枯草芽孢杆菌来源的表面活性剂素具有作为食品配方的 O/W 乳化剂的良好特性。

Surfactin from Bacillus subtilis displays promising characteristics as O/W-emulsifier for food formulations.

机构信息

Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstr. 12, 70599, Stuttgart, Germany.

Department of Food Science, University of Massachusetts Amherst, Amherst, MA, 01003, USA.

出版信息

Colloids Surf B Biointerfaces. 2021 Jul;203:111749. doi: 10.1016/j.colsurfb.2021.111749. Epub 2021 Apr 7.

DOI:10.1016/j.colsurfb.2021.111749

PMID:33862574

Abstract

BACKGROUND

Biosurfactants are surface-active molecules produced by different microorganisms and display a promising alternative to synthetically derived food emulsifiers. One of these biosurfactants, synthesized by Bacillus subtilis, is the lipopeptide surfactin, which composes a linear fatty acid and cyclic peptide moiety. This study explores the interfacial and emulsion forming properties of surfactin to further characterize its suitability as an O/W emulsifier in food formulations.

RESULTS

Surfactin revealed a high interfacial activity with a reduction of interfacial tension of 83.26 % to 4.21 ± 0.11 mN/m. O/W emulsions (c = 10 % w/w) were prepared by high-pressure homogenization, which yielded volume-based mean particle sizes below 1 μm already at low emulsifier concentrations of 0.01 % (w/w). Environmental stress experiments revealed that emulsions were stable between pH 6 to pH 9. Furthermore, neither phase separation nor extensive emulsion instability was observed with NaCl addition up to 0.5 M. However, CaCl addition (> 3 mM) destabilized surfactin mediated emulsions. Finally, the main emulsion forming and stabilization effect of surfactin was related to its high interfacial activity and the high degree of electrostatic repulsion between the oil droplets (i.e. zeta-potential of up to -100 mV).

CONCLUSION

In comparison to other natural and synthetic emulsifiers, the results showed that surfactin is a strong candidate to form and stabilize O/W emulsions under the reported conditions.

摘要

背景

生物表面活性剂是由不同微生物产生的具有表面活性的分子，它们是合成衍生食品乳化剂的有前途的替代品。其中一种生物表面活性剂是由枯草芽孢杆菌合成的脂肽表面活性剂，它由线性脂肪酸和环状肽组成。本研究探讨了表面活性剂的界面和乳化形成特性，以进一步表征其作为食品配方中 O/W 乳化剂的适用性。

结果

表面活性剂具有很高的界面活性，可将界面张力降低 83.26%至 4.21 ± 0.11 mN/m。通过高压均质法制备 O/W 乳液（c = 10%w/w），在低乳化剂浓度 0.01%（w/w）下，已经可以得到体积平均粒径低于 1μm 的乳液。环境压力实验表明，乳液在 pH 6 到 pH 9 之间稳定。此外，即使添加高达 0.5 M 的 NaCl，也不会发生相分离或乳液严重不稳定的情况。然而，添加 CaCl（>3 mM）会使表面活性剂介导的乳液不稳定。最后，表面活性剂的主要乳化和稳定作用与其高界面活性和油滴之间的高静电排斥（即高达-100 mV 的 ζ-电位）有关。