Effect of temperature on mass diffusivities in dragon fruit (Hylocereus undatus)
2009
Chalermchat, Y. | Boonprasom, P.
Mass diffusion of water and solids during osmotic dehydration of dragon fruit flesh was studied. Dragon fruits with commercial maturity that had average total soluble solids to titratable acidity ratio equal to 46.65 were used in the experiment. Dragon fruit flesh were cut into a rectangular shape with a dimension of 5x5x1 cm, then osmotically dehydrated in the solution of sucrose, sodium chloride, calcium chloride, potassium sorbate, and potassium metabisulphate in the amount of 55, 2, 0.15, 0.25, and 0.25 grams, respectively in 100 grams of water for 5 hours at the temperature of 30, 40 and 50 deg C. It was found that the moisture contents of dragon fruit flesh decreased rapidly at the first 30 minutes and slowly decreased when the time increased. The solution temperature significantly had an effect on the moisture content (p0.05). Water diffusivity increased with increase temperature and had a value of 6.45x10sup-10 plus or minus 0.48x10sup-10, 7.17x10sup-10 plus or minus 0.32x10sup-10 and 10.02x10sup-10 plus or minus 1.88x10sup-10 sq m/s. for 30, 40 and 50 deg C, respectively. Arrhenius model could be used to describe the effect of temperature on the diffusivities. The results showed that the temperature of the osmotic solution significantly increased solids gain percentage, and water loss percentage (p0.05)
显示更多 [+] 显示较少 [-]