Thermodynamic and Quality Properties of Lemon Juice Powder as Affected by Maltodextrin and Arabic Gum

Sorption isotherms of lemon juice (LE) powders with and without additives—18% maltodextrin (MA) or 18% gum Arabic (GA)—were determined at 20-50°C. Addition of additives was shown to affect the isotherms in such a way that, at the same water activity, samples LE + GA and LE + MA presented lower equilibrium moisture content and were not so affected by varying temperature. The net isosteric heats of sorption of juice powders with additives were higher (less negative) than those of lemon juice powders, suggesting that there are more active polar sites in the product without addition of GA or MA. In general, the quality properties decreased with the addition of maltodextrin and gum arabic and it was obtained similar values for LE + GA and LE + MA.     

Thermodynamic and Quality Properties of Lemon Juice Powder as Affected by Maltodextrin and Arabic Gum

Sorption isotherms of lemon juice (LE) powders with and without additives—18% maltodextrin (MA) or 18% gum Arabic (GA)—were determined at 20–50°C. Addition of additives was shown to affect the isotherms in such a way that, at the same water activity, samples LE + GA and LE + MA presented lower equilibrium moisture content and were not so affected by varying temperature. The net isosteric heats of sorption of juice powders with additives were higher (less negative) than those of lemon juice powders, suggesting that there are more active polar sites in the product without addition of GA or MA. In general, the quality properties decreased with the addition of maltodextrin and gum arabic and it was obtained similar values for LE + GA and LE + MA.     

Microencapsulation of Cinnamon Oleoresin by Spray Drying Using Different Wall Materials

Microencapsulation of spice oleoresin is a proven technology to provide protection against degradation of sensitive components present therein. The present work reports on the microencapsulation of cinnamon oleoresin by spray drying using binary and ternary blends of gum arabic, maltodextrin, and modified starch as wall materials. The microcapsules were evaluated for the content and stability of volatiles, entrapped and total cinnamaldehyde content for six weeks. A 4:1:1 blend of gum arabic:maltodextrin:modified starch offered a protection, better than gum arabic as seen from the t_1/2; i.e., time required for a constituent to reduce to 50% of its initial value.     

Microencapsulation of Cinnamon Oleoresin by Spray Drying Using Different Wall Materials

Microencapsulation of spice oleoresin is a proven technology to provide protection against degradation of sensitive components present therein. The present work reports on the microencapsulation of cinnamon oleoresin by spray drying using binary and ternary blends of gum arabic, maltodextrin, and modified starch as wall materials. The microcapsules were evaluated for the content and stability of volatiles, entrapped and total cinnamaldehyde content for six weeks. A 4:1:1 blend of gum arabic:maltodextrin:modified starch offered a protection, better than gum arabic as seen from the t_1/2; i.e., time required for a constituent to reduce to 50% of its initial value.     

Microencapsulation of Rosemary Essential Oil: Characterization of Particles

This study evaluated the influence of wall material concentration (10–30%), inlet temperature (135–195°C), and feed rate (0.5–1.0 L · h^?1) on the properties of rosemary oil microencapsulated by spray-drying, with gum arabic as carrier. Powder recovery, surface oil, oil retention, and hygroscopicity varied from 17.25%–33.96%, 0.03%–0.15%, 7.15%–47.57%, and 15.87%–18.90%, respectively. The optimized conditions were determined to be a wall material concentration of 19.3%, an inlet air temperature of 171°C, and a feed flow rate of 0.92 L · h^?1. At this condition, particles presented no fissures and the compositions of pure and microencapsulated oil were similar. The sorption isotherms could be described by the GAB model.     

Microencapsulation of Kaffir Lime Oil and Its Functional Properties

This paper describes the effects of spray drying temperature and wall materials on functional properties of kaffir lime oil microcapsules. The effects of spray drying were studied at inlet air temperatures at 160, 180, and 200°C. Two coating materials (konjac glucomannan and gum arabic) were employed in this study. The results indicate that kaffir lime oil had antibacterial activity against all tested pathogens and was able to inhibit Vibrio cholerae comparable to a standard antibiotic. The combination of konjac glucomannan and gum arabic (KGM+GA) can enhance the yield and retention of total oil in the microcapsules more than using konjac glucomannan alone as a wall material. Increasing inlet air temperature resulted in a decrease of antibacterial activity and amount of bioactive volatile compounds. Physical and chemical properties of the microcapsules did not differ significantly (p > 0.05) in terms of process yield, a _w , moisture content, efficiency in retention of total, surface and inner oil, water solubility index, and color except at inlet air temperature of 200°C. However, it was found that the kaffir lime oil microcapsules from KGM+GA produced at inlet temperature of 180°C had the best functional properties in terms of antibacterial activity and efficiency of retention of total encapsulated oil.     

Hydrolytic Activity of Castor Bean Powder: Effect of Gum Arabic,Lipase and Oil Concentrations

Lipase activity from castor bean seed powders was evaluated in hydrolysis reactions at 37 °C. The effects of different concentrations of lipase powder (LP), substrate (high oleic sunflower oil, O) and surfactant (gum arabic, A) on lipase activity (R) were assessed using experimental designs. Considered variable bounds were: 0.05–0.15 g_LP, 0.07–0.20 oil:aqueous phase (w/w) and 0–0.025 g gum arabic/mL. All variables had significant effects on the transformed response, R ^1/2. The most important result was the negative effect of gum arabic in lipase activity, even when high oil concentrations were used. Experimental lipase activities involved in this work were within 0.32–16.90 mmol_FFA/g_oil·g_LP·h. Using 0.05 g_LP and 0.20 oil:aqueous phase (w/w) without gum arabic, the activity of 20.47 ± 7.19 mmol_FFA/g_oil·g_LP·h was reached.     

Microencapsulation of Flaxseed Oil by Spray Drying: Effect of Oil Load and Type of Wall Material

The objective of this work was to evaluate the effect of the type of wall material and the oil load on the microencapsulation of flaxseed oil by spray drying. Gum arabic, whey protein concentrate, and a modified starch were used to produce the microcapsules, each with four oil concentrations (10, 20, 30, and 40% oil, w/w, with respect to total solids), for a total of 12 tests. Initially, the feed emulsions were characterized for stability, viscosity, and droplet size. Then they were dried in a laboratory-scale spray dryer and the resulting particles were analyzed for encapsulation efficiency, lipid oxidation, moisture content, and bulk density. The increase in oil concentration led to the production of emulsions with larger droplets and lower viscosity, which directly affected powder properties, resulting in lower encapsulation efficiency and higher lipid oxidation. Among the three wall materials evaluated, the modified starch showed the best performance, with the highest encapsulation efficiency and lowest peroxide values.     

Microencapsulation of Gac Oil by Spray Drying: Optimization of Wall Material Concentration and Oil Load Using Response Surface Methodology

The objective of this study was to optimize the wall material concentration and the oil load on the encapsulation of Gac oil using spray drying by response surface methodology. Results showed that the quadratic polynomial model was sufficient to describe and predict encapsulation efficiencies in terms of oil, β-carotene, lycopene, peroxide value (PV), moisture content (MC), and total color difference (Δ E) with R ² values of 0.96, 0.95, 0.86, 0.89, 0.88, and 0.87, respectively. Under optimum conditions (wall concentration of 29.5 % and oil load of 0.2), the encapsulation efficiencies for oil, β-carotene, lycopene, PV, MC, and Δ E were predicted and confirmed as 92 %, 80 %, 74 %, 3.91 meq/kg, 4.14 % and 12.38, respectively. The physical properties of the encapsulated oil powders obtained by different formulations were also determined. It was concluded that the protein-polysaccharide matrix as the wall material was effectively used for spray-drying encapsulation of Gac oil.     

Chemical Composition and Antibacterial Activity of the Essential Oil of Kauri Pine [ Agathis robusta (C. Moore ex F. Muell.) F.M. Bailey] from India

Agathis robusta (C. Moore ex F. Muell.) F.M. Bailey, commonly known as Queensland Kauri or smooth-barked Kauri, is a coniferous tree in the family Araucariaceae. This study aimed to investigate the chemical composition and antibacterial activity of the essential oil of A. robusta from India. The hydrodistilled resin and leaf essential oils were analyzed using GC-FID and GC-MS. Altogether, 34 constituents (forming 98.2% of the resin oil) and 43 constituents (forming 91.2% of the leaf oil composition) were identified. Major constituents of the resin oil were isobornyl acetate (37.9%), limonene (12.3%), bornyl acetate (7.4%), and myrtenol (5.8%), while the leaf oil contained β-selinene (18.1%), rimuene (14.2%), caryophyllene oxide (11.5%), spathulenol (10.5%), α-selinene (9.8%), and γ-muurolene (5.8%) as main constituents. The resin essential oil showed minimum inhibitory concentration (MIC) in the range of 250–500 μg/mL and minimum bactericidal concentration (MBC) in the range of 500 to >1000 μg/mL against pathogenic strains of eight bacteria.     

Dual Bioactivities of Essential Oil Extracted from the Leaves of Artemisia argyi as an Antimelanogenic versus Antioxidant Agent and Chemical Composition Analysis by GC/MS

The study was aimed at investigating the antimelanogenic and antioxidant properties of essential oil when extracted from the leaves of Artemisia argyi, then analyzing the chemical composition of the essential oil. The inhibitory effect of the essential oil on melanogenesis was evaluated by a mushroom tyrosinase activity assay and B16F10 melanoma cell model. The antioxidant capacity of the essential oil was assayed by spectrophotometric analysis, and the volatile chemical composition of the essential oil was analyzed with gas chromatography-mass spectrometry (GC/MS). The results revealed that the essential oil significantly inhibits mushroom tyrosinase activity (IC₅₀ = 19.16 mg/mL), down-regulates B16F10 intracellular tyrosinase activity and decreases the amount of melanin content in a dose-dependent pattern. Furthermore, the essential oil significantly scavenged 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzthiazoline- 6-sulphonic acid) ABTS radicals, showed an apparent reduction power as compared with metal-ion chelating activities. The chemicals constituents in the essential oil are ether (23.66%), alcohols (16.72%), sesquiterpenes (15.21%), esters (11.78%), monoterpenes (11.63%), ketones (6.09%), aromatic compounds (5.01%), and account for a 90.10% analysis of its chemical composition. It is predicted that eucalyptol and the other constituents, except for alcohols, in the essential oil may contribute to its antioxidant activities. The results indicated that essential oil extracted from A. argyi leaves decreased melanin production in B16F10 cells and showed potent antioxidant activity. The essential oil can thereby be applied as an inhibitor of melanogenesis and could also act as a natural antioxidant in skin care products.