Effect of carrier oil on α-tocopherol encapsulation in ora-pro-nobis (Pereskia aculeata Miller) mucilage-whey protein isolate microparticles

• Published in: Food hydrocolloids 2020-08, Vol.105, p.105716, Article 105716
• Main Authors: Neves, Isabelle Cristina Oliveira, Silva, Sérgio Henrique, Oliveira, Natália Leite, Lago, Amanda Maria Teixeira, Ng, Natalie, Sultani, Arianna, Campelo, Pedro Henrique, Veríssimo, Lizzy Ayra Alcântara, de Resende, Jaime Vilela, Rogers, Michael A.
• Format: Article
• Language: English
• Subjects: Bioaccessibility; Canola oil; Carrier oil; Coconut oil; Degradation kinetics; Isothermal behavior; Vitamin E
• ISSN: 0268-005X; 1873-7137
• DOI: 10.1016/j.foodhyd.2020.105716

Microparticles of whey protein isolate (WPI) and ora-pro-nobis mucilage (OPN) encapsulated α-tocopherol were made using long-chain unsaturated (e.g., canola oil (CA)) or medium-chain saturated oil (e.g., coconut oil (CO)) as the carrier oil. Microparticles were produced from CO- or CA-in-water emulsions by freeze-drying emulsions with various ratios of WPI/OPN. Before freeze dying, emulsions exhibited Newtonian or shear-thinning behavior. Drying yields for freeze-dried emulsions ranged between 74.1% and 87.1% w/w, depending on the biopolymers-to-oil ratio and varied depending on whether CA or CO was used as the carrier. WPI:OPN ratios (between 23:1 and 7:1) nor oil phase (e.g., CO or CA) significantly affected the physical properties (e.g., oil retention, water content, and activity) of the dried powder between treatments. Higher powder bulk density (0.22 g cm−3) and encapsulation efficiency (79.8% w/w) were obtained from freeze-drying CO-, compared to CA-in-water emulsions and with higher concentrations of OPN. Over 35 days, α-tocopherol retention and degradation kinetics differed between CO and CA and was dependent on relative humidity. Bioaccessibility of encapsulated α-tocopherol was higher with WPI/OPN and CA (55.0 ± 1.89%) compared to CO (42.4 ± 1.78%), while the rate of α-tocopherol release and induction time for release were statically equal. [Display omitted] •Encapsulation of α-tocopherol in microparticles obtained from freeze-drying o/w emulsions using natural polymers.•Microcapsules presented high yield and oil retention with low moisture and aw.•α-tocopherol bioaccessibility was altered by unsaturated/medium-chain fatty acids.•WPI/OPN powders are effective encapsulation materials and would be an excellent functional additive.