Extraction and Characterization of Oil Bodies from Soy Beans: A Natural Source of Pre-Emulsified Soybean Oil

Abstract

Soybeans contain oil bodies that are coated by a layer of oleosin proteins. In nature, this protein coating protects the oil bodies from environmental stresses and may be utilized by food manufacturers for the same purpose. In this study, oil bodies were extracted from soybean using an aqueous extraction method that involved blending, dispersion (pH 8.6), filtration, and centrifugation steps. The influence of NaCl (0-250 mM), thermal processing (30-90 degrees C, 20 min) and pH (2-8) on the properties and stability of the oil bodies was analyzed using zeta-potential, particle size, and creaming stability measurements. The extracted oil bodies were relatively small ( d 32 approximately 250 nm), and their zeta-potential went from around +12 mV to -20 mV as the pH was increased from 2 to 8, with an isoelectric point around pH 4. The oil bodies were stable to aggregation and creaming at low (pH = 2) and high (pH >/= 6) pH values but were unstable at intermediate values (3 </= pH </= 5), which was attributed to their relatively low zeta-potential. The oil bodies were stable to aggregation and creaming at relatively low salt concentrations (NaCl </= 25 mM, pH 7) but were unstable at higher values as a result of electrostatic screening effects. The oil bodies were stable to thermal processing from 30 to 90 degrees C (0 mM NaCl, pH 7), but there appeared to be a change in their interfacial properties (decrease in zeta-potential) at temperatures exceeding 60 degrees C. These results suggest that oil bodies extracted from soybeans have similar or improved stability compared to soybean oil emulsions produced from bulk ingredients and may provide a new way of creating functional soy products for the food industry.

Is nano safe in foods? Establishing the factors impacting the gastrointestinal fate and toxicity of organic and inorganic food-grade nanoparticles

“…Nanoscale materials are naturally present in many commonly consumed foods, such as the casein micelles in milk or certain organelles found in plant or animal cells. [3][4][5] Engineered nanoscale materials (ENMs) may be intentionally added to foods (such as nanoparticle-based delivery systems), or they may inadvertently find their way into foods (such as nanoparticles in packaging materials that leach into the food matrix). [6][7][8] ENMs are typically nanoparticles whose composition, size, shape, and interfacial properties are specifically designed to achieve one or more functional attributes.…”

Aroma encapsulation and aroma delivery by oil body suspensions derived from sunflower seeds (Helianthus annus)

“…The stabilizing proteins offer significant levels of structural stability to the oil bodies both in vivo and ex vivo. Oil bodies' intrinsic chemical [2] and physical stability [3,4] and the low cost of extraction, combined with the presence of natural antioxidants [3,5], illustrate the significant potential of oil bodies as stable food ingredients.…”

“…Within the pharmaceutical industry, oleosin protein has been used as an effective carrier agent for recombinant proteins fused to its hydrophilic regions, allowing a simple route to purification and isolation. The use of oil bodies in food has been investigated by a number of authors who have characterized their physical-chemical properties and demonstrated the use of multilayer coatings on the surface and enzymatic surface modification as potential routes to further enhance structural stability [2][3][4][6][7][8][9][10][11].…”

Rheological Analysis of the Aggregation Behavior of a Soymilk Colloidal System

“…The average particle diameter of an oil body in soymilk is approx. 250 nm (Iwanaga et al, 2007). Oil bodies containing soymilk lipids were stabilized by the presence of oleosin and phospholipids on their surface (Chen and Ono, 2010).…”