Luz Sanguansri

Encapsulation of food ingredients

Microencapsulation is a relatively new technology that is used for protection, stabilization, and slow release of food ingredients. The encapsulating or wall materials used generally consist of starch, starch derivatives, proteins, gums, lipids, or any combination of them. Methods of encapsulation of food ingredients include spray-drying, freeze-drying, fluidized bed-coating, extrusion, cocrystallization, molecular inclusion, and coacervation. This paper reviews techniques for preparation of microencapsulated food ingredients and choices of coating material. Characterization of microcapsules, mechanisms of controlled release, and efficiency of protection/stabilization of encapsulated food ingredients are also presented.

Synbiotic Microcapsules That Enhance Microbial Viability during Nonrefrigerated Storage and Gastrointestinal Transit

ABSTRACT A Bifidobacterium infantis strain was microencapsulated within a film-forming protein-carbohydrate-oil emulsion. This novel encapsulant incorporated prebiotics and substantially protected the bacterium during nonrefrigerated storage and gastrointestinal transit. The dried microcapsules were small (15 to 20 μm), had low water activity (0.2 to 0.3), and rapidly released the bacteria in simulated intestinal fluid.

Microencapsulated Lactobacillus rhamnosus GG Powders: Relationship of Powder Physical Properties to Probiotic Survival during Storage

Freeze-dried commercial Lactobacillus rhamnosus GG (LGG) were encapsulated in an emulsion-based formulation stabilized by whey protein and resistant starch and either spray-dried or freeze-dried to produce probiotic microcapsules. There was no difference in loss of probiotics viability after spray drying or freeze drying. Particle size, morphology, moisture sorption, and water mobility of the powder microcapsules were examined. Particle size analysis and scanning electron microscopy showed that spray-dried LGG microcapsules (SDMC) were small spherical particles, whereas freeze-dried LGG microcapsules (FDMC) were larger nonspherical particles. Moisture sorption isotherms obtained using dynamic vapor sorption showed a slightly higher water uptake in spray-dried microcapsules. The effect of water mobility, as measured by nuclear magnetic resonance (NMR) spectroscopy, at various water activities (a(w) 0.32, 0.57, and 0.70) and probiotic viability during storage at 25 °C was also examined. Increasing the relative humidity of the environment at which the samples were stored caused an increase in water mobility and the rate of loss in viability. The viability data during storage indicated that SDMC had better storage stability compared to FDMC. Although more water was adsorbed for spray-dried than freeze-dried microcapsules, water mobility was similar for corresponding storage conditions because there was a stronger water-binding energy for spray-dried microcapsule. This possibly accounted for the improved survival of probiotics in spray-dried microcapsules.

Nano- and micro-encapsulated systems for enhancing the delivery of resveratrol

There has been interest in the use of trans‐resveratrol as a natural preventative agent for improving health and alleviating a range of diseases. However, resveratrol has low bioavailability, and this has been associated with its poor water solubility, its low stability against environmental stress, and its inability to reach a target site in the body to exert the desired health effect. Encapsulation offers a potential approach for enhancing the solubility of resveratrol, stabilizing it against trans‐to‐cis isomerization, and improving its bioavailability. A range of encapsulant materials, formulations, and technologies have been examined for enhancing the delivery of resveratrol. Research on the efficacy of encapsulated resveratrol formulations and relevant doses for specific applications is required before recommendations may be made for the use of these formulations for human health outcomes.

Binding of resveratrol with sodium caseinate in aqueous solutions

The interaction between resveratrol (Res) and sodium caseinate (Na-Cas) has been studied by measuring fluorescence quenching of the protein by resveratrol. Quenching constants were determined using Stern-Volmer equation, which suggests that both dynamic and static quenching occur between Na-Cas and Res. Binding constants for the complexation between Na-Cas and Res were determined at different temperatures. The large binding constants (3.7-5.1×10(5)M(-1)) suggest that Res has strong affinity for Na-Cas. This affinity decreases as the temperature is raised from 25 to 37°C. The binding involves both hydrogen bonding and hydrophobic interaction, as suggested by negative enthalpy change and positive entropy change for the binding reaction. The present study indicates that Na-Cas, a common food protein, may be used as a carrier of Res, a bioactive polyphenol which is insoluble in both water and oils.

Oxidative Stability of Microencapsulated Fish Oil Powders Stabilized by Blends of Chitosan, Modified Starch, and Glucose

Various indices of lipid oxidation were used to assess the oxidative stability of microencapsulated fish oil powders prepared from tuna oil-in-water emulsions (pH 4.9 or 6.0) containing chitosan, an emulsifying starch, and glucose. There were good agreements among the induction period for oxidation under accelerated conditions (80 degrees C, 5 bar oxygen), the development of oxidation volatile markers from fish oil (namely, propanal, 1-penten-3-ol, 1-penten-3-one, 2,4-(Z,E)-heptadienal, and 2,4-(E,E)-heptadienal), and the loss of eicosapentanoic acid (EPA) and docosahexanoic acid (DHA) over four weeks of storage at 25 degrees C. All indices of oxidation showed that powders prepared from emulsions at pH 6.0 were more stable to oxidation than corresponding formulations at pH 4.9. It is suggested that the increased electrostatic interactions between the chitosan and emulsifying starch at the higher pH contributed to the increased stability of the microcapsule powders.

Challenges and solutions to incorporation of nutraceuticals in foods.

Manufacturers often cannot simply add a nutraceutical to a food when formulating functional foods that have acceptable sensory appeal as well as the desired health benefits. The appropriate application of microencapsulation for stabilizing nutraceuticals enables their effective delivery through food. Careful design of the delivery system helps protect sensitive nutraceuticals from the environment and processing stresses encountered during food manufacture, and prevents undesirable interactions of the nutraceutical with components in the food matrix. Microencapsulation technologies overcome hurdles associated with the successful delivery of nutraceuticals in healthy foods if due consideration is given to challenges at all stages throughout the supply chain. This encompasses stabilizing and protecting nutraceuticals from degradation in ingredient formats, during processing, in the final food product, and during intestinal transit until they are released at the desired site in the gastrointestinal tract to impart their targeted health effects.

Food matrix effects on in vitro digestion of microencapsulated tuna oil powder.

Tuna oil, containing 53 mg of eicosapentaenoic acid (EPA) and 241 mg of docosahexaenoic acid (DHA) per gram of oil, delivered as a neat microencapsulated tuna oil powder (25% oil loading) or in food matrices (orange juice, yogurt, or cereal bar) fortified with microencapsulated tuna oil powder was digested in simulated gastric fluid or sequentially in simulated gastric fluid and simulated intestinal fluid. The level of fortification was equivalent to 1 g of tuna oil per recommended serving size (i.e., per 200 g of orange juice or yogurt or 60 g of cereal bar). The changes in particle size of oil droplets during digestion were influenced by the method of delivery of the microencapsulated tuna oil powder. Lipolysis in simulated gastric fluid was low, with only 4.4-6.1% EPA and ≤1.5% DHA released after digestion (as a % of total fatty acids present). After sequential exposure to simulated gastric and intestinal fluids, much higher extents of lipolysis of both glycerol-bound EPA and DHA were obtained (73.2-78.6% for the neat powder, fortified orange juice, and yogurt; 60.3-64.0% for the fortified cereal bar). This research demonstrates that the choice of food matrix may influence the lipolysis of microencapsulated tuna oil.

Interactions of buttermilk with curcuminoids.

The ability of buttermilk to carry and stabilise a preparation of curcuminoids was examined. The quenching of intrinsic protein fluorescence confirmed that the curcuminoids interacted with proteins in buttermilk. The Stern-Volmer quenching constant was ≥ 9.4 × 10³ M⁻¹. The apparent binding constant of curcuminoids to whole buttermilk was ≥ 2.2 × 10⁴ M⁻¹. Centrifugation of buttermilk (5% total solids, TS)--curcuminoid mixtures demonstrated that curcuminoids were partitioned into the cream (18.0%w/w, 0.64% TS), milk serum (73.3%w/w, 2.86% TS) and the casein-rich precipitate (6.76% w/w, 1.87% TS) fractions in the ratio of 1:3.7:3.5. The interaction of curcuminoids with components in the buttermilk improved its stability, as evidenced by the faster degradation of curcuminoids in phosphate buffer (pH=6.8) than in buttermilk. The ability of buttermilk to carry and stabilise curcuminoids has the potential to enable the delivery of these components into functional foods.

The batch adsorption of the epigallocatechin gallate onto apple pomace

The ability of apple pomace for carrying a polyphenol (epigallocatechin-3-gallate, EGCG) was examined. The adsorption characteristics of epigallocatechin gallate onto apple pomace from aqueous solution were determined over a range of concentrations (25-600 mg/L) and temperatures (25, 40 and 55 °C). The adsorption of EGCG decreased with increasing temperature. Both the Langmuir and Freundlich models adequately describe the isothermal adsorption of EGCG onto apple pomace. The Gibbs free energy change (ΔG°) for the adsorption of EGCG onto apple pomace ranged from -15.90 to -22.98 kJ/mol over the temperature range 25-55 °C, indicating the adsorption of EGCG onto apple pomace is a spontaneous process, and further that the adsorption process is likely to be dominated by a physisorption mechanism. Our results show that apple pomace has good adsorption characteristics, suggesting that apple pomace may be a useful EGCG carrier for functional food applications.