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End date: 2008 × Start date: 2008 × Thesis Type: M.Tech. ×
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    ThesisItemOpen Access
    Development and evaluation of a convective type dryer for nutmeg mace(myristica fragrans houtt)
    (Department of Post Harvest Technology and Agricultural Processing, Kelappaji College of Agricultural Engineering and Technology,Tavanur, 2008) Chikkanna, G S; KAU; Prince, M V
    A convective type nutmeg mace dryer was developed and its performance was evaluated. The major parts of the developed dryer are Drying chamber, Plenum chamber, Heating coil box, Air flow control and Blower with power source. The dryer was evaluated at three different air temperatures of 40 oC, 45 oC and 50 oC and at three air velocities 1.6 m/s, 2.0 m/s and 2.4 m/s. Unblanched samples dried at drying air temperature of 45 oC and with air velocity of 2.4 m/s produced better quality dried mace in terms of volatile oil content, myristicin content, oleoresin content and color. Also at this treatment combination the drying time was lower and the energy consumption minimum. It was also found that the quality of the dried samples in the developed dryer is superior to conventional sun drying method. It was also established from the studies that blanching pretreatment prior to drying by dipping in hot water at 75 oC for 2 min further increased the quality of dried mace. The convective type nutmeg mace drier is simple in construction, efficient in operation and produces better quality mace.
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    ThesisItemOpen Access
    Studies on osmotic dehydration of green pepper
    (Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2008) Smitha, K E; KAU; Santhy, Mary Mathew
    Experiments were conducted using a newly developed osmotic dehydration plant for the production of osmotically dehydrated green pepper. Several trials were done for different concentrations of NaCl (20% to 40%), time periods (1hr to 4hr)at different temperatures (30,40 and 50 0C) and sample to solution ratios(1:2 to 1:6). Blanched and unblanched samples of panniyur and karimunda varieties were used for the study. The effect of process temperature, time, sample to solution ratio and concentration of the osmotic agent were studied. Optimum condition was selected on the basis of the water loss, solid gain and weight reduction. The results obtained for water loss in panniyur and karimunda were statistically analysed. It was inferred that the water loss was significantly influenced by concentration of the solute, osmosis time and sample to solution ratio. The best result obtained from panniyur blanched samples treated was 30% NaCl, 3 hr and 1:4 sample to solution ratio at 40 0C and are selected for the secondary stage of drying using tray drier and freeze drier. The colour of dried product was recorded using Hunter lab colour flex meter and values were represented as colour difference from that of the fresh samples. The best colour was achieved at 50 0C. The optimum conditions for secondary drying were assessed on the basis of volatile oil content, component and colour as 50 0C and 6 hr for hot air drying and 50 0C and 10 hr for freeze drier.