Soybean lipid bodies in situ are small (0.2-0.5 #m in diameter) and have an affinity for plasmalemma, protein bodies, endoplasmic reticulum and other cell organelles but not for mitochondria or nuclei. Isolated lipid bodies contain 15% protein after extensive washing and have densities ranging from less than 1.O066 to 1.0788. We concluded that lipid bodies are surrounded by a specific delimiting membrane.

Studies were conducted to establish the differences in yolk cholesterol concentrations in eggs from various avian species. Cholesterol was determined by a modification of the colorimetric procedure of Pearson et al. (1953). Species listed in increasing concentrations of cholesterol per gram of yolk, were guinea fowl, chicken, pheasant, quail, turkey, duck, goose, and dove with an overall range of 12.77 to 21.99 mg of cholesterol per gram of yolk. Significant differences in cholesterol concentrations also were found between domestic and wild genetic groups for turkeys and ducks. In a second study, eggs from 7 inbred lines of chickens showed significant differences in yolk cholesterol. The same general result was found in an analysis of eggs from 17 commercial test strains of chickens at two different ages. Yolk cholesterol tended to decrease as age of hen increased. These results confirm the possibility of genetically selecting for decreased yolk cholesterol if economic or other conditions warrant. The increased efforts required to decrease yolk cholesterol by this approach would undoubtedly be expensive.

Soybean Seed Anatomy 4 Subcellular Components 8 Protein bodies 8 Starch granules 13 Calcium oxalate crystals Lipid Bodies 17 Soybeans The controversy 20 Appearance 22 Light microscopy Electron microscopy Membrane Cellular distribution and association Chemical composition Function Cellular origin Germination and Developmental Studies of Soybean Cotyledons Germination Maturation Relationship of Processing and Soybean Ultrastructure Conversion of soybeans to several food products Processing of soybeans to desolventized-toasted flakes Solvent extraction of lipids iii Page MATERIALS AND METHODS 63 Soybeans 63 Processed Soybean Samples 63 Proximate Analysis 63 Moisture determination 63 Protein determination 63 Crude lipid 64 Ash determination 65 Carbohydrate 65 Protein Dispersibilify Index (PDI) Microscopy Studies 67 Light microscopy (LM) Paraffin embedding Resin embedding Transmission electron microscopy (TEM) Scanning electron microscopy (SEM) Energy dispersive X-ray (EDX) analysis Photography: (LM), (TEM) and (SEM) Germination and Maturation Studies Germination Cytochemical studies 71 Acid phosphatase localization 71 Catalase localization 72 Lipase localization 73 Maturation 73 îv Page Processing Methods 74 Solvent extraction of soybean cotyledons 74 Physical treatments 74 Heat treatment (boiling) 75 Freezing-thawing treatment 75 Sonication treatment 75 Enzyme treatment (trypsin) 75 Lipid Body Isolation 75 Density Gradient Centrifugation 76 RESULTS AND DISCUSSION 78 Soybean Cytology with Emphasis on Protein Bodies 78 Starch Granules 97 Calcium Oxalate Crystals Soybean Lipid Bodies Appearance and distribution Light microscopy Electron microscopy Isolation and chemical characterization of lipid bodies Isolation of lipid bodies Chemical composition Effect of isolation medium Effect of soybean cotytedon:isolation medium ratio Effect of centrifugation temperature Effect of heating V Page Microscopic examination of isolated lipid bodies 135 Membrane 143 Effect of trypsin treatment 150 Examination of centrifugation pellet 153 Problems associated with microscopical preparation of 158 isolated lipid bodies Density gradient centrifugation of lipid bodies 158 Germination and Developmental Studies of Soybean Cotyledons 159 Germination Maturation 189 Relationship of Processing and Soybean Ultrastructure 211 Ultrastructural changes in soybeans during processing to yield 211 desolventized-toasted meal Effect of boiling Effect of trypsin treatment Effect of freezing-thawing Effect of solvent extraction Effect of son ication

Microscopic examination of conventionally processed soybeans showed that flaking was sufficient to disrupt almost all of the cotyledon cells but had little effect on protein bodies or lipid bodies. Hexane extraction changed the surface of protein bodies from smooth to granular. Desolventizing-toasting was disruptive to cell walls and caused protein bodies to agglomerate.