KAJIAN MODEL ISOTERMIS SORPSI AIR DAN FRAKSI AIR TERIKAT PADA BUBUK ANDALIMAN (Zanthoxylum acanthopodium DC)
Daftar Isi:
- This research aims were to study the water sorption isotherm and determine a suitable mathematical model of water sorption isotherm and to study the bound water fraction on andaliman powder. The research was conducted at the Department of Agriculture Technology, University of Sriwijaya. The research used descriptive method with three stages: preparation of andaliman powder samples, determination of the equilibrium moisture content, and data analysis. Sample preparation conducted by dehydration at temperature 54oC for 8 hours, pulveryzation use pinmill grinder, and sieving at 60 mesh. Determination of equilibrium moisture content was conducted used a static method of saturated salt solution. The research used eight relative humidity treatments of storage (7% - 83%), three temperature treatments (30 oC, 40 oC and 50 oC), with three replications. Data were analyzed using microsoft Excel, to obtained the water sorption isotherm curve, a suitable mathematical model of water sorption isotherm, and bound water fraction on andaliman powder. The results showed that the water sorption isotherm curve of andaliman powder were Sigmoidal. The equilibrium moisture content of andaliman powder was affected by storage temperature. The higher the storage temperature, the lower the equilibrium moisture content of andaliman powder. The higher the temperature, the higher the aw and the decay risk of andaliman powder on a certain moisture content will be increate. Hasley model were the most appropriate model to describe the water sorption isotherm curve andaliman powder at temperature 30 oC, 40 oC and 50 oC. Water sorption isotherm curve were divided into three regions: the primary bound water fraction, secondary, and tertiary. Primery bound water of andaliman powder on storage temperature 30 oC, 40 oC and 50 oC were 6.510 %bk, 6.188 %bk, and 4.617 %bk. Secondary bound water of andaliman powder on storage temperature 30 oC, 40 oC and 50 oC were 16.074 %bk, 13.481 %bk and 12.550 %bk. Tertiary bound water of andaliman powder on storage temperature 30 oC, 40 oC and 50 oC were 42.470 %bk, 41.288 %bk, and 39.455 %bk. Mold growth was not found on andaliman powder at relative humidity up to 83% on andaliman powder, allegedly due to anti microbial compounds in andaliman. The decay that occurs during storage was the changes of flavour and color. To minimize the risk of decay and extend the shelf life, andaliman drying must be conducted until primary bound water content.