Thermal processing - F0, B* and C* for ESL Dairy products.

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F0, B* and C* for ESL Dairy products.

Printed From: Dairy Science and Food Technology
Category: Thermal processing
Forum Name: Thermal processing
Forum Description: Effects of heat on food, enzymes and microorganisms
URL: https://www.dairyscience.info/forum/forum_posts.asp?TID=270
Printed Date: 19 Apr 2024 at 12:30am
Software Version: Web Wiz Forums 12.03 - http://www.webwizforums.com

Topic: F0, B* and C* for ESL Dairy products.

Posted By: formula123
Subject: F0, B* and C* for ESL Dairy products.
Date Posted: 23 May 2011 at 8:42pm

I received the query below yesterday: "Can you please provide the calculator (Fo calculator) to calculate F0, B* and C* for ESL Dairy products. I am particularly interested in custard, stabilised thickened cream and milk".

Need much more information before I can do this? Please provide some more information.

NOTE

An article on UHT processing with a range of On Line calculatiors is now available, see https://www.dairyscience.info/index.php/thermal-processing/325-uht-processing.html" rel="nofollow - https://www.dairyscience.info/index.php/thermal-processing/325-uht-processing.html .

Replies:

Posted By: formula123
Date Posted: 19 Oct 2011 at 11:40pm

I have produced a spreadsheet using Simpson's rules that calculates F0, B* and C* for ESL Dairy and other UHT treated products. Simpson's rules give more accurate estimates of the area under the typical time/lethality plot than spreadsheets programmed using the trapezoid rule.

This spreadsheet uses advanced Excel programming (basically using conditional arguments). Users can also use a simple trapezoid rule macro to compare calculations performed using both methods of numerical integration.
I have also developed a trapezoidal based spreadsheet for doing this On Line.
These spreadsheets will be available by mid-November

Posted By: formula123
Date Posted: 22 Oct 2011 at 11:01pm

I have been asked to add a facility to estimate the effect of UHT-processing on lactulose and have added this to the On Line calculator that I am now testing.

Lactulose has been calculated using the estimated equivalent time (s) at 135° C and the relationship developed by Browning et al. (2001).

Happy to let a few users test out the new calculator if they agree to provide me with some feedback on ease of use and any problems found. If interested Email me including spreadsheet testing in the title.

Posted By: formula123
Date Posted: 02 Nov 2011 at 9:50pm

After some weeks of testing, a calculator for determining F0, B* and C* for ESL Dairy and other UHT treated products has been added. I have tested several methods for predicting lactulose levels and have found that the relationship developed by Dr Roeland Rombaut and his colleagues, using an activation level of 134.65 kJ/mole, to work well. The calculator can be accessed at

http://www.dairyscience.info/uht123.asp - http://www.dairyscience.info/uht123.asp .

Note the B* values may (highly likely!) require adjustment to allow for for the flow conditions in the heat processing plant. This usually means reducing them by a factor of 2 (Tran et al, 2008). I will add a tutorial explaining how to do this.

Posted By: Guests
Date Posted: 03 Nov 2011 at 11:13am

Great calculator! Re flow, divide B* by 2 because most flow is turbulent and particles travelling slower than fastest flow point?

Would u know what UHT does to prions?

Posted By: formula123
Date Posted: 04 Nov 2011 at 9:43pm

Hi Marvin

Welcome back to the forum. I have responded to your prion query elsewhere. The heat treatments involved in UHT processing are unlikely to have much effect on prions; I have not seen any data suggesting milk as a source of prions.

Your observation re turbulent flow is essentially correct.

Posted By: formula123
Date Posted: 30 Apr 2013 at 10:17pm

I have included an update on recent work with http://www.dairyscience.info/_content/user_pages/news-articles1.asp - ESL dairy products on the site news page.