title: Effect of high pressure processing on dispersive and aggregative properties of almond milk.
abstract: 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 k450MPa,30°C  = 0.0058 s(-1) and k600MPa,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.
authors.affiliation: Department of Food Science & Technology, The Ohio State University, Columbus, OH, 43210, USA.
authors.forename: Santosh
authors.initials: S
authors.lastname: Dhakal
authors.affiliation: Department of Food Science & Technology, The Ohio State University, Columbus, OH, 43210, USA.
authors.forename: M Monica
authors.initials: MM
authors.lastname: Giusti
authors.affiliation: Department of Food Science & Technology, The Ohio State University, Columbus, OH, 43210, USA.|Department of Food Agricultural and Biological Engineering, The Ohio State University, Columbus, OH, 43210, USA.
authors.forename: V M
authors.initials: VM
authors.lastname: Balasubramaniam
mesh_terms: D000465:Algorithms; D005511:Food Handling / Q000379:methods*; D063427:Food Quality; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D018613:Microscopy, Confocal; D041941:Milk Substitutes / Q000737:chemistry* / Q000302:isolation & purification; D009753:Nutritive Value; D009754:Nuts / Q000737:chemistry* / Q000191:economics; D009820:Ohio; D010316:Particle Size; D061352:Pasteurization / Q000379:methods; D010860:Pigments, Biological / Q000032:analysis; D014674:Plant Proteins, Dietary / Q000032:analysis / Q000737:chemistry; D011312:Pressure / Q000009:adverse effects; D011489:Protein Denaturation; D000068181:Prunus dulcis / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D010860:Pigments, Biological; D014674:Plant Proteins, Dietary
keywords: aggregation kinetics; high pressure processing; micrographs and color; particle size; thermal processing