Influence of gum arabic and homogenization process on the physicochemical stability of strawberry suspensions

Abstract The generation of value from the strawberry agro-chain requires in some cases the disintegration of the structure and formulation of the fruit, resulting in suspensions that behave as thermodynamically unstable colloidal systems and are affected by various forces, such as Van der Waals, electrostatic, steric, hydration, hydrophobic, and phase separation. The aim of this research was to evaluate the influence of the homogenization process and the concentration of gum arabic (GA) on the stability of strawberry-based suspensions. Strawberries with a 9% solid content were used and a centralized-composite central design was proposed (pressure (P) from 4.14-10.34 MPa), time (t) (3-5 min), and GA (0.2-0.4%)) and the dependent variables zeta potential (ζ), spectral absorption index (R), viscosity (μ), and particle size were evaluated. The ζ potential and R-index were not affected by the homogenization process and GA; the suspension was stabilized by the increase of ζ due to t, the GA effect, and the t-GA interaction. Particle size was affected by P but not by t, whereas GA mainly affected D [3,2], D [4,3], and D90. The results indicate that the homogenization and the use of GA as a hydrocolloid confer chemo-physical stability to the strawberry suspension.

摘要 从草莓农业产业链中获取价值，在部分场景下需对果实进行结构与组成解构，由此得到的悬浮液属于热力学不稳定胶体体系，会受到范德华力、静电力、位阻力、水化力、疏水作用力以及相分离等多种因素影响。本研究旨在探究均质工艺与阿拉伯胶（gum arabic, GA）浓度对草莓基悬浮液稳定性的影响。实验采用固形物含量为9%的草莓样本，设计了中心复合设计方案，考察均质压力（P：4.14~10.34 MPa）、均质时间（t：3~5 min）与阿拉伯胶添加量（0.2%~0.4%）三个因素，并对Zeta电位（zeta potential, ζ）、光谱吸收指数（spectral absorption index, R）、黏度（viscosity, μ）以及粒径等因变量进行测定。研究结果显示，Zeta电位与光谱吸收指数不受均质工艺及阿拉伯胶浓度的影响；悬浮液的稳定性可通过均质时间、阿拉伯胶添加量以及二者的交互作用带来的Zeta电位提升得以保障。粒径参数受均质压力影响，但不受均质时间影响；而阿拉伯胶浓度主要对表面积平均粒径D[3,2]、体积平均粒径D[4,3]以及累积粒径分布90%对应粒径D90产生作用。本研究结果表明，均质工艺与阿拉伯胶作为水胶体的联用，可赋予草莓基悬浮液良好的物理化学稳定性。