RELATIONSHIP BETWEEN TYPE OF BUTTER AND ITS RHEOLOGICAL PROPERTIES | ||
| Journal of Food and Dairy Sciences | ||
| Article 6, Volume 25, Issue 7, July 2000, Pages 4369-4379 PDF (838.61 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/jfds.2000.259193 | ||
| Authors | ||
| M. H El-Senaity,1; M. Zin El-Din2 | ||
| 1Department of Food Technology and Dairying, National Research Centre, Dokki, Cairo, Egypt. | ||
| 2Dairy Dept., Fac. of Agric., Mansoura Univ., Mansoura, Egypt. | ||
| Abstract | ||
| Fresh whole buffaloe, cow, mixed of buffaloe and cow, ewe and goat milk were separated to cream. Cream was divided into two parts, the first part was churned into sweet cream butter while the second part was fermented using starter and churned to fermented cream butter. Rheological properties of the resultant butter were studied. Results showed that buffaloe butter was harder than other types of butter, and it was able to resist more shearing forces than the others at the same level of shear rate. Goat butter gave the lowest shear stress for the upward curve at the same shear rate, while buffaloe butter can suffer high value of stress than the others at the same shear rate. In fermented cream butter, fermentation process decreased shear stress of the resultant butter. Yield value of sweet cream butter was higher than that of fermented cream butter. Buffaloe butter gave high yield, whereas the lowest yield was observed in butter made from goat milk. It means that goat butter requires low values of stress to flow while buffaloe butter needs high values of stress to flow and was able to reform or rebuild more strongly than goat butter. Structural viscosity of buffaloe sweet butter was higher than the other types of butter at all shear rate, while it was lower in fermented cream butter also for all shear rates. Changes in deforming and reforming of butter can be divided into the following: 1) main changes would happened on rate level of 5 – 12.5 (sec-1), 2) at shear rate 12.5 – 25 (sec-1) changes would be slowly mild., 3) between rates 25 – 50 (sec-1) changes showing a very slight differences., and 4) sequence of butter flowing and then reforming for different types as follows:- Buffaloe > Ewe > Mixed (buffaloe and cow) > Cow > Goat. Correlation coefficient (r) between iodine value and structural viscosity was calculated and showed that in either sweet or fermented cream butter there were negatively highly significant (P < 0.01) at different shear rates. It means that when iodine value of butter increased structural viscosity decreased. | ||
| Keywords | ||
| Rheology; fermented cream butter; sweet cream butter | ||
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