Planejamento simplex-centroid aplicado ao estudo das propriedades mecânicas de filme de pectina, emulsão de óleo de canela e polpa de chuchu

Abstract

Active films are packages produced to act interrupting oxidative reactions, bacterial / fungal proliferation, etc. in food. Active compounds are incorporated into films matrix when and when in contact with food are released to its surface, that is where most of the chemical and microbiological reactions occur. Edible active films can be prepared on carbohydrates basis and protein basis. Essential oils, such as cinnamon oil which has significant antimicrobial activity, have been used as an alternative to the incorporation of chemical additives and do not present toxicity. Another promising way in films formulation is the incorporation of vegetable pulps such as chayote pulp (Sechium edule), which has a high content of carbohydrates and nutrients, adding nutritional value to the edible film and consequently to the packaged product. In this study, antimicrobial films based on pectin containing chayote pulp and cinnamon oil were formulated with a simplex centroid design for modeling the mechanical behavior of materials depending on mixtures composition. For Elongation at Break data (E%) the best results were found for the adjustment to the special cubic model (p = 0.041903) as well as for data Tensile Strength (TS) (p = 0.006789). In the case of Young's modulus (YM) any of the tested models showed significant adjustment for the experimental results. For E% and TS models the components related to pectin, chayote and cinnamon oil had a positive effect. Also, the term referring to pectin was more significant. Furthermore, E% model the most significant interaction component was the ternary (X1.X2.X3) with p = 0.024092, presenting a positive influence, but for the TS effect was inverse. The formulation produced to with 0; 0,5; 0;5 (X1; X2; X3) in terms of pseudocomponent was used to evaluate the antimicrobial activity and presented effect against microorganisms S. aureus and E. coli. With the results it was possible to conclude that the mathematical models described the influence of films composition in the responses E% and TS properly.