Stabilization of the Antioxidant Properties in Spray-Dried Microcapsules of Fish and Chia Oil Blends

Even with healthy foods, there is still a need to protect the functionality during processing. The stabilization and enrichment of fish oil (FO) extracted from fish fillets using solvent extraction might make this healthy oil more available. FO was stabilized by mixing it with chia seed oil (CSO) at 50:50 at room temperature. The antioxidant properties of the blends were evaluated using the total phenolic content (TPC), free radical scavenging activity (DPPH), ferric reducing antioxidant potential (FRAP), and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) activities with FO and CSO as controls. The blends of FO and CSO increased the oxidative stability, while FO was the most susceptible to degradation. The stability and bioactivity of antioxidants against environmental factors were improved by using encapsulation. Response surface methodology (RSM) was used to optimize spray-drying operating conditions for spray-dried microcapsules (SDMs). The independent variables were the inlet air temperature (IAT), which varied from 125 to 185 °C; wall material (WM) concentration, which varied from 5 to 25%; pump speed (PS), which varied from 3 to 7 mL/min; and needle speed (NS), which varied from 3 to 11 s. The results indicated that the maximum antioxidant activity of SDM was obtained at 140 °C IAT, 10% WM, 4 mL/min PS, and 5 s NS, while the minimum value was obtained at 170 °C IAT, 20% WM, 6 mL/min PS, and 9 s NS. The IAT had a significant effect on the antioxidant activities, and the stability of SDMs was increased. These SDMs can be used in the formulation of food matrices due to their therapeutic and nutritional properties.

Oxidative stability and sensory evaluation of sodium caseinate-based yak butter powder

Yak butter's high unsaturated fatty acid level predisposes it to oxidation, hence must be converted into more stable forms like powder. This study aimed to spray dry yak butter using 10% yak butter and four sodium caseinate (NaCas) formulations: sample A: 100% NaCas; sample B: 50% NaCas, 50% lactose; sample C: 75% NaCas, 25% lactose; and sample D: 25% NaCas, 75% maltodextrin. The powders were vacuum and hermetically sealed, and evaluated for oxidative stability, physical and sensory properties during storage at 65 ℃ for 30 days. The results showed that samples B and D had similar and most favorable physical properties (such as, moisture, water activity, particle size, bulk density re-dispersion time, and encapsulation efficiency); though sample B, together with sample C, browned the most during storage. The majority of the sensory panelists preferred samples B and D; observed high caking in samples C and B; and the least whiteness loss and caking in samples D and A but high off-flavors in samples A and C. After storage, peroxide and thiobarbituric acid values of powder samples ranged from 34.98 to 69.54 meqO2/kg and 1.85-9.43 mg MD/kg, respectively, in the decreasing order of A, C, B, and D. Sample D, followed by B, showed the highest radical scavenging activity. Therefore, for optimum yak butter powder physical properties and oxidative stability, 50%:50%, NaCas: lactose, and 25%:75%, NaCas: maltodextrin formulations should be used. This study provides essential knowledge for butter powder processors.

Effects of Wall Material on Medium-Chain Triglyceride (MCT) Oil Microcapsules Prepared by Spray Drying

A medium-chain triglyceride (MCT) oil microcapsule was prepared by spray drying. The effects of the wall-material parameters of wall-to-oil ratio (1:1 to 3:1) and type of wall material (gum arabic (GA), whey protein isolate (WPI), and octenyl succinic anhydride (OSA) starch) on the microcapsules were evaluated. The droplet size, size distribution, viscosity, zeta potential, and stability of the emulsions were measured. The spray-dried powder was characterized by its morphology, yield, encapsulation efficiency, and moisture content. The wall material influenced the characteristics of the emulsions and microcapsules. The formulation with a 2:1 wall-to-oil ratio and OSA starch/maltodextrin as the wall material resulted in a small droplet size (0.177 ± 0.002 µm) with high encapsulation efficiency (98.38 ± 0.01%). This formulation had good physical stability over three months under accelerated conditions. Thus, OSA starch/maltodextrin is an appropriate wall material for encapsulating MCT oil.

Microencapsulation of rice bran oil using pea protein and maltodextrin mixtures as wall material

In this work, the encapsulation of rice bran oil extracted using supercritical CO2 has been studied. In the first stage, the emulsification process by high pressure homogenization was studied and optimized. The effect of the working pressure (60-150 MPa), the composition of the carrier (mixtures of pea protein isolate (PPI) and maltodextrin (MD), from 50 to 90% of PPI) and the carrier to oil ratio (2-4) on the emulsion droplet size (EDS) was studied. To minimize the EDS, moderate pressures (114 MPa), a carrier composed mainly by PPI (64%) and carrier to oil ratios around 3.2 were required. The emulsion obtained in the optimal conditions (EDS = 189 ± 3nm) was dried using different technologies (spray-drying, PGSS-drying and freeze drying). The supercritical CO2 based drying process (PGSS) provided spherical particles that resulted in the smallest average size (but broader distribution) and lower encapsulation efficiency (53 ± 2%).

Emulsifying Properties of Tremella Fuciformis: A Novel Promising Food Emulsifier

In this paper, the emulsifying properties of Tremella fuciformis (TFS) were assessed in comparison with lotus seed (LTS), purple sweet potato (PSPP) and gum arabic (GA) in oil-in-water (O/W) emulsions. Emulsifying properties were evaluated in terms of the emulsifying activity (EA), emulsifying stability, mean droplet size, zeta potential, shear viscosity and freeze-thaw stability of their emulsions. The results revealed that TFS exhibited excellent EA and best emulsifying stability (100 %) after 21 days at 21 °C. When exposure to 100 °C for 20 min, TFS emulsions showed reduced in droplet size, which was superior as compared to LTS, PSPP, and GA. In zeta-potential test, TFS was proved to be more suitable emulsifier as compared with LTS and GA as it had a comparatively larger magnitude. TFS emulsions showed the smallest droplet size at pH 10.0 followed by pH 3.0 and pH 6.5. Non-Newtonian shear-thinning behavior of all four samples remained same at 4.0 % concentration while the apparent viscosity of TFS was the highest among all. The cream index of 4.0 % TFS was also the highest at freeze-thaw cycles. Therefore, the TFS could be used as emulsifier and thickener in food industry.

Microencapsulation of β-Carotene by Spray Drying: Effect of Wall Material Concentration and Drying Inlet Temperature

Carotenoids are a class of natural pigments found mainly in fruits and vegetables. Among them, β-carotene is regarded the most potent precursor of vitamin A. However, it is susceptible to oxidation upon exposure to oxygen, light, and heat, which can result in loss of colour, antioxidant activity, and vitamin activity. Thus, the objective of this work was to study the microencapsulation process of β-carotene by spray drying, using arabic gum as wall material, to protect it against adverse environmental conditions. This was carried out using the response surface methodology coupled to a central composite rotatable design, evaluating simultaneously the effect of drying air inlet temperature (110-200°C) and the wall material concentration (5-35%) on the drying yield, encapsulation efficiency, loading capacity, and antioxidant activity. In addition, morphology and particles size distribution were evaluated. Scanning electron microscopy images have shown that the particles were microcapsules with a smooth surface when produced at the higher drying temperatures tested, most of them having a diameter lower than 10 μm. The conditions that enabled obtaining simultaneously arabic gum microparticles with higher β-carotene content, higher encapsulation efficiency, and higher drying yield were a wall material concentration of 11.9% and a drying inlet temperature of 173°C. The systematic approach used for the study of β-carotene microencapsulation process by spray drying using arabic gum may be easily applied for other core and wall materials.

Encapsulation of omega 3-6-9 fatty acids-rich oils using protein-based emulsions with spray drying

With an increased awareness of the link between the consumption of omega 3-6-9 fatty acid-rich oils and health, the food industry has been developing innovative strategies for raising their levels within the diet. Microencapsulation is one approach used to protect those oils from oxidative deterioration and to improve their ingredient properties (e.g., handling and sensory). Spray drying is the most commonly used technique to develop microcapsules. The preparation of protein-stabilized emulsions is a fundamental step in the process in order to produce microcapsules with good physical properties, effective protection and controlled release behaviors. This review describes types of emulsions prepared by animal and plant proteins, discusses the relationship between emulsion properties and microcapsule properties, and identifies key parameters to evaluate physical properties (e.g., moisture content, water activity, particle size, surface oil and entrapment efficiency), oxidative stability and release behavior of spray-dried microcapsules for industrial application.

Producing Powders Containing Active Dry Probiotics With the Aid of Spray Drying

Probiotics are microorganisms capable of conferring health benefits to humans and animals when ingested. Probiotic products that prevail in food market usually contain viable bacteria from Lactobacillus and Bifidobacterium genera. Bacterial strains in these genera often have complex nutrient requirements and tend to be fragile under environmental stresses. How to incorporate the cells into food matrix without causing undesired viability loss is a key issue for developing products of viable probiotics. Spray drying offers a rapid way to produce powders encapsulating probiotics in a matrix of protectant(s), which may extend the term of viability preservation and expand the application of probiotic products. In spray drying, feed solution that contains probiotic cells and dissolved or suspended protectant solids are atomized into droplets, which are quickly converted into particles by drying in a hot airflow. The harsh conditions and interplaying stresses make the maintenance of cell viability a challenging task. To enhance cell survival in dried powders, various approaches have been attempted, including the enhancement of the intrinsic stress tolerance of cells, adjustment of protectant composition, and optimization of the production process and dryer settings. This chapter discusses important factors influencing probiotic viability during spray drying from aspects of microbiology, food chemistry, and drying process. The mechanisms underlying the influences at the droplet and cellular levels and strategies taken to protect cell viability at the process level are discussed.