Effect of CO₂ nanobubbles incorporation on the viscosity reduction of fruit juice concentrate and vegetable oil

Abstract

Viscosity is one of key parameters to handle liquid food during processing and transport. In this work, viscosities of apple juice concentrate (APJC) and canola oil (CANO) injected with CO2 nanobubbles (NBs), having size ranged approximately from 50 to 850 nm, were investigated. A significant (P ≤ 0.05) viscosity reduction was observed by up to 18% and 10% in APJC and CANO, respectively, after the NBs injection. When being stored at ambient (23 °C) and refrigerated (4 °C) temperatures for 7 days, the reduction effect on viscosities of samples treated with NBs tended to diminish in accordance with the growth of NBs’ size and the decrease of dissolved CO2 concentration. Besides, the suspension of CO2 NBs insignificantly affected pH, total soluble solid content of APJC, as well as densities of APJC and CANO. These findings suggested that utilisation of NBs can be a feasible mean to reduce viscosity and enhance processing efficiency of food fluids.

Application of Micro- and Nano-Bubbles as a Tool to Improve the Rheological and Microstructural Properties of Formulated Greek-Style Yogurts

“…The average η 100 for the MNB-GSY was ~31% less than C-GSY after week-1 storage. Similarly, Phan, Truong, Wang, and Bhandari [ 30 ] noted that the viscosities of apple juice concentrate and canola oil was significantly reduced to 18% and 10%, respectively, after CO 2 NB treatment (size: 50–850 nm). However, after the week-2, week-3, and week-4 storage, the MNB-GSY samples showed ~58.4%, ~43.1%, and ~50.1%, respectively, lesser η 100 values compared to the respective weeks C-GSY samples.…”

“…The average density of the MNB-GSY was ~6.7% less than C-GSY. Remarkably, Phan, Truong, Wang, and Bhandari [ 30 ] reported no significant ( p > 0.05) changes in densities of NB incorporated liquids (apple juice concentrate and canola oil). The density of the ice cream mix made with NB liquid was 0.77 g/mL, whereas density of the ice cream mix made with regular water was reported be 0.74 g/mL [ 38 ].…”

“…Previously, Chen et al [ 29 ] noted that the viscosity of the MNB-incorporated GSY showed significant lower viscosity and remained lower throughout the 3-day test period, demonstrating that the MNBs remained stable within the yogurt product. The viscosity lowering effect of NB treatment for a 7-day test period (at 23 and 4 °C) in apple juice concentrate and canola oil was demonstrated by Phan, Truong, Wang, and Bhandari [ 30 ], and it was attributed to the NB size and concentration. Körzendörfer, Schäfer, Hinrichs, and Nöbel [ 15 ] reported a 40% reduction on η 100 values of sonicated GSY compared to control GSY.…”

“…However, after the week-2, week-3, and week-4 storage, the MNB-GSY samples showed ~58.4%, ~43.1%, and ~50.1%, respectively, lesser η 100 values compared to the respective weeks C-GSY samples. Likewise, Phan, Truong, Wang, and Bhandari [ 30 ] reported the lowering effect on viscosities with NB treatment declines over time as the size of the NBs grew larger and the concentration of dissolved gas decreased. Overall, the MNB treatment had a noticeable effect on the flow behavior of GSY compared with C-GSY.…”

“…Authors also claimed MNBs utilizing a venturi-type hydrodynamic cavitation method displayed impressive results on diverse dairy food systems. Likewise, Phan, Truong, Wang, and Bhandari [ 30 ] noted the viscosities of apple juice concentrate, and canola oil was significantly reduced using CO 2 NBs (size: 50–850 nm). In bulk aqueous solutions, the gaseous MNBs are produced by cavitation, which can be caused by four different mechanisms: hydrodynamic, acoustic, particle, and optical.…”