Food science questions...

[Azbubu]

My girl-friend is on a mostly vegetable soup diet (she has it for breakfast and lunch, and then meat and veggies for supper - no bread, rice or pasta) I must confess that it's working for her and she has lost a lot of weight and is looking v sexy! The problem is that the soup makes her very gassy. I tried for 2 days and indeed I was gassy also. What gives?

So your problem is no putting in the poopah?

 

[DJ...]

Depends on what's in the soup. Problem is many vegetables contain sugars called verbascose, raffinose and stachiose which are not metabolised by our human metabolisms. This means that bacteria in our gut have a field day with these sugars as they pass through us and simply never really break down properly. A by-product of this bacterial reaction is gas - a lot of it. Other vegetables contain various polysaccharides that undergo a similar process in the gut and release some seriously wafty gases. Vegetables simply make us fart, because as omnivores, we need to be able to break down meat, and if we could break down some of these polysaccharides, we wouldn't be able to as effectively break down meat...

 

[blunomore]

To the OP: Is there any food science question that YOU are battling with ?

 

[unskinnybob]

No need to worry about that. If they follow that diet, they'll die young enough to avoid the new species entirely...

I find your lack in faith disturbing. Our earliest ancestors were herbivores. Our distant forefathers made the great transition from herbivore to omnivore. If we quit now, we're a disgrace to our future species man!

 

[DJ...]

To the OP: Is there any food science question that YOU are battling with ?

Well I'm currently struggling through cold extrusion methods of lupins to obtain fibrous textures. My struggle is in trying to identify the role of steam in creating fibrous protein strands. If someone can explain this to me I'd greatly appreciate it. My problem here is in the role of water retention in attaining the necessary protein bonds...

 

[blunomore]

Well I'm currently struggling through cold extrusion methods of lupins to obtain fibrous textures. My struggle is in trying to identify the role of steam in creating fibrous protein strands. If someone can explain this to me I'd greatly appreciate it. My problem here is in the role of water retention in attaining the necessary protein bonds...

Hey, have you noticed we battle with THE BASICS here .... how to oven bake salmon and how to store biltong?

 

[DJ...]

Hey, have you noticed we battle with THE BASICS here .... how to oven bake salmon and how to store biltong?

So if I understand you correctly, you mean to say that the slow reduction of heat under pressure results in no steam loss, which reverts the pressure into the protein structures to bond with each other. Thanks. But my issue is understanding their propensity to link in long chains to replicate fibrous structures. Maybe you can go into more depth?

 

[370z]

You should get a medal for this thread.

Not sure if you can answer this as its more health related. I have one of those Phillips Air Fryer machines. Is there a huge health benefit using it? The food is a bit less tasty than usual but if its making me much healthier, I'm not gonna complain

 

[blunomore]

So if I understand you correctly, you mean to say that the slow reduction of heat under pressure results in no steam loss, which reverts the pressure into the protein structures to bond with each other. Thanks. But my issue is understanding their propensity to link in long chains to replicate fibrous structures. Maybe you can go into more depth?

As soon as my issues with Vodacom are sorted, I will try to help with this

 

[DJ...]

You should get a medal for this thread.

Not sure if you can answer this as its more health related. I have one of those Phillips Air Fryer machines. Is there a huge health benefit using it? The food is a bit less tasty than usual but if its making me much healthier, I'm not gonna complain

LOL. I was just discussing this today in a separate thread. Here it is - http://mybroadband.co.za/vb/showthr...to-make-them?p=8783689&viewfull=1#post8783689

I personally think that they're mostly bullschit, if you already own a convection oven. The science backs me up. Other people love what the marketers feed them...

 

[370z]

Thanks!

 

[lived666]

I personally think that they're mostly bullschit, if you already own a convection oven. The science backs me up. Other people love what the marketers feed them...

See you are stubborn, its nothing to do with marketing, you just set in certain ways and that’s it, not a train smash, some people are just stubborn.
One day when you near a Philips air fryer try and make some buffalo wings sans oil, just a dry rub of your choice which will only take you 15 - 20 minutes as compared to about 40 in a convection oven, and the flavour and texture will be completely different, its all in the science dude.

but lets not side track, do you have any science tip on making hummus dip which I'm busy making right now - I soaked my garbanzo beans in water overnight with a pinch of baking soda as what’s his name said, that weird dude from the food channel and now I'm busy slow cooking them in water to soften and in a couple of hours will get to the hummus, smell is awesome.

The science I hear is to first mix the tahini with the lemon juice as some molecular thingy happens
Then to crush the garbanzos and then to mix the two, any science tips here welcome, I like my hummus extra creamy and yummy

 

[DJ...]

See you are stubborn, its nothing to do with marketing, you just set in certain ways and that’s it, not a train smash, some people are just stubborn.
One day when you near a Philips air fryer try and make some buffalo wings sans oil, just a dry rub of your choice which will only take you 15 - 20 minutes as compared to about 40 in a convection oven, and the flavour and texture will be completely different, its all in the science dude.

I have used the air fryer sans oil for chicken. Cooks it really well. No different to my convection oven. The fat in chicken skin is sufficient to cook them with no added oil. Try do the same thing with a fish fillet and you'll land up with a rubbery texture. The same applies to skinless chicken breasts. Like I said, my only gripe is that it is a convection oven that is marketed as an air fryer. It is simply a small convection oven, and the saving in electricity will never cover the cost of the thing, if you already own a convection oven. They are a gimmick in that sense...

but lets not side track, do you have any science tip on making hummus dip which I'm busy making right now - I soaked my garbanzo beans in water overnight with a pinch of baking soda as what’s his name said, that weird dude from the food channel and now I'm busy slow cooking them in water to soften and in a couple of hours will get to the hummus, smell is awesome.

The science I hear is to first mix the tahini with the lemon juice as some molecular thingy happens
Then to crush the garbanzos and then to mix the two, any science tips here welcome, I like my hummus extra creamy and yummy

I don't buy into the subsequent processes involved in making hummus, apart from getting the beans right and to add any oil after pulsing in the food processor quite a few times already. You have to cook them low and slow for hummus and the soak in baking soda isn't necessary if you're making hummus. Just chuck them in a pressure cooker for a few hours or cook them longer in a pot at a low temperature, topping up water when necessary. I can't see what sciency thing would take place between the lemon juice and tahini. There are no proteins to break down there.

My tip here is to use a little lemon zest as well, to roast an extra few garlic cloves beforehand as well and add them, and to make sure you get the seasoning right - pinch by pinch add the salt.

If you want an extra creamy hummus then you need to cook the beans for an age. You need to blitz the beans for quite a while before adding any additional oil. And then don't blitz for too long after you've added the oil or it emulsifies too far and becomes gloopy...

 

[lived666]

I don't buy into the subsequent processes involved in making hummus, apart from getting the beans right and to add any oil after pulsing in the food processor quite a few times already. You have to cook them low and slow for hummus and the soak in baking soda isn't necessary if you're making hummus. Just chuck them in a pressure cooker for a few hours or cook them longer in a pot at a low temperature, topping up water when necessary. I can't see what sciency thing would take place between the lemon juice and tahini. There are no proteins to break down there.

My tip here is to use a little lemon zest as well, to roast an extra few garlic cloves beforehand as well and add them, and to make sure you get the seasoning right - pinch by pinch add the salt.

If you want an extra creamy hummus then you need to cook the beans for an age. You need to blitz the beans for quite a while before adding any additional oil. And then don't blitz for too long after you've added the oil or it emulsifies too far and becomes gloopy...

I am really trying to perfect my hummus, I am almost at Israeli standards. I don't add any oil though, I try and avoid oil where possible, hence we end up chatting about the air fryer.

Re the science and tahini, from online:

The secret to good hummus, and the difference between hummus and chickpea mash, is to understand what is really going on with the tahini.What is milk? Milk is generally an emulsion of protein and fat in a water-based liquid. An emulsion is when you mix one liquid into another that don't generally mix, like oil and water when you make salad dressing. They're not dissolving into each other, but the little molecules of one are suspended in the other.
For dairy milk, it's an emulsion of animal protein, fats, lactose, etc. For soy milk and nut milk, it's the same thing, but now it's nut proteins and oils. But in all cases, the emulsion is where the creaminess comes from in "milk". If you have less water, you call it cream (either dairy cream or nut creams).
Tahini is sesame butter, and to make creamy hummus, the secret is to first turn that into sesame cream! To do that, you need to emulsify the tahini in a water based liquid first. This will not happen if you just put everything into a food processor all at once!'

I usually use citric acid instead of lemon juice, its less lemongy but still with the tang. I have also imported my tahini from Israel, I wanted some palestinian tahini from Nablus but alas didnt happen, even though its just crushed sesame not all tahinis are made equal, who knows why?

 

[DJ...]

There is enough water in the chick peas to emulsify the tahini with, but the secret to creamy tahini is the way the chick peas are cooked, not the emulsification, which will happen regardless in the blender. And you really need lemon juice imo - it adds that earthy citrus flavour inherent in all good tahinis. I personally love the stuff. You will also often need oil as it can be very tight once it begins to emulsify - oils are not as bad for you as people are led to believe. Hydrogenated oils can be bad but natural seed oils, in the quantity you're discussing are perfectly good for you and in fact contain numerous nutritious properties...

 

[chrisc]

Have a Hostess milk frother which has a rotation tool and warmer. Pour about 100 ml milk in. 70% of the time the milk froths perfectly, 25% of the time about 1/2 the milk froths and sometimes there is no froth at all. Always use 2% milk but it makes no difference if milk is fresh or not. Of course its all homogenised milk

 

[DJ...]

Have a Hostess milk frother which has a rotation tool and warmer. Pour about 100 ml milk in. 70% of the time the milk froths perfectly, 25% of the time about 1/2 the milk froths and sometimes there is no froth at all. Always use 2% milk but it makes no difference if milk is fresh or not. Of course its all homogenised milk

I'll quote myself from a previous post from abzo's thread - it should answer your question:

Yes you can, however how long the bubbles remain is the important question - this known as foam stability and the science stems from my favourite pass-time - beer making. You can frothy water for a few seconds too but the foam is incredibly unstable. This has been the basis for much food science work and basically it revolves around fats, gases, proteins, sugars etc present in the liquid and in what quantities however the most important aspect is the protein. When mixed, proteins entangle and encase each other (known as electrostatic interaction and denaturing) into bubbles, which is why whisking egg whites forms such a stable foam. It's these protein bonds which produce a decent foam. The more protein, the better the foam.

Now foam will collapse in on itself in the presence of lipids - fat is a lipid which explains why skim milk foams much better than full cream milk - because it has a better ratio of proteins to lipids. However a little bit of fat does help to create a stable foam in some cases but that gets rather complex to explain.

The other thing to think about is temperature. Room temperature liquids will create a foam much better than very cold liquids because at room temperature and higher, the proteins are already unravelling themselves. Lastly for tonight's science lesson, if you're trying to whip up a mixture that has sugar in it it will be rather difficult because sugar is hygroscopic, which means that it attracts and holds on to water molecules. These water molecules get in the way of the proteins and prevent them from foaming up. This is why when you beat egg whites or creams you always add the sugar towards the end of the process.

Hope this little bit of science helps you out...

Oh and btw, if you want to froth up some stuff very easily just add one leaf of gelatin to the mix and stir it in thoroughly. The mixture will foam brilliantly. You need to make sure that you soak the leaf gelatin in cold water though and then add it to warm mixtures to dissolve. Otherwise if the mixture is cold, then soak the gelatin in cold water, then mix it into a small amount of the mixture you have that has been heated up, then add that mix to the cold mixture while stirring constantly...

 

[blunomore]

Can DJ - or any one else - tell me if it is a problem using eggs that are slightly over their "best before" date?

 

[OMB]

Can DJ - or any one else - tell me if it is a problem using eggs that are slightly over their "best before" date?

define slightly?

food producers usually build in a safety factor in their best before dates

however if you want to check if an egg is ok, just put it in a bowl of cold water about twice the depth of the egg and see if it sinks or floats, if it sits on the bottom of the bowl then it's still ok

 

[Gielie Geelmielie]

How to...

1.) Prawns in a pan or any other way?
2.) Calamari steak.

The prawns I am getting sort of right, Calamari steak is a tough disaster every time.