Properties of an Emulsion Prepared from Silk Sericin and Vitamin E

Abstract

: An emulsion (SR-EM) was prepared from vitamin E and aqueous sericin solution obtained from cocoons of Bombyx mori. Properties such as emulsifying degree, heat stability and radical scavenging activity of SR-EM were compared with those of CS-EM and AL-EM, vitamin E emulsions prepared from casein and bovine serum albumin, respectively. The degree of emulsifying for SR-EM was three times higher than that for CS-EM. CS-EM and AL-EM were a heat-stable emulsion, whereas SR-EM was a heat-labile emulsion because absorbance spectra changed exclusively in SR-EM after treated from 115 to 127!. These results indicated that the oil-water interface of SR-EM was unstable under the high pressure-high temperature treatments compared to those of CS-EM and AL-EM. Each emulsion showed lower radical scavenging activity than a vitamin E solution,suggesting that the interaction of vitamin E and a radical molecule may be interfered by a protective protein colloid. SR-EM and CS-EM were more stable in 60% ethanol solution at ambient temperature than AL-EM because the radical scavenging activity of SR-EM and CS-EM was some 50% lower than that of AL-EM.

Studies on structural and functional properties of sericin recovered from silk degumming liquor by membrane technology

“…The color of sericin powder also depends on heat exposure during degumming process. Kurioka et al23 have also reported that increase in the temperature of HTHP degumming process from 115 to 125°C, the color of sericin changed from dull yellow to dark brown. Tsukada24 have found that the color of sericin cocoon (Nds/Nd‐S) is changed from white to light yellow, deep yellow, light brown, and black on heating from 170 to 210°C.…”