Peas, extracts

Fig. 9 Reversed-phase chromatogram of frozen pea extract. The C, 8-column was subjected to an isocratic elution by acetone water (70 17 13). The chlorophylls and pheophytins were detected by fluorescence, with the excitation wavelength at 413 nm and the emission wavelength at 669 nm. (From Ref. 107.)...

Our present efforts are being devoted to studying pea lipides in situ, in the hope of determining whether hormone activation by lipide substances is a natural method of growth regulation. Gas chromatography has already confirmed that our original active pea extract is a mixture of conventional fatty acid esters. 

The quaternary salts 257 (R = R = H, n = 0, 1) were oxidized to compounds 99 ( = 0, 1) by means of cell-free pea extract - or by chromic acid in acidic medium. ° The betaine 260 gave the tetrahydro-pyrrolo[2,l-i>]quinazolin-9-one 95 with 5 molar equivalents of potassium ferricyanide, but the tetrahydropyrrolo[2,l-6]quinazolin-9-ol 186 with 2 molar equivalents of potassium ferricyanide. The action of potassium ferricyanide converted the hexahydropyrrolo[2,l-i ]quinazoline-3a-carbox-ylic acid (327) to the tetrahydropyrrolo[2,l- >]quinazoline 124. ... 

Although pyruvate and 2-oxobutyrate are substrates of acetohydroxyacid synthase, measurements of the activity of this enzyme have been almost exclusively based on the production of acetolactate from pyruvate. This reaction product is readily decarboxylated under acidic conditions and the acetoin produced can be measured spectrophotometrically. However, ace-toin can be formed during reactions which need not be related to amino acid biosynthesis. Therefore it is unclear whether the enzyme activity characterized by Saytanarayana and Radhakrishnan (1963) can be completely ascribed to acetohydroxyacid synthase. Only a portion of the acetolactate forming activity measured in pea extracts was considered to represent the activity of this enzyme (Davies, 1964). However, the enzyme(s) isolated from barley was shown to facilitate formation of acetohydroxy derivatives of 2-oxobutyrate and pyruvate (Miflin, 1971). Mg or Mn " " as well as the substrate, hydroxyethylthiamine-pyrophosphate, was required for maximum enzyme activity. The fact that the acetolactate forming activity of the barley... 

Higher plants are generally agreed to possess no detectable B12 except in the nodules of symbiotic nitrogen fixers (Evans and Kliewer, 1964). In accord. Woods et al. (1965) reported that pea extracts contain only... 

Some properties of the different isoforms extracted from mung bean hypocotyi cell walls (called respectively PEa, PEP and PEy, a for the neutral isoform, P for the PME with a pi around 8.5 and y for the most basic one) are reported in Table 3. The three esterases differed not only in their pi but also by their Mr, their pH optimum and the ionic strength necessary for their solubilization. 

Weigh 20 g (fresh weight) of chopped and homogenized plant samples into a 300-mL Erlenmeyer flask. Add 80 mL of acetone and shake the flask vigorously for 30 min with a shaker. In the case of brown rice and pea, add 20 mL of water to 10 g of sample and allow to stand for 2 h before adding 80 mL of acetone. Filter the extraction mixture by suction through a glass filter and re-extract the residue on the filter with 50 mL of acetone, then filter the mixture by suction. Concentrate the combined filtrate in the 300-mL of round-bottom flask to remove acetone at below 30 °C after addition of a 25% aqueous solution of potassium carbonate (0.2 mL). 

Manganese deficiency occurs principally in soils with a high pH or calcareous soils since Mn in these soils is mostly present in insoluble oxides. Manganese deficiency has been found for more than 20 crops including oats, rye, wheat, rice, maize, peas, soy beans, potatoes, cotton, tobacco, sugar beets, tea, sugar-cane, pineapples, pecans, peaches, spinach, citrus, and a number of forest trees (Table 7.8) (Sillanpaa, 1982). The critical DTPA-extractable Mn for Mn deficiency has been suggested to be 1.6-3.9 mg/kg, and soils with up to 5.2-6.5 mg/kg DTPA-extractable Mn has been considered to indicate susceptibility (Sillanpaa, 1982). 

The field pea (Pisum sativum) and small fababean (Vicia faba minor) were pin milled and air classified into protein and starch fractions or, alternately, the protein, starch and fiber were extracted by an aqueous alkali procedure. 

The objectives of the present study were to compare the processes of protein and starch concentration by dry air classification and wet alkali extraction of protein and starch from field pea and fababean. The yields, composition and functionality of the crude and refined products were compared. 

The final pH of the initial extract from the vibrating screen was 7.5 but this increased to pH 9.6 and 10.2 for fababean and field pea, resp., during the second extraction. The filtrates were combined and centrifuged on a Fletcher basket centrifuge at 3400 rpm (1800 x g) to separate the starch and protein (Figure 2). 

Figure 4. Pea stem material was sequentially extracted with hot 70% ethanol, 0.1 M EDTA and 4% KOH-0.1% NaBH4 to leave xyloglucan-cellulose cell wall ghosts . Binding of fluorescent fucose-binding lectin from Ulex europeus as visualized by fluorescence microscopy shows xyloglucan distributed over the whole wall surface. Photograph courtesy of Dr. T. Hayashi.

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