SciELO - Scientific Electronic Library Online

 
vol.31 issue3Identification of volatile compounds in thinning discards from plum trees (Prunus salicina Lindl.) cultivar Harry PickstoneCharacterization of fruits from the savanna: Araça (Psidium guinnensis Sw.) and Marolo (Annona crassiflora Mart.) author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Food Science and Technology (Campinas)

Print version ISSN 0101-2061

Abstract

MOLINA FILHO, Lucídio; GONCALVES, Ana Karla Rebes; MAURO, Maria Aparecida  and  FRASCARELI, Elen Cristina. Moisture sorption isotherms of fresh and blanched pumpkin (Cucurbita moschata). Ciênc. Tecnol. Aliment. [online]. 2011, vol.31, n.3, pp. 714-722. ISSN 0101-2061.  http://dx.doi.org/10.1590/S0101-20612011000300025.

Moisture desorption isotherms of fresh and heat blanched pumpkins (Cucurbita moschata) were determined at three temperatures (30, 50 and 70 °C), using the standard, static-gravimetric method. The GAB, Oswin, BET, Halsey, and Henderson models were tested and, with the exception of the Henderson model, showed satisfactory fits to the experimental data. The GAB model was used to analyze the fitting ability to describe the isotherm type. The shape of the desorption isotherms of fresh and blanched pumpkin at 30 and 50 °C was intermediate to types II and III, and at 70 °C it was of type II for the blanched pumpkin and close to type II for the fresh sample. The influence of blanching on the decrease in equilibrium moisture was very small compared to the fresh samples and it was related to the loss of soluble solids during the pre-treatment. The isosteric heat of sorption measures indicated that a larger amount of heat was required to remove the water from the fresh samples than from the blanched ones.

Keywords : blanching; pumpkin; desorption isotherms; isosteric heat; GAB model.

        · abstract in Portuguese     · text in English     · pdf in English