we produce in a small factory almond biscuits known as Biscotti. They are cutted after baking. So you see in the biscuits section the almond sliced. After 5-6 months the colour of the almond sliced change from white to yellow/green as if it was old, there is no problem in taste only in aspect. We already made analysis about peroxides but there is no difference between a sample with white almond and yellow almonds, so it seems to be not a problem of oxydation of fats. The biscuits are packed in protective atmosphere with nitrogen. Do you have some suggestion to discover the cause?
It's related to quality control of the product. For quality control is important to control the important things and analyse the results as well. For example The quality of your Roh Products, Temperature, Time & etc is important. I usallally don't guess and say something without exact analyse the process. Everything should analyse exactly due to quality control of the product to get the best results and the great quality.
We believe the problem is related to oxidation as it is a common problem in almonds when they are cut or processed
FPS019427A – Anti-OX RMT
FPS019423A – Mixed Tocopherols (50%)
These can be sprayed onto the nuts before adding to the mix to coat them, or alternatively you would need to coat the biscuit after its been cut and before packaging. Every time the nut is cut, the surface area prone to oxidation is increased so its quite a tricky one.
Happy to work out
application but would need to know a lot more about your process methods to
get a good idea of where and when antioxidants should be applied.
Let me know if you would like to see samples for evaluation or if you would like us to look more deeply into it for you.
I would like to mention a subject.
Especially in dried fatty foods such as almond and hazelnuts,
oil migration occurs over time. This results in color change.
Please check your Storage Temperature and Water activity in your Product.
Because high storage temperatures can promote lipid peroxidation in almonds and thus reduce the shelf life. The water activity influences the lipid oxidation process.
Thanks to all of you.
The point I do not understand is that if it is a problem of oxidation then peroxides should be higher in yellow almonds than in white ones. And this is not the case. We did analysis and there is no difference in peroxides. maybe as Nezaket said is a problem of oil migration?
that problem is the oil migratin problem... Nezaket is absolutelly true.. u cant prevent the oil migration problem..during the sehlef life u will see the color changing ..
may be u can use the lowest almond pieces. not whole almond.. u can supply defatted almond /nut pieces..
Procedures were developed for producing partially defatted almonds by pressing natural (with skins) or blanched (without skins) almonds to remove approximately 55% oil, expanding them in ca. 96.1°C (205°F) water containing dextrose, then salting and roasting in almond oil at about 162.8°C (325°F). Blanched partially defatted roasted almonds were better products since they had 45.1% of original oil removed compared to 11.3% for natural partially defatted products. Physical appearance and breakage tests showed blanched products to have 82.8–94.6% acceptable nuts compared to approximately 50% for natural products. Effects of moisture during pressing on oil removal from natural and blanched almonds were determined.
Thank you very much Beyhan,
unfortunately we have to use whole natural almonds because of a set of rules of the biscuit.
Maybe the oil migration changes with almond variety? Which could be a variety with less oil migration?