Chitosan has been exploited as a material for the development of edible films, and additionally can be used as a carrier of functional compounds such as a-tocopherol. The aim of this work was to evaluate the effects of the incorporation of a-tocopherol in chitosan-based films. FTIR and thermal analyses were performed and showed that the incorporation of a-tocopherol affects the chemical structure of chitosan-based films with the establishment of new chemical bonds and the decrease of crystallinity. Results also showed that the increase of a-tocopherol concentration promotes a decrease of water content (from 12.6 to 11.4%) of the films. The addition of a-tocopherol to chitosan films leads to a significant reduction (p < 0.05) of tensile strength from 34.06 to 16.24 MPa, and elongation-at-break from 53.84 to 23.12%. Film opacity values (ranging from 4.74 to 7.83%) increased when a-tocopherol was incorporated into the film. Antioxidant capacity of chitosan-based films was evaluated and was enhanced when a-tocopherol was present in the film matrix. Results showed that a-tocopherol can be successfully added to the chitosan films enhancing the final quality and shelf-life extension of food products.

a b s t r a c tThe purpose of this study was to evaluate the effects of the application of chitosan coating containing natamycin on the physicochemical and microbial properties of semi-hard cheese. Three cheese groups were prepared: samples without coating, samples coated with chitosan and with chitosan containing 0.50 mg mL À1 of natamycin, whose minimum inhibitory concentration was previously determinated on cheese surface. Microbiological analyses showed that natamycin coated samples presented a decrease on moulds/yeasts of 1.1 log (CFU g À1 ) compared to control after 27 days of storage. Addition of natamycin also affected O 2 and CO 2 permeability, increasing from 7.12 to 7.68 Â 10 À15 gÁ(Pa s m) À1 , and from 10.69 to 64.58 Â 10 À14 gÁ(Pa s m) À1 , respectively. The diffusion coefficient values of natamycin from the film to phosphate buffered saline solution and to the cheese were 3.60 Â 10 À10 and 1.29 Â 10 À12 cm 2 s À1 , respectively. This study demonstrated that chitosan-based coating/films can be used as release system containing natamycin to create an additional hurdle for moulds/yeasts in cheese thus contributing to extend its shelf-life.

A B S T R A C TThe present study was carried out to evaluate the effect of chitosan-based edible coatings with Aloe vera extract on the postharvest blueberry fruit quality during storage at 5 C. Firstly, A. vera fractions (pulp and liquid) were extracted from leaves and evaluated in terms of antifungal and antioxidant capacities. The choice of the most adequate chitosan and A. vera fraction concentrations to be incorporated in coating formulation was made based on the wettability of the corresponding coating solutions. Coatings with 0.5% (w/v) chitosan + 0.5% (w/v) glycerol + 0.1% (w/v) Tween 80 + 0.5% (v/v) A. vera liquid fraction presented the best characteristics to uniformly coat blueberry surface. Physico-chemical (i.e., titratable acidity, pH, weight loss) and microbiological analyses of coated blueberries (non-inoculated or artificially inoculated with Botrytis cinerea) were performed during 25 d. Microbiological growth and water loss levels were approximately reduced by 50% and 42%, respectively, in coated blueberries after 25 d compared to uncoated blueberries. After 15 d, weight loss values were 6.2% and 3.7% for uncoated and chitosan-A. vera coated blueberries, respectively. Uncoated fruits presented mold contamination after 2 d of storage (2.0 AE 0.32 log CFU g À1 ), whilst fruits with chitosan-based coatings with A. vera presented mold contamination only after 9 d of storage (1.3 AE 0.35 log CFU g À1 ). Overall, coatings developed in this study extend blueberries' shelf-life for about 5 d, demonstrating for the first time that the combination of chitosan and A. vera liquid fraction as edible coating materials has great potential in expanding the shelflife of fruits.