03777cas a2200421 a 4500 20260818090115.0 111005s1990 th uu|m rtt 0| a1eng d .b1018868x AIT Thesis no. AE-90-17 Chouw Inprasit Design and development of laboratory scale freeze dryer for tangerine juice powder Bangkok : Asian Institute of Technology, 1990 71 p. Thesis ; no. AE-90-17 A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development Thesis (M.Eng.) - Asian Institute of Technology, 1990 A laboratory scale freeze dryer was designed and developed to produce tangerine juice powder and also to study the effect of freeze drying process on the quality of prod u ct. The main components of freeze dryer consist of chamber, refrigeration unit, vacuum pump, and plate heat exchanger . Electrical plate heat exchanger was us e d instead of hot water plate h eat exchanger for reduced the heating time . The effete of process parameter e . g. p late temperature on the quality of powder obtained in term of color change and ascorbic acid loss was found to b e non-significant at 50 and 60°C has a plate temperature . How eve r, at 7 0 °C plate temperature , product has a high loss of ascorbic acid and browning development . Optimum condition for freeze drying is at 60°C plate temperature on the basis of color change, ascorbic acid, and energy consumption. The best sample was at 60°C plate temperature and was selected for the determination of physical properties. The physical properties of powder such as particle size , loose bulk density, packed bulk density, and reconstitution time were 248. 17 w.m, . 0 . 59 g /ml, 0.83 g/ml, a nd 4.5 minutes respective l y. Total bacteria count for non-pasteurized juice powder about 3,000 colonies per gram of powder but in pasteurized juice powder less than one colony per gram of powder was presented. Energy consumption from experiment was 130, 376. 36, 167, 134. 25, and 222,460.57 kJ/kg of powder at 50, 60, and 70°C plate temperature respectively. The sensory evaluation test of color of the reconstituted juice reveal e d a slight difference from the fresh juice , however more significant differences were observed for taste and flavor since texture were damaged by grinding the powder after freeze drying. Tangerine Food, Freeze-dried Athapol Noomhorm, Chairperson Jindal, Vinod Kumar, Examination Committee Illangantileke, Sarath G., Examination Committee The Royal Government of the Netherlands, Scholarship Donor Asian Institute of Technology. Thesis ; no. AE-90-17 Full-Text http://203.159.5.9/ait-thesis/detail.php?q=B18239 .b1018868x mnait s 240411 2 951012 m a s 0 mnait mnait mnarc 20 40 Barcode : 30050003005252 CREATED : 1994-05-16 RECORD # : i10225572 LPATRON : 1017933 LCHKIN : 2005-08-04 # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 4 TOT RENEW : 0 Barcode : 30050003005286 CREATED : 1994-05-16 RECORD # : i10225584 LPATRON : 1017901 LCHKIN : 2005-01-07 # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 8 TOT RENEW : 9 Barcode : 30050120363451 CREATED : 2016-05-27 RECORD # : i12998977 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 26907 26907 0 0 0 0 MAIN MAIN mnait 2026-08-18 0 AIT Thesis no. AE-90-17 30050003005252 2026-08-18 09:01:15 1 2026-08-18 20 0 0 0 0 MAIN MAIN mnait 2026-08-18 0 AIT Thesis no. AE-90-17 30050003005286 2026-08-18 09:01:15 2 2026-08-18 20 0 0 0 0 MAIN MAIN mnarc 2026-08-18 0 AIT Thesis no. AE-90-17 30050120363451 2026-08-18 09:01:15 2026-08-18 40