Raspberry flavour

The supermarket where I buy much of my shopping do an interesting line in budget cakes. Some of them are really poor quality, but others are not so bad and they are ideal for over-running grad students! I quite like the Raspberry Flavour Tarts. These are jam tarts with red jam and they do taste of raspberry BUT the ingredients listing makes it clear that they have never so much as waved to a raspberry from a distance. There is some apple as well as the usual gelling agents and preservatives and that old stalwart glucose-fructose syrup, but the flavour comes from just 'flavouring'. Today I've discovered what this mystery compound probably is.

Meet 'raspberry ketone' aka 'rheosmin' aka 4-(4-hydroxyphenyl)butan-2-one.

Apparently this is what they add to get a raspberry flavour. Being a good synthetic chemist it doesn't bother me in the least that chemicals are added to my food, since I'm well aware that 'natural' ingredients are just cocktails of chemicals anyway. I do, however, still find it fascinating that such a small molecule can give rise to such a distinctive taste. It's a 10-carbon unit and hence probably a biosynthetically produced as a monoterpene with post-condensational aromatisation.

A little gentle googling informs me that it's a white crystalline solid (though if I made it I'd probably end up with a yellow oil!), it is insoluble in water (but soluble in fats and alcohols) and the taste threshold is 40 ppm. It is apparently a major component of real raspberries (Rubus idaeus) and has been shown to be an effective anti-obesity drug - which seems like a good excuse to keep eating cake!

Next time you see 'Raspberry Flavour', think raspberry ketone!

Autumn has arrived!

It's been feeling really rather like summer this past week in Oxford, though in the evenings there has been a coolness in the air and birds have started flocking. However I've woken up this morning to find really thick mist shrowding us in Botley - I can't see the far side of the crescent.

I suppose that Keats is responsible for the association between mists and autumn, since as a meterological phenomena, they happen all year round. I'm not a huge Keats fan, but I do like To Autumn (and also La Belle Dame Sans Merci). For those of you that aren't familiar with it, To Autumn starts like this:

Season of mists and mellow fruitfulness!
Close bosom-friend of the maturing sun;
Conspiring with him how to load and bless
With fruit the vines that round the thatch-eaves run;
To bend with apples the moss'd cottage-trees,
And fill all fruit with ripeness to the core;
To swell the gourd, and plump the hazel shells
With a sweet kernell to set budding more,
And still more, later flowers for the bees,
Until they think warm days will never cease,
For summer has o'er brimmed their clammy cells.


Yes, I rather like it.


The oak leaves on the tree opposite my window are starting to turn too: 'Summer's lease hath all too short a date', as Shakespeare has it.

That's probably enough literature for this time on a Sunday morning. Suffice to say that I have decided that it's now officially autumn as far as I'm concerned.

I used to really like autumn above the other seasons, but as I've grown older I've come to appreciate the stark beauty of winter (even in the absence of snow), the freshness of spring, even the heat of the summer - my affection for autumn is now matched with an admiration for the rest of the year, which I consider to be something of a blessing, since each year will inevitablty expose me to all four!