Abstract
ABSTRACT The aim of this study was to obtain the equilibrium moisture content of grape (variety ‘Tannat’) pomace through desorption isotherms, to evaluate the drying kinetics, determine the coefficient of effective diffusivity and physico-chemically characterize the grape pomace and the product obtained after drying. The desorption isotherms were determined at 50, 60 and 70 ºC and the experimental data were fitted using the GAB model (Gugghenheim, Anderson and de Boer). Drying was evaluated using a 22 factorial experimental design with three center points and effective diffusivity was obtained through the diffusion model of Fick’s second law. The grape pomace was characterized regarding the contents of moisture, protein, carbohydrates, lipids, ash and dietary crude fiber. The obtained isotherms showed sigmoid shape and the experimental data fitted well to the GAB model. The drying curves showed only a decreasing rate period. The effective diffusivity values were within the range for organic materials. Dry grape pomace showed high contents of protein and fiber and can be used in the development of new products, in order to increase the nutritional content and add value to this byproduct.
Highlights
The generation of residues in wine production is approximately 18 kg of grape pomace for every 100 L of wine (Rockenbach et al, 2011), whose main destination is animal feed and composting
Based on the importance of the knowledge on the stability of products subjected to drying and the presence of various wineries in the state of Rio Grande do Sul, which generate large amounts of fermented grape pomace, from the processing of wine, it becomes necessary to study the reuse of this dry byproduct, in order to add nutritional value to the foods intended for human consumption
The desorption isotherms of grape pomace were performed through the static gravimetric method, with acid solutions at eleven different concentrations
Summary
The generation of residues in wine production is approximately 18 kg of grape pomace for every 100 L of wine (Rockenbach et al, 2011), whose main destination is animal feed and composting. Based on the importance of the knowledge on the stability of products subjected to drying and the presence of various wineries in the state of Rio Grande do Sul, which generate large amounts of fermented grape pomace, from the processing of wine, it becomes necessary to study the reuse of this dry byproduct, in order to add nutritional value to the foods intended for human consumption In this context, this study aimed to determine the equilibrium moisture of ‘Tannat’ grape pomace through desorption isotherms, evaluate its drying kinetics, determine the effective diffusivity coefficient (Def) and physico-chemically characterize the grape pomace and the product obtained after drying, for probable use in the preparation of new food products
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
