8 replies to this topic

[gofes]

Hello,

I am based in the UK and make and sell my own Ice Cream.

For a number of flavours I use fresh fruit. Environmental Health have questioned how I can guaranty each batch is safe for consumption. I have had my end product bacterially tested which was fine, but the next batch of fruit will be different (picked at a different time, possibly from a differnt farm.)

Talking to the Ice Cream alliance once suggestion is to lower the PH of the fruit to 4.5 with lemon juice or citric acid. Does anyone know of any documentation or proof I can used to justify this metod to Enviromental Health?

Cheers

[Charles.C]

Dear gofes,

I assume this is a kind of follow-up to yr previous FSMS post. Seems that not many ice cream specialists here including myself so can I ask a little more to maybe promote some activity. I looked up a model HACCP plan for ice cream on IT and noted that the typical CCP is the pasteurisation step although the precise requirements differed between 2 refs I checked which is not uncommon IMEX.

Any reason why this step not cover yr query regarding ingredients like fruit inputs ? Did the "Health" specify what particular risk from fruit was considered possible ? Or was this just part of his "check menu" that all ingredients were required to be "safe" before adding into the process even if a later CCP took care of possible hazards.

The pH value you mention is (maybe) a general comment since many bacteria are inactivated at pHs below 4 - 4.5. This info. is available from most Food Science textbooks but the exact figure will probably depend on the specific species I think and perhaps the matrix around it which will be related to the fruit / your ice cream procedure. Maybe most fruits are groupable together in this respect (outside my immediate knowledge, sorry, anybody ???))
Also the addition of citric acid may significantly affect the characteristics of ice-cream, flavour etc, do you hv satisfactory knowledge on this already?

Apologies if you hv covered all these aspects already but yr question maybe needs a bit more process info for people to think about. Any existing experts here may well know all this and soon appear.

Rgds / Charles.C

[gofes]

Hello there.

The ice cream mix goes through a pasteurisation strep, in which the mix is raised to 85oc which is satisfactory for the (raw) milk I use, but Environmental Health have questioned whether this would kill all the bacteria, specifically campilobacteria.

There is one other ice cream producer in the area and they use brought in fruit pastes, but thats not really something I want to do.

But I have yet to make a batch using the lower ph fruit solution as I am waiting for my litmus paper to turn up.

[Charles.C]

dear gofes,

thks the clarification.

I forgot to ask 1 other question -

Is the fruit item added before or after the pasteurisation ? The relevance is obvious.

Also any idea how long at 85degC (eg 1sec., 10secs etc ?). Strictly it's T/t which controls.

Rgds / Charles.C

added - sorry, I jumped yr last paragraph, all ingredients are presumably pasteurised together.

Clearly you are using some kind of a HTST process, i assume this is a UK standard procedure. If it's of any interest, i found this data (2003) from a NZ report -

Ice cream treatment means heat treatment of an ice cream mix to be used in ice
cream by retaining the ice cream mix –
o At a temperature of not less than 69ºC for not less than 20 minutes; or
o At a temperature of not less than 74ºC for not less than 10 minutes; or
o At a temperature of not less than 79.5ºC for not less than 15 seconds; or
o At a temperature of not less than 85.5ºC for not less than 10 seconds; or
o At another temperature for a time which achieves an equivalent result to
the treatments above;
o and followed by freezing the ice cream mix

and in same publication -

3.3.4 Campylobacter spp.
Milk inoculated with 1.6 x 106 C. jejuni/ml did not yield post pasteurisation survivors
under HTST conditions, but the organism did withstand 10 seconds exposure at this
temperature (Gill et al. 1981).
Data from the ICMSF give D times of 1.3-5.4 minutes in skim milk at 50oC, and 0.74-
1.0 minute at 55oC in the same medium (ICMSF 1996). In physiological saline D
times were 0.71-0.78, 0.24-0.28, 0.12-0.14 minutes at 56, 58 and 60oC respectively
(Sorqvist 1989).

 pasteurisationreview.pdf   271.34KB   45 downloads

The usual approach is to select the most heat resistant species and specify the required "reduction" of that species. This then enables via measured D,z values the generation of a table of possible T/t pairs. The tricky part is geting reliable D,z data which can be used for different matrices.
Didn't read it all but I presume the Camp. data was calculated as compatible with the tabulated values.
If you are using similar UK approved T/t conditions, I would hv thought such to be sufficient validation assuming similar justifications to the above are available / match yr situation.

[Simon]

Hi Gofes, did Charles answer your query?

[gofes]

Yes I am following the pasturisation guide lines as shown in the NZ report, 85.5ºC for 15 seconds in my case for the milk. But I am less keen to put the fruit through this process as well, as heating fruit to such temperature as it has a detremental effect on the taste.
But as I am struggling to find an alternative solution I might well be going for this approach.

Thanks

Ben

[Charles.C]

Dear Ben,

Yes, I can understand the potential flavour problem.

I did previously see examples of ingredients (not fruit) added after heat treatment but other controls then obviously become relevant, eg this process example -

 haccp_toffee_ice_cream_.pdf   181.48KB   122 downloads

Also, I saw 2 possibly useful links for yr original pH query, one a general comment and the second detailing pHs for a range of pathogens inc. Campylobacter (exact matrices unspecified). You can see that various levels are possible acc. to this ref. The UK may have their chosen own regulatory specifics of course.

 FDA_CFSAN___Food_Safety_A_to_Z_Reference_Guide.htm   40.37KB   33 downloads

 pH___veg.pathogen_growth.doc   107.5KB   33 downloads

Rgds / Charles.C

[Hongyun]

Hello,

I am based in the UK and make and sell my own Ice Cream.

For a number of flavours I use fresh fruit. Environmental Health have questioned how I can guaranty each batch is safe for consumption. I have had my end product bacterially tested which was fine, but the next batch of fruit will be different (picked at a different time, possibly from a differnt farm.)

Talking to the Ice Cream alliance once suggestion is to lower the PH of the fruit to 4.5 with lemon juice or citric acid. Does anyone know of any documentation or proof I can used to justify this metod to Enviromental Health?

Cheers

Hi Ben,

I assumed you purchased the fruits from local supermarkets for your ice cream? Which is why you might be worried about the quality of your fruits, and whether they are safe for consumption as it differs from batch to batch.

I'm no expert on this as well, but, will buying fresh fruits from a food industry like Fresh Del Monte help? They even have their own QA, which I believe they will provide Certificate of Assurance that their products are OK. This should be able to convince the Enviromental Health that your products are safe and checked by supplier.

But if all else fails and you decide to purchase blanched fruits (mild heat treatment), you can always add natural or artificial flavors to make up or mask the detrimental taste.

---


In the food industry, there is a method of introducing the moist food (e.g. fruits, vegetables, sauce, ready-to-eat meats) under high pressure to kill off pathogens without any effects to it's taste, nutritional values, color or shape of the food product.

But I'm not sure which Company currently uses this preservation technique for their products...

FYI

Added: See attached on a brief information of HPP, taken from IFT.

Seems like some fruits/vegetables with porous structure containing air voids are not suitable for this processing...

Attached Files

•  Preserving_Foods_through_High_Pressure_Processing.pdf   265.56KB   63 downloads

Edited by Hongyun, 15 November 2008 - 03:22 PM.

[Jean]

Dear Ben,

Charles and Hongyun have helped you a lot. But as a matter of curiosity, are the fresh fruits sanitized before being adding to the mix, especially after the heat treatment, as I didn’t notice it being mentioned (hope this was not a stupid question).