Search

High‐pressure homogenization (HPH) was applied within a range of 300 to 1000 bar for 2 to 8 cycles. At constant dry matter (6.2%), pulp mass increased from 3.7 to 8%, indicating a change in particle organization. D90 varied from 197 to 20 μm depending on the pressure and number of cycles. The aggregation of particles, then destruction of the aggregates depending on the number of cycles, explained viscosity behavior. HPH delayed phase separation by an average 28.5 h. Sedimentation velocity was 10 times higher at 8 cycles than at 3 cycles, at 1000 bar. At 1000 bar, browning was observed, resulting from Maillard reactions, and was linked to the furan‐2‐pentyl content (10‐fold higher) and a 45% loss of carotenoids. This study will help in understanding changes induced in mango nectar by HPH and will be of use in developing processing technologies to preserve mango‐based products. Novelty impact statement: This study provides some additional scientific indications for understanding the subtility of HPH impacts in stabilizing mango nectar. The optimum pressure treatment for delaying phase separation (1000 bar, 3–6 cycles), i.e., reducing particle size and forming adequate re‐aggregation, also causes a Maillard reaction (2‐fold color difference, 10‐fold furan increase, etc.), hence browning through an increase in local temperature. It will therefore be necessary to find a compromise to limit degradation reactions caused by the process, and to guarantee greater consumer acceptance (phase separation and sensory quality). [ABSTRACT FROM AUTHOR]

An innovative method was developed to study the specific uncoupled effect of temperature and water activity (Aw) during mango drying. Thermal treatment of reconstituted lyophilized mango powder at targeted Aw enabled evaluation of the inactivation of polyphenol oxidase and peroxidase activity in a range 0.98–0.6 Aw and a time-temperature range of 1–4 h and 50–60°C. We established that thermal treatment of the enzymatic extract was not the same as the inactivation phenomena that occurred in the mango matrix, mainly due to differences in the pH of the buffer extract (6.4) and reconstituted food matrix (3.8). Even if the inactivation of these two enzymes was directly correlated with the temperature of the treatment, this behavior was also strongly linked to the Aw. A two-step change in the fruit was observed at high Aw (i.e., at 0.98 in fresh fruit), polyphenol oxidase (PPO) was shown to be more thermostable than peroxidase (POD), whereas when evaporation reduced the Aw to around 0.6, the opposite behavior was observed. As a consequence, enzymatic inactivation during drying should be considered as the result of the coupled effects of time-temperature and water activity. [ABSTRACT FROM AUTHOR]