Simple Extraction Method of Non-allergenic Intact Soybean Oil Bodies That Are Thermally Stable in an Aqueous Medium

This study supplied a simple extraction method for intact soybean oil body (ISOB) and examined the heating effect on ISOB. ISOB, which just contained its intrinsic protein (oleosin), could be obtained by pH 11 extraction (50000g, 45 min). ISOB suspension was dialyzed to deionized water (1:3600) and named DISOB. DISOB aggregated at pH 5.7, but NaCl pre-addition (5−500 mM) made ISOB disperse well at pH 5.7. The heating (30, 40, 50, 60, 70, 80, and 90 °C and boiling water baths, 30 min) did not affect the particle size distributions of ISOB. The pH and CaCl2 effects on DISOB and its surface hydrophobicity were also not affected by heating (>95 °C, 5 min). Both unheated and heated ISOB were bound to native soybean protein but were not bound to the heat-denatured one. Thus, it was suggested that ISOB changed little by heating. This study was meaningful in two aspects: (1) pH 11 extraction removed β-conglycinin, glycinin, and allergenic proteins (such as Gly m Bd 30K), and the obtained ISOB had good stability in an aqueous medium. (2) Heating could denature the contamination allergenic proteins.