Assessing Drying Characteristics of Apple using Hyper-spectral Imaging Technology

Samarakoon, S.M.C.S (2016) Assessing Drying Characteristics of Apple using Hyper-spectral Imaging Technology. Masters thesis, UNSPECIFIED.

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Abstract or Summary

Drying is one of the oldest methods used for the preservation of agricultural products such as fruits and vegetables. Apple has a significant share in fruit production both in the World and in New Zealand. It is also an important raw material for many food products. The moisture migration process during drying is very complex and involves one or more transport mechanisms. The study researched into assessing drying characteristics of apple using hyper-spectral imaging (HSI) technology. Apple cylinders (D=15mm, L=30 mm,13.06 ± 0.02oBrix and 85.35 ± 0.21% moisture, w.b.) were used in the drying experimentwhich was conducted in a food dehydrator at 57◦C at an average air flow rate of 0.965±0.02ms-1.Blanching was done to avoid the effect of enzymatic browning and lateral area of the cylinder was covered to facilitate one dimensional moisture diffusion from circular bases.The drying data obtained for initial 6 hours of drying time was used in the calculation of diffusivity. Hyper-spectral scanning was performed in each 2 hours of drying time to obtain the mean reflectance values at three cross sectional areas along the axial direction of the apple cylinder. Highest absorption for moisture and fructose were recorded at 969 nm and 913 nm respectively.The drying data was used to build the relationship between both moisture content and sugar concentration with the hyper-spectral image data. Fick’s diffusion model was used in determining the effective diffusivities of moisture and sugar for the axial and radial locations of the apple cylinder. The values of average effective moisture diffusivity increased with drying time which is ranged between 9.01×10-10 and 8.07×10-09m2s-1 and the average effective sugar diffusivity values were in the range of -2.73×10-10m2s-1 to 7.22×10-09m2s-1.

Item Type:Thesis (Masters)
Keywords that describe the item:drying, hyper-spectral imaging technology
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Subjects:Q Science > Q Science (General)
Q Science > QC Physics
T Technology > TP Chemical technology
Divisions:Schools > Centre for Science and Primary Industries
ID Code:5453
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Deposited On:02 Nov 2018 02:12
Last Modified:02 Nov 2018 02:12

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