EFFECT OF OSMOTIC DEHYDRATION ON PHYSIOCHEMICAL PROPERTIES OF RED CARROTS | ||||
| Egyptian Journal of Agricultural Research | ||||
| Article 26, Volume 90, Issue 4, December 2012, Page 1773-1787 PDF (363.14 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/ejar.2012.164852 | ||||
 View on SCiNiTO | ||||
| Authors | ||||
| KADRY H. EL-WASEIF; MOHAMED R. MASOUD; EL-SAUD M. EL-SAEEDY | ||||
| Food Technology Research Institute, Agricultural Research Center, Giza, Egypt. | ||||
| Abstract | ||||
| This study was carried out to assess the quality parameters of osmo-dried red carrots pretreated with various types of osmotic sucrose syrup i.e. 40%, 50%, 60% and 70%sucrose syrup, compared with those produced by untreatedred carrots(control). The sucrose syrup 70% had the lowest osmosis time for osmosedcarrots followed by 60%, 50%, and 40% sucrose syrup respectively. However, the reduction time of dehydration for both red carrots caused the increase in solid gain (SG) and total solids (T.S) than that obtained bythe control (untreated) drying. Furthermore, the dehydration parameters (WL and WC) were strictly related to the type and concentration of the used osmosis solution. The phsico-chemical properties, microbiological assessment and quality attributes of both osmo-dried and controlred carrotsjust after processing and during storage for 6 months were also undertaken. Results indicate that, osmo-dried red carrotspretreated with sucrose syrup 70% had the highest retention of ascorbic acid followed by 60%, 50% and 40% sucrose syrup, respectively. Reducing sugars content ranged between 51.69 to 56.50% for osmos-dried red carrotswith various pretreatments just after processing. While, the corresponding values of fibers ranged from 9.53 to 9.75% respectively. The control- dried carrots had the highest total microbial counts (9.1x102 cfu/g) followed by osmo-dried pretreated with sucrose syrup 40% (6.3x 102cfu/g), 50% sucrose syrup (5.2 x102cfu/g), 60% sucrose syrup (3.7x102cfu/g) and 70% sucrose syrup (2.6 x102cfu/g), respectively. On the other hand, all tested counts of microorganisms either total counts of bacteria or yeasts and molds showed proportional reduction with extending the storage period and reached to the maximum reduction after 6 months of storage. The osmo-dried red carrotspretreated with sucrose syrup 70% recorded the highest scores of color, texture, taste, flavour and overall acceptability followed by osmo-dried samples pretreated with 60%,50% and 40% sucrose syrup and the un treated (control) just after processing and after 3 and 6 months of storage at ambient temperature. Therefore, pretreatment of carrots with osmotic sugar solution to produce osmo-dried product played an important role for producing high quality dried red carrotsthan those produced by the control drying process. | ||||
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