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Background: A viable possibility for the best use of bioactive compounds present in camu-camu, fruit native to the Amazonian rainforest, is the preparation of microcapsules using different biopolymers by the spray-drying technique, which would increase the possibilities for innovation in the food industry, as well as facilitate the application in different food matrices. In this context, the chemical, physicochemical, and morphological properties and stability of camu-camu extract (peel and pulp) spray-dried using maltodextrin, inulin, and oligofructose as encapsulating agents were investigated, as well as lyophilized camu-camu extract (CEL). Different relative humidities (22%, 51%, and 75%) and temperatures (25 °C and 45 °C) were evaluated., Results: The moisture, water activity, and solubility values varied from 18.4 to 107.9 g water per kilogram dry powder, 0.06 to 0.27, and 950.80 to 920.28 g microparticles per kilogram of water respectively. Retention of the bioactive compounds varied in the ranges 5.5-7.1 g per kilogram ascorbic acid fresh weight and 7.2-9.0 g per kilogram anthocyanins fresh weight. The increase in temperature and relative humidity during storage provided a significant decrease in the stability of the bioactive compounds for all treatments. However, the CEL presented higher water adsorption kinetics and degradation under all storage conditions, indicating the importance of the use of encapsulating agents., Conclusion: In general, the prebiotic biopolymers used as encapsulating agents in the microencapsulation of extracts of camu-camu by spray-drying presented satisfactory results, suggesting that this technique is an effective strategy to increase the stability of bioactive compounds contained in fruits and vegetables. © 2020 Society of Chemical Industry., (© 2020 Society of Chemical Industry.)

The objective of this study was to investigate the kinetic stability of lime essential oil emulsion using gum arabic (GA) and whey protein isolate (WPI) biopolymers as emulsifiers and stabilizers. Different solid compositions were evaluated: GA, GA/WPI (1:1) and WPI, as well as oil concentration (5.0, 7.5 and 10% w/w). Emulsions were prepared using an ultrasonic homogenizer. Viscosity, oil droplet size, zeta potential, pH and conductivity were measured to predict the emulsion stability over a period of 4 h (estimated time until complete drying in microencapsulation processes). Emulsion rheological behaviour and microstructure were characterized. All emulsions were stable during the time period analysed, and no destabilization characteristic was observed. The pH, conductivity and viscosity showed no significant difference (p > 0.05) over the 4-h period. Emulsions with WPI showed higher zeta potential values, confirming the biopolymer electrosteric stabilization. The combination of wall materials (GA/WPI) and the oil concentration increased the average droplet size. The results of the apparent viscosity at shear rate of 100 s-1 confirmed the emulsions stability. These values did not change significantly considering the fresh emulsions and emulsions after 4 h of preparation. The emulsifying biopolymers showed to be excellent natural stabilizers for lime essential oil emulsions, highlighting the results using WPI. [ABSTRACT FROM AUTHOR]

The aim of this work was to study the use of different prebiotic biopolymers in lime essential oil microencapsulation. Whey protein isolate, inulin and oligofructose biopolymers were used. The addition of prebiotic biopolymers reduced emulsion viscosity, although it produced larger droplet sizes (0.31–0.32 µm). Moisture values (2.94–3.13 g/100 g dry solids) and water activity (0.152–0.185) were satisfactory, being within the appropriate range for powdered food quality. Total oil content, limonene retention values and antioxidant activity of the microparticles containing essential oil decreased in the presence of the carbohydrates. The addition of prebiotic biopolymers reduced the microparticle thermal stability. X-ray diffraction confirmed the amorphous characteristic of the microparticles and the interaction of the essential oil with the wall material. The presence of prebiotic biopolymers can be a good alternative for lime essential oil microparticles, mainly using fibre that has a functional food appeal and can improve consumer health. [ABSTRACT FROM PUBLISHER]

Buriti (Mauritia flexuosa) oil, native from the Amazon region, is a natural compound with several antioxidant properties and high carotene content. This oil can be used for cosmetic and dietary purposes. Considering the industrial importance of this oil, it is proposed a new high-tech product consisting in buriti oil microparticles. In this sense, the effect of biopolymers (inulin and gum arabic) on the physicochemical properties of freeze-dried buriti oil microparticles was evaluated in different combinations. The increase of inulin addition significantly increased (p ˂ 0.05) the Aw values and the moisture content of microparticles. Negative zeta potential near −30 mV was observed for all treatments indicating stability. The polydispersity index (PI) ranged from 0.14 to 0.37. The wettability found ranged from 59 s to 71 s, considered optimal for powdered foods for industry and consumer market requirements. Equal amount of wall material showed higher solubility value. The diffractograms showed that the incorporation of buriti oil in the microparticles does not significantly change the amorphous character already observed in the isolated materials. Hence, the combination in equivalent proportions of inulin and gum Arabic is a viable alternative for application of freeze-dried buriti oil microparticles in foods that present hydrophilic character. • Amount of IN and GA strongly affected the physicochemical properties of freeze-dried buriti oil microparticles. • With the condition GA50IN50 a maximum encapsulation efficiency (EE) and β-carotene retention was achieved. • Different proportions of IN and GA freeze-dried microparticles were amorphous with rough surface and variable sizes. • For all treatments, a negative zeta potential near −30 mV was observed indicating high stability. • Minor contents of IN in the formulation resulted in monodisperse colloids. [ABSTRACT FROM AUTHOR]

• Camu-camu extract was subjected to microencapsulation with prebiotic biopolymers. • High volatiles retention was observed in the camu-camu extract microparticles. • Korsmeyer-Peppas model described the controlled release of bioactive compounds. • Controlled release occurred through Fickian diffusion mechanism. • Encapsulating materials were effective in production of camu-camu extract powder. Camu-camu (Myrciaria dubia [H.B.K] McVaugh) is a Amazonian fruit rich in ascorbic acid and phenolic compounds, and has been attracting great interest from the food, pharmaceutical and nutraceutical industries due to its potential health benefits. The bioactive compounds from camu-camu are considered sensitive and unstable, resulting in nutritional losses and impairment of its commercialization and export. For this reason, the camu-camu extract (pulp and peel) was subjected to microencapsulation by spray drying process using maltodextrin (MD), inulin (IN), and oligofructose (OL) as carrier agents. Lyophilized in natura camu-camu extract (CEL) was also evaluated. Thus, physicochemical and thermal properties and controlled release at different temperatures (25 °C and 35 °C) were investigated. In contrast with the IN and OL microparticles, the MD microparticles showed lower density and hygroscopicity, besides greater thermal stability, antioxidant activity, and retention of ascorbic acid and anthocyanins. FTIR spectra allowed the qualitative evidence of encapsulation of the bioactive compounds from the camu-camu extract. The highest percentage of volatile compounds was observed in IN microparticles, followed by OL and MD microparticles. The major group of compounds identified in CEL were terpenes (88%). The Korsmeyer-Peppas mathematical model allowed to describe the controlled release behavior of ascorbic acid and anthocyanins in the powder extracts. The controlled release followed a Fickian diffusion mechanism (n ≤ 0.43). The increase of temperature from 25 °C to 35 °C influenced on the release of bioactive compounds in all treatments, showing greater release for MD microparticles. The encapsulating materials were considered effective for the production of camu-camu extract powder, contributing to the better use of this Amazonian fruit. In addition, the encapsulation process increased the stability of its bioactive compounds, representing a tool to facilitate their incorporation in several matrices to act as antioxidant and coloring agents, as well as nutraceutical. [ABSTRACT FROM AUTHOR]

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. Image 1 • 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 a w. • 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. [ABSTRACT FROM AUTHOR]