Estudo experimental e modelagem matemática da secagem do espinafre (Tetragonia tetragonioides) para obtenção de farinha

Abstract

Vegetable waste is increasing due to its high perishability, so one of the alternatives is to subject these products to the drying process, a method used as a form of food preservation, being one of the oldest unitary operations. For this process, one of the tools is the use of dryers, equipment that uses heat transfer to reduce the free water in the food, making it safer both from attacks by microorganisms and increasing its durability. In this sense, this study aimed to dry branches of spinach (Tetragonia tetragonioides) in order to transform it into flour for greater use, evaluating whether drying changes the amount of phenolic compounds in the natural product. At the same time, analyzes of the absorption and solubility of this flour were carried out, and mathematical modeling of the process was carried out, aiming to obtain information for future simulations. The experiments were carried out at temperatures of 50, 60 and 70 ºC. Based on the results achieved in this research, it was feasible to note that the moisture loss followed the theoretically established leaf drying pattern, where there is a faster moisture loss at the beginning of the process. Furthermore, at the highest temperature, 70 ºC, better results were obtained in relation to phenolic compounds as drying occurred more quickly. The Modified Henderson and Pabis model better represented the adjustment of the drying curve of spinach branches, with a coefficient of determination (𝑅2) closer to expected, mean relative error (𝑃) and estimated error (𝑆𝐸) lower. The flour obtained at a temperature of 70 ºC also presented a better water absorption index (IAA) and was within the highest water solubility indexes (ISA) even though both were below the stipulated standard, showing temperature interference in the product. In this condition, current research is able to assist in the application of the method of drying spinach branches, making its use viable.