15 replies to this topic

[Hongyun]

Hi,

I've been with my Company for almost a year as a QC technician now, and throughout this one year we often have issues with coliform / E. coli problems with our pepper...

I'm not the one handling the grd pepper production, so I don't really know the details. But what I know is this:

The raw whole peppers will be steam sterilized under moist heat at 130 - 140 deg C for less than 5 mins, after which they are further heat dried at 150 - 160 deg C for 20 - 25 mins. E. coli having a optimum temperature of 37 deg C should not be able to survive under this condition. After sterlization, samples will be drawn and sent to the microbiology lab for testing. Both coliform / E. coli came back negative.

Without a cooling system, our sterilized whole pepper were stacked and stored while waiting for the micro results.

Once we have confirmation that the pathogens are not there, we will proceed to grind it for the customers (No heat invovled). Operators sanitized their hands with suitable alcohol and wore gloves before handling the goods.

Here comes the problem. After grinding, we will draw another set of samples for micro testing again. However, this time round, they came back positive.

How is that possible, especially since the steam-sterilized whole pepper came back negative? Are we missing out something here that might cause the sterilized whole pepper to get contamined?

Hope someone here has experience with microbiology issues...

-HY

[bibi]

Hi,

I've been with my Company for almost a year as a QC technician now, and throughout this one year we often have issues with coliform / E. coli problems with our pepper...

I'm not the one handling the grd pepper production, so I don't really know the details. But what I know is this:

The raw whole peppers will be steam sterilized under moist heat at 130 - 140 deg C for less than 5 mins, after which they are further heat dried at 150 - 160 deg C for 20 - 25 mins. E. coli having a optimum temperature of 37 deg C should not be able to survive under this condition. After sterlization, samples will be drawn and sent to the microbiology lab for testing. Both coliform / E. coli came back negative.

Without a cooling system, our sterilized whole pepper were stacked and stored while waiting for the micro results.

Once we have confirmation that the pathogens are not there, we will proceed to grind it for the customers (No heat invovled). Operators sanitized their hands with suitable alcohol and wore gloves before handling the goods.

Here comes the problem. After grinding, we will draw another set of samples for micro testing again. However, this time round, they came back positive.

How is that possible, especially since the steam-sterilized whole pepper came back negative? Are we missing out something here that might cause the sterilized whole pepper to get contamined?

Hope someone here has experience with microbiology issues...

-HY

hi

what about your grinding process?

bibi

[Hongyun]

Before grinding, 70% IPA will be used to sanitized the machines. Once dried, they will insert the cleaned sieves, start the milling / grinding process and pour in the steam-sterilized whole pepper. As mentioned, there is no heat involved in this process.

[Charles Chew]

Check evidence of introduction of bacteria during the storage / cooling process. The stoarge bags (if re-used) may be a problem through cross contamination arising from food handlers since product is wet.....etc AM SURE the problem is from the sterilazation process onwards

[Hongyun]

According to my collegue, the temperature of the just-packed steam sterilized whole pepper is around 75 deg C. They are they packed in PP woven bags and stacked up while waiting for micro results to return. Even on the 2nd day, the temperature of the whole pepper was around 50 deg C. Being in Asia, our ambient temperature and humidity tends to be on the high side.

I believe there are no cross-contamination, because no-one would be poking the insides of the packaging until it is ready for grinding; whereby they will sanitized their hands with alcohol and wore gloves. Besides, i don't think coliforms are air-borne, right?

So, despite having the best temperature to grow (34 deg C --> our warehouse), there shouldn't have any coliform / E. coli as there are no cross-contamination, ya?

My collegue had another idea. The reason why we do not use it immediately was due to
1. micro results not out yet and
2. because they are still rather moist from all the steam, which may clog the seives when ground
3. and the possiblity of a mold attack after grinding.

No. 1 was not a problem, as they have collected data from the past and almost all of them (i think) are coliform-free. So we can actually forgo the test, or at least not wait for it.

As for No. 2, she was thinking we can wait for a day, while the temperature is still ard 50 deg C to grind. This way, not only are the whole peppers less moist, the temperature of the peppers also does not promote the growth of E. coli. Then, hopefully we will get negative for coliform!

Is this even feasible?

[Hongyun]

I can't seemed to edit my post, so I'll just post another one.

Some one suggest the use of UV radiation to kill off coliform. Our question would be, will finished goods being exposed to UV radiation be considered Irradiated Food? I've search web-sites, but have not found the answers we are looking for.

I know Charleschew had similar questions on Irradiated Foods, but got no reply what so ever. Just trying my luck here...

BTW, is there a particular web-site showing the food regulations of different countries? Was trying whether Japan allows Irradiated Foods or not.

[Charles Chew]

Hi HongYun,
I do have a lot of information on irradiation but problem is there are all copyrighted so I really cannot post them on the forum. However, UV wld do the job but I am not sure as there are no direct infor as to whether it wld be considered irradiated product as it claims that UV, Microwave or RF etc do not leave residue on product unlike Gamma or X-Ray.

For your infor I am introducing one of the methods for fish thawing but at a level before latent heat transfer onto the product itself therefore it wld not be considered irridiated.

On the issue of the pepper - I believe the issue cld be due to Aw or high moisture content even though it may "look" dry. Suggest you test the Aw prior to grinding.

Contamination may come from any food contact surfaces or handling points. The problem is likely to be within these possibilities. You will just have to analyse by risk elimination on potential root cause.

[Charles.C]

I'm not a pepper man so these comments are from experience other wet foods. One thing is usually true that if you had basically achieved a satisfactory process situation and now not, something(s) is usually the root cause - control of raw mat, process, environment, storage etc, analysis methods, change in specs.
If you do not achieve 100% initial destuction seems you have quite a good environment for re-establishment of bacteria. As per other posts, further contamination is not so easy to rule out. Any monitoring of surfaces of post-process objects, gloves?
Original levels of bacteria involved are low / high?, this might be relevant. Is the process you are using stable?, from a standard ref.? Quantity control of foods during processing? Idea levels found after treatment? In general for cooking foods with elevated levels of coliform I think it is not so easy (or mandatory?) to achieve total absence of coliforms. E.coli is rather different matter, presumably original levels already v.low?
Would also make sure that the analytical methodology is secure for E.coli, especially if you are looking at very low levels.

[Hongyun]

However, UV wld do the job but I am not sure as there are no direct infor as to whether it wld be considered irradiated product as it claims that UV, Microwave or RF etc do not leave residue on product unlike Gamma or X-Ray.

That's the problem. We do not know if UV-ed products are considered Irradiated Foods or not, and some of our customers don't want Irradiated products.

The worst part is, the mangers actually engaged contractors to equip the plant with UV tubes without finding out if the customers can accept it or not. And the way i heard they were gonna place the tubes, it's bound to have other consequences like peppers stuck at the corners of the tube, thus causing problems during sanitation. Besides, it's placed near the output and I don't think it's given enough time to kill the pathogens.

Anyway, it's the "upper" levels' decision to make, so we technicians just sit around and wait till something happens...

In general for cooking foods with elevated levels of coliform I think it is not so easy (or mandatory?) to achieve total absence of coliforms. E.coli is rather different matter, presumably original levels already v.low?
Would also make sure that the analytical methodology is secure for E.coli, especially if you are looking at very low levels.

Coliform and E.coli are generally low, with detections of sometimes less than 10. But the customers had a stringent requirement of "Not Detected", as in less than 0.3 results.

After production, we would pack samples to our external micro labs for testing, and once approved (< 0.3 E. coli), we would proceed to send preshipment samples to the customers, where they will conduct their own micro testings.

At times, they would show us positive results and reject our preshipment samples, thus we'ld had to reproduce new pepper grd for them and think of a way to sell the rejected lot to other customers with lower requirements.

We've been wondering for sometime now, that maybe they are the ones who screwed up and contaminate the samples, thus giving them the positive results. But of coz, the Sales won't listen and insist that customers' are always right...

Sigh... looks like whatever we do and the postings here might not help much. Afterall, they prefer to listen to their own kind.

[bibi]

That's the problem. We do not know if UV-ed products are considered Irradiated Foods or not, and some of our customers don't want Irradiated products.

The worst part is, the mangers actually engaged contractors to equip the plant with UV tubes without finding out if the customers can accept it or not. And the way i heard they were gonna place the tubes, it's bound to have other consequences like peppers stuck at the corners of the tube, thus causing problems during sanitation. Besides, it's placed near the output and I don't think it's given enough time to kill the pathogens.

Anyway, it's the "upper" levels' decision to make, so we technicians just sit around and wait till something happens...
Coliform and E.coli are generally low, with detections of sometimes less than 10. But the customers had a stringent requirement of "Not Detected", as in less than 0.3 results.

After production, we would pack samples to our external micro labs for testing, and once approved (< 0.3 E. coli), we would proceed to send preshipment samples to the customers, where they will conduct their own micro testings.

At times, they would show us positive results and reject our preshipment samples, thus we'ld had to reproduce new pepper grd for them and think of a way to sell the rejected lot to other customers with lower requirements.

We've been wondering for sometime now, that maybe they are the ones who screwed up and contaminate the samples, thus giving them the positive results. But of coz, the Sales won't listen and insist that customers' are always right...

Sigh... looks like whatever we do and the postings here might not help much. Afterall, they prefer to listen to their own kind.

hi

it seems the discusion is just between you two
not on vacancy other experts!
I am not expert in pepper but you said

[Charles.C]

Had not realised you use ext. lab. This is not easy for production monitoring and you need confidence their results. Claimed to be standard method? Same as customer? Number of samples ? Unfortunately the list is not short. Would hope that E.coli levels are not frequently close to 10, this looks high to me, coliforms maybe different story. APC's are ok?
As you prob. know the most common way of expressing the E.coli results is a probability derived MPN/g but I think yr 0.3 spec. may be a pass/fail method, as bibi is also perhaps referring. Something like - one detection in 3g is a failure so if product gives negative result, level of 'x'must be less than 1/3 (= <0.33 cols per gram). I may be completely wrong here so pls correct me if so, not very familiar with this type of number. Properly derived MPN data should be more fair to the producer I think but this may be no help if the customer does not agree.
Had a quick look on IT at treated peppers, one industry spec gave Ecoli MPN/g max3, + no comment re coliforms, ie 10x yr limit, so yr spec.looking tough. Is there a spec for APC'? ok?
Maybe this is a very special customer for some reason.
I also noted in passing a regulatory comment that finding "unusually" low levels of micro.data could be potentially indicative of irradiation (!!)
Bibis's suggestion seemed good idea if possible but it's easier if you have own lab so as to get quick reliable data.
Rgds / Charles.C

Edited by Charles.C, 26 March 2006 - 05:38 AM.

[Hongyun]

I am not expert in pepper but you said <0.3 is it in 25g taken from a batch of (weight?)
is it possible to reheat the grinding pepper, or the quality will be affected?

bibi

I'm not too sure myself on the procedure. But it should be a dilution from 11g of pepper for the MPN testing. As for re-heating of the grd pepper, I've asked them (senior) before. They replied that it will darken the color of the pepper and that the customer may reject the lot.

Had not realised you use ext. lab. This is not easy for production monitoring and you need confidence their results. Claimed to be standard method? Same as customer? Number of samples ? Unfortunately the list is not short. Would hope that E.coli levels are not frequently close to 10, this looks high to me, coliforms maybe different story. APC's are ok?
As you prob. know the most common way of expressing the E.coli results is a probability derived MPN/g but I think yr 0.3 spec. may be a pass/fail method, as bibi is also perhaps referring. Something like - one detection in 3g is a failure so if product gives negative result, level of 'x'must be less than 1/3 (= <0.33 cols per gram). I may be completely wrong here so pls correct me if so, not very familiar with this type of number. Properly derived MPN data should be more fair to the producer I think but this may be no help if the customer does not agree.
Had a quick look on IT at treated peppers, one industry spec gave Ecoli MPN/g max3, + no comment re coliforms, ie 10x yr limit, so yr spec.looking tough. Is there a spec for APC'? ok?
Maybe this is a very special customer for some reason.
I also noted in passing a regulatory comment that finding "unusually" low levels of micro.data could be potentially indicative of irradiation (!!)
Bibis's suggestion seemed good idea if possible but it's easier if you have own lab so as to get quick reliable data.
Rgds / Charles.C

Ya, we are engaging outsiders to do the micro testings, as we are a small company and it is not feasible to setup/construct a micro lab here. So we do not have a choice except to trust their results.

Herbs and Spices are usually used as sprinkles here. Meaning no further heat treatments. Maybe that's why they want it as low as possible, so it will not cause food poisoning to consumers.

Anyhow, recently, a few of our customers came to look at our plant and brought with them, some agar plates from Nissui Pharamaceutical to swab our equipments. The agar plates are small, with the agar protruding out, so you can swab the surface with it and incubate straight away. http://www.nissui-ph...y/seihin.html#2

And the results came back negative... Contrasting results...

[Witch]

I read the discussion lately, but nevertheless try to help.
Would you please repeat where you found the contamination and where not. Was a bit confusing to collect...
One thing first: did you check your Disinfection alcool?

Andrea

Edited by Witch, 05 April 2006 - 11:50 AM.

[Charles.C]

Apologies for delay, forgot to reply.
The comments illustrate the complexities of using microbiological specifications as accept/reject criteria.
It is not so unusual for customer microbiological requirements to be acceped by suppliers which are subsequently (or occasionally knowingly) found to be either unrealistic or unattainable without substantial process modifications. The problem then often passes down to the QA section for a magical solution.
In the present case yr 'accept' requirement seems in practice to be almost 'zero tolerance' for coliform / E.coli which seems to me unrealistic as a consistent, routine expectation for the end product of this process - Specification/Process Validation ??
If validated, I guess you need to compare the requirement with the typical range of (hopefully reliable) data which you have already accumulated, eg how large / frequent is the deviation. A specific trial lot(s) is often also subjected to a highly intensive sampling / micro.analysis study to define the situation at all steps of the process but this may be expensive in yr case. Depends on the incentive for the extra business.
Sounds like yr company have already decided the cost effective solution is the UV route. Maybe they are right, I hope so.
Regards / Charles.C

[Hongyun]

I read the discussion lately, but nevertheless try to help.
Would you please repeat where you found the contamination and where not. Was a bit confusing to collect...
One thing first: did you check your Disinfection alcool?

Andrea

We did not find the source of contamination. That's the problem. We do not know where and how the product got contaminated.

Quite recently, we've received information from one of the microbiologist that the ground pepper was not contaminated by our processing. Swabs were done on serveral points of machine and results came back negative. But rather, it was from the raw pepper. It was sort of a good news, at least the problem was'nt due to improper sanitation of our machine.

They have isolated the organism and found out that the source was from soil. Can't recall the name of the coliform, but it can form heat-stable capsules... which is probably why we are getting coliform results.

Sounds like yr company have already decided the cost effective solution is the UV route. Maybe they are right, I hope so.

They are in the mid of testing it out now. But I seriously doubt it will have a positive effect, since it's an opaque object that we're talking about here. There will bound to be some parts that are not exposed to the light...



But then another problem arises. We've checked our Grd Pepper as suggested and found that the Aw is well below 0.6. By right, it is too low for bacteria (require 0.8) to survive and grow, correct? Then, how is it possible that they don't die??

[Charles Chew]

Hongyun,

This thread has gone on for quite some time now and I am not going to read through the whole debate but believe that your micro tests are done externally.

IMO, I think there could be a situation of cross contamination from the external laboratory.....i.e. contaminated test apparatus or an inefficient chain of custody on sample handling procedures leading to contaminations. My suggestion to you is to do a parallel test with two different laboratories using the same test methods with samples drawn from the same source.........w/o letting each other know of the parallel tests of course!

Charles