ISOSTERIC HEAT, ENTROPY, AND GIBBS FREE ENERGY OF PUMPKIN SEEDS (Cucurbita moschata)

AUTOR(ES)

Teixeira, Luciana P., Andrade, Ednilton T. de, Devilla, Ivano A.

FONTE

Eng. Agríc.

DATA DE PUBLICAÇÃO

2018-01

RESUMO

ABSTRACT To maintain seed and soil quality of pumpkin, energy knowledge associated with processing and storage stages is strategic for the optimization of the thermodynamic processes needed for product stabilization. Thus, the objective of this study was to determine isosteric heat, differential entropy, and Gibbs free energy within a temperature range from 20 to 70° C, and relative air humidity levels between 10.75 and 85.11%. The study was based on empirical data for water activity determination. As a result, we verified that as moisture content decreased, the integral isosteric heat of the product increased from 2502.35 to 6231.17 kJ kg-1, differential entropy raised from 1.18 to 12.43 kJ kg-1 K-1, and Gibbs free energy ranged from -243.84 to -432.59 kJ kg-1. Thus, we concluded that the lower the water availability in seeds, the greater the energetic requirement for its removal, as there is a major interaction between water and the product (seeds), indicating an increasingly less spontaneous desorption process.

Documentos Relacionados

• Characterization of bioactive compounds, antioxidant activity and minerals in landraces of pumpkin (Cucurbita moschata) cultivated in Southern Brazil
• Does crotalaria (Crotalaria breviflora) or pumpkin (Cucurbita moschata) inter-row cultivation in restoration plantings control invasive grasses?
• Isotermas de sorção de umidade de abóbora (Cucurbita moschata) fresca e branqueada
• Cooking effects on bioactive compounds and sensory acceptability in pumpkin (Cucurbita moschata cv. Leite)
• Different cooking styles enhance antioxidant properties and carotenoids of biofortified pumpkin (Cucurbita moschata Duch) genotypes