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#1 tripathi

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Posted 02 July 2009 - 03:13 PM

Dear all
Please define underneath term in retort processing
Presently I switch Bakery to RTE industry.

1.Fo value calculation.
2.Z value calculation
3.How to conduct HD test.
4.How to conduct HP test.and what is base of these.



Thanks,
Tripathi


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#2 Simon

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Posted 02 July 2009 - 08:58 PM

Dear all
Please define underneath term in retort processing
Presently I switch Bakery to RTE industry.

1.Fo value calculation.
2.Z value calculation
3.How to conduct HD test.
4.How to conduct HP test.and what is base of these.

Thanks,
Tripathi

Can anyone help Tripathi with this one?
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#3 SaRaRa

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Posted 02 July 2009 - 09:34 PM

Hello Tripathi,

What kind of food is your industry producing?

Here is a video of a fish processing line. I did my internship in a pet-food industry in Portugal and I can say that the process is similar to this video!

I think you can find easily info about the D, z and F values on the links below. Some pages are missing though. If you are not covered by these PM me. I have some very good notes which describe the Graphical Method (or General Method), the Formula Method, the Nomogram Method, the determination of can center temperature and Can Size conversion.

Sterilization Process Engineering

Principles of Thermal Processing

Thermal Processing of Canned Foods

Simulating Thermal Food Processes Using Deterministic Models

Thermal Processing of Food

Continuous Thermal Processing of Foods

Improving the Thermal Processing of Foods


Cheers!


Edited by SaRaRa, 02 July 2009 - 09:40 PM.

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#4 tripathi

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Posted 03 July 2009 - 01:30 PM

Dear SaRaRa,

Here we are engaged to manufacturing RTE for human eating & 100%exporting.

Product like: Retorted-- Rice, Curry, Vegetable, and Sauce.

Name Like: Dal mukhani, Chana Masala, Steamed Basmati Rce, Korma sauce, Roganjosh sauce.



All products prepared in Kitchen & packed by Toyo in retorted 3D pouches then processed in our batch retort.



We process in FMC Water Steam Batch Retort.



Please provide me guidance.


Cheers!

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#5 SaRaRa

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Posted 03 July 2009 - 05:21 PM

Dear tripathi,

In order to get a better understanding of thermal processing you should read this chapter (starting from page 73). PRINCIPLES OF THERMAL PROCESSES

There it states that:

"In order to determine the extent of the heat treatment, several factors must be known:

1) Type and heat resistance of the target microorganism, spore or enzyme present in the food
2) pH of the food
3) Heating conditions
4) Thermophysical properties of the food and container shape and size
5) Storage conditions following the process"


After time and temperature data for a given product in a given can size have been obtained by heat penetration studies, these data may be analysed by either of 2 methods:

a) The General of Graphical Method of Bigelow et al.

b) The Formula Method of Ball

The General Method is used when it is desired to measure the exact sterilizing value of a process, when such conditions as come-up time (which is the time required in order for the retort temperature to reach the highest value), cooling water temperature, or the holding time after processing but before water cooling are different from normal retorting procedures. This method is also adapted to conditions when the heat penetration curve cannot be represented by one or two straight lines within the lethal temperature range on semi-logarithmic paper. Is it not readly adapted to the calculation of processes when the retort temperature and/or initial temperature are different from those under which the heating data were obtained. Time and temperature data during the cooling cycle as well as the heating cycle must be recorded in order to use the Graphical Method.

The Formula Method is used when the heat penetration curve can be represented by not more than two straight lines on semi-logarithmic paper. The formula permits evaluationg processes for retort and initial temperature conditions differing from those under which the heating data were obtained. In the case of heating curbes represented by one line only on semi-log paper, the heat penetration factors can be converted to different can sizes.

The Nomogram Method is merely a graphical solution of the previously used equations. No additional reference to charts, log tables or slide rules is needed; only a straight edge (preferably transparent) is required. Different nomograms are required for the two types of problems represented by a single straight line heating curve and a broken two-slope heating curve.

You can find the above methods in the links that I have provided you.
Here is also another good start which includes also the basics like steady and unsteady state heat transfer: THERMAL PROCESSING OF FOODS

STANDARDS

It is first necessary to set up a standard sterilizing value. The greatest interest in processing canned foods is with low acid products. With such foods, 250 F (121,1 C), has been generally established as the reference temperature and the lethal heat expressed in terms of minutes at 250 F.

F, D and z values

(The above link concerns pharmaceuticals but the terms used are the same in the food industry. You can find out more if you look in the links that I have provided you).

So according to the food item (and its pH) you have, you have to find by microbial analysis and by literature the extact D and z values of the most thermostable pathogenic microorganism (and/or enzyme that is undesirable) in it.

Foods can be devided into classes according to their pH:

- Low pH foods (pH >~ 4,5): meat, fish, milk, poultry, eggs, vegetables etc
- Acidic foods (pH = 4,0 - 4,49): tomato, pineapple, pear
- High acidic foods (pH < 4,0): fruits




SPOILAGE (AND SOME PATHOGENIC) MICROORGANISMS:

I. LOW pH FOODS

A. Thermophilic microorganisms

1. B. stearothermophilus. Causes flat sour due to the production of lactic and formic acid which are volatile acids so the product gains a distinctive smell but the can doesnt get deformed cause no gases are produced. D121,1 = 4-5 min.

2. C. thermosaccharolyticum. Causes anaerobic spoilage due to the production of butyric, lactic and formic acid, carbon dioxide and hydrogen so the product gains a distinctive smell and the can gets deformed. D121,1 = 3-4 min.

3. C. nigrificans. Causes sulphuric spoilage. The hydrogen sulphide produced affects the sulphur containing proteins like cysteine and cystine so the product gains a distinctive smell. D121,1 = 2-3 min.

B. Mesophilic microorganisms

1. C. botulinum. Causes rotting. There is also production of carbon dioxide, hydrogen sulphide, ammonia etc so the product gains a distinctive smell and the can gets deformed. D121,1 = 0,1-0,2 min.

2. C. sporogenes. The same as above. D121,1 = 0,8-1,5 min.

II. ACIDIC FOODS

Mesophilic mircoorganisms

1. B. coagulans. Causes flat sour due to the production of lactic and acetic acid. D100 = 1,29 - 9,04 min. D121,1 = 0,01 - 0,07 min.

2. C. butyricum. Causes butyric fermentation. Butyric and acetic acid, carbon dioxide and hydrogen are produced. D100 = 0,1-0,5 min.

3. C. pasteurianum. The same. D100 = 0,1-0,5 min.

III. HIGH ACIDITY FOODS

Mesophilic microorganisms

1. Byssochlamys and Paecilomyces. They cause softening of the fruits due to the production of pectinolytic enzymes. D90 = 1-2 min.

2. Lactobacillus and Leuconostoc. They cause lactic fermentation. Lactic and acetic acid are produced among with carbon dioxide. D65 = 0,5 - 1 min.

3. Escherichia coli, Aerobacter aerogenes, Mycobacterium tuberculosis, Salmonella, Brucella, Streptococcus, Staphylococcus. They cause food poisining and diseases. D65 ~< 0,6 min.



In products of low acidity (pH>4,5) it is very probable that C. botulinum is present. It is the most thermoresistant, mesophilic, sporogenic, anaerobic, pathogenic bacterium. The tightly sealed cans offer an ideal enviroment for C. botulinum to grow and produce toxins. The persentage of death of individuals who consumed foods which contained those toxins is over 65%. Because C. botulinum is very common in nature and especially in soil/dirt, all food products can be concerned as infected with its spores. For this reason every product with a pH > 4,5 has to be sterilized in such a way that C. botulinum spores are destroyed unless special measures are taken which can inhibit their development.

For the ensuring of the safety of the consumers, in products of low acidity, and with C. botulinum as a reference, a thermal process equal with:

Fo = m D = 12 x 0,1 min to 12 x 0,3 min = 1,2 to 3,6 min

...should be applied because for C. botulinum m = 12 and D at 121,1 C is 0,1 to 0,3 min. Where m is the reduction exponent and is equal with:

m = log Ni / N, where Ni = initial count of microorganism and N = final count after the processing.

So for the calculation of the required time of the thermal process (F), the above type can be used. But in the specific case where z = 10 C and the reference temperature is 121,1 C, F should be symbolized as Fo. Fo expresses the reduction of the microbial population of reference (with a z = 10 C) which the heating process at 121,1 C for 1 min induces. Heating at 121,1 C for 1 min means instant increasing of the product's temperature at 121,1 C, sustaining the product at this temperature for 1 min and then instantly reducing the temperature. Please do read more about it in the links I have provided you.



THERMAL STERILIZATION OF SOME PRODUCTS:

FOOD / Fo (time required for the total destuction of microorganisms in minutes)

Beans / 7-15 min
Spinach / 4-5 min
Tomato / 0,7-1 min
Corn / 9-15 min
Mushroom / 6-10 min
Meat / 6-8 min
Fish / 2,5-8 min
Chicken / 6-8 min
Condensed milk / 5-6 min



FACTORS AFFECTING THE THERMAL RESISTANCE OF MICROORGANISMS:

A. Factors relevant with the microorganism
1. Physical resistance. Generally bacteria are more resistant than moulds & yeasts. Also the bacterial spores are very resistant.
2. Initial concentration/microbial load. It is obvious that the smaller the initial micro load the smaller the thermal resistance.
3. The stage of development. Microorganisms are very heat sensitive at the log phase of their development because in that phase they still haven't developed a resistant membrane.

B. Factors relevant with the natural enviroment of development
1. Temperature. Microorganisms have the maximal resistance when they are in their optimal temperature of development
2. Chemical composition. Microorganisms have the maximal resistance when they are in a enviroment with optimal chemical composition.

C. Factors relevant with the thermal destruction enviroment
1. Temperature. The highest the temperature the easiest the microorganism dies.
2. Chemical composition.
- pH. The highest the pH the more difficult to kill the microorganism
- Sugar concentration. The highest it is the more difficult to kill the microorganism because sugars create a protective "covering" around it.
- Fat concetration. The same with sugar.
- Water. It reduces the thermal resistance of the microorganism.



METHODS TO MEASURE THE THERMAL RESISTANCE OF MICROORGANISM:

1. Tube method
- In pyrex tubes with a diameter of 7 mm and length of 130 mm we add 1-4 ml of product in each one. The concentration of the reference microorganism must be known.
- Closure of the tube next to fire.
- Heating in a specific temperature and different times.
- Cooling.
- Inoculation in appropriate substrate.


2. Can method
- In cans (15 ml capacity) we add 10-15 g of product. The concentration of the reference microorganism must be known.
- Closure of the cans with mechanical vacuum (so the microorganism will survive).
- Heating in a specific temperature and different times.
- Cooling.
- Inoculation in appropriate substrate.


The first method requires small quantities of product so that heat can penetrate it fast. The second method, even though is not instant/fast, it simulates "real conditions".



FACTORS AFFECTING THE VELOCITY OF THEMAL PENETRATION IN THE FOOD ITEM:

1. The texture. Velocity in a liquid product > Velocity in a solid product.
2. Packaging material. Velocity in metal > Velocity in glass.
3. Sugars. High concentration decrease the velocity.
4. Hydrocolloids (water soluble proteins, carrageennans, starch, pectins, agar etc). They reduce the velocity.
5. Size of the product. Big size reduces the velocity.
6. Movement of the product. Increases the velocity.
7. Temperature difference between retort and product. The highest it is the highest the velocity.


For a better insight and understanding of the thermal processing please do read the links I have provided you in the last post.

If you are going to use pouches check out this link:
Sterilization of Food in Retort Pouches


Best Regards and lots of luck!


P.S. I hate thermal processing.

Edited by SaRaRa, 25 April 2013 - 10:32 PM.

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#6 cancan

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Posted 07 July 2009 - 04:41 AM

HD or TD testing, is the test that designed to ensure that the temperature distribution in the retort is uniform and TD test will also determine come-up time for the retort with will specific to each retort. Come-up time will depends on your product IT, steam supply, loading style etc

HP test, is the test to establish the commercial sterile process for the product which specific to the product, packed size, formulation etc. This process calculation is a combination of product heating rate (measure from cold spot of the product during process) ,D value, Z value and target Fo

Both tests should be done by process authority only. Your retort supplier, FMC is the one that also expert about this. They should able give you a lot information about this.

Sorry my english is not good..but I used to be there…in the retort..:P
CANCAN


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#7 Simon

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Posted 10 July 2009 - 06:23 PM

Have your questions on this been answered Tripathi?


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#8 tripathi

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Posted 13 July 2009 - 12:59 PM

Dear CANCAN,

If we want to cheack our sys.

So how, We want to know the location of probes in our tray.Whre we put these thermocoples in whole retort system, is there any relation with heat & product or predicted.we use only 18 Thermocoples for ouer retort these are make by elab.


Please provide if there is any procedure for Maping of Thermocoples in retort.


Thanks to All

Tripathi


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#9 SaRaRa

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Posted 13 July 2009 - 02:41 PM

I did my internship in Portugal in a petfood production factory and once I saw how they conducted the heat penetration test. It has been a long time so I don't remember exactly the proceedure (they did this test maybe 4 to 6 times while I was there - Something like that... I am not sure).

So... After canning the cans where chilled, passed through inspection by a worker and placed in layers in big metal wagons and between each layer of cans, a layer of plastic was placed as well (something like that). So each wagon would fit loads of cans.
The wagons would then enter the retorts and I think that 5 thermocouples were placed in 5 cans in one of those wagons (I think only one wagon had cans with thermocouples but I don't remember very good). The cans that the thermocouples were placed, were in all 4 corners of the wagon and the 5th was placed in the center of the wagon. That wagon was placed as close to the center of the retort as possible (I think - I am not sure). The thermocouples were joined together with a tape and they were passed through a hole (with a special kind of insulation closing tap/lid) out of the retort and they were connected in a special adaptor which was connected with a laptop. The temperature data were recorded, kept and processed with a specific software installed into the laptop after the thermocouples were calibrated. I forgot to mention that there was also another thermocouple measuring the ambient temperature of the retort.

The place of the thermocouple in the can was kinda random I think. I am not sure if it was predetermined from initial tests (I also didn't ask about this so I don't know). So while still being in the Quality Control lab one of the food scientists took a can and made a hole at the side with a special instrument. Then those cans were filled with pet food manually, seamed and placed in specific places in the wagon as I mentioned before.

You can find more about the use of thermocouples in temperature measurement here.

If you want to find out more about the placement of the thermocouples in the can look here. You can also look out for the following titles in journals:

- The mechanics and interpretation of heat penetration tests in canned foods
- Computer aided heat penetration tests for the food canning industry
- Heat transfer to a canned corn starch dispersion under intermittent agitation


You can also find more info here:

The use of data loggers to validate thermal processes

The quality and stability of canned meats

Cheers!


Edited by SaRaRa, 25 April 2013 - 10:32 PM.

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#10 tripathi

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Posted 14 July 2009 - 06:20 AM

Thanks to all members for kind support.


Tripathi


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#11 Abdul Qudoos

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Posted 14 July 2009 - 06:59 AM

Dear all
Please define underneath term in retort processing
Presently I switch Bakery to RTE industry.Posted Image

1.Fo value calculation.
2.Z value calculation
3.How to conduct HD test.
4.How to conduct HP test.and what is base of these.



Thanks,
Tripathi


Very interesting thread and full of valuable information, Learned most of the methods and processing...
How can i favorite this thread or save in my member's page? for future references,
Any Idea Simon!

Edited by Abdul Qudoos, 14 July 2009 - 07:01 AM.

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#12 cancan

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Posted 14 July 2009 - 10:43 AM

The position of TC will depend on many factors..eg. how the heating medium circulate in your retort (direction of steam/water spray), how the product is load, how the tray gaps etc...but very much you have to random put TC every where until you find the cold zone of the retort. Must remember..the test must conduct on FULL LOAD condition and WORSE CASE retort operating condition eg. lowest steam supply..lowest IT. 18 Tcs from Ellab that sound not bad..but you still have to do the test many times...many time until you really confident to identify cold zone in the retort. Information I mentioned above about retort, loading style, steam/water spray system will help you to determine which area that may slower heating..which area you should put TC..example you would not need to out TC on the top tray which is the first tray that contact hot water?

Since you get slower heating zone (I rather to call this than cold spot/zone...its cant be cold in there right?) then conduct the test to get retort come-up time..still must go on WORST CASE & FULL LOAD

You may perform the test internally...but initially you may need process authority to review your data to ensure that your data and the evaluation are right specially if you send product to USA…you will need to submit the process to USFDA .

Hope it help
CANCAN


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#13 Sakura

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Posted 01 June 2010 - 04:00 AM

My company is testing Specialty product which is packed in can. This product use for people need high energy and key ingredient is soy protein isolate. Would you pls advise us the method calculate F0 Value and microbiology, engineering of this sterilization processes.

Thanks you very much
Sakura


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#14 SaRaRa

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Posted 01 June 2010 - 09:31 PM

Could you provide more details of the product ?
i.e. type of food, composition, pH, aw etc.


What are soy protein isolates?

Soy protein isolate is a highly refined or purified form of soy protein with a minimum protein content of 90% on a moisture-free basis. It is made from defatted soy flour which has had most of the non-protein components, fats and carbohydrates removed. Because of this, it has a neutral flavor and will cause less flatulence due to bacterial fermentation.

Soy isolates are mainly used to improve the texture of meat products, but are also used to increase protein content, enhance moisture retention, and as an emulsifier. Flavor is affected, but whether it is an enhancement is subjective.

Before 2006, the U.S. Food and Drug Administration (FDA) was examining flavor reversion concerns related to levels of the toxin furan in soy protein isolate and other foods.[5] This problem has been solved by David Min of the Ohio Agricultural Research and Development Center. The chlorophyll in soy oil was reacting in the presence of light to form trans-2-heptenal and 2- pentenylfuran . Chlorophyll in soy oil is now removed with diatomaceous earth filters (www.wikipedia.org, 2010).



Cheers!

Edited by SaRaRa, 25 April 2013 - 10:33 PM.

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#15 Sakura

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Posted 02 June 2010 - 06:14 AM

Could you provide more details of the product ?
i.e. type of food, composition, pH, aw etc.





Cheers,
Filip




pH of product = 7.0 - 7.2
Composition: Soy protein isolate, canola oil, corn suryp, potasium citrate, stabilizer, emulsifier, and MCT, vitamin premix which contain high calcium carbonate.
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#16 SaRaRa

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Posted 03 June 2010 - 06:28 PM

Dear Sakura,



You can see the previous posts in order to get a better insight into thermal food processing and Fo value calculation. You should do some heat penetration studies on your product with your given can size. Then you will have to analyse the data that you will obtain by one of the two following methods:



a) The General of Graphical Method of Bigelow et al.

b) The Formula Method of Ball



…which you can find in links that I provided in previous posts in this thread.





I will just repeat some basic stuff that you need to keep in mind:



In order to determine the extent of the heat treatment, several factors must be known:



1) Type and heat resistance of the target microorganism, spore or enzyme present in the food (you will have to choose a target microorganism according to the pH category that your product belongs to in order to ensure consumer safety. You should check regulations for your product in your country and other countries if you are exporting. You will also have to keep in mind quality factors so you will have to heat the product just enough to make it safe and also have the minimum possible loss of nutrients. Thus you will probably have also to make some sort of sensory evaluation and/or analysis of the important quality attributes of your final product that you want to offer to your consumers).

2) pH of the food (7.0-7.2 in your case)

3) Heating conditions (what kind of heat treatment are you using? Check out literature that has to do with your chosen microorganism/quality attribute and your chosen heat treatment or try to find similar ones).

4) Thermophysical properties of the food and container shape and size (I suppose that you already know those).

5) Storage conditions following the process (what sort of storage conditions follow after cooling of your product? You have to store in a dry and cool place in order to avoid oxidation by moisture and high temperatures that might contribute in the spoilage of your product and increasing the risk of thermophilic bacteria growth.



Since your product has a pH of 7.0-7.2 you should be aware of the following Important spoilage and pathogenic microorganisms in low pH foods



A. Thermophilic microorganisms



1. B. stearothermophilus. Causes flat sour due to the production of lactic and formic acid which are volatile acids so the product gains a distinctive smell but the can doesnt get deformed cause no gases are produced. D121,1 = 4-5 min.



2. C. thermosaccharolyticum. Causes anaerobic spoilage due to the production of butyric, lactic and formic acid, carbon dioxide and hydrogen so the product gains a distinctive smell and the can gets deformed. D121,1 = 3-4 min.



3. C. nigrificans. Causes sulphuric spoilage. The hydrogen sulphide produced affects the sulphur containing proteins like cysteine and cystine so the product gains a distinctive smell. D121,1 = 2-3 min.



B. Mesophilic microorganisms



1. C. botulinum. Causes rotting. There is also production of carbon dioxide, hydrogen sulphide, ammonia etc so the product gains a distinctive smell and the can gets deformed. D121,1 = 0,1-0,2 min.



2. C. sporogenes. The same as above. D121,1 = 0,8-1,5 min.



In products of low acidity (pH>4,5) it is very probable that C. botulinum is present. It is the most thermoresistant, mesophilic, sporogenic, anaerobic, pathogenic bacterium. The tightly sealed cans offer an ideal enviroment for C. botulinum to grow and produce toxins. The persentage of death of individuals who consumed foods which contained those toxins is over 65%. Because C. botulinum is very common in nature and especially in soil/dirt, all food products can be concerned as infected with its spores. For this reason every product with a pH > 4,5 has to be sterilized in such a way that C. botulinum spores are destroyed unless special measures are taken which can inhibit their development. For the ensuring of the safety of the consumers, in products of low acidity, and with C. botulinum as a reference, a thermal process equal with:



Fo = m D = 12 x 0,1 min to 12 x 0,3 min = 1,2 to 3,6 min



...should be applied because for C. botulinum m = 12 and D at 121,1 C is 0,1 to 0,3 min. Where m is the reduction exponent and is equal with:



m = log Ni / N, where Ni = initial count of microorganism and N = final count after the processing.



So for the calculation of the required time of the thermal process (F), the above type can be used. But in the specific case where z = 10 C and the reference temperature is 121,1 C, F should be symbolized as Fo. Fo expresses the reduction of the microbial population of reference (with a z = 10 C) which the heating process at 121,1 C for 1 min induces. Heating at 121,1 C for 1 min means instant increasing of the product's temperature at 121,1 C, sustaining the product at this temperature for 1 min and then instantly reducing the temperature.



You should also keep in mind the following factors which affect the thermal resistance of microorganisms:



A. Factors relevant with the microorganism

1. Physical resistance. Generally bacteria are more resistant than moulds & yeasts. Also the bacterial spores are very resistant.

2. Initial concentration/microbial load. It is obvious that the smaller the initial micro load the smaller the thermal resistance.

3. The stage of development. Microorganisms are very heat sensitive at the log phase of their development because in that phase they still haven't developed a resistant membrane.



B. Factors relevant with the natural environment of development

1. Temperature. Microorganisms have the maximal resistance when they are in their optimal temperature of development

2. Chemical composition. Microorganisms have the maximal resistance when they are in a environment with optimal chemical composition.



C. Factors relevant with the thermal destruction environment

1. Temperature. The highest the temperature the easiest the microorganism dies.

2. Chemical composition:

- pH. The highest the pH the more difficult to kill the microorganism

- Sugar concentration. The highest it is the more difficult to kill the microorganism because sugars create a protective "covering" around it.

- Fat concentration. The same with sugar.

- Water. It reduces the thermal resistance of the microorganism.



Here are some methods in order to measure the thermal resistance of microorganisms:



1. Tube method

- In pyrex tubes with a diameter of 7 mm and length of 130 mm we add 1-4 ml of product in each one. The concentration of the reference microorganism must be known.

- Closure of the tube next to fire.

- Heating in a specific temperature and different times.

- Cooling.

- Inoculation in appropriate substrate.


2. Can method

- In cans (15 ml capacity) we add 10-15 g of product. The concentration of the reference microorganism must be known.

- Closure of the cans with mechanical vacuum (so the microorganism will survive).

- Heating in a specific temperature and different times.

- Cooling.

- Inoculation in appropriate substrate.



Ι suppose that your product is in liquid form. This is important since heat penetration is faster in liquid products is faster than solid products. You should also be aware of other factors affecting the velocity of thermal penetration in your product:





1. Packaging material. Velocity in metal > Velocity in glass.

2. Sugars. High concentration decrease the velocity.

3. Hydrocolloids (water soluble proteins, carrageennans, starch, pectins, agar etc). They reduce the velocity.

4. Size of the product. Big size reduces the velocity.

5. Movement of the product. Increases the velocity.

6. Temperature difference between retort and product. The highest it is the highest the velocity.





Good luck!!!

Edited by SaRaRa, 25 April 2013 - 10:33 PM.

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#17 SaRaRa

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Posted 03 June 2010 - 06:32 PM

Hmm... why dont you add some sort of acidulant or carbonate your product? Then you would have to pasteurise and not sterilize.


Edited by SaRaRa, 03 June 2010 - 06:33 PM.

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#18 Hongyun

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Posted 04 June 2010 - 12:40 AM

Hmm... why dont you add some sort of acidulant or carbonate your product? Then you would have to pasteurise and not sterilize.


Not every item is suitable for hurdle system. For this case, reducing pH would make the food less appetizing (too sour), not to mention the possibility of breakdown of protein to amino acids in long term storage.




If I'm not wrong, this item is solid? Like mock meat for the vegetarians?



Sakura, you could probably try out the formula provided by Filip. Do some trials from your side to see if it works or not.


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#19 Sakura

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Posted 04 June 2010 - 02:42 AM

Hmm... why dont you add some sort of acidulant or carbonate your product? Then you would have to pasteurise and not sterilize.


Dear Fillip,
Thanks for your information. I will check our systems and new product when I make labscale, after that, we will discuss this matter for more information.
Reducing pH by acidulant or carbonate would make the food less appetizing (too sour), not to mention the possibility of breakdown of protein to amino acids in long term storage, the structure of product changing ( age gelation, sedimentation,..).

Would you pls advise the best course or book for guiding food retort processing?

Thanks you very much,
Sakura

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#20 SaRaRa

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Posted 04 June 2010 - 12:51 PM

@ Hongyun:
Hey! Long time no talk! Wuuzzzaaa! :P
Indeed I see your points! :)

@ Sakura:
ome books that you can check are:

Continuous Thermal Processing of Foods (2000)

Thermal Technologies in Food Processing (2001)

Sterilization of Food in Retort Pouches (2006)

Thermal Food Processing - New Technologies and Quality Issues (2006)

Thermal Processing of Packaged Foods (2007)

Engineering Aspects of Thermal Food Processing (2009)

Most of them include the thermal processing of cans.
Just check the contents of each book and see what interests you the most.


Here are some videos that I found:

Canned Food - From Field to Table

Canned Foods (Ready to eat) Safety BBC Jimmy's Food Factory

Simulating Temperature versus Time Relationships in the Thermal Preservation of Foods
Survival Curves of Bacilli Spores with an Activation Shoulder


Good luck! :D



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#21 Sakura

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Posted 16 September 2010 - 07:27 AM

Would you please to give the book which guide quality control in food retort processing? Why choose C. botulinum to set control quality in retort whereas choosing B. stearothermophilus or B. cereas to set control quality of product?

Please give me your advise
Thanks you very much
Sakura.


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#22 SaRaRa

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Posted 19 September 2010 - 07:58 PM

Dear Sakura,

You can find many useful links on my previous posts on your first question. However a good book on quality issues I think is "Thermal Food Processing - New Technologies and Quality Issues (2006)". Concerning your second question: C.botulinum is chosen for safety reasons mainly because it can be lethal if it manages to produces its toxins. You can check more about B. stearothermophilus and B. cereus on my previous posts.
Cheers!


Edited by SaRaRa, 25 April 2013 - 10:33 PM.

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#23 Dhruv

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Posted 19 November 2010 - 07:03 AM

Dear Mr. Tripathi

I am with Retort manufacturer.

If need any help do contact me.


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#24 Simon

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Posted 19 November 2010 - 09:19 AM

Dear Mr. Tripathi

I am with Retort manufacturer.

If need any help do contact me.


If you have some commnets or ideas of value to add to the topic Dhruv, please do so.
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#25 DAVE84

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Posted 28 December 2010 - 07:29 PM

Hi Tripathi,

Again the place of the thermocouple will depend on your own retort. What you need to do is prepare a whole batch of pouches or cans which ever you use, filled with water. Now you need to load the retort with this water filled samples and each time you need to place your thermocouple in defferent zones. Repeat this procedure untill you find few cold spots( spots where pouches gets heated slowly). That will be your target spots. Now when you process the actual process you need to place your thermocouples in that cold spots whihc you found prior. And make sure that you achieve required F0 value in that cold spot, which will utlimately give you confident that each can has passed through minimum required F0 value. Feel free to ask any other question you have. There are some softwares like ellab (mostly used in india) that will give you online temperature of the product. They are bit costly but worth to spend money.


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