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Effect of high pressure processing on dispersive and aggregative properties of almond milk
Author(s) -
Dhakal Santosh,
Giusti M Monica,
Balasubramaniam VM
Publication year - 2016
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.7576
Subject(s) - particle size , particle size distribution , pascalization , chemistry , particle (ecology) , absorption of water , microstructure , thermal treatment , high pressure , analytical chemistry (journal) , materials science , food science , chromatography , composite material , crystallography , thermodynamics , physics , oceanography , geology
BACKGROUND A study was conducted to investigate the impact of high pressure (450 and 600 MPa at 30 °C) and thermal (72, 85 and 99 °C at 0.1 MPa ) treatments on dispersive and aggregative characteristics of almond milk. Experiments were conducted using a kinetic pressure testing unit and water bath. Particle size distribution, microstructure, UV absorption spectra, pH and color changes of processed and unprocessed samples were analyzed. RESULTS Raw almond milk represented the mono model particle size distribution with average particle diameters of 2 to 3 µm. Thermal or pressure treatment of almond milk shifted the particle size distribution towards right and increased particle size by five‐ to six‐fold. Micrographs confirmed that both the treatments increased particle size due to aggregation of macromolecules. Pressure treatment produced relatively more and larger aggregates than those produced by heat treated samples. The apparent aggregation rate constant for 450 MPa and 600 MPa processed samples were k 450MPa,30°C = 0.0058 s −1 and k 600MPa,30°C = 0.0095 s −1 respectively. CONCLUSIONS This study showed that dispersive and aggregative properties of high pressure and heat‐treated almond milk were different due to differences in protein denaturation, particles coagulation and aggregates morphological characteristics. Knowledge gained from the study will help food processors to formulate novel plant‐based beverages treated with high pressure. © 2015 Society of Chemical Industry