducing sugars yield in comparison to that obtained on untreated substrate. A three 32 experimental plans were conducted to investigate the influence of polyethylene glycol molecular weight/polyethylene glycol concentration, enzyme concentration/solids load and temperature/polyethylene glycol 4000 on the reducing sugars yield obtained during enzymatic hydrolysis of cellulose in sugar beet shreds. Statistical analysis, based on the results of the Fisher's test and determination coefficients, revealed that proposed quadratic models for experimental plans were significant and had the ability to represent relationship among the independent variables. The highest yield of reducing sugars was obtained at the highest investigated solids load (3% w w−1) with enzyme dosage 10 FPU g−1 substrate and polyethylene glycol 4000 as additive at 1 g (g substrate)−1, while temperature and hydrolysis time were 47.5 °C and 48 h, respectively. This yield of the reducing sugars was 1.6 times higher than the one obtained at lower solids load and temperature and in absence of the polyethylene glycol. Results indicated that by addition of polyethylene glycol 4000 at 1 g (g substrate)−1, enzyme concentration and hydrolysis time could be reduced by approximately two thirds and one third, respectively, without loss in sugars yield.

Simultaneous recovery of pectin and colorants from solid agro-wastes formed in processing of colorful berries

Extraction of pectic substances from solid agro-wastes and the application of recovered pectin in the food, pharmaceutical and cosmetic industry can significantly contribute to a more economic and environmentally sound agro-industrial production. Thus investigation of the physicochemical properties of extracted pectic substances seems important not only from human health preservation considerations, but their advantageous properties can be confirmed for the possible manufacturers, potential processing, as well. Therefore, in this work pectic substances were extracted from red currant, black currant, raspberry, blackberry and elderberry press residues by hot water and the composition, antioxidant activity, total phenol, anthocyanin content and the color coordinates of pectins were determined. The results show that the pectin colors fall in the range between reddish purple (black currant and elderberry) and yellow (citrus and apple). Moreover some of the pectins in a powder form have different color coordinates than in the form of aqueous solutions or gels. This might be very important when the pectins are selected for different production processes. The anthocyanin content of pectin preparations is lower than the values of fruit juices. It can be concluded that the colorants found in pectin preparations belong to the group of phenolics and have adequate antioxidant capacity, which is extremely beneficial for human health. As a summary it was concluded that the investigated pectins can be easily extracted and successfully used as natural colorants or antioxidants since they have adequate antioxidant activity, total phenol and anthocyanin content and suitable color coordinates.

Changes in firmness and structure of Chinese quince after successive extraction of pectic substances

Changes in firmness and structure of Chinese quince after successive extraction of pectic substances

Investigation of some physical characteristics of plant structures which are used as sources of pectic substances

We have investigated the physical parameters characterizing the porous structure of dried apple and orange peels, which are sources of pectic substances (PS). Mercury and nitrogen porosimetry were used to obtain quantitative data describing the characteristic diameter of the pores (d char ). Normally the diameter is between 0.13 and 0.39 μm for the apple samples, depending on the cultivar and treatment, and d char ∼ 0.27 μm for the orange samples. The total surface area of the capillaries (S tot ) for the apple samples is in the range 7.18-25.52 m 2 g -1 , and is 6.86 m 2 g -1 for the orange samples. The total density (ρ tot ) for the apple samples is 142.6-661.2 kg.m -3 , and 684.4 kg.m -3 for the orange samples. The skeletal density for the apple samples is 226.8-864.4 kg.m -3 , and 997.5 kg.m -3 for the orange samples. The porosity (e) varies from 23.5% to 37.12% for the apple samples, and is 31.4% for the orange samples. The scanning electron microscopy investigation confirmed the conclusions from the mercury porosimetry that both sources of PS have a complex capillary-porous structure. The latter structure includes pores with different shapes and dimensions, connected with each other in an unspecified manner. We present a suggested description of the kinetics of the water-binding capacity in dried apple and orange peels, using the exponential equation q = q x (1-e -kt ). The values obtained for the kinetic parameters k and q x are: q x = (2.78 ± 0.02) g/g and k = (2.60 ± 0.13) × 10 -3 s -1 for the apple peels, and q x = (4.62 ± 0.17) g/g and k = (3.23 ± 0.16) × 10 -4 s -1 for the orange peels. The results obtained enable the development of theoretical models describing the processes of extraction of PS, and the construction of machines to be used in the PS extraction.

Extraction of pectic substances from dehulled rapeseed

The water-insoluble residue of dehulled, defatted, and 80% ethanol-treated rapeseed was extracted following 10 different procedures, with initial extractions, comparing the effect of extracting agent [cyclohexane- trans-1,2-diamine- N, N, N′, N′-tetraacetate (CDTA) or buffer], pH (5 or 6.5), and ionic strength (0.02, 0.05 M, and in the case of buffer also 0.1 M) on yield and composition of the extracts. All 10 initial extractions were followed by two extractions with sodium carbonate at pH 10. The highest yield of pectic substances was obtained with CDTA at pH 6.5. A synergistic effect on the extracting efficiency between CDTA and pH seemed to exist. The monosaccharide composition of the polysaccharides was also different. The pectin extracted at pH 6.5 with CDTA had a higher proportion of uronic acids, suggesting a less branched variety of pectin. The sodium carbonate-extractions partly extracted a different population of pectin than CDTA. Two extracts (0.05 M CDTA/pH 6.5 and 0.02 M CDTA/pH 5) were further characterised by ion-exchange chromatography and monosaccharide analysis of the fractions. The proportion of neutral (non-retained) and acidic (gradient-eluted) polysaccharide material differed between the two extracts. The gradient-eluted material of the 0.05 M CDTA/pH 6.5 extract was retained longer on the column than the 0.02 M CDTA/pH 5 extract. Different conditions were evaluated for the extraction of pectic substances from dehulled rapeseed by chemical characterisation of the extracts.

Dietary fiber pectic substances: Source of discrepancy between methods of fiber analysis

A survey of methods for analysis of dietary fiber suggested that a number of differences between the methods could result in large discrepancies between them in extraction of pectic substances, which are a major component of cell walls and soluble fiber from most fruit and vegetables. Accordingly, the influence of buffer (phosphate versus sodium acetate), buffer concentration, pH, the presence of Ca 2+, and sample/buffer ratio on pectic polyuronide extraction was investigated. Within the ranges used in published methods, phosphate extracted much more polyuronide than acetate buffer. Extraction by acetate but not phosphate buffer was dependent on pH, buffer molarity, and sample/buffer ratio, and Ca 2+ suppressed polyuronide extraction in water but not in acetate buffer. Comparison of Englyst and Cummings' (1988, J. Assoc. Off. Anal. Chem. 71, 808–814) method, which uses phosphate buffer, with that of Theander and Westerlund (1986, J. Agric. Food Chem. 34, 330–336), which uses sodium acetate buffer, showed a large discrepancy (>400% in some cases) in polyuronide extraction. As soluble fiber may contain more than 70% polyuronide the results indicate an urgent need for standardization in fiber methodology. But (it is argued), standardization or precision with existing methods may be of questionable benefit as the extraction conditions they use have limited nutritional relevance.

Method for rapid extraction of pectic substances from plant materials

A method is described for the rapid extraction of pectic substances from alcohol insoluble solids (AIS) from material of plant origin, especially fruit. Samples of AIS can be prepared for galacturonic acid assay within 60 min using extraction with 0·5 m HCl in a Fibertec-1 system (Tecator) for 30 min. The extraction conditions are carefully standardised and operator error is reduced by the elimination of transfer steps, particularly during filtration. The results obtained for plant-derived alcohol insoluble solids containing from 10% to 33% pectic substances were in close agreement with those obtained by enzymic hydrolysis using a commercially available enzyme preparation (Ultrazyme). The method will have application in the rapid, routine estimation of pectic substances in plant materials.

Hindrance of Hemicellulose and Cellulose Hydrolysis by Pectic Substances

Treating the tissue of the grapefruit segment membrane with pectinase and cellulase decreased the content of xylose and glucose significantly more than the sum of the separate effects. The synergistic effect obtained by the combination of pectinase and cellulase showed that the pectic substance sterically masked the hemicellulose and cellulose. Breaking down the barrier of the pectic substance with pectinase allowed a significant increase in the hydrolysis of the hemicellulose and cellulose. Preparation of alchol‐insoluble solids from fresh tissue modified the structure of the pectin in the cell wall and prevented its steric hindrance to breakdown of hemicellulose and cellulase. Extraction of pectic substances from the tissue by NaOH greatly increased cellulose hydrolysis by cellulase.

Characterization of absorption sites for aluminum in the roots

Several experiments on the absorption sites for Al in the roots and the changes in the chemical fonns of Al absorbed with time were carried out. Among plant species the Al content in the roots was positively correlated with the CEC of the dry root powder. Extraction of pectic substances, nucleic acids, cold 10% trichloroacetic acid soluble phosphates (namely inorganic phosphates, ATP. sugar phosphates, etc.) significantly decreased the subsequent absorption of Al. Al content of the dry root powder was considerably higher than that of the excised roots which were treated with Al. The time course of Al uptake by the dry root powder was different from that by the excised roots: after approximately 1 hr of Al treatment the Al uptake by the dry root powder increased remarkably and proportionally to the time of Al treatment, while that by the excised roots increased only slightly. These results indicate that most of Al is bound to the pectic substances in the cell walls but a part of Al enters the protoplast an...

Removal of pectins from methylated rRNA and precursors by LiCl

The methyl group of radioactive methylmethionine is incorporated preferentially into pectin, a methylated polysaccharide, which massively contaminates RNA preparations. This makes it difficult to discern the methylated RNA species of growing tissues of higher plants. A method for the extraction of pectic substances from RNA preparations of plants is described. Ethanol precipitates containing RNA are suspended in 2 m lithium chloride (LiCl) and the pectin is removed with the supernatant after centrifugation. LiCl purification of RNA from Vicia faba root meristems allows the direct identification on polyacrylamide gels of methylated RNA species labeled with [ 3H]methyl methionine. Presumpive precursors of rRNA which fall into the range of apparent molecular weights of 2.7–2.9, 2.2–2.4, 1.4–1.5, and 0.72–0.75 × 10 6 are shown to be methylated, in addition to the methylation of the fully processed rRNAs of MW 1.3 and 0.7 × 10 6.

Some problems in the analysis of pectin in potato tuber tissue

Simultaneous determination of the degree of esterification and pectin content, without extraction, by Cu2+ ion exchange is described. The method, based on the high affinity of Cu2+ for pectic carboxylic acid groups, is applied to potato tuber tissue and potato, tuber cell wall material, and the results are compared with a combination of pectolytic extraction for pectin content and methanol determination after saponification and distillation. Cu2+ ion exchange appeared a valuable method for potato cell wall analysis. During analysis of potato tissue phosphate covalently bound to starch interferes in ion-exchange and leads to erroneous results. A means of correction is given for interference of neutral sugars in the carbazole test after pectolytic extraction of pectic substances.

Quality of pectin in pears, with special reference to the changes during maturation and subsequent after-ripening in Bartlett pears

Changes of quality in the pectic substances of Bartlett pears produced in the different growing areas during maturation and after-ripening, of canned products of ripened Bartlett pears, and of Japanese pears of optimum ripeness were investigated. Preparation and extraction of pectic substances from pears: The fruits were peeled, halved, cored and grinded. They were extracted with boiling 70% ethylalcohol to remove sugars. Extraction of pectin from sugar-free dried samples was performed successively with three agents in the order; cold water, cold 0.4% sodium hexametaphosphate, and 0.05N hydrochloric acid at 85°C. Water soluble pectinate and pectate (WSP) were extracted with cold water, water insoluble pectinate and pectate (PSP) with hexametaphosphate solution, and protopectin (HSP) with hydrochloric acid solution. Total pectin is the sum of these three fractions. Pectin content (Capectate), inherent viscosity and pectin unit were determined for each extracted pectin solution.

Studies on the quality of pectin in Citrus unshiu and C. natsudaidai, with special reference to the changes in the properties of pectic substances in peel and pulp at different stages of maturity

Changes of qualities occurring in the pectic substances of citrus peel and pulp at different stages of maturity were investigated. Preparation and extraction of pectic substances from citrus peel and pulp were obtained with the procedure described in the previous paper (studies on the quality of pectin in pears).

Effects of gamma radiation on the pectic constitutents of Citrus unshiu

Changes which occurred in the pectic substances of Satsuma orange (Citrus unshiu) induced by gamma radiation were studied. Satsuma oranges were purchased fresh through the market. Irradiation was performed with gamma rays from the Cobalt -60 source, does being at 0, 0.9×104, 9.6×104, 53.2×104, and 117.8×104 rep.Preparation and extraction of pectic substances: Juice, peel and pulp were separated from each other. Peel and pulp were extracted with boiling 70% ethyl alcohol to remove sugar. Extractions from sugar-free dried samples were performed successively with three agents: cold water; cold 0.4% sodium hexametaphosphate; 0.05N hydrochloric acid at 85°C (HCl-soluble A). Water soluble pectinate and pectate were extracted from cold water, water insoluble pectinate and pectate from hexametaphosphate solution, and protopectin from hydrochloric acid solution. Total pectin is the sum of the 3 fractions.Also, extractions from sugar-free dried peel and pulp were immediately performed with 0.05N hydrochloric acid at 85°C (HCl-soluble B).Determination of pectin content: Each of the extracts was determined by the calcium pectate method of CARRE and HAYNES.Inherent viscosity measurement: Approximately 0.1% pectin solution containing 0.6% sodium chloride and 0.4% sodium hexametaphosphate at pH 6.0 ±0.2 was used for determining relative viscosity (ηγ). Viscosity was measured at 30°C by OSTWALD-CANN0N-FENSKE viscosimeter. Inherent viscosity of pectin was calculated from relative viscosity ({η}=ln ηγ/C, C is concentration of pectin in the solution [wt./vol.%]).1. In juice, soluble pectin increased and inherent viscosity decreased by gamma radiation.2. In peel and pulp, water-soluble and hexametaphosphate-soluble pectin contents increased by gamma radiation and that of HCl-soluble A decreased, and then inherent viscosities of all fractions decreased, especially that of hexametaphosphate-soluble fractions in peel and pulp, and that of water-soluble one in pulp. This indicated that depoly merization occurred during irradiation. Both pectin content and viscosity decreased more in pulp than in peel.3. The pectin contents and viscosities of three fractions, especially of water-soluble and hexametaphosphate-soluble fractions, in the peel, differed from those in the pulp, and consequently it was apparent that properties of pectin between peel and pulp were different.4. Owing to the reduction of jelly units obtained by multiplying together the yield and jellly grade calculated from inherent viscosity of the pectin in HCl-soluble B, irradiated peel and pulp were unsuitable as the material of manufacture of pectin.