Spray-dried encapsulation of chia essential oil (Salvia hispanica L.) in whey protein concentrate-polysaccharide matrices

Eight chia essential oil-in-water fresh emulsions (E) variations were prepared using biopolymers blends whey protein concentrate (WPC) with mesquite gum (MG) or gum Arabic (GA), core to wall material ratios (C_o:W_a) of 1:2 and 1:3, and total solids contents (TSC) of 30 and 40 wt%. All E variations displayed volume-weighted mean size (d_4,3) droplet sizes that fell within 2.32 and 3.35 μm and rates of droplet coalescence (k_C) of 10⁻⁸ s⁻¹. E variations were spray-dried and the resulting microcapsules (M) had d_4,3 falling within the range of 13.17–28.20 μm. The encapsulation efficiency (EE) was higher than 70% for all M, but those obtained from E with lower TSC and higher C_o:W_a displayed higher EE and lower surface oil, independently of M particle size. The reconstituted emulsions (RE) exhibited significantly higher d_4,3 and k_C values of the same magnitude as E variations.     

Effect of caking and stickiness on the retention of spray‐dried encapsulated orange peel oil

Flavour microcapsules containing amorphous carbohydrate as wall material can undergo changes such as crystallisation, clumping, sticking and caking during handling and storage. Such physical changes may lead to the release of entrapped flavours. The objective of this study was to investigate the effect of storage temperature and water activity on caking, stickiness and glass transition temperatures and to evaluate the relative degree of protection provided to orange peel oil entrapped in mesquite (Prosopis juliflora) gum by spray drying. The powders were stored at water activities (a_w) ranging from 0.108 to 0.972 at 25 and 35 °C. The surface caking temperature (T_sc) and advance caking temperature (T_ac) were determined by the modified ampoule and sealed glass tube methods respectively. The glass transition temperature was determined by differential scanning calorimetry. Changes in the amount of encapsulated oil were determined by Clevenger hydrodistillation. As expected, both T_sc and T_ac decreased with increasing storage a_w. Above a_w 0.628 the powders caked and collapsed during storage at 35 °C. Below a_w 0.628 the capsules were not damaged and high retention levels (above 90%) were obtained. Increasing a_w in the range 0.743–0.972 caused progressive dissolution of the wall polymer, and the retention level dropped sharply. The volatiles are protected and retained by mesquite gum as long as the capsule structure remains intact. Copyright © 2003 Society of Chemical Industry     

Carotenoid retention and storage stability of spray-dried encapsulated paprika oleoresin using gum Arabic and Soy protein isolate as wall materials

The performance of gum arabic (GA) and soy protein isolate (SPI) on paprika oleoresin microcapsules preparation and their storage were evaluated. Paprika oleoresin emulsions with a ratio of paprika oleoresin/wall material of 1:4 (w/w) were prepared using high-pressure homogenization, and then spray dried. Both treatments showed that carotenoid retention in the microcapsules increased as inlet air temperature was increased from 160 to 200 °C, and the yellow fraction was more stable than the red fraction at all temperatures tested. Microcapsules with the highest carotenoid retention were stored at different a_w’s at 35 °C. Maximal stability for carotenoid oxidation was found at a_w’s of 0.274 and 0.710 for microcapsules prepared with GA and SPI respectively. In both treatments the lowest carotenoid degradation was associated to the minimum integral entropy zone and affected in the same way to the red and yellow pigments, during storage at 35 °C. Additionally, in contrast to microcapsules prepared with SPI, GA microcapsules were unable to retain their structural integrity at water activities above 0.743.     

Improving the oxygen barrier of microcapsules using cellulose nanofibres

In this study, the oxygen barrier and physical properties of two maltodextrin/gum Arabic (MD/GA) (3:1 w/w) microcapsules with dextrose equivalence (DE) 26 and 6 were assessed with or without the incorporation of cellulose nanofibres (CNF). The oxygen diffusion coefficient (D_eff) was between 10.6 × 10⁻¹⁵ m² s⁻¹ and 17.3 × 10⁻¹⁵ m² s⁻¹ for all microcapsules. The addition of CNF improved the oxygen barrier of MD/GA microcapsules. The incorporation of CNF did not significantly impact T_g due to the low quantity of CNF present in the microcapsules. Wettability was higher in CNF incorporated microcapsules, and dispersibility was lower only for microcapsules with maltodextrin of DE 26. Spray-dried microcapsules exhibited poor flowability and high cohesiveness due to the moisture content (2.0–2.5%) of the powders. The results suggest that incorporation of CNF can increase the oxygen barrier of MD/GA microcapsules which may lead to better oxidative stability of micronutrients incorporated in the microcapsules.     

Stability of anthocyanins in frozen and freeze-dried raspberries during long-term storage: in relation to glass transition

Abstract: Anthocyanins, natural plant pigments in the flavonoid group, are responsible for the red color and some of the nutraceutical benefits of raspberries. This study explores anthocyanin degradation in frozen and freeze‐dried raspberries during storage in relation to glass transition temperatures. Frozen raspberries were stored at ?80, ?35, and ?20 °C, while freeze‐dried raspberries were stored at selected water activity (a_w) values ranging from 0.05 to 0.75 at room temperature (23 °C) for more than a year. The characteristic glass transition temperatures (T′_g) of raspberries with high water content and glass transition temperature (T_g) of raspberries with small water content were determined using a differential scanning calorimeter. The pH differential method was used to determine the quantity of anthocyanins in frozen and freeze‐dried raspberries at selected time intervals. The total anthocyanins in raspberries fluctuated during 378 d of storage at ?20 and ?35, and ?80 °C. Anthocyanin degradation in freeze‐dried raspberries ranged from 27% to 32% and 78% to 89% at a_w values of 0.05 to 0.07 and 0.11 to 0.43, respectively, after 1 y. Anthocyanins were not detectable in freeze‐dried raspberries stored at a_w values of 0.53 to 0.75 after 270 d. First order and Weibull equations were used to fit the anthocyanin degradation in freeze‐dried raspberries. The 1^st‐order rate constant (k) of anthocyanin degradation ranged from 0.003 to 0.023 days^?1 at the selected water activities. Significant anthocyanin degradation occurred in both the glassy and rubbery states of freeze‐dried raspberries during long‐term storage. However, the rate of anthocyanin degradation in freeze‐dried raspberries stored in the glassy state was significantly smaller than the rate of anthocyanin degradation in the rubbery state.     

Rheological characterization of dispersions and emulsions used in the preparation of microcapsules obtained by interfacial polymerization containing <Emphasis Type="Italic">Lactobacillus</Emphasis> sp.

The main objectives of this work were the rheological characterization of dispersions and emulsions used in the microcapsules preparation and the microcapsules obtain from gum arabic (A), gellan gum (G) and mesquite seed gum (M) to keep lactic bacteria (Lactobacillus sp.) viable using the interfacial polymerization technique (IP). Dispersions of A, G and M were prepared to obtain microcapsules, as well as binary mixtures of gum arabic and gellan gum (AG), gum arabic and mesquite seed gum (AM) and gellan gum and mesquite seed gum (GM); these dispersions exhibited a shear thinning non-Newtonian behavior. The emulsions were prepared using sunflower oil as the oily phase in a 1:1, 1:3 and 1:5 ratio with the disperse phase; the oily phase was added with Span 85 (surfactant) at 1, 2 and 3% concentrations; the emulsions A (1:5 and 3% Span 85) and GM (1:5 and 2% Span 85) showed higher viscosity and stability. Microcapsules were obtained using 0.05 mol L⁻¹ glutaraldehyde (crosslinking agent) with a reaction time of 3 min. The mean diameter of the microcapsules obtained was 30.17, 16.86 and 10.34 μm according to the AG, AM and GM mixtures, respectively. In the AG and AM dispersions, the microcapsules diameters became larger as the viscosity increased. The microorganism microencapsulates using gum arabic, gellan gum, and mesquite seed gum, was possible. The highest viability (46.7%) of Lactobacillus sp. was obtained with the GM mixture.     

Ferrous bisglycinate content and release in W1/O/W2 multiple emulsions stabilized by protein–polysaccharide complexes

Ferrous bisglycinate aqueous solution was entrapped in the inner phase (W₁) of water-in-oil-in-water (W₁/O/W₂) multiple emulsions. The primary ferrous bisglycinate aqueous solution-in-mineral oil (W₁/O) emulsion contained 15% (w/w) ferrous bisglycinate, had a dispersed phase mass fraction of 0.5, and was stabilized with a mixture of Grindsted PGPR 90:Panodan SDK (6:4 ratio) with a total emulsifiers concentration of 5% (w/w). This primary emulsion was re-emulsified in order to prepare W₁/O/W₂ multiple emulsions, with a dispersed mass fraction of 0.2, and stabilized using protein (whey protein concentrate (WPC)):polysaccharide (gum arabic (GA) or mesquite gum (MG) or low methoxyl pectin (LMP)) complexes (2:1 ratio) in the W₂ aqueous phase. The W₁/O/W₂ multiple emulsion stabilized with WPC:MG (5% w/w total biopolymers concentration) provided smaller droplet sizes (2.05 μm), lower rate of droplet coalescence (7.09 × 10⁻⁷ s⁻¹), better protection against ferrous bisglycinate oxidation (29.75% Fe³⁺) and slower rate of ferrous bisglycinate release from W₁ to W₂ (K_H = 0.69 mg mL⁻¹ min^−0.5 in the first 24 h and 0.07 mg mL⁻¹ min^−0.5 for the next 19 days of storage time). Better encapsulation efficiencies, enhanced protection against oxidation and slower release rates of ferrous bisglycinate were achieved as the molecular weight of the polysaccharide making up protein:polysaccharide complex was higher. Thus, the factor that probably affected most the overall functionality of multiple emulsions was the thickness of the complex adsorbed around the multiple emulsion oil droplets. These thicknesses determined indirectly by measuring the z-average diameter of the complexes, and that of the WPC:MG (529.4 nm) was the largest.     

Effects of different wall materials on stability and umami release of microcapsules of Maillard reaction products derived from Aloididae aloidi

Umami has a fast release in the long time high temperature cooking process. Microencapsulation technology can be used to control the release of aromas, and spray drying is the method most commonly used for preparing microcapsules. In this study, the Maillard reaction products from the enzymatic hydrolysate of the Aloididae aloidi were combined with chitosan (C); maltodextrin (M); chitosan and gum arabic (C + GA); M + GA; and C + M + GA via spray drying. Characterisation, flavour characteristics and umami release of microcapsules were analysed and determined. The results showed that the obtained microcapsules had the characteristics of low water content and high solubility, and had good embedding effect and thermal stability (especially M_{C + GA}). Scanning electron microscopy results showed that the addition of wall material increased the diameter of the particles. The microcapsules in M_C group and M_{C + GA} group showed the best apparent structure, which was round without pits or pores. In the controlled release study of umami, M_{C + GA} group showed the best sustained umami release, released 13.95%, 38.08% and 80% umami at 0.5, 4 and 32 min, respectively. In conclusion, adding C + GA as wall material of microcapsules had the best stability, flavour and taste sustained-release effect.     

DEGRADATION KINETICS OF ANTHOCYANIN IN ETHANOLIC SOLUTIONS

The objective of this study was to investigate the degradation kinetics of anthocyanin in ethanolic model solutions simulating wine and liqueur in aging or long‐term storage. Malvidin‐3‐glucoside, as the predominant anthocyanin in many cultivars of grape, was chosen to represent anthocyanins. The results from high performance liquid chromatography analysis show that the disappearance of malvidin‐3‐glucoside follows apparent first‐order kinetics, and accelerates with the increase in ethanol concentration. The E_a values were found to be 22.80, 24.45, 24.35 and 22.75 kcal/mole at 0, 10, 30 and 50% ethanol concentrations, respectively. We propose that the decreased stability of anthocyanin at an elevated ethanol concentration is a result of a decreased extent of self‐association in the solution.     

Determination of critical storage conditions of coffee oil microcapsules by coupling water sorption isotherms and glass transition temperature

Coffee oil microcapsules were produced by spray‐drying using as encapsulating agents gum Arabic, whey protein isolate (WPI) and mixtures of maltodextrin (MD) and WPI, at three different proportions (3:1, 1:1 and 1:3). Sorption isotherms were determined by the gravimetric method, and the glass transition temperature (T_g) was measured by differential scanning calorimetry. Microcapsules produced with gum Arabic showed the highest water adsorption and underwent a stronger water plasticising effect. At the highest water activity (0.843), this sample had a T_g value of ?18.3 °C, while those produced with WPI at higher proportions showed values around 25 and 30 °C. The good fit of experimental data by Guggenheim‐Anderson‐de Boer and Gordon–Taylor models allowed the determination of the critical storage conditions, at which powders are not susceptible to deteriorative physical changes. The samples produced with 1:1 and 1:3 of MD/WPI were the most stable ones, showing critical water activity values of 0.890 and 0.938, respectively.     

Thermodynamic analysis of the sorption isotherms of pure and blended carbohydrate polymers

The adsorption isotherms of gum Arabic (GA), mesquite gum (MG), and maltodextrin DE 10 (MD), and a blend of the three gums (17%GA–66%MG–17%MD) were determined at 25, 35, and 40 °C. All isotherms were fitted using the GAB model and the thermodynamic properties (enthalpies and entropies, differential and integral) were estimated by the Clausius–Clapeyron method. The minimum integral entropy was considered as the point of maximum stability where strong bonds between the adsorbate and adsorbent occurred, and water is less available and likely to participate in spoilage reactions. The point of maximum stability was found between 12.24 and 14.68 kg H₂O/100 kg d.s. (corresponding to water activity, a_w, of 0.32–0.57) for GA, 12.12–14.27 kg H₂O/100 kg d.s. (a_w = 0.33–0.55) for MG, and 11.37–13.84 kg H₂O/100 kg d.s. (a_w = 0.28–0.55) for the biopolymer blend, in the temperature range studied.     

Comparison of molecular and emulsifying properties of gum arabic and mesquite gum using asymmetrical flow field-flow fractionation

The molecular and emulsifying properties of gum arabic (GA) and mesquite gum (MG) were characterized using asymmetrical flow field-flow fractionation connected to multi-angle light scattering and refractive index detection. Properties such as molar mass, root-mean-square radius (r_rms), hydrodynamic radius (r_h), conformation, apparent densities and distribution of proteinaceous matter over the whole molar mass range were determined. GA displayed a low molar mass (3.4 × 10⁵ g/mol), protein-poor component (population 1) and a high molar mass (1.9 × 10⁶ g/mol), protein-rich component (population 2). MG displayed one molar mass population with an average molar mass of 1.1 × 10⁶ g/mol. For both GA and MG, the conformation (r_rms/r_h) was increasingly spherical with increasing molar mass. However, MG had higher values of r_rms/r_h for a specific molar mass suggesting differences in structure between GA and MG. The protein content increased with increasing molar mass for both gums, although to a higher extent for GA. Selective adsorption, during emulsification experiments, could be observed of population 2 of GA which may be due to a combination of the higher protein content and a more flexible structure rendering it more surface active than population 1. Comparing GA and MG in terms of emulsion stability, it could be concluded that GA-stabilized emulsions have considerably higher stability against coalescence.     

Pressure Degradation Kinetics of Anthocyanin Pigment and Visual Color of Chinese Bayberry Juice

Pressure degradation kinetics of the anthocyanin pigment content and visual color (L, a, and b values) of Chinese bayberry juice were evaluated at selected pressures (400, 500, and 600 MPa) and holding times (5–10 min). Results indicated that the degradation of anthocyanin content after high pressure processing and during storage followed the first-order models, as well as the change of a and L × a × b values after high pressure processing. The activation energies (V_a) for anthocyanin content, a and L × a × b changes after high pressure processing were –19.845, –14.915, and –12.908 cm³ mol^–1, respectively. V_a analysis indicated that anthocyanin was more pressure sensitive than visual color parameters.     

EFFECT OF ADDITION OF PEACH GUM ON PHYSICOCHEMICAL PROPERTIES OF GELATIN-BASED MICROCAPSULE

The physicochemical properties of the microcapsules, which were prepared by spray drying, were evaluated. Gelatin‐sucrose (Gel‐Suc) and gelatin‐peach gum‐sucrose (Gel‐PG‐Suc) were used as wall material, while vitamin A was used as core material. The microencapsulation efficiency of Gel‐Suc and Gel‐PG‐Suc microcapsules significantly varied from 94.77 to 96.70% (P < 0.05). By adding peach gum, the microcapsules exhibited a spherical shape with a smooth surface, as evidenced by scanning electron microscopy, and the volume average diameter (D_4,3) showed significant difference from 73.95 to 68.72 µm (P < 0.05). By employing Fourier transform infrared spectroscopy, it was shown that OH‐stretching vibrations of Gel‐PG‐Suc microcapsules shifted to a lower wave number than that of Gel‐Suc microcapsules (Gel‐Suc microcapsules absorption peak: 3403.80/cm, Gel‐PG‐Suc microcapsules absorption peak: 3395.23/cm), so H‐bonding was strengthened by adding peach gum. Corresponding to the band of C=O in —C=ONH—, Gel‐Suc and Gel‐PG‐Suc microcapsules were 1652.72/cm and 1646.31/cm, respectively. Differential scanning calorimetry results revealed that the glass transition temperature (T_g) increased significantly from 46.103 to 50.448C by the addition of peach gum (P < 0.05).     

The influence of powder morphology on the effect of rosemary aroma microencapsulation during spray drying

The influence of particle morphology of spray dried powders obtained by using different carriers on the efficiency of microencapsulation of rosemary aroma is shown in the present research. It was found that the type of the carrier influenced the size but not the shape of rosemary aroma capsules and all the capsules were spherical with cracks. The biggest particles, d₅₀ = 55 μm, were obtained with 25% maltodextrin (MD) as a carrier, and the smallest, d₅₀ = 29 μm with 30% gum arabic (GA). The efficiency of encapsulating aroma inside of the capsules depended on the particles size and apparent density. An increase in the quantity of microencapsulated aroma from 10% for 25% MD to about 60% for 30% GA as the carrier was seen, which co‐related with a decrease in the average diameter of the powder particles. Similarly, an increase in the efficiency of aroma retention was followed by an increase of apparent density of powders from 796 (25% MD) to 1156 kg m^?3 (30% GA).     

Investigations into the stabilization of a volatile aroma compound using a combined emulsification and spray drying process

The aromatic compound 3-methylbutyraldehyde (3-mba) was stabilized using a combined emulsification (W₁/O/W₂) and spray drying process. The process suitability and the encapsulation properties of eight materials were evaluated. Whey protein concentrate (WPC), sodium octenyl succinate modified starch (modified starch 1), maltodextrin, and gum Arabic (GA) were found to be the best process-adapted microencapsulation materials. These materials were chosen for further experiments in which the influence of the solids content on flavor intensity and flavor retention during storage were determined. The amount of encapsulated 3-mba increased with increasing solids content from 40–50% using WPC, modified starch 1, and maltodextrin. Microcapsules with GA reached the maximum value of encapsulated 3-mba at 45% solids. After 11 days of storage, flavor retention decreased in the following order: GA > modified starch 1 > WPC ∼ maltodextrin. Finally, the spray drying process was optimized by design of experiments (DoE). The optimized parameters were a feed temperature of 40 °C, a dry mass in W₂ of 60%, and an amount of W₁/O of 40% using modified starch 1.     

Effect of the presence of gum arabic on the thermostability of thaumatin

Summary The objective of this research was to evaluate the effect of gum arabic on thermostability of thaumatin. Thermodegradation of solutions of thaumatin with gum arabic at various temperatures (50, 70 and 90 °C) was studied. This degradation appeared to follow first‐order kinetics at whatever temperature was used for thermodegradation. The experiments revealed an activation energy (E_a) of 41.4 kJ mol^?1 and a t_90% (time necessary to obtain a decrease of 10% of the initial concentration) of about 24 days for thaumatin with gum arabic, at 20 °C, at pH 4.90.     

Anthocyanins: optimisation of extraction from Cabernet Sauvignon grapes,microcapsulation and stability in soft drink

The aim of this study was to establish the optimum conditions for the extraction of anthocyanins from Cabernet Sauvignon (Vitis vinifera L.) grapes using the response surface methodology and to evaluate the stability of these anthocyanins encapsulated with different carrier agents in an isotonic soft drink system under different light and temperature conditions. The extraction process was optimised with the response surface methodology to obtain the highest anthocyanin concentration (40 mL of ethanol:1.5 N HCL (85:15) as solvent, extraction time 29.4 h at pH 2.4). The degradation of the anthocyanins followed first‐order kinetics in the situations evaluated. Maltodextrin, maltodextrin/γ‐cyclodextrin and maltodextrin/arabic gum were tested as carrier agents and the combination of maltodextrin/arabic gum presented the longest half‐life time and lowest degradation constant for all the conditions evaluated. The formation of microcapsules was observed through scanning electron microscopy.     

Molar Mass Distribution and Size of Hydroxyethyl Starch Fractions Obtained by Continuous Polymer Fractionation

By the use of continuous polymer fractionation (CPF) the initial polymer can be separated into fractions of different molar masses, which makes it possible to obtain hydroxyethyl starch (HES) fractions tailor‐made for specific application. Two samples of HES (HES A and HES B) were fractionated by means of CPF. By size‐exclusion chromatography‐multi‐angle laser light‐scattering‐differential refractive index (SEC/ MALLS/DRI) measurements it was shown that CPF is able to remove the low‐molarmass components and to adjust the samples to various desired molar masses with lower polydispersities than the original samples. In terms of the weight‐average mean molar mass M_W , the sol fractions have smaller molar masses than the starting sample, whilst the gel fractions have higher molar masses. Furthermore the radius of gyration R_G could be determined for the initial sample HES B with 19.7 and 19.4 nm and also for some of its fractions. However, no general R_G—M_W relationship could be established for the HES samples fractionated using CPF. This is probably due to the complex branched structure of amylopectin. M_W and M_W/M_n of the six fractions obtained from HES A with M_W = 161, 000 g/mol and M_W/M_n = 4.7 ranged from 19, 000 to 362, 000 g/mol with M_W/M_n from 1.8 to 3.1. The molar masses of the four fractions obtained from HES B with M_W = 460, 000 g/mol and M_W/M_n = 6.0 were between 18, 000 and 680, 000 g/mol with M_W/M_n from 1.7 to 4.8 or between 202, 000 and 1, 005, 000 g/mol with M_W/M_n from 2.7 to 4.7 depending on fractionation strategy.     

Effect of Hemicellulose as a Coating Material on Water Sorption Thermodynamics of the Microencapsulated Fish Oil and Artificial Neural Network (ANN) Modeling of Isotherms

In this study, effect of hemicellulose as a coating material on sorption behavior of the microencapsulated fish oil is presented. For this purpose, water sorption isotherms of the fish oil microcapsules prepared using gum arabic (GA) and gum arabic-hemicellulose (GA-HC) were determined at 10, 25, and 35 °C using the gravimetric technique. The equilibrium moisture content (EMC) data were fitted to several empirical mathematical models, namely Oswin, BET, GAB, and Freundlich equations and the novel artificial neural network (ANN) model. The GA-HC microcapsules had higher EMC values than GA, due to the sugar content of hemicellulose. The EMC of the samples were more accurately predicted by the ANN model than by the empirical models at the entire range of a _w. Heat of sorption of fish oil microcapsules was then predicted using the data obtained from the ANN model and fitted to the power model (R ²?=?0.985–0.978). A linear relation existed between the differential enthalpy and the differential entropy for microcapsules, thus satisfying the enthalpy-entropy compensation theory.