Interfacial/foaming properties and antioxidant activity of a silkworm (Bombyx mori) pupae protein concentrate

Abstract The current consumer demand for healthier diets, the growing interest in the search for new sources of protein, and the desire to reduce the negative effects on the environment have increased interest in the study of insect proteins. The present study focused on the technofunctional characteristics (interfacial and foaming properties) and the in-vitro antioxidant activity of a protein concentrate obtained from silkworm (Bombyx mori) pupae (SPC). The isoelectric point of the SPC was close to pH 4.0–5.0 as determined by protein solubility and z potential analysis. Given that the SPC had solubilities of ∼50% and z potentials of ∼20 mV at pH 2.0 and 8.0, it was decided to further study SPC properties at these pH values. The supernatant obtained after adjustment of SPC to pH 8.0 showed higher (p  k D ∗ = 69.2 ± 0.4 Vs. 29.5 ± 0.9 m N / m · s − 1 / 2 at pH 2.0). However, lower kinetic values at pH 2.0 increased the elastic behaviour of the viscoelastic interfacial film formed (E's ⁓ 30 mN/m at pH 2.0 V. E's ⁓ 20 mN/m at pH 8.0), which can be related with the higher protein sizes found at pH 2.0. These rearrangements of the SPC components appeared to increase its foaming capacity, whereas the foaming capacity of SPC adjusted to pH 8.0 was minimal.