Microencapsulation of Juniper and Black Pepper Essential Oil Using the Coacervation Method and Its Properties after Freeze-Drying

Abstract

Essential oils are mixtures of chemical compounds that are very susceptible to the effects of the external environment. Hence, more attention has been drawn to their preservation methods. The aim of the study was to test the possibility of using the classical model of complex coacervation for the microencapsulation of essential oils. Black pepper (Piper nigrum) and juniper (Juniperus communis) essential oils were dissolved in grape seed (GSO) and soybean (SBO) oil to minimize their loss during the process, and formed the core material. Various mixing ratios of polymers (gelatin (G), gum Arabic (GA)) were tested: 1:1; 1:2, and 2:1. The oil content was 10%, and the essential oil content was 1%. The prepared coacervates were lyophilized and then screened to obtain a powder. The following analyses were determined: encapsulation efficiency (EE), Carr index (CI), Hausner ratio (HR), solubility, hygroscopicity, moisture content, and particle size. The highest encapsulation efficiency achieved was within the range of 64.09–59.89%. The mixing ratio G/GA = 2:1 allowed us to obtain powders that were characterized by the lowest solubility (6.55–11.20%). The smallest particle sizes, which did not exceed 6 μm, characterized the powders obtained by mixing G/GA = 1:1. All powder samples were characterized by high cohesiveness and thus poor or very poor flow (CI = 30.58–50.27, HR = 1.45–2.01).

Preliminary Assessment of Tara Gum as a Wall Material: Physicochemical, Structural, Thermal, and Rheological Analyses of Different Drying Methods

“…Hygroscopicity values below 13.41% were found, a fundamental value, considering that the wall materials must present inert properties toward the active ingredients of the core, which must also be non-hygroscopic [ 39 ]. Hygroscopicity is a critical factor affecting the stability of food products [ 32 ]. Powders with values above 15.1% are considered highly hygroscopic [ 40 ].…”

“…To determine the particle size and polydispersity using a laser light scattering method, the sample particles were dispersed in isopropanol and subjected to ultrasound for 30 s. Then, a 600 nm helium–neon laser was incident on the sample, and the resulting diffraction pattern was measured using a Mastersizer 3000 instrument (Malvern Instruments, Worcestershire, UK) [ 30 ]. The polydispersity was determined using the amplitude index [ 31 , 32 ] according to the following relationship: where , , and correspond to the diameters relative to 10%, 50%, and 90% of the cumulative size distribution.…”

Microencapsulation of Essential Oils Using Faba Bean Protein and Chia Seed Polysaccharides via Complex Coacervation Method

“…To determine the encapsulation efficiency (EE), we used the methodology from our previous study [60]. Briefly, the encapsulation efficiency was determined as the ratio of internal oil to the total oil content of the samples.…”

Understanding emulsifier influence on complex coacervation: Essential oils encapsulation perspective

“…PP was dissolved in water at room temperature, and GA was dissolved at 50 • C. After cooling down the GA solution, both were mixed in different mixing ratios: 1:1, 1:2, and 2:1. The mass of each system was 200 g. We employed the same wall material ratio as in our previous studies corporating gelatin to ensure direct comparison of results (Napiórkowska et al, 2023). Material concentrations were selected based on a literature review.…”

“…The study aims to assess PP's viability as a gelatin alternative in complex coacervation of essential oils, building upon our previous research (Napiórkowska et al, 2023). An additional aim was to investigate the impact of emulsifier addition on coacervation and encapsulation efficiency and analyze the resulting powder properties.…”