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The proximate composition of defatted edible groundnut flour, processed and unprocessed, has been determined. The flour contains about 38 % total carbohydrates of which oligosaccharides account for 18 %, starch 12.5 %, hemicelluloses A and B 0.5 and 3.5% respectively and fibre (cellulose) 4.5%. Sucrose 13.90 and 14.55 %, raffinose 0.89 and 0.92 %, stachyose 1.56 and 1.60 %, and verbascose 0.41 and 0.42 % represent the oligosaccharide fractions (from 70 % alcoholic extract) of unprocessed and processed flour, respectively. In addition the unprocessed flour also contained glucose 0.80% and fructose 0.41 % along with two unidentified spots 0.70 %. Hemicellulose A consisted of glucose, arabinose, and xylose (4 :0.5 : 0.1) whereas hemicellulose B had galacturonic acid, glucose, galactose, arabinose and xylose (1 :4 : 1 : 12 : 6). The fibre fraction on hydrolysis yielded predominantly glucose with only traces of galacturonic acid and rhamnose. The presence of verbascose and xylose in groundnuts has not been previously reported.

Starch has been isolated from the millet varagu in 63% yield. Study of the physical properties revealed: moderate swelling and low solubility power in water; extensive solubility in dimethyl sulfoxide, probably indicative of easy solvent penetration due to labile and heterogeneous bonding forces within the granule. Brabender amylogram indicated little retrogradation on cooling, owing to strong bonding between the linear and branched molecules of starch. The amylose content of the starch was 24% as determined by paper chromatographic fractionation and “Blue value” method.

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A BS TRA CTDegradative changes in the constituents of rice straw substrate during the growth and commercialproduction of fruit bodies by Pleurotus flabellatus were investigated. There was a continuous increase in the free sugars from the time of inoculation until the end of harvesting of the fruit bodies, whereas the free amino acids reached a maximum at the end of mycelial growth and showed a slight decrease after fructification. Glucose, xylose, arabinose, cellobiose and a higher oligosaccharide represented the spectrum of sugars produced. Of the 12 amino acids (apart from two peptides) identified, aspartic acid, histidine and tyrosine were the major components, Solubilities and spectral characteristics of lignin degraded in the straw substrate were studied using alkali-extracted lignin. Laccase and protease activities in the straw substrate at different stages of fungal 'degradation could be correlated to the decreases in the staw lignin and protein contents, respectively. Colour reactions of the fungus on several phenolic media, demonstration of phenolic oxidases in the straw substrate, and ability of the fungus to degrade lignin conclusively proved that the fungus under study is a typical 'white rot' fungus. Degradation of the straw substrate by the fungus reached a maximum at the end of harvest of the fruit bodies. The spent straw substrate (left over after harvesting the fruit bodies) contained free sugars and amino acids, respectively 5 and 2 times the concentration of those in the undegraded straw substrate, and lignin decreased to about 25% of the level in the straw before fermentation. Potential applications of the spent straw substrate as an upgraded form of rumen feed and for the production of single-cell protein are discussed.

The carbohydrate composition of winged bean has been studied, The seeds contain about 42.2% total carbohydrates of which starch alone accounts for 36.2%. The total monosaccharides constituted 2.7% and were identified as glucose (1.17%) and fructose (1.5%); oligosaccharides amounted to only 0.61% and were identified as sucrose, raffinose, stachyose, and verbascose, on a dry defatted basis. The cold water soluble gum of winged bean contains glucose and xylose as the major sugars together with a small amount of arabinose while hot water soluble gum was found to be a glucantype polymer. Hemicellulose A consisted of glucose, xylose, and arabinose (15.5:9:1) whereas hemicellulose B consisted exclusively of glucose indicating that it is also a glucan-type polymer.

This review summarises comparative studies conducted here and elsewhere on the various carbohydrate fractions of groundnut. Mono-and oligosaccharides, starch, xylan, glucomannan and cellulose were some of the fractions isolated and characterised. The xylan was shown to be highly branched, having a backbone of /3-1,4-linked D-xylopyranose residues and further substituted at C-2 (9.6%) and C-2, C-3 (15.6%). The glucomannan, containing more of glucose than mannose (mol ratio, 4: 1) was a linear ,!?-l,Clinked polymer. Investigations using scanning electron microscope of enzymically digested groundnut starch revealed several types of 'pitting' on the starch granular surface. The effects of processing and germination on the make up of groundnut carbohydrates were also investigated. Incubation of the defatted groundnut flour (GNF) with a partially purified hemicellulase preparation indicated almost complete breakdown of the pentosan constituents and resulted in a greater extraction (over 90%) of proteins from GNF.