TOASTING AND HEXANE:ETHANOL EXTRACTION OF DEFATTED SOY FLAKES Flavor of Flours, Concentrates and Isolates

Abstract

Flours and protein concentrates, prepared from defatted soybean flakes steamed up to 20 min before or after extraction with hexane:ethanol azeotrope 82/18 v/v, were presented to a 15-member trained taste paneL Flavors and odors were &scribed and rated for intensity on a scale of 1 to 10 where 1 is strong and 10 is bland. Azeotropic extraction for 6 hr by itself significantly affected flavor of flours and of concentrates so that they scored 7.4 and 6.8, respectively, compared to 4.0 for raw, hexane-defatted, soy flour. Toasting after azeotropic extraction raised flavor scores of flours and protein concentrates to 7.9, a value which compares favorably with 8.1 for wheat flour. Toasting is also necessary to inactivate trypsin inhibitors and other antinutritional factors in azeotropi*extracted soybean flakes A protein isolate from toasted, azeotropioextracted flakes scored 7.3 compared to 8.0 for sodium caseinata Yields of protein isolates are good if the heatprocessed fiakes are extracted with hot water at 74°C and pH 7.2.

Efficiency of lupine seed (Lupinus angustifolium and Lupinus luteus) in sow, piglet and fattener feeding

“…As the lupine used was relatively low alkaloid (< 0.05%) it can be assumed that the poor results were due to the not removed hexane residue. If there was no further processing, hexane extraction alone could reduce the smell and nutritive value of the feed (Honig et al 1976). In the present experiment reproduction rates of the sows receiving soybean were better than those fed with lupines taking in account the weight of the piglets born.…”

Legume lipids

“…Honig et al 65 studied the effect of toasting and solvent extractions (hexanerethanol, water, calcium hydroxide) in an attempt to improve nutrition and flavor of defatted soy flakes, protein concentrates, and protein isolates. They found that toasting and azeotropic extraction improved the flavor of soybean flour and protein concentrates, due to a reduction in grassy/beany, bitter, and astringent flavors.…”

Effect of equilibrium oil extraction on the chemical composition and sensory quality of soy flour and concentrates

“…Toasting. Defatted flour was toasted with live steam for 10 min at 100~ in a preheated sterilizer autoclave and air dried for 24 h (8).…”

“…Sensory analysis. Sensory evaluation of the soy flour, toasted soy flour, soy flakes and soy concentrates was performed according to Honig et al (8) by eleven trained panelists. Overall odor and flavor intensities of the samples were based on a 10-point scale in which 1 was bland and 10 was strong.…”

“…The sensory panel was trained with the following reference standards prepared with filtered bottled water: bitter, 0.04% caffeine; astringent, 0.035% tannic acid; grassy, 2.00% raw soy flour; cooked beany, 100 g soybeans that were cooked in 300 mL water for 20 min and 100 mL of the liquid was then diluted to 200 mL (8). Intensity values for these attributes were on the 3-point intensity scale Reference standards were presented at each testing session.…”