Physicochemical stability of pineapple suspensions: the integrated effects of enzymatic processes and homogenization...

The pineapple (Ananas comosus) is an important tropical fruit in the world market. Its pulp has significant nutritional value while the peel and the core, in spite of being high in dietary fibre and nutrients, are generally considered to be agro-industrial waste. The aim of this research was to evaluate the effect that the integrated enzymatic and shear homogenization processes have on the physicochemical stability of pineapple base suspensions (pulp, core, and peel extract). Initially, an enzymatic hydrolysis process was evaluated with a completely randomized factorial design. Independent variables: incubation time (t_inc) (1-4 h) and [enzyme] (0-200 ppm). Dependent variables: viscosity (μ) and particle sizes (D_[3;2] and D_[4;3]). The results showed a reduction of (μ) (70.7%), D_[3;2] (54.2%), and D_[4;3] (61.8%) for the optimized treatment (t_inc = 3.2 h and [enzyme] = 200 ppm) compared to the control (t = 0, without enzyme). The effect of the integrated enzymatic treatment with a serial homogenization process was subsequently evaluated. Independent variables: high-speed homogenization time (t₁) (15-20 min), recirculation time in high pressure homogenizer (t₂) (3-7 min), and arabic gum (AG) (0.6-1.0%). Dependent variables: total suspension solids (TS_S), zeta potential (ζ), μ, spectral stability index (R), D_[3;2], and D_[4;3]. The application of the integrated processes of enzymatic treatment and serial homogenization was more effective to be able to obtain a stable pineapple-based suspension. The experimental optimization of multiple responses defined t₁ = 16.4 min, t₂ = 7 min, AG = 0.98%, and TSs = 15.7 ± 0.5%, ζ = - 23.1 ± 0.4 mV, µ = 221 ± 11 cP, D_[3;2] = 56.8 ± 2 µm and D_[4;3] = 120.6 ± 4 µm and R = 0.58 ± 0.02 were obtained.