Effect of production parameters and stress conditions on beta-carotene-loaded lipid particles produced with palm stearin and whey protein isolate

Abstract

Microencapsulation is currently used by the food industry for different purposes, including the protection of ingredients against factors such as oxidation and volatilization, as well as to increase the bioavailability and bioaccessibility of nutrients. The current study aimed to encapsulate beta-carotene in solid lipid microparticles stabilized with whey protein isolate (WPI), and also investigate their integrity during storage and under stress conditions such as different ionic strengths, sucrose concentrations and thermal treatments. Solid lipid microparticles were produced using palm stearin, a food grade vegetable fat, using a single-step high shear process. Of the different formulations used for lipid microparticle production, characterization studies showed that the greatest stability was obtained with systems produced using 1.25% (w/v) whey protein isolate, 5% (w/v) palm stearin and 0.2% (w/v) xanthan gum. This formulation was applied for the production of beta-carotene-loaded solid lipid microparticles, with different concentrations of alpha-tocopherol, in order to verify its possible antioxidant activity. The results showed that the addition of alpha-tocopherol to the dispersions provided an increase in encapsulation efficiency after 40 days of storage that ranged from 29.4% to 30.8% when compared to the system without it. Furthermore, the solid lipid microparticles remained stable even when submitted to high ionic strength and to heating in the proposed temperature range (40 °C to 80 °C), highlighting their feasible application under typical food processing conditions. Keywords: Lipid particles; Beta-carotene; Stress conditions; Microencapsulation; Palm stearin; Whey protein isolate. ResumoA microencapsulação é atualmente utilizada pela indústria de alimentos com diferentes propósitos, incluindo a proteção de ingredientes contra fatores, como a oxidação e a volatilização, assim como o aumento da biodisponibilidade e da bioacessibilidade de nutrientes. Este estudo teve por objetivo a encapsulação de betacaroteno em micropartículas lipídicas sólidas estabilizadas com isolado proteico de soro, além de verificar sua integridade sob armazenamento refrigerado e após submissão a diferentes condições de estresse, tais como força iônica, presença de açúcar e tratamentos térmicos. As partículas lipídicas sólidas foram produzidas utilizando estearina de palma, uma gordura vegetal de grau alimentício, a partir de homogeneização de alto cisalhamento. Dentre as diferentes formulações utilizadas durante a produção das partículas lipídicas sólidas, os estudos de caracterização mostraram que uma maior estabilidade foi obtida pelo sistema produzido com 1,25% (m/v) de isolado proteico de soro, 5% (m/v) de estearina de palma e 0,2% (m/v) de goma xantana. Essa formulação foi então escolhida para a posterior produção de partículas lipídicas sólidas encapsulando betacaroteno, etapa na qual foram testadas diferentes concentrações de alfa-tocoferol, a fim de verificar seu potencial antioxidante. Os resultados mostrara...

Recent Developments in Solid Lipid Microparticles for Food Ingredients Delivery

“…Results showed that the formed microparticles efficiently protected the Quercetin from oxidation, and 85% of the initial amount of the flavonoid was remained after 30 days. A high-shear homogenization method was also used to produce β-carotene-loaded solid lipid microparticles [ 39 , 69 ]. These SLM were prepared by dispersing the aqueous phase (containing hydrolysed soy protein isolate, HSPI) in the palm stearin with ultra-agitation at 15,000 rpm.…”