Hirsch Andrew, Cho Young-Hee, Kim Yuan H Brad, Jones Owen G
Purdue University, Department of Food Science, West Lafayette, IN, USA.
Whistler Center for Carbohydrate Research, West Lafayette, IN, USA.
Curr Res Food Sci. 2019 Sep 28;1:17-23. doi: 10.1016/j.crfs.2019.09.002. eCollection 2019 Nov.
Interfacial and emulsifying properties of fractionated cricket powder were assessed to identify whether emulsification properties originate from protein or chitin particles. Fractions extracted in alkaline water, containing high protein and mineral contents, increased the surface pressure of heptane-water interfaces with near-saturation equilibrium surface pressure of 31 mN/m. Dynamic surface pressure profiles indicated adsorption of protein clusters to the interface. Emulsification capacity of protein fraction was 50% greater than that of the source cricket flour, although oil-in-water emulsions prepared with 1-2% (w/w) protein fraction formed a cream layer within one day of storage. Emulsified layers persisted for up to 20 days, and light scattering measurements described a stable population with surface-volume-mean diameter of approximately 3 μm. Chitin-rich fractions milled to a particle size of 0.5-200 μm contributed negligible surface pressure, and its emulsification capacity was 5% of the value for the source cricket flour. Emulsions prepared with chitin-rich fractions coexisted with an unstable precipitate layer comprising 60% of the added solid, which was attributed to larger particles with poor emulsifying capability. Stable chitin-stabilized emulsion phases were resistant to creaming, yet volume-mean droplet diameter surpassed 50 μm within 24 h of storage. Both protein and chitin fractions have emulsifying capabilities but would require further processing or secondary additives to achieve desirable storage stability.
评估了分级蟋蟀粉的界面和乳化特性，以确定乳化特性是源自蛋白质还是几丁质颗粒。在碱性水中提取的级分含有高蛋白和矿物质含量，增加了庚烷 - 水界面的表面压力，接近饱和平衡表面压力为31 mN/m。动态表面压力曲线表明蛋白质簇吸附到界面上。蛋白质级分的乳化能力比原料蟋蟀粉高50%，尽管用1-2%（w/w）蛋白质级分制备的水包油乳液在储存一天内形成了乳脂层。乳化层持续长达20天，光散射测量描述了一个稳定的群体，表面体积平均直径约为3μm。研磨至粒径为0.5 - 200μm的富含几丁质的级分对表面压力的贡献可忽略不计，其乳化能力为原料蟋蟀粉值的5%。用富含几丁质的级分制备的乳液与包含60%添加固体的不稳定沉淀层共存，这归因于乳化能力差的较大颗粒。稳定的几丁质稳定乳液相抗乳析，但在储存24小时内体积平均液滴直径超过50μm。蛋白质和几丁质级分都具有乳化能力，但需要进一步加工或添加二次添加剂以实现理想的储存稳定性。
