Hemp milk, an emerging beverage with high nutritional value and low allergenicity, is an attractive alternative to dairy, soy, and nut milks. To obtain a non-thermally processed, physically and oxidatively stable hemp milk, high pressure homogenization (HPH) combined with pH shift treatment was investigated. For hemp milk (4% protein, 5% fat) without pH shift, increasing the homogenization pressure (up to 60 MPa) resulted in a more uniform distribution of emulsion droplets (2.2-2.7 μm). When pH shift was applied prior to HPH, large clusters and aggregates of oil droplets (3.5-8.2 μm) were formed. Interestingly, hemp milk with such interactive structures was remarkably stable, showing negligible phase separation within 3-day storage at 4 °C. Moreover, hemp milk made by combined pH shift and HPH exhibited delayed hydroperoxides (expressed as peroxide value, PV) and malondialdehyde (expressed as thiobarbituric acid-reactive substances, TBARS) production, suggesting the resistance of such emulsion cluster structures to radicals. On the other hand, a significant reduction of microbial population was observed in hemp milk prepared by pH shift combined with HPH. The results indicate that the pH shift + HPH combination treatment may potentially be employed for the production of non-thermally processed hemp milk.
Keywords: 2-Thiobarbituric acid (PubChem CID: 2723628); Acetic acid (PubChem CID: 176); Emulsion stability; Fluorescein isothiocyanate (PubChem CID: 18730); Hemp milk; Nile red (PubChem CID: 65182); Oxidation stability; Particle size; Trichloroacetic acid (PubChem CID: 6421); Trichloromethane (PubChem CID: 6212); Viscosity; pH shift.
Copyright © 2018 Elsevier Ltd. All rights reserved.