Thursday, May 7, 2015

07/05/2015: Beer & Seafood R&D: For those used to the finer things in life.... does the perfect pairing of freshly cooked lobster with a cool beer sound, especially as we head into the warmer summer months?

By Karen Wilson, PhD 

Making sure the beer is a pilsner, IPA or Belgian witbier of course, to balance the citrus notes and stand up to the meaty texture of the lobster.

Sounds exquisite, doesn’t it? Well, some recent research news may change your perception of such delicacies, and make you think more deeply about the wonder of nature.

A multinational team of scientists has recently attempted to explain the colour change mechanism from dark blue to orange when a lobster is cooked. The dark blue colour arises from an astaxanthin-crustacyanin protein complex.

Crustacyanin is not heat-stable, so denatures when cooked and releases unbound astaxanthin (an orange colour). Spectroscopic studies, paired with quantum chemical calculations used to reproduce the experimental observations, determined that the crustacyanin protein-bound astaxanthin exists in its negatively charged enolate ion state, blue in colour.
Image: m o
Once subjected to heat, the enolate inion bathochromically shifts (i.e. the spectral band position changes to a longer wavelength) from the neutral α-crustacyanin, to give the colour shift from blue to orange. Interestingly, an estimated 1 in 100 million lobsters are albino (compared with the rare blue lobster – 1 in 2 million, and yellow lobster – 1 in 30 million). Without any astaxanthin pigment in its shell, an albino lobster is the only lobster species that does not change colour when cooked.
And just when you were thinking I’d forgotten about that beer, spare a thought for the amount of work Finnish and German researchers have put into analysing samples of a 170-year old beer recovered from a shipwreck in the Baltic Sea, in a bid to uncover its composition and how it was made. Physicochemical characteristics and flavour compound profiles were analysed using high performance liquid chromatography (HPLC) and gas chromatography-mass spectroscopy (GC-MS). It was noted that extensive degradation had taken place, as well as the beer being diluted with seawater.
Image: Quinn Dombrowski
Optical and electron microscopy revealed numerous bacteria present, producing organic acids that gave the beer a vinegary, soured milk flavour. Despite the degradation, high levels of beta acids were measured, typical of older hop varieties, and the presence of glucose (which would normally be fermented out) suggested addition for sweetness. An absence of Pad1 enzyme, typically used in wheat beers, suggested that the yeast used was domesticated and not wild. 

The research was enough to pass to Stallhagen brewery in Finland, to recreate the beer (albeit without the degradation qualities!), and ‘1843 beer’ can now found on the supermarket shelves of Finland.

Visit the R&D news site HERE.

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