Marcelo Thomazini

Microencapsulation of aspartame by double emulsion followed by complex coacervation to provide protection and prolong sweetness.

The objective of this work was to microencapsulate aspartame by double emulsion followed by complex coacervation, aiming to protect it and control its release. Six treatments were prepared using sunflower oil to prepare the primary emulsion and gelatin and gum Arabic as the wall materials. The microcapsules were evaluated structurally with respect to their sorption isotherms and release into water (36°C and 80°C). The microcapsules were multinucleated, not very water-soluble or hygroscopic and showed reduced rates of equilibrium moisture content and release at both temperatures. FTIR confirmed complexation between the wall materials and the intact nature of aspartame. The results indicated it was possible to encapsulate aspartame with the techniques employed and that these protected the sweetener even at 80°C. The reduced solubility and low release rates indicated the enormous potential of the vehicle developed in controlling the release of the aspartame into the food, thus prolonging its sweetness.

Microencapsulation of xylitol by double emulsion followed by complex coacervation.

The objective of this study was to produce and characterise xylitol microcapsules for use in foods, in order to prolong the sweetness and cooling effect provided by this ingredient. Complex coacervation was employed as the microencapsulation method. A preliminary double emulsion step was performed due to the hydrophilicity of xylitol. The microcapsules obtained were characterised in terms of particle size and morphology (optical, confocal and scanning electron microscopy), solubility, sorption isotherms, FTIR, encapsulation efficiency and release study. The microcapsules of xylitol showed desirable characteristics for use in foods, such as a particle size below 109 μm, low solubility and complete encapsulation of the core by the wall material. The encapsulation efficiency ranged from 31% to 71%, being higher in treatments with higher concentrations of polymers. Release of over 70% of the microencapsulated xylitol in artificial saliva occurred within 20 min.

Functional properties and stability of spray-dried pigments from Bordo grape (Vitis labrusca) winemaking pomace.

The stability of anthocyanin and phenolic compounds, the antioxidant capacity, the antimicrobial activity and the capacity to inhibit arginase from Leishmania were evaluated in spray-dried powders from Bordo grape winemaking pomace extract. The pigments were produced using maltodextrin as the carrier agent at concentrations varying from 10% to 30% and air entrance temperatures varying from 130 to 170°C. A sample of freeze-dried extract without the carrier was also evaluated. The anthocyanins in the spray-dried samples showed good stability during storage, better than the freeze-dried and liquid extracts. The samples were capable of inhibiting the growth of Staphylococcus aureus and Listeria monocytogenes and showed high inhibitory capacity against the enzyme arginase from Leishmania. These results provide evidence that Bordo grapes from the winemaking process have the potential to be used as natural pigments with functional properties.

Microencapsulation of Bifidobacterium animalis subsp. lactis and Lactobacillus acidophilus in cocoa butter using spray chilling technology

In the present study, the cells of Bifidobacterium animalis subsp. lactis (BI-01) and Lactobacillus acidophilus (LAC-04) were encapsulated in cocoa butter using spray-chilling technology. Survival assays were conducted to evaluate the resistance of the probiotics to the spray-chilling process, their resistance to the simulated gastric and intestinal fluids (SGF and SIF), and their stability during 90 days of storage. The viability of the cells was not affected by microencapsulation. The free and encapsulated cells of B. animalis subsp. lactis were resistant to both SGF and SIF. The micro-encapsulated cells of L. acidophilus were more resistant to SGF and SIF than the free cells; the viability of the encapsulated cells was enhanced by 67%, while the free cells reached the detection limit of the method (103 CFU/g). The encapsulated probiotics were unstable when they were stored at 20 °C. The population of encapsulated L. acidophilus decreased drastically when they were stored at 7 °C; only 20% of cells were viable after 90 days of storage. The percentage of viable cells of the encapsulated B. animalis subsp.lactis, however, was 72% after the same period of storage. Promising results were obtained when the microparticles were stored at −18 °C; the freeze granted 90 days of shelf life to the encapsulated cells. These results suggest that the spray-chilling process using cocoa butter as carrier protects L. acidophilus from gastrointestinal fluids. However, the viability of the cells during storage must be improved.

Effect of spray drying on the sensory and physical properties of hydrolysed casein using gum arabic as the carrier

This study was aimed at spray drying hydrolysed casein using gum Arabic as the carrier agent, in order to decrease the bitter taste. Three formulations with differing proportions of hydrolysed casein: gum Arabic (10:90, 20:80 and 30:70) were prepared and characterized. They were evaluated for their moisture content, water activity, hygroscopicity, dispersibility in water and in oil, particle size and distribution, particle morphology, thermal behaviour (DSC) and bitter taste by a trained sensory panel using a paired-comparison test (free samples vs. spray dried samples). The proportion of hydrolysed casein did not affect the morphology of the microspheres. The spray drying process increased product stability and modified the dissolution time, but had no effect on the ability of the material to dissolve in either water or oil. The sensory tests showed that the spray drying process using gum Arabic as the carrier was efficient in attenuating or masking the bitter taste of the hydrolysed casein.

Protection of echium oil by microencapsulation with phenolic compounds

The consumption of omega-3 enables the reduction of cardiovascular disease risk; however they are unstable. The aim of this work was to encapsulate echium oil (Echium plantagineum L.), a rich source of omega-3 fatty acids, with phenolic compounds (sinapic acid and rutin) by double emulsion followed by complex coacervation or by complex coacervation with sinapic acid in the capsule wall. Analyses of morphology, particle size, circularity, water activity, moisture, Fourier transform infrared spectroscopy, thermogravimetry, process yield, accelerated oxidation and identification and quantification of fatty acids present in the encapsulated oil were performed. Samples presented values of encapsulation process yield of phenolics and oil in the range of 39-80% and 73-99%, respectively. Moreover, all samples protected the oil against oxidation, obtaining induction time (accelerated oxidation) of 5h for pure oil and values in the range from 10 to 18h for samples. Thus, better protection to the oil was possible with sinapic acid applied in the capsule wall, which enhances its protection against lipid oxidation.

Production and structural characterization of solid lipid microparticles loaded with soybean protein hydrolysate

The aims of this study were to produce and evaluate solid lipid microparticles (SLMs) loaded with soy protein hydrolysate (HP). The SLMs were produced by spray chilling with an active material and carrier ratio of 1:5 and 1:10 and in two feed preparations: emulsion and suspension. The rheological parameters of the feeds produced by emulsions were studied, morphological characteristics of the SLMs were examined via scanning electron microscopy (SEM) and confocal microscopy, the particle size and distribution were measured via laser light diffraction, and the structural properties of the SLMs were characterized via infrared (FTIR) spectroscopy and X-ray diffraction (XRD). SEM images showed that SLMs were spherical and agglomerated. The analysis of X-ray diffraction indicated that the microparticles after 90days of storage had β polymorphic form. The preparation methods for feeds, emulsion and suspension, had no influence on the rheological parameters, and the median particle size of the SLMs and interactions between the ingredients were not detected via FTIR spectroscopy; however, the SLMs prepared by emulsion contained pores and had a higher incorporation efficiency of HP. The spray chilling technique is suitable method for microencapsulation of soy protein hydrolysate. So, this technique could be useful for attenuating HP unpleasant taste, for its protection and also for promoting its release in the intestine, during fat digestion.

Development of functional yogurt containing free and encapsulated echium oil, phytosterol and sinapic acid

The consumption of omega-3 fatty acids and phytosterol promotes the reduction of cholesterol and triacylglycerol levels. However, such compounds are susceptible to oxidation, which hampers their application. The objective of this work was to coencapsulate echium oil, phytosterols and sinapic acid (crosslinker/antioxidant), and incorporate the obtained microcapsules into yogurt. The microcapsules were evaluated for particle size, accelerated oxidation by Rancimat, and simulation of gastric/intestinal release. The yogurts were assessed for morphology, pH, titratable acidity, color, rheology and sensory analysis. The microcapsules (13-42μm) promoted protection against oil oxidation (induction time of 54.96h). The yogurt containing microcapsules, presented a pH range from 3.89 to 4.17 and titratable acidity range from 0.798 to 0.826%, with good sensorial acceptance. It was possible to apply the microcapsules in yogurt, without compromising the rheological properties and physicochemical stability of the product.

Development of solid lipid microparticles loaded with a proanthocyanidin-rich cinnamon extract (Cinnamomum zeylanicum): Potential for increasing antioxidant content in functional foods for diabetic population

Cinnamon proanthocyanidins play an important role on the attenuation of complications associated to diabetes, but the daily ingestion of these compounds is not always satisfactory due to several aspects such as low stability and unpleasant taste. Thus, in the present study, a proanthocyanidin-rich cinnamon extract (Cinnamomum zeylanicum) was incorporated into solid lipid microparticles (SLMs) by spray chilling technique using vegetable fat as carrier. The microparticles were characterized with regard to their physical and chemical properties, morphology, proanthocyanidin stability and sensory properties. SLMs were spherical with a unimodal size distribution between 60 and 130μm, and proanthocyanidins were highly stable in SLM stored for up to 90days at 5, 25 and 37°C. Moreover, SLMs were able to mask the bitter taste and astringent sensation of proanthocyanidins and other polyphenols from cinnamon extract. Taken together, these results show the potential of SLM loaded with cinnamon proanthocyanidins for improving functional properties in new foods.

Evaluation of the release profile, stability and antioxidant activity of a proanthocyanidin-rich cinnamon (Cinnamomum zeylanicum) extract co-encapsulated with α-tocopherol by spray chilling

Cinnamon has many health improving compounds such as proanthocyanidins, which also have potential for the prevention of damages caused by diabetes. Similarly, α-tocopherol is a natural antioxidant with important role on protection of fatty acids in membranes and lipoproteins. However, the addition of antioxidants in food may result in interaction with food matrix, low stability and unpleasant taste. In the present study, a proanthocyanidin-rich cinnamon extract (PRCE) (Cinnamomum zeylanicum) was co-encapsulated with α-tocopherol into solid lipid microparticles (SLMs) by spray chilling. The microparticles were characterized with regard to the physical and chemical properties, morphology, proanthocyanidin stability and release profile. SLMs were spherical with an average diameter of ca. 80μm. Proanthocyanidins were highly stable in SLMs stored for up to 90days at 5, 25 and 37°C. Moreover, SLMs gradually released proanthocyanidins in simulated gastrointestinal fluids by a diffusional process, following a Korsmeyer-Peppas kinetic. Analyses of the antioxidant compounds indicated that PRCE components exhibited a higher scavenging capacity against reactive oxygen species (ROS) and reactive nitrogen species (RNS). Thus, the SLMs produced in the present study have potential for application in the development of new functional foods and nutraceuticals, also providing an alternative for the controlled release of proanthocyanidins and α-tocopherol into the intestine.