A hypothesis on sugar conversions in toasting

[Michibacy]

I've been researching on WHY toasting makes tobacco so much more pleasant. I've began compiling documents in my office on different temperatures and conversions when heat is applied. I'm sure I'm only touching on the first 1% of this but i don't have a chemistry lab to find the other 99 .

what I have began to see is the ph of tobacco changes as you apply heat, obviously the sugars in tobacco begin to convert at certain temperatures. I believe this is the caramelization of sugar.

Caramelization temperatures
Sugar Temperature
Fructose 110°C, 230°F
Galactose 160°C, 320°F
Glucose 160°C, 320°F
Sucrose 160°C, 320°F
Maltose 180°C, 356°F

to reinforce what others have said on toasting and what I have experienced, toasting at lower temperatures makes a better product. Slowly heating the sugar allows the PH to be easily controlled.

This is is just the beginning of the info I have compiled, with as much research as I am putting into it (and testing ) I think I'll be able to come up with a very effective toasting process.

feel free to post any observations you have noted!

 

[DGBAMA]

Those are huge temps. I never even thought of more than 165F. That seems more like burning than toasting.

Sugar conversion in baccy leaf bears a striking resemblance to conversion of corn to sugar for fermentation a far as temp thresholds are concerned.

Will be interested in your findings.

 

[DonH]

Those are huge temps. I never even thought of more than 165F. That seems more like burning than toasting.

Sugar conversion in baccy leaf bears a striking resemblance to conversion of corn to sugar for fermentation a far as temp thresholds are concerned.

Will be interested in your findings.

I'm pretty sure commercial toasting gets up to 250F. Toasting is different than flue curing where you go to 160 for stem drying. Toasting is done for a much shorter time, more like 20 minutes.

 

[deluxestogie]

Jeremy,
Please provide a citation for any information you copy from another source.

Bob

 

[Michibacy]

My apologies, using my cell phone isn't as efficient as my laptop at typing. The caramelization temps came from Wikipedia.

 

[Nikfits]

My apologies, using my cell phone isn't as efficient as my laptop at typing. The caramelization temps came from Wikipedia.

I once posted a bible study using Xbox (took me about 5 or so hours doing so) - laptop crashed and I buried it in my closet. A cell phone, I'm sure would have been much harder in doing so.

Is this the page from Wikipedia?
http://en.wikipedia.org/wiki/Caramelization

Gary

 

[Michibacy]

Yes it is, thank you for the link!

 

[holyRYO]

I have never heard of toasting flue cured. They "stove" flue cured, a moist cooking process to effect the sugars. Burley has little or no sugars, so not much in the way of carmelization, unless sugar is added. According to something I read by Phillip Morris, toasting burley at 300 F (did not say how long), reduces the nicotine 15 to 20%. Toasting burley baffles me some, anything less than 250 F and less than 45 miniutes has little effect from my trials. I now bake WLT's and BB's, both burley and maryland, at 250 F for 80 minutes, comes out smoother with little reduction in flavor. Attribute this to a reduction in nicotine, but can not prove it.

 

[DonH]

I have never heard of toasting flue cured. They "stove" flue cured, a moist cooking process to effect the sugars. Burley has little or no sugars, so not much in the way of carmelization, unless sugar is added. According to something I read by Phillip Morris, toasting burley at 300 F (did not say how long), reduces the nicotine 15 to 20%. Toasting burley baffles me some, anything less than 250 F and less than 45 miniutes has little effect from my trials. I now bake WLT's and BB's, both burley and maryland, at 250 F for 80 minutes, comes out smoother with little reduction in flavor. Attribute this to a reduction in nicotine, but can not prove it.

I toast flue cured when using it for pipe blends. It tones town the tongue bite you get from flue cured in a pipe.

As for the Burley, before toasting it at 250F I spray it with about a teaspoon of honey in 8 oz water to moisten it before toasting, then toast for 15 minutes, turn it over with a spatula and toast it until bone dry. Then I spray it again after taking it out of the oven. It will definitely smooth out strong Burley. My own homegrown Burley doesn't need toasting for some reason.

 

[chillardbee]

I've been thinking about the sugars in tobacco on the ways they can be converted. Like caramelization with the application of heat as is mentioned here, but there are other ways to convert them as well. Like fermentation useing yeast or bacterial to produce alcohols or catalytic conversion useing enzymes to break down a complex surgar to a simpler sugars. So far, I've seen in the processing of tobacco where all of these have been used whether by it self or in combination. Intresting thing is the the conversion of complex sugars to simple sugars almost doubles the sweetness. For example, Lactose in milk is converted with lactic enzyme and produces an overly sweeted milk (to sweet for me anyway)

 

[Michibacy]

I have no scientific basis for this, but I wonder if the mass of the sugar changes as it melts, such that fructose to caramel or glucose to caramelized glucose condenses the sugar molecules, creating more of a "sweeter" taste. My physics and chemistry might be off in this assumption though.

As a test I will be burning some toasted and untoasted leaf, measuring caloric mass as well as burning temp (that will tell us which sugars are present before and after)

 

[istanbulin]

Wikipedia says,

"Wet caramels" made by heating sucrose and water instead of sucrose alone produce their own invert sugar due to thermal reaction

Invert sugar is sweeter than glucose.

You may find more here;
http://www.fao.org/WAIRdocs/x5434e/x5434e0a.htm

When a sugar solution is heated, a certain percentage of sucrose breaks down to form 'invert sugar'. This invert sugar inhibits sucrose crystallization and increases the overall concentration of sugars in the mixture. This natural process of inversion, however, makes it difficult to accurately assess the degree of invert sugar that will be produced.

I guess this inversion only occurs when sugar solution is used. When sugar is used alone for caramelization (without water) it may lose its sweetness due to decomposition of existing sugar and formation of new compounds.

 

[leverhead]

....My own homegrown Burley doesn't need toasting for some reason.

What variety is it?

 

[Jitterbugdude]

I've been researching on WHY toasting makes tobacco so much more pleasant.

It is really quite simple. When the sugars are burned (either natural sugar in the leaf, or added sugar) it lowers the pH of the tobacco. with a lower pH the nicotine becomes bound. Bound nicotine does not have the harshness (impact) that free base nicotine has. There are 2 types of sugars used by industry, Reducing Sugars (Glucose, Fructose and Invert Sucrose) and Non Reducing Sugars( Sucrose). Non reducing sugars ae more chemically reactive than reducing sugars. This allows Industry to use a combination of both to obtain the results they are looking for. Some of these reducing sugars act with the free amino acids of the tobacco or other flavoring substances. This produces a very uniquely flavored tobacco.

Another way Industry can lower the impact of tobacco smoke is to use acids (such as acetic, citric etc) on tobacco that is low in sugar like Burley. The acid has the same effect of lowering the pH thus lowering the impact to the throat. Acids won't produce the specific flavors that one would get by having the reducing sugars react with the free form amino acids.

So it appears to me that toasting increasing the smoothness and flavor because the sugars added reduce the impact (smoothness) and reacting the sugars with something like cocoa causes an interaction between the sugar and amino acids that increases the flavor.

 

[holyRYO]

Another way Industry can lower the impact of tobacco smoke is to use acids (such as acetic, citric etc) on tobacco that is low in sugar like Burley. The acid has the same effect of lowering the pH thus lowering the impact to the throat. Acids won't produce the specific flavors that one would get by having the reducing sugars react with the free form amino acids.

I made invert sugar once. Boiled sugar water with lemon juice, was surprised at how bad it tasted, attributed taste to the high PH. Based on the theory that both acid and sugar smooth burley, will have to revist making more as a casing. Commercial invert sugar is "nuetralized", I suppose to improve the taste in other applications like food.

 

[Jitterbugdude]

Maybe the bad taste came from using lemon juice? You can also make it with cream of tarter or just buy Invertase and add it to sugar water.

 

[DonH]

What variety is it?

In 2012 it was TN90. That year I primed them which may have made it smoother. This past year I grew TN90, Harrow Velvet, Kelly Burley, and Yellow Twist Bud and stalk cured most or it. Not as smooth as the 2012 but that could be because of the aging. Also, since I didn't get a kiln until last year, it got great results kilning my 2012 Burley and VBL for just one week, since it had already aged for a year.

 

[holyRYO]

Maybe the bad taste came from using lemon juice? You can also make it with cream of tarter or just buy Invertase and add it to sugar water.

The stuff I made, I think the bad taste came from the lemon juice (acid), impression was from tasting the raw invert sugar (how can something made from sugar taste bad?). Even though, it may work when smoked on tobacco, was not that bad, can see it working on burley.

 

[chillardbee]

I made some invert sugar for my tobacco (OK, I made a lot) because in the JTI ingredients list, it calls for it. I was trying to source some out but found out along the way that it was a whole lot simpler and cheaper to make. The recipe I found calls for 2 grams of citric acid, 8 cups of white granulated cane sugar (sucrose), 2 cups of water. Combine all ingredients and heat to a boil then reduce to a simmer 30 minutes stirring constantly. I did this and what I got was a very thick (perhaps 9% moisture) sirup that was water white, very sweet but not in the same way as sucrose. It is now just starting to granulate but the crystals are different then what you'd get from regular sucrose. In fact, the crystals look more like dextrose derived.

In everything I've read about it, invert sugar is a mixture of fructose and glucose caused by the splitting of sucrose into these components.

here is a recipe I think i'll try for the next batch using the citric acid.

http://www.chefeddy.com/2009/11/invert-sugar/

Will

 

[Jitterbugdude]

In everything I've read about it, invert sugar is a mixture of fructose and glucose caused by the splitting of sucrose into these components.
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And that's why you can probably just use honey. Honey is a mix of Fructose and Glucose, depending on the floral source the ratios vary.
If making invert sugar you can also use cream of tarter. Basically anything that is acidic. If making it for beas you should use Invertase because the acid conversion( citric, cream of tarter etc) has been implicated too many times to negatively affect the bees health.