Dear Fermsam,
Since this is not my field I am not sure I understand your requirements right but below there are some information and links that may apply to the wider category of the grape
juices.
On the FDA website there are these
regulatory guidelines (from point 4.0) regarding fruit
juices which take into account a number of variables but I am not sure which will apply to your product. They main aim seems to be the achievement of 5log reduction of target pathogens.
In one book I found the following: 'In this method [flash pasteurisation], the
juice is heated rapidly for about 1 min to a temperature just 5°C higher than the pasteurization temperature and filled into containers, which are sealed airtight under cover of steam to sterilize the seal and then cooled. This process can be used for orange
juice, apple
juice, grape
juice, etc.' (CRC Press, Handbook of food preservation).
On another book is recommended a heat treatment of 71.1C/>3 sec to achieve 5log reduction of E.Coli, Salmonella and Listeria Mono. (CRC Press, Beverages quality and safety) in grape
juice.
On this FAO
document (paragraph 13.7) there is a reference to apple
juice being flash pasteurised at 88C for 25-30 sec. but I could not find much about concentrated grape
juice.
I hope some of the above will prove useful as I was not able to find anything specific to concentrated grape
juice.
Regards,
Marco
