Talita A. Comunian

Fabrication of solid lipid microcapsules containing ascorbic acid using a microfluidic technique

The importance of ascorbic acid (AA) in the human diet has motivated food researchers to develop AA-fortified food products. However, this compound is very unstable. The aim of this work was to produce solid lipid microcapsules (SLMs) loaded with AA using microfluidic technology. The morphology of the SLMs was analysed by optical, scanning electron and confocal microscopy. We determined the encapsulation efficiency, particle size and stability of the encapsulated material. Two different means of enhancing the encapsulation efficiency and stability of AA were demonstrated: a pore blocking method and a micromolecule-chelating agent within the core. The results indicated the enormous potential of the designed vehicle to prevent AA degradation in a food product; additionally, this vehicle could mask the acidic taste of AA.

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.

Effect of different polysaccharides and crosslinkers on echium oil microcapsules

Microencapsulation by complex coacervation using gelatin and arabic gum (AG) as wall materials and transglutaminase for crosslinking is commonly used. However, AG is only produced in a few countries and transglutaminase is expensive. This work aimed to evaluate the encapsulation of echium oil by complex coacervation using gelatin and cashew gum (CG) as wall materials and sinapic acid (S) as crosslinker. Treatments were analyzed in relation to morphology, particle size, circularity, accelerated oxidation and submitted to different stress conditions. Rounded microcapsules were obtained for treatments with AG (45.45μm) and microcapsules of undefined format were obtained for treatments with CG (22.06μm). The S incorporation for 12h improved the oil stability by three fold compared to oil encapsulated without crosslinkers. Treatments with CG and S were resistant to different stress conditions similar to treatments with AG and transglutaminase, making this an alternative for delivery/application of compounds in food products.

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.

Physico-Chemical Properties, Stability, and Potential Food Applications of Shrimp Lipid Extract Encapsulated by Complex Coacervation

Lipid extract from shrimp cephalothorax is a potential food coloring owing to its intense red color. However, it presents some drawbacks, such as its characteristic odor, astaxanthin instability, and difficult dosage and manipulation. The present work is an attempt to overcome these problems by means of complex coacervation encapsulation using gelatin and gum arabic as wall materials. Round molecules in which the lipid extract was efficiently encapsulated in the form of multiple droplets were obtained. The resulting microcapsules stabilized by freeze-drying had good properties with a view to their application as food coloring, owing to their intense red color, improved astaxanthin stability, and low water activity, water solubility, and hygroscopicity. The coloring capacity and sensory properties were evaluated when added to yogurt and a gellified fish product. For yogurt, a trained sensory panel determined that encapsulation effectively reduced the characteristic odor, whereas the coloring capacity was improved, as compared to non-encapsulated lipid extract. For the gellified fish product, no sensory improvement was observed, but the encapsulated lipid extract provided an attractive, uniform color.

Enhancing stability of echium seed oil and beta-sitosterol by their coencapsulation by complex coacervation using different combinations of wall materials and crosslinkers

Intake of omega-3 fatty acids and phytosterols aids in the reduction of cholesterol and serum triglycerides. However, both fatty acids and phytosterols are susceptible to oxidation. This work coencapsulated echium oil (source of stearidonic and alpha-linolenic fatty acids) and beta-sitosterol (phytosterol) by complex coacervation using different combinations of wall materials, and sinapic acid (SA) and transglutaminase as crosslinkers. High encapsulation yields were obtained (29-93% for SA; 68-100% for the mixture of oil and phytosterols) and retention of 49-99% and 16% for encapsulated and free SA, at 30 days-storage. Treatment with gelatin-arabic gum and 0.075 g SA/g gelatin showed the best results: 0.07 mg MDA/g capsule, and retention of 96, 90 and 74% for alpha-linolenic, stearidonic acid and beta-sitosterol at 30 days of storage, respectively. Thus, coencapsulation of echium oil and phytosterol using SA as the crosslinker was possible, obtaining effective vehicles for protection and application of these compounds in foods.