Influencia da estrutura celular e da geometria da amostra na taxa de transferencia de massa do processo de desidratação osmotica de banana nanica (Musa cavendishi) e de mamão formosa (Carica papaya L.)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2002

RESUMO

In this work was studied mass transfer in banana (Musa cavendish) and papaya (Carica papaya L.) in osmotic dehydration process. It was analyzed the influence of geometry and cells structures to verify the best performance in mass transfer. Osmotic dehydration was carried on with constant agitation of 80 rpm and analyzed through a factorial experimental design 24-1with 3 repetitions of central point for each geometry. Analized variables were temperature (30, 45 and 60°C), sucrose concentration (3,5; 4,5 and 5,5 M), lactic acid concentration (O; 0,05 and O,lM) and sample geometry (fIat plate and cube). Analyzed responses were water 1055,solid gain and water activity. Water loss and solid gain were influenced more by temperature and after by sucrose concentration. In osmotic dehydration process, fIat plate geometry facilitated water loss in both banana and papaya. Peleg and Azuara s models fitted well to experimental data, but equilibrium data were better approached when they were calculated by Azuara s model. Analyzing obtained images through electronic microscopy scanning it was possible to verify that banana cells presented elongated shape with starch granules and tanine, while papaya cells presented egg-shaped. The variable that caused more influence in occurred changes during osmotic dehydration was sample geometry and after the temperature

ASSUNTO(S)

banana microscopia eletronica de varredura desidratação mamão osmose

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