Plantains （Musa paradisiaca L.） are a major food staple in West Africa and are cooked in various forms. The objective of this work was to evaluate the frying characteristics of plantains at different stages of ripen...Plantains （Musa paradisiaca L.） are a major food staple in West Africa and are cooked in various forms. The objective of this work was to evaluate the frying characteristics of plantains at different stages of ripening. The plantains used in the study were at the unripe stage through four different ripening stages. The samples were peeled and sliced into 2 mm thickness and blanched in hot water at 70 ℃ for 3 min. The slices were then deep flied in canola oil at 180 ℃. The result showed that ripening stage significantly affected moisture loss and fat absorption profiles of the plantain chips. Fully ripened plantain absorbed up to 34% （db） oil during 4 min frying, much higher than unripe plantain. The oil uptake and moisture loss during frying of the plantain chip samples were modelled using 1st order kinetics. The kinetic parameters including rates of moisture loss and oil uptake varied according to the different stages of ripening. Ripening had a significant effect on the colour lightness （L） of the chips. Similarly, the redness （a）, the yellowness （b） and textural characteristics were significantly affected by ripening stage.展开更多
The effects of varying the mass and volume of ground chip and pellet particles on the particle drying rate were analyzed. Samples of whole pellets and chips were hammer milled using a 3.2 mm screen and the ground chip...The effects of varying the mass and volume of ground chip and pellet particles on the particle drying rate were analyzed. Samples of whole pellets and chips were hammer milled using a 3.2 mm screen and the ground chip and pellet particles were found to have similar size distributions, although the pellet particles were denser and more spherical than the chip particles. Prior to drying, water was added to the particles to obtain 0.10, 0.30, 0.50, 0.70, and 0.90 moisture contents （on a dry mass basis）. The moistened particles were subsequently dried in a constant temperature thin layer dryer set at 50,100, 150, or 200 ~C under dry pure nitrogen, dry compressed air, or atmospheric air. The chip and pellet particles exhibited similar degrees of shrinkage, but the pellet particles underwent a greater reduction in their bulk volume during drying. It appears that the more spherical pellet particles are prone to shrinkage in more than one direction, whereas the needle-like chip particle shrink only in one direction. A variable radius first order drying model was found to fit the experimental data better than a fixed radius model.展开更多
文摘Plantains （Musa paradisiaca L.） are a major food staple in West Africa and are cooked in various forms. The objective of this work was to evaluate the frying characteristics of plantains at different stages of ripening. The plantains used in the study were at the unripe stage through four different ripening stages. The samples were peeled and sliced into 2 mm thickness and blanched in hot water at 70 ℃ for 3 min. The slices were then deep flied in canola oil at 180 ℃. The result showed that ripening stage significantly affected moisture loss and fat absorption profiles of the plantain chips. Fully ripened plantain absorbed up to 34% （db） oil during 4 min frying, much higher than unripe plantain. The oil uptake and moisture loss during frying of the plantain chip samples were modelled using 1st order kinetics. The kinetic parameters including rates of moisture loss and oil uptake varied according to the different stages of ripening. Ripening had a significant effect on the colour lightness （L） of the chips. Similarly, the redness （a）, the yellowness （b） and textural characteristics were significantly affected by ripening stage.
文摘The effects of varying the mass and volume of ground chip and pellet particles on the particle drying rate were analyzed. Samples of whole pellets and chips were hammer milled using a 3.2 mm screen and the ground chip and pellet particles were found to have similar size distributions, although the pellet particles were denser and more spherical than the chip particles. Prior to drying, water was added to the particles to obtain 0.10, 0.30, 0.50, 0.70, and 0.90 moisture contents （on a dry mass basis）. The moistened particles were subsequently dried in a constant temperature thin layer dryer set at 50,100, 150, or 200 ~C under dry pure nitrogen, dry compressed air, or atmospheric air. The chip and pellet particles exhibited similar degrees of shrinkage, but the pellet particles underwent a greater reduction in their bulk volume during drying. It appears that the more spherical pellet particles are prone to shrinkage in more than one direction, whereas the needle-like chip particle shrink only in one direction. A variable radius first order drying model was found to fit the experimental data better than a fixed radius model.
