High Coliform Counts in initial testing of frozen burritos

Hello,

In doing testing of a benchtop sample to set micro standards, I was given an initial report that stated my total coliform count was 2000 cfu/g in one item and 3300 (estimated) cfu/g in another. E. Coli was negative.

Subsequent tests throughout the shelf life seemed to be in normal range, but the high coliform number in the initial test has me a bit concerned, as I am unsure how the count could be so high, because I took all appropriate measures to ensure a clean environment and that all componenets were treated beyond lethality. I have sent more samples to be tested for coliform only, to see if maybe it was a fluke. 

My question is:

Would a high coliform count indicated in initial testing, constitute a shelf life failure, if all other numbers are within range?

There seems to be a lot of debate and no real clear limits for total coliform in frozen foods. All data I can find is geared toward water and poultry products. Some of the limits state a target of <10 with the M being 10 to the fourth, which would be 10,000...correct?

Any insight would be helpful.

Thanks!

What type of products are you referring to?  When initially tested is the product in frozen or fresh state?

These are two frozen burritos, that were being tested in a refrigerated environment. Submitted as frozen, then slacked naturally throughout the test.

Hi jasonholste,

Apologies for ignorance regarding burritos.

I deduce from yr mention of lethality that this product is supposed to be RTE ? If so, the coliform is high. Possibly undercooked.

What are the ingredients ?

What do you mean by tests ... seemed to be in normal range ?

Hello Charles,

The product is RTE. Ingredients are Natural Tortilla, Eggs, Soy Chorizo, Potatoes, Pinto Beans, Tomatillo Salsa. All components were cooked separately, chilled, then mixed before being assembled into the finished product. We monitored each ingredient/component during cooking and cooling and all temps/times were good, all necessary sanitation guidelines were followed.

The product was in shelf life testing, we tested a full spectrum and all other counts (E.Coli, Listeria, Salmonella, Yeast, Mold, APC, LAB, HLAB) were negative or acceptable, aside from the Coliform on the initial test.

Hello Charles,

 

The product is RTE. Ingredients are Natural Tortilla, Eggs, Soy Chorizo, Potatoes, Pinto Beans, Tomatillo Salsa. All components were cooked separately, chilled, then mixed before being assembled into the finished product. We monitored each ingredient/component during cooking and cooling and all temps/times were good, all necessary sanitation guidelines were followed.

 

The product was in shelf life testing, we tested a full spectrum and all other counts (E.Coli, Listeria, Salmonella, Yeast, Mold, APC, LAB, HLAB) were negative or acceptable, aside from the Coliform on the initial test.

Hi jasonholste,

I have no experience burrito but the typical result for fully cooked snacks IMEX is a coliform value  less than 10cfu/gram, often undetectable. Maximum probably 100cfu/gram

The colifom value is not necessarily related to any of the other measurements (not sure about LAB, HLAB(?)). What was the APC result ?

The classic cooking condition in Europe to achieve RTE status  is such that the core temperature attains >= 70degC/2min or equivalent lethality. Perhaps you used some other conditions ?.

It is also feasible that one or more of the ingredients had an astronomic coliform level.  Do you have any idea of their micro. data ?

I wold go back to the ingredients and do have each tested individually to see what their coliform count is like. Did you have a high APC in the sample?

APC numbers were OK. about 10K, which went down throughout the test..until a small spike on the 15th day. Which was the last day of the test cycle. 

Thank you all for your responses, I'm going to retest the product and all of its components individually.

Are all the components used right away or are there leftovers(wip) of components saved for future runs?

Hi jason,

I’m unsure as to the specific objective of yr test. The prodecure you describe sounds a little odd.

I deduce yr burrito normally has a designated shelf-life of max. S days in a refrigerator chilled section.

I deduce the objective is to determine if the designated shelf life is acceptable.

Is that correct ?

Or is the normal storage condition frozen for a designated maximum  T months ?

The criteria for determining shelf life acceptability depend on the typical method of storage.

Hi jason,

 

I’m unsure as to the specific objective of yr test. The prodecure you describe sounds a little odd.

 

I deduce yr burrito normally has a designated shelf-life of max. S days in a refrigerator chilled section.

I deduce the objective is to determine if the designated shelf life is acceptable.

 

Is that correct ?

 

Or is the normal storage condition frozen for a designated maximum  T months ?

 

The criteria for determining shelf life acceptability depend on the typical method of storage.

Are all the components used right away or are there leftovers(wip) of components saved for future runs?

All components are used right away, aside from the salsa, which has a shelf life of 45 days as an in process item. All components are cooked in sealed bags well over 165ºF, then chilled in the same bags to below 40ºF in about 45 minutes to an hour.

The normal condition is a frozen finished product, with a shelf life of 9 months. Our client has particular customers who want to know if and for how long they can merchandise the product in the refrigerated section. This was the purpose of the test. We will ship the burritos frozen and they will be placed in the refrigerated section, where they will thaw naturally over the course of a few days. We tested from day one frozen to day 15 thawed.

 

 

The normal condition is a frozen finished product, with a shelf life of 9 months. Our client has particular customers who want to know if and for how long they can merchandise the product in the refrigerated section. This was the purpose of the test. We will ship the burritos frozen and they will be placed in the refrigerated section, where they will thaw naturally over the course of a few days. We tested from day one frozen to day 15 thawed.

Hi Chef,

Thanks for the clarification.

I wonder as to your criteria for (a) thawed, and (b) "merchandisable" ?

I'm no expert on shelf-life testing and I understand your intention but I fear that the procedure you describe is arbitrary, and possibly dangerous eg -

(1) Different items will not thaw at the same rate.

(2) Your (refrigerator) thawing condition is likely to differ from other people's.

(3) L.monocytogenes if present in the cooked product may multiply/exceed safety limits.

But perhaps you are using a standard thawing procedure / criteria  from your customer ?

PS - Basically I suggest you perform 2 preliminary actions -

(i) Validate yr cooking process

(ii) Establish criteria to define/evaluate the acceptable "storage" life for yr (frozen-thawed) product.