17 replies to this topic

[Hongyun]

Hi guys,

Anyone here knows anything about nanotechnology?

I've been trying to work on oil in water emulsions having oil sizes of less than 0.1 micron... but so far has not been successful.

Major contributors to having good oil size is a good emulsifier/surfactant, and a high pressure homogenizer.

Anyone here have experience with a specific emulsifier/surfactant that can produce nano-sized oil particles?

[Jean]

Hi Hongyun,



Interesting subject –nanotechnology! I have heard of nanotechnology being used almost everywhere like to purify water systems, in textile, cosmetic, pharmaceutical, agricultural, including food industries for food additive / preservatives, flavorings, colourants. Even used in the production of edible oil with unsaturated fatty acids. This field has advanced a lot and has biocatalysis, surfactants and oil and gas as the initial areas for industry exploitation.





Are there any risks associated with nanotechnology?? Any studies yet on this subject?

[Jean]

Hi Hongyun,





Hope this link will be useful to you, though it is a bit outdated (2004).



http://www.kuehnle.uni-osnabrueck.de/paper/CollSurfA251(2004)53.pdf



http://www2.iesmat.com/Lectura%20recomendada/Productos-FOR/W-O%20nanoemulsion.pdf

[Hongyun]

Hi Jean,

I remembered briefly that there were some questions on health and environment issues while searching for more info, but did not really pay much attention to the links as I was thinking like you. There are many existing food additives like vitamins, coenzyme Q10, Omega-3 fatty acids, etc. which are in nano size and selling in the market right now. So, I assumed they have done the necessary testings to gain FDA approval?

But I'm not so sure on the agricultural, cosmetic and military industries working on nanotechnology...

http://en.wikibooks....f_nanoparticles

Yes, the links have been helpful as I, too, had found them on the net before.

PIT (phase inversion temperature) is a rather new technology for me.. It uses the special properties of the surfactants, changing from O/W to W/O with increasing temperature.

This process thus eliminates the use of mechanical force like high pressure homogenizer and can probably reduce the production cost. Am definitely looking into it, once i find time for more trials...

The other link uses a mixture of SPAN/TWEEN to create nano-sized emulsion. But there may be regulation issues and permitted levels for the use of both surfactants...

[SaRaRa]

Hope those links can be useful:

http://members.ift.o.../0/Nanotech.pdf

http://www.nano.ait....P... A View.pdf

http://www.nanoforum...?11072006040222

http://www.iufost.or...otechnology.pdf

http://www.fda.gov/n.../report2007.pdf

Cheers!

[AS NUR]

Hi guys,

Anyone here knows anything about nanotechnology?

I've been trying to work on oil in water emulsions having oil sizes of less than 0.1 micron... but so far has not been successful.

Major contributors to having good oil size is a good emulsifier/surfactant, and a high pressure homogenizer.

Anyone here have experience with a specific emulsifier/surfactant that can produce nano-sized oil particles?

Dear Hongyun..

IMO.. you have to find emulsifier with function to modification crystal.. such as DATEM or DMG (Distilled monoglycerides).. I use that combine emulsifier to control fat globule size in O/W emulsion...and my fat globule size is ± 0.1 micron..

May be with the correct combination you can control your fat globule size less then .1 micron...

rgds

AS Nur

Note : i use temperature for HIgh pressure process ± 75oC.. that ttemperature can effect to the fat globule too...

[Hongyun]

Hi Sarara,

The links gave a good introduction on Nanotechnology and its application. I believe it will help the community here understand more about this technology.

Hi AS NUR,

Thanks for the recommendation. I understand from other literature that increasing temperature do help in some way. But I don't think I can increase the temperature as the citrus flavor may oxidize or turn rancid very fast...

As for the emulsifier, there is just too much selection and it's very confusing... Gum, Osan starches, sucrose ester, DATEM, lecithin, PGE, etc... And each group are further divided into more sub groups...

I guess it takes a chemist to understand their chemical structure and its compatibility with the product you are going to produce...

[AS NUR]

Hi AS NUR,

Thanks for the recommendation. I understand from other literature that increasing temperature do help in some way. But I don't think I can increase the temperature as the citrus flavor may oxidize or turn rancid very fast...

As for the emulsifier, there is just too much selection and it's very confusing... Gum, Osan starches, sucrose ester, DATEM, lecithin, PGE, etc... And each group are further divided into more sub groups...

I guess it takes a chemist to understand their chemical structure and its compatibility with the product you are going to produce...

Dear Hongyun...

I just make 75oC only ± 4 second before homogenizer.. that can help fat to stay in liquid phase.. and your right the temperature depend on your fat/oil.. and that make easily to break during homo process.. is that temperature with short time can effect significantly to your citrus flavor ?...

IMEX, i using 2 stages homogenizer.. 1st stage is 175 BAR and 2nd stage is 55 BAR.. and i Got the size of fat globule ± 0.1 micron.... That pressure have big effect to fat/oil globule...so i think you have to consider about that too...

And for Emulsifier.. Yes you'r right thats for vegetable fat spray dried products...IMO, some literature state,For Flavor Microencapsulation, usualy using Arabic Gum.. and Siclodextrin as a matrix to covered fat/oil globule...

[Hongyun]

Hi AS NUR,

Citrus flavor usually have very short shelf life like 3 - 6 months and tends to oxidize very quickly because of limonene. To heat up the solution to 75°C before homogenizing will hasten the rate of oxidation. It will also cause some of the top notes (volatiles) to vaporize, thus changing the sensory profile of the intended flavor.

Since the flavor is already in liquid form, we try to minimize any increase in temperature. The current pressure we are using is 150/50 and the result I got was 0.3 micron. I tried 250/50 today and the size went down to 0.1 micron, but I don't think the machine allows me to increase the pressure further as the knob is already very tight and difficult to turn to adjust the pressure...

Next trial for me would be to try out sucrose esters...

You are right about flavor microencapsulation. We usually use modified starches and gum arabic as they act not only as emulsifiers, but they also form films to protect the flavor oil against oxidation.

I am also trying cyclodextrin as I have heard so much about them. But IMO, they are best suited to form complex with ingredients rather than a mixture of flavors.

So much trials to be done and so little time...!

Edited by Hongyun, 11 November 2008 - 12:50 PM.

[AS NUR]

Dear Hongyun..

I think the volatile compound (top notes) will not goingout.. because to increase the temperature we using tubular (or plate) heat exchanger.. the system is close loop...

IMO.. the oxidize will not significantly increase if you increase the temp around 75oC.. that case as same as with poliunsaturated fat that i coated with dextrin and emulsifier.. IMEX the oxidized product will not appear during and after process... and after the study of shelf life that process will not effect to shel life...

thats my opinion..


NOTE : hope you can solve the problem shortly...

[Hongyun]

Oh... no wonder you are not worried about loss of flavors because of closed system.

But for now, our R&D homogenizer is open system. So, we have to heat up the solution externally and pour them into the hopper for homogenization.

Thanks for your concern. But I think this will take some time, as there are shelf life testings to be done before we can introduce the products to customers.

[GMO]

I have a chemistry background although it's a long time ago now! If you use some kind of host like a cyclodextrin to encapsulate the molecules, there is a risk of it being selective for only part of the 'mix' of compounds you will naturally get. So, if you're talking about limonene, it's a terpenoid I think and highly hydrophobic so to encapsulate this, you would ideally need a receptor which has a highly hydrophobic centre.

It depends what you want it for whether that kind of selectivity is a problem it might be useful, especially if you are particularly interested in 'protecting' part of the mix. I think alpha cyclodextrin (6 glucose units) would be the first point to try and as they are composed of natural ingredients, they are more likely to be approved for food use (although I'd check whether they have been, I don't think it can be assumed.)

By the way, if you want to check if encapsulation is happening in solution, from my experience, it's useful to look at the 1H NMR chemical shifts if you have access to a machine and deuterated solvent.

[Hongyun]

Hi GMO,

Yes, there is a risk of selective compounds being complexed by the cyclodextrin (CD), which is not good. That is why I said that they are better off forming complexes with individual chemicals.

Too bad we do not have the machine you mentioned about... The other way to check is to observe the solution when the chemical is added. You will know that the chemical is encapsulated when you see the solution starts to precipitate out. But further testings have to be done to check what is the percentage being encapsulated...

Also, each type of CD (alpha, beta, gamma) has specific affinity to specific structured chemicals. GMO, you have more details on this?

I also tried CD in this case too, thinking maybe it will create nanoemulsion, but alas...

[SaRaRa]

Quick search about CD:

Encyclopedic Handbook of Emulsion Technology

Handbook of Food Preservation

Cyclodextrins and Their Complexes

Multiple Emulsions: Technology and Applications

[Hongyun]

As usual, thanks Sarara for the search results.

[SaRaRa]

[AS NUR]

just continue on NAno tech issue...

Are any body have knowledge in effect and regulation of nanotech to human health.. just chalenge my little knowledge.. if we eat nano structure calcium, that make calcium easily absorbed by our biological system, its possible that have negative effect on our body cause of to fast absorbance process... so what do you think about this ??

[SaRaRa]

Hey,

Just a little reminder on the topic cuz nanotechnlogy really interests me! :P

Nanotech and Agricultural Industry

Do you think that (food) nanotechnology is going to thrive or not? Is there a future in this area?

@ AS NUR: I will try to find more info about the effects that certain nanoparticles have on humans.



Cheers!
Filip