Green tea, a product made from Camellia sinensis leaves, is recognized worldwide by its high polyphenol content, in special the catechins. Tea catechins are linked to the prevention of several degenerative diseases as cancer and diabetes. However, several drawbacks need to be overcome in order to increase the use of this products, being their bioavailability one of the upmost. The development of carrier lipid based containing bioproducts is a recent technology, which can solve several bioavailability problems presented by natural products, producing a structure which confer protection to active compounds. The aim of this work was the development of carrier lipid based compositions containing bioactive compounds of Camellia sinensis (green tea) by spray drying evaluating processes of preparation, type of excipients and characterization of physicochemical properties and evaluation the antioxidant activity in vitro of the product. Bioactive compounds from dried and milled green tea leaves was extracted by dynamic maceration, filtered, concentrated and freeze-dried. The formulation was developed through the utilization of Hydrophilic Lipophilic Balance System (HLB) using the non-ionic surfactants and a co-solvent and characterized by organoleptic analysis, centrifugation, rheology, optical microscopy, size distribution and zeta potential. The most stable compositions were submitted to spray drying. The compositions were dried in a labscale spray dryer at flow rate of 4.0 g/min at temperatures of 100, 120 and 150 °C. The spray drying performance was characterized by determination of the powder production yield. Spray dried powders were characterized by moisture content, water activity, density, size distribution, flow properties, crystallinity, morphology, and redispersibility. After, it was evaluated the antioxidant activity of the product in vegetable oil (soybean oil) using the accelerated oxidative stability test Rancimat®. The HLB, the type of surfactant and the preparation method of the formulation influenced the system stability. For the formulations studied, the surfactant which confers the greater stability was Gelucire® 44/14, which was selected to prepare composition for spray drying. The powder production yield falls around 51.3 ±3.5 %, typical for lab scale spray dryers. Wrinkled and rounded particles, without visible presence porosities were mostly generated, independent of the adjuvant (trehalose or lactose). The product presented low water activity (<= 0.20) and low moisture content (<= 1.79). Increasing in drying temperature caused a slight increase in mean particle diameter, when lactose was used as drying carrier (9.8 ±5.9 ?m to 13.65 ±8.4 ?m). Low density powders were generated, but density tends to be lower at high drying temperatures composition were submitted to spray drying. Carr index and Hausner ratio of the product (< 15% and < 1.25, respectively) were indicative of good compressive and flow properties. The product was promptly redispersible, regaining its original consistency straight forwardly. The accelerated oxidative stability using the Rancimat demonstrated that the encapsulation increased the solubility and protection of bioactive compounds, resulting to increased antioxidant activity of the product. The results here reported confirm the feasibility of entrapment of herbal bioactive compounds of Camellia sinensis in lipid carrier by spray drying. The product has potential to be used as raw material for production of oral dosage forms, inclusion in nutraceutical and cosmetic products. (AU) |
