Isolation and characterization of arabino-galactan from black gram (phaseolus mungo)

Abstract

sample, using relative peak heights from a GLC curve to follow changes in oil composition with maturity.The ratio of octanal to decanal in grapefruit oils has been suggested as a quality index. Kesterson et al. (1971) reported ratios of 1:l.l to 1:1.4 for white grapefruit oil and ratios of 1.2:l to 1.3:l for red grapefruit oil. A later study (Braddock and Kesterson, 1976) indicated that the ratio was greater than 1 in a white grapefruit oil sample. The ratio we found was about 1.2:l.Several of the identified compounds were part of mixtures and/or present in quantities too small to be accurately quantitated. Nootkatone eluted as small, broad peak with a very long retention time (95 min) and could not be integrated accurately. Only the peak for one mixture (myrcene and sabinene) was sufficiently large and sufficiently well resolved from surrounding peaks to make integration possible. The response factor for the sabinene-myrcene peak was determined from that of myrcene only in the synthetic mixture.In other cases, adjustments had to be made for accurate quantitation. Sufficient quantities of chromatographically pure P-elemene were not available to allow us to determine its response factor; so its corrected weight percent is based on the response of 0-copaene. The response factor for citral (containing 51% geranial) was used as that for geranial, and the corrected weight percentage of geranial is based on the percentage of geranial present in the citral sample.Thus, we quantitated 19 major components of a typical Florida white grapefruit oil by a procedure involving GLC without preliminary separation steps that uses response factors and corrects for the presence of nonvolatiles. Only few comparisons could be made, but our results are similar to previously reported values. We quantitated ten com-J. Agric. Food Chem., Vol. 26, No. 6, 1978 Susheelamma, Rao ponents not previously quantitated, including octyl and neryl acetates. These esters were reported by Moshonas (1971) to be two of the major carbonyl flavor components present in grapefruit oil.An arabinogalactan type of polysaccharide has been isolated from black gram by extracting the meal with aqueous 10% (w/v) trichloroacetic acid and precipitation with acetone. Reprecipitation and dialysis gave an ultracentrifugally homogeneous preparation with a high molecular weight (ca. 144 000) as determined by gel filtration through Bio-Gel P-200. Aqueous dispersions possessed high viscosity around pH 5-7 which decreased with increase in temperature.Black gram (Phaseolus mungo) has been the traditional choice among the common grain legumes as an essential ingredient of some of the most popular and typical Indian breakfast foods which possess a characteristic soft, spongy texture and are made out of leavened mixtures of the legume and cereals (usually rice). A noteworthy feature of batters containing this legume is their high viscosity ascribed to the presence in it of a mucilagenous principle that is also held to be responsible for the gas-holding and dough-raising qualit...

Accelerated fermentation of ‘idli’ batter using soy residue okara

“…This is also because of combined contribution of both heterofermentative lactobacilli and non LAB (Thyagaraja et al 1992). Since both leavening and acid development are required for 'idli' (Susheelamma and Rao 1978), determination of the end point of the 'idli' fermentation becomes rather arbitrary. However, the use of different ingredients in different proportions resulted in raise in volume besides reduction of fermentation period.…”

Effect of α-amylase addition on fermentation of idli—A popular south Indian cereal—Legume-based snack food

“…The viscosity plays a role in retaining the gases, which cause leavening in the idli batter. This, in turn, is essential for the porosity of the steamed pudding (Susheelama & Rao, 1978). Further it is indicated that increase in viscosity stabilizes the network of foam formed by the surface-active proteins and is essential for raising the batter volume.…”

Scope of colloid mill for industrial wet grinding for batter preparation of some Indian snack foods

“…This may be due to the nature of the grain. Black gram contains a lot of mucilaginous (slimy) matter (Susheelamma & Rao, 1978), which may provide a cushioning effect to the starch granules protecting them from greater damage.…”