Fry Step Validation ''Kill step''.
Colleagues,
Seeking advice on validation of a frying process. We deal in fried products. Basically, thin chips made from dough (flour, eggs, palm oil & other ingredients) are fried at temperatures above 325 degrees F for 2-3 minutes. Internal temperature readings are usually 215 degrees F and water activity less than 0.5. We annually send samples to an independent Lab for APC analysis and the results are always great.
A potential big customer wants us to validate the fry step. We use it as a CCP. We monitor Oil temperature (> 325 F) and dwell time (2-3 minutes). Speed of conveyor belt determines the time the product spends within the oil.
How would you design an experiment to validate this step? Please, anybody with links to scientific literature linking product internal temperature, low water activity to reduced microbial loads in fried products?
Experimental design thoughts: Different sizes of chips, different frying temperature & time combinations. Get results for internal temp, water activity and microbiological analysis.
Thank you.
Mambo
Hi mambo,
The question is - Validate the step for what ? BCPA ?
If so, a risk assessment is required.
If so, a specific product / process is required.
For example, the (core) T vs t data you measure will certainly eliminate all vegetative micro-organisms unless the "other ingredients" are something unusual. Some spores are maybe not eliminated.
Chemical contaminants / allergens may be unaffected.
Stones will certainly be unaffected.
In the context of shapes/sizes, the usual procedure is to select the slowest heating item, ie worst case scenario.
Hi Charles C,
Thank you. You're always helpful on the forum. You deserve an award.
Basically, the validation would be concerned with Food Safety (Microbiological). We have a comprehensive program which comfortably marshals the Chemical and Physical hazards.. The chips are fried in palm oil at T > 325 degrees F for 2-3 minutes using an industrial conveyor belt fryer. 40 years in business, zero food safety incident. APC counts on samples are always less than 50 cfu/g. Customer is insisting on a validation study!! :helpplease: :helpplease:
Hi mambo,
Thks yr kind words.
The (2015) article (1st URL below) illustrates some reasons why micro. validation of the frying stage / connected process steps may now be being focused on by customers. Looks like baking may have been/be in an analogous situation also (see 2nd (2010) URL). This is in some contrast to these extracts from a 2001 document –
frying.png 133.11KB 0 downloads
http://www.foodsafet...re-snack-foods/
http://www.bakingbus...cade.aspx?cck=1
This (2014) link indicates a typical (baking) validation procedure –
http://www.snackandb...step-validation
This (2014) attachment illustrates aspects of the almond nut validation procedure –
validation - pathogen - reduction steps.pdf 3.54MB 268 downloads
The difficulty is that (unlike, say, poultry cooking) there do not yet seem to be any accepted, safe, general critical limits for yr type of product for oil frying processes although I noted this (nut-only?) comment in 1st link –
If one looks at the processes currently used in the industry—frying, baking, continuous oven cooking and dry roasting—it is probably safe to say that if a company is frying or oil-roasting their products, they are safe. The Almond Board’s “Guidelines for Oil Roasting” are 260 °F for 2 minutes. Most oil-roasting or frying operations use considerably higher temperatures that will enhance lethality.
Yr product/process may have been studied / characterized / validated already but I couldn’t find a specific reference. You may need to do a little digging/consulting unless you have technical support readily available.
Thank you Charles. C
The links were helpful. Under normal circumstances, i wonder if any common pathogens of public health concern like Salmonella, e-coli, listeria spp would survive a frying operation where the internal product temperatures reach 215 degrees F? FDA guidance on pathogen growth lists 131 degrees F as maximum temp for growth of most of the Pathogens.
Came across a nice validation study for the Baking Industry
http://www.snackandb...-baking-process
Cheers,
Mambo
Thank you Charles. C
The links were helpful. Under normal circumstances, i wonder if any common pathogens of public health concern like Salmonella, e-coli, listeria spp would survive a frying operation where the internal product temperatures reach 215 degrees F? FDA guidance on pathogen growth lists 131 degrees F as maximum temp for growth of most of the Pathogens.
Came across a nice validation study for the Baking Industry
http://www.snackandb...-baking-process
Cheers,
Mambo
Hi mambo,
The curious aspect of the baking document (and 1st link in my previous post) is that there is no mention of spores. It is well-established that certain pathogenic Bacillus species may survive some baking processes in this way. One control measure is via the input material meeting appropriate micro.specifications.
For example, the data (Dvalues for vegetative / spore forms) in post below (see pic.) suggest that a 1log reduction of B.cereus spores in rice requires ca. 30 mins at 100degC, ie 2hrs for 4log reduction.
http://www.ifsqn.com...ion/#entry58869
From the D-values shown in above post, Salmonella is clearly relatively easy to eliminate for the (unspecified) food matrixes/Salmonella Species.
However for the table of "Resistant" Salmonella species in certain Food matrixes as shown below, the conclusion is quite different.
Salmonella D-values.pdf 96.23KB 140 downloads
Another imprtant aspect is that some pathogenic vegetative species are "potent" at very low levels in the Food, ie growth is not necessary to create an unsafe product. E.coli O157 is the classic example but certain Salmonella species also meet this requirement.
So the answer to the query in yr previous post is "It all depends".