Wednesday, 11 January 2012

Baking with Light at Heart

I think we all know that it's difficult to reconcile a love of cakes, pastries, cookies and chocolate with healthy eating and even more difficult for some of us to keep a steady weight, let alone lose weight while eating these regularly. There are things we can do to make baked goods a little healthier - reduce saturated fat, use wholemeal flour, add fresh fruit and vegetables, and so on, but these tweaks don't really address the issue of calorie intake.

Now Tate and Lyle have introduced a new product called Light at Heart which may be able to help - it's a mix of sugar and stevia. Stevia is a plant extract which is so sweet that even though only only 1% is added to ordinary sugar, it makes it so sweet that only half as much is needed, thus cutting the calories contributed by sugar by half too. It is available in brown and white varieties, and Tate and Lyle claim it can be used in baking, as well as a substitute for sugar in things like drinks and on cereals. I think it's ingenious of Tate and Lyle to adjust the use of stevia so that exactly half the usual amount of sugar is needed - easy to remember!

When I was offered free samples of Light at Heart, I was only too happy to try them, even though it's not the sort of product I would usually consider buying. However, I had doubts that it would be suitable for every baking situation, as much of the success of a cake depends on the amount of sugar used. Sugar contributes to moistness, texture and volume when used in cakes, as well as sweetness, and I've read that you can only reduce the sugar by 20-25% before these are affected. Cutting it by 50% seemed a big step to take!

Left-hand cake baked with Light at Heart
I decided the best way of comparing the use of sugar and Light at Heart was to do a side by side bake of two cakes, where the only difference was whether sugar or Light at Heart was used. I picked an oil-based sponge recipe which is simple and quick to mix. This enabled the cakes to be mixed side by side in just a few minutes. Each was then baked in a 10 x 5" rectangle - two halves of a 10" square tin.

There were no other factors affecting the cakes apart from the use of either sugar or Light at Heart.

Each cake was made by whisking 120ml sunflower oil, 2 eggs, 70ml semi-skimmed milk, the zest of half an orange and 1 teaspoon of orange extract together with either 180g caster sugar or 90g Light at Heart, until well amalgamated. Then 180g plain flour and 1 rounded teaspoon baking powder was sifted in and whisked just enough to give a smooth mixture with no flour showing. The cakes were baked at 190C for 30 minutes, when a test probe came out clean.

Left-hand cake baked with Light at Heart
It was obvious as soon as the cakes were baked that there was a significant difference between the two. The cake using Light at Heart didn't rise as much and was paler, with a speckled unevenly coloured surface. When the cold cakes were cut, there didn't seem much visible difference between the two, apart from the volume, but the cake made with Light at Heart seemed a little drier when eaten. The speckling was due to the Light at Heart having larger crystals than caster sugar - it was more like granulated sugar, which I don't usually use in baking.

These differences aren't great, and if you really want to reduce calorie intake and still eat cakes, then you might be able to overlook them and be happy with cakes baked with Light at Heart. I'm not sure you'll be able to overlook the price difference though - Light at Heart costs around £2.50 for 500g which makes it about 4 times more expensive than sugar.

Left-hand cake baked with Light at Heart
I'm going to try Light at Heart in other baking situations, where I think it might be more succesful. The issue of volume and texture isn't as important in things like pastry and crumble toppings, where sugar is used mainly for it's sweetness. I'm hoping that using Light in Heart in cookies will be successful too. However, I don't think I'll be using Light at Heart in cakes where lightness, moistness and volume are important.


Kavey said...

Very useful experiment, thanks for the helpful write up.

How did you find the taste?

I remember trying Stevia in liquid form several years ago and found the after taste deeply unpleasant. Is this something that still comes through or have they found a way of minimising that?

Suelle said...

Hi Kavey, I didn't notice any difference in flavour between the two cakes, or any aftertaste from the stevia, so perhaps the men in white suits have been working on the problem. This is the first time I've tried stevia in any form.

Foodycat said...

Kavey, that was my question too! The only time I used stevia it was horrible! Really put me off this Light at Heart stuff.

My verification word is PRICE. Seems apt.

Choclette said...

Oh well done Suelle, this is really useful. The volume issue has always been my problem with using other forms of sweetener in a cake. Rapadura is the best one as you use the same amount, but it is meant to be healthier than sugar, but it is very expensive. I didn't know we now had stevia back in the UK - it was banned a few years ago and we were unable to buy it anymore. Luckily, we can grow it and we do, but we use it in it's leaf form for sweetening fruit where looks don't matter, tomato sauces etc I've not had any problem with nasty aftertastes though.

Suelle said...

Hi Choclette. Interesting that you grow stevia!

I don't think I would class rapadura as a sugar substitute in the same way as artificial sweeteners or stevia, as it must have the same calorific content as ordinary sugar.

C said...

Very interesting comparison, good to see the two cakes side by side. There really is quite a marked difference in the volume of the cakes, which I suppose is unsurprising really.

Good to know that there isn't really any aftertaste though.