Carrots polysaccharides

The structural features of ceU wall polysaccharides of carrots have been studied by Stevens and Selvendran (1984) and Massiot et al.(1988). Plat et al.(1991), Ben Shalom et al.(1992) and Massiot et al.(1992) investigated the changes in pectic substances of carrots after blanching, dehydration and extended heat treatment. Data on the changes in ceU waU polysaccharides of canned carrots are lacking. This study aims to investigate the effect of preheating time at low temperature and the addition of CaCL on texture and on the composition of various pectin fractions of carrots canned by conventional and by a new process. 

Effect of preheating time on firmness and pectic polysaccharides Firmness of canned carrots preheated at 65 C for 15, 30 and 60 min is illustrated in Fig. 1. Preheating for 15 min showed a firmness of 261.6N. When preheating time was increased higher tissue firmness was observed. Similar observations have been reported by Lee et al., (1979) and Quintero-Ramos et al., (1992) who found that firmness of carrot tissues was increased with increasing the time of blanching at 65 C. 

M. Baranska, H. Schulz, R. Baranski, T. Nothnagel and L.P. Christensen, In situ simultaneous analysis of polyacetylenes, carotenoids and polysaccharides in carrot roots, J. Agric. Food Chem., 53, 6565-6571 (2005). 

Stevens, B. ]. H., and R. R. Selven-dran. Structural features of cell-wall polysaccharides of the carrot Daucus carota. Carbohydr Res 1984 128(2) 321-333. 

Liners, F., Van Cutsem, P. (1992). Distribution of pectic polysaccharides throughout walls of suspension-cultured carrot cells - An immunocytochemical study. Protoplasma, 170,10-21. 

Incubation of D-[U-I4C]apiose with sterile Lemma minor (duckweed) produced less than 0.01% incorporation into the cell-wall polysaccharides.75 Most of the d-[U-i4C]apiose appeared as 14C02 some remained in solution in the medium and in the duckweed plants, primarily as degradation products of D-[U-14C]apiose, but not as the branched-chain sugar.75 There is an efficient synthesis of the [U-14C]apiose moiety of cell-wall polysaccharides from D-[U-14C]glucose under similar conditions.81 Of the plant tissues tested, only L. minor contained an enzyme system able to metabolize free apiose. Carrot, lettuce, and spinach tissues are unable to metabolize the free, branched-chain sugar.75... 

Isolation of Plant Cell Walls and Fractionation of Cell Wall Polysaccharides Materials Plant material, fresh and free from bruises and pathogens Ethanol Carrot (for leafy materials optional) Toluidine blue 0 (see recipe) Phloroglucinol-HCl solution (see recipe) Nail varnish or other sealant Iodine in potassium iodide solution (see recipe) Scalpel Double-edged razor blades Watch glass Artists brush, small Compound light microscope with appropriate glass microscope slides and coverslips... 

Microbial polysaccharides have been shown to stress plant cells, resulting in elicitation (induction) and increased metabolite synthesis. Induction of various enzymes has been reported. Chitosan successfully elicited chitinase production in carrot (Daucus carota) cell cultures and elicitation of desired food ingredients and processing aids via chitosan has been attempted. 

Asamizu, T., and Nishi, A., 1979, Biosynthesis of cell-wall polysaccharides in cultured carrot cells. Planta 146 49-54. 

Cellulose Polysaccharide composed of glucosyl residues linked p-1,4. Whole wheat flour, unprocessed bran, cabbage, peas, green beans, wax beans, broccoli, brussel sprouts, cucumber with skin, green peppers, apples, carrots... 

Structural Chemistry of Some Nonstarchy Polysaccharides of Carrots and Apples... 

Problems In the extraction, isolation, fractionation, and subsequent analysis of non-starchy polysaccharides, which may function as dietary fibre components, are discussed for such substances from carrots and apples. Structural studies on polysaccharides from carrots have resulted In the characterization of a branched arablnan, an esterlfled galacturonan (pectin), and an acidic iqrlan as individual components, and further evidence points to the presence of a 4 -linked galactan and a 4-linked glucomannan. 

In our studies on the polysaccharide constituents of carrots and apples the following considerations have been borne in mind (i) that account must be taken of the readily soluble as well as of the more obviously fibrous non-starchy polysaccharides (11) that cell wall materials must be prepared with minimum loss of these more readily soluble polysaccharides (ill) Chat broad spectrum analyses of pectlc substances and hemlcelluloses, even when supported by determinations of Individual sugar components, are rarely sufficient to establish the nature of these substances since the same sugar constituents occur In quite... 

Scheme 1 Flow sheet for polysaccharide extractions from carrot pulp...

TABLE II. Sugar composition (%) graded extraction of of polysaccharide fractions carrot CWM or AIR ... 

TABLE III. Methylation analyses of carrot pectin and the carboxyl-reduced polysaccharide... 

Extraction of Polysaccharides from Carrot OHM. CWM (25 g) was extracted three times by stirring in water (1 L) for 2 h at 80°. After each extraction Che suspension was centrifuged and Che combined supernatant liquids were freeze-dried Co give polysaccharide fraction A (0.5 g). 

Preparation of Carrot AIR and Isolation of Polysccharlde Fraction Carrots (900 g5 were cut into small pieces and blended In 95% ethanol (1.5 L), and the suspension was heated under reflux for 2 h. The residue was then extracted continuously with fresh ethanol until all colour had disappeared affording carrot AIR (35 g). Carrot AIR (35 g) was extracted thrice by stirring vigorously in water (2 L) at room temperature to give polysaccharide fraction F (5.3 g). 

Preparation of Apple CWM and AIR and Extraction of Pectin Fractions. Apples ( Granny Smith variety) were cored and peeled and the resulting pulp (2 kg batches) was stored in ethanol suspension to minimize enzymic oxidation. Separate batches of pulp were processed, as described for carrot preparations, to furnish apple CWM (32.5 g) and apple AIR (39.8 g) for which analytical data are recorded in Table VI. Polysaccharide fractions B (4 g) and C (2.5 g) were extracted from CWM with water at 80° and aqueous 1% ammonium oxalate at 80°. Likewise polysaccharide fractions A (2.1 g), B (5.2 g), and C (4.5 g) were Isolated from AIR by extraction with water at room temperature, 80°, and with aqueous 1% ammonium oxalate... 

In studies on the biosynthesis of cell-wall polysaccharides in cultured carrot cells, D-glucose was only incorporated into the neutral sugar residues, particularly cellulose, whereas myo-inositol appeared in the uronic acid and pentose residues. " An increase in cellulose content was observed during the thickening of the cell walls of parenchymous tissue of Discorea dumetorum tubers during storage. 

Kikuchi, A., Satoh, S., Nakamura, N. Fujii, T. (1995). Differences in pectic polysaccharides between carrot embryogenic and nonembryogenic calli. Plant Cell Reports Vol. 14, No. 5, (February 1995), pp. 279-284, ISSN 0721-7714... 

Small complex polysaccharide containing apiose, 2-0-methyl-L-fucose, 2-0-methyl-D-xylose, acetic acid, Penta-Ac, 3-deoxy-D-/yxo-heptulosaric acid and other sugars depending on source. Obt. by the action of liquefying enzymes on apple, tomato and carrot juice pectin. The main nondegraded soluble polysaccharide component of the juice. Also present in various other plant products, e.g. leaves of Panax ginseng (ginseng). 

The components of dietary hber are derived mainly from the cell walls of plant material in the diet. These include cellulose, hemicellulose (P-glucans, arabinoxy-lans, etc.), and pectin, collechvely referred to as the NSP. Food gums, also called hydrocolloids, are polysaccharides and are considered dietary hber. Lignin, a noncarbohydrate component of the cell wall and a nonpolysaccharide, is also included as hber that is very tough. Most edible fruits and vegetables, with the excephon of carrots, contain low levels of lignin. 

In recent studies, Roman et al. showed that the distribution of polyacetylenes within the phloem tissue is not uniform and areas with high amounts of these compounds may also occur occasionally [17]. In addition, the authors could not find higher concentration of polyacetylenes close to the periderm. Significant amounts of falcarindiol detected in wild carrot species are related to their resistance to some plant diseases such as root knot nematodes. Raman mapping was also used to assess the distribution of lignin and polysaccharide substances in carrot tissues. Based on the results obtained, the individual accumulation of starch and cell wall components such as lignin, pectin, and cellulose could be successfully demonstrated. 

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