Discourse Journal of Agriculture and Food Sciences
Volume 6 Issue 2 Page 11 - 16. March 2018

Copyright 2018 Discourse Journals


Abdel Moneim E. Sulieman, Osama M. Elamin, Elamin A. Elkhalifa, Loouis Laleye

A Comparative Study of Physicochemical Properties of Freeze-dried Camel’s Milk and Cow's Milk Powder

1Department of Biology, faculty of Science, University of Hail, Kingdom of Saudi Arabia
2Department of Food Science and Technology, Faculty of Engineering and Technology, University of Gezira, Wad-Medani, Sudan

3Department of Food Science, Faculty of Agriculture, University of Al-Ain, United Arab Emirates

 

Abstract

In the present study, fresh raw camel and cow's milk were concentrated to 20-30% total solids, and then freeze-dried under the temperature of (-50 °C to -75 °C), under vacuum. The physicochemical characteristics of the various freeze-dried powders were determined. The water activity (aw) of freeze-dried camel milk (FDC) and freeze-dried cow milk (FDW) ranged 0.253-0.307 and 0.148- 0.301, respectively. While aw of the commercial milk sample (CMD) was 0.326. Both FDC and FDW had reasonable flowability as indicated by measuring their hausner ratio which ranged between 1.15 and 1.24. FDC had higher insolubility index (0.65-0.85) when compared with those of FDW(0.25-.055). The yield and hygroscobisity of freeze-dried samples ranged between (81.42-94.57) and 22.12-27.32, respectively. The measurements for colour characteristics indicated that the lightness ranged between 91.20 and 94.34 while the commercial sample had a value of 94.45. All samples had acceptable lightness, yellowness and redness when compared with those of the commercial sample. Small variation were determined in some of the chemical components of the various samples of FDC, FDC and CMD. It is recommended in the present investigation that freeze-drying of milk could be an extremely effective method for producing dried powder from camel and cow’s milk with little changes in most nutrient compounds.

Keywords: Freeze drying, water activity, flow-ability, acidity, concentration, protein

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