Abstract

Dry or powdered formulations of food additives facilitate transportation, storage, preservation and handling. In this work, dry formulations of bacterial cellulose and carboxymethyl cellulose (BC:CMC), easily redispersible and preserving the functionality of the never-dried dispersions are reported. Different processing parameters and their effect on the materials properties were evaluated, namely: (i) wet-grinding of BC (Hand-blender, Microcut Head Impeller, High-pressure Homogenizer), (ii) drying of BC:CMC mixtures (fast drying at ≈ 130 °C and slow drying at 80 °C) and subsequent (iii) comminution to different particle sizes. The dispersibility of the obtained BC:CMC powders was evaluated, and their functionality after redispersion was assessed by measuring the dynamic viscosity, the effect in oil/water interfacial tension (liquid–liquid system) and the stabilization of cocoa in milk (solid–liquid system). The size of BC fibre bundles was of paramount relevance to its stabilizing ability in multiphasic systems. A more extensive wet-grinding of the BC fibres was accompanied by a loss in the BC:CMC functionality, related to the increasingly smaller size of the BC bundles. Indeed, as the Dv (50) of the wet BC bundles was reduced from 1228 to 55 µm, the BC:CMC viscosity profile dropped and the effect on interfacial tension decreased. This effect was observed both on the never-dried and dry BC:CMC formulations. On the other hand, the drying method did not play a major effect in the materials’ properties. In a benchmarking study, the BC:CMC formulations, at a low concentration (0.15%), had better stabilizing ability of the cocoa particles than several commercial cellulose products.

Graphic abstract

中文翻译：

---

具有界面活性的干细菌纤维素和羧甲基纤维素制剂：加工条件和再分散

摘要

食品添加剂的干粉或粉状制剂有助于运输，存储，保存和处理。在这项工作中，细菌纤维素和羧甲基纤维素（BC：CMC）的干燥配方易于重新分散，并保留了从未干燥的分散液的功能。评估了不同的加工参数及其对材料性能的影响，即：（i）BC的湿磨（手动搅拌机，Microcut Head叶轮，高压均质机），（ii）BC：CMC混合物的干燥（快速干燥）在约130°C下干燥，然后在80°C下缓慢干燥），然后将（iii）粉碎成不同的粒径。评估所得BC：CMC粉末的分散性，并通过测量动态粘度评估其再分散后的功能性，油/水界面张力的影响（液-液系统）和牛奶中的可可稳定化（固-液系统）。BC纤维束的大小与其在多相系统中的稳定能力息息相关。BC纤维的更广泛的湿磨伴随着BC：CMC功能的丧失，这与BC束的尺寸越来越小有关。实际上，随着湿BC束的Dv（50）从1228减小到55 µm，BC：CMC粘度曲线下降，对界面张力的影响减小。在从未干燥和干燥的BC：CMC配方中均观察到了这种效果。另一方面，干燥方法对材料的性能没有主要影响。在基准研究中，低浓度（0.15％）的BC：CMC配方，

图形摘要