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Tuesday 29 August 2017

A tender moment – Part 1

One somewhat odd disadvantage of living in rural France is, quite honestly, the extreme freshness of much of the produce. 
A tender moment – Part 1
A piece of raw ribeye steak. Photo: VisualHunt/YourBestDigs
Wherever possible, we like to get our food from local markets and organic stalls (or we sometimes pick the fruits directly from trees and bushes during the seasons) – this means great greens and fruits, though the downside is that we have to eat the stuff quickly before they go off due to the (mostly) untreated nature of the produce.
Not having a huge freezer means we cannot order a side of beef or lamb from a farmer – so this means weekly trips by car to get meats from the butcher in the next village.
Sometimes, I prefer walking the distance of 5.5km each way there and back with a chiller bag in the rucksack – the scenery is lovely and the 11km walk is often exhilarating (though one has to watch out for snakes in summer) while anticipating the taste of homemade pates, sausages, rillettes de porc and other stuff on arrival home.
The bummer is that the butcher gets his meat fresh from local farms and this means his beef is not really that aged.
Eating fresh beef is generally not terribly enjoyable as the muscle structure of beef tends to be tough, even for steak cuts like tenderloin, and therefore beef generally needs ageing to soften it – the ageing process also develops the delicious flavours of meat.
Most of the local beef here in my rural part of France is aged for only a couple of weeks or less before sale – and this explains why dishes based on local beef are often stews cooked for hours to soften the muscle tissues. This is quite regrettable as I usually dislike such overcooked meat.
A meat ageing cellar. Beef generally needs ageing to soften it – the ageing process also develops
the delicious flavours of meat. Photo: VisualHunt/Dottorpeni












There is of course very good aged beef available in France, but for me this involves a 50km trip to a big, sprawling town – and although I like beef, I do not enjoy doing a 100km round trip to pay three or four times the price for a piece of meat.
Also, I am not such an ardent, picky gourmet that making such a trip makes sense, especially if there is some scientific way to make fresh local beef taste better.

The breed matters

Having lived in London for many years, my preferred steaks there are rib-eyes and they tend to come from Angus cattle bred mostly in Scotland – they are succulent, flavourful with a good balance of fat and meat.
Travelling around Europe meant tasting awesome breeds like Chianina, Simmental and Charolais – all stunningly delicious meats, though the best beef in Europe might be the massive rib-eyes called chuletón from the Rubia Gallega cattle in the Basque region of Spain.
And then of course, there is the ubiquitous wagyu beef (derived from various breeds), originally from Kobe, Japan and now also other countries – very fine meat but perhaps a little too precious for me.
What defines good beef? Apart from breed, there is a very strong link between how long meat has been aged after slaughter and the taste. Photo: VisualHunt/BrownGuacamole

Clearly, the genetics of the various breeds matter very much and therefore good tasting beef is not only just about ageing.
So to clarify the situation, the aim of this investigation is to examine ways to maximise the best texture and flavour from any breed in the shortest possible time.
In this case, the breed available at my local butcher is Limousin supplied from farms close to the region – a good enough breed but perhaps not the finest in the world for dining. Better results may well be achieved if I had access to Chianina or Angus – but I do not.

A little aside about consumption

Although it might sound like a trifling first world problem quibbling about the taste of beef, in reality the simple life here is reasonably pleasant – and I am just curious about the biochemistry of how to make steaks better.
However, even here it can be seen that the global culture of consumerism seems very much based on keeping people profoundly but vaguely discontented.
The unstated insidious intent appears to be keeping people distractedly dissatisfied – wearing down our scepticism and resistance until we finally buy the glitzy products or unnecessary artifices marketed on TV, newspapers, magazines, the internet, et cetera.
Then we find that such goods are pointless (perhaps even somewhat unhealthy), can never fulfil our expectations – and then we feel even more disenchanted and need to buy something else to compensate.
Living in a remote area does help to quantify things as it is simple to use distance as a measure of marginal utility or desirability – thus far, it has never been worth travelling 50km to eat fried chicken or a burger, though I might eat fried chicken once every few months if there is a shop less than 100m from home.
The irony of course is that I would probably never want to live in such a place – but we are just talking abstract quantification here.
The same unsatisfactory situation is also true with nutrition – the constant bombardment of “health news” keeps people confused, anxious and desirous of “better nutrition” solutions, notwithstanding the probability that over 85% of such “news” is actually sponsored in one way or another by various factions of the food industry.
I suppose the idea is to keep people muddled enough to keep ingesting bad food while simultaneously persuading them to buy expensive “healthier” options. Either way people just end up consuming more – and that seems to be the only thing that matters.

Firstly, what is meat?

Returning to the subject, the desire for good meat got me looking into what defines good beef – and apart from breed, there is a very strong link between how long meat has been aged after slaughter and the price (and therefore by implication the taste).
So it makes sense to find out what happens when beef is left to age after slaughter and also to investigate if there are any scientific tricks to get the same tasty aged effect using the limited resources available in a rural setting. This soon got very fascinating indeed.
We need to start with understanding what meat really is – we all know it is muscle tissue of some kind and it would be useful to know about the types of muscles and how they work.
image: http://www1.star2.com/wp-content/uploads/2017/08/str2_curious130817_jg_5.jpg

Basic structure of skeletal muscle.
Muscle cells are known as myocytes – they range from several millimetres to over 10cm in length and between 10 to 100 micrometres in width. There are three kinds of muscles: smooth muscle, cardiac muscle and skeletal muscle – and each have very different functions.
Smooth muscle is usually managed autonomously; that is, without any conscious effort, and examples are the stomach and intestines. Cardiac muscle is another specialised muscle found in the myocardium of the heart – and it fortunately also functions autonomously as otherwise mammals would have to continuously think about making their hearts beat, even while sleeping.
The only muscles over which mammals can exert control are the skeletal muscles – which are the muscles mammals use to walk, run, chew, swim, climb trees, et cetera. They are also usually the animal muscle (meat) that humans generally prefer to eat so this is what we will focus on.
Muscles in almost all vertebrates are formed of myofibrils and sarcomeres. Myofibrils are strands of muscle fibres made up of alternate thin and thick filaments called myofilaments which are repeated as patterns of muscle tissue along the whole length of the muscle fibre.
The thin myofilaments are mostly made up of a protein called actin bound into little columns by another protein called nebulin. Integral to the thin filaments are also the proteins tropomyosin and a complex group of three proteins known as troponin – more on this a little later.
The thick myofilaments consist mainly of a protein called myosin which in turn is interlaced with another protein titin.
As mentioned, thin and thick strands of myofilaments overlap and alternate with each other along a single myofibril. Groups of myofibrils in turn are organised so that they all have their thin and thick sections of myofilaments aligned in the same direction – this gives rise to the pattern of light and dark bands seen in muscle tissue under a microscope.
Each sub-section between two dark bands (known as Z lines) is known as a sarcomere. There is also the M line, which is a ring of myomesin proteins encircling the middle sections of thick myofilaments.
Large groupings of myofibrils (with their thin and thick myofilaments) become known as muscle tissue or meat.
Skeletal muscles work due to changes in intracellular levels of calcium in the tissues – in short, muscles contract when the levels of calcium increase and muscles relax when the calcium levels drop.
How muscles contract starts with calcium binding to various proteins in the troponin group (troponin C, troponin T and troponin I) in the thin myofilaments – this then triggers three almost simultaneous reactions.
The first calcium reaction affects troponin C which then activates and changes the configuration of troponin I, making it ready to bind with actin.
The next reaction binds troponin T to tropomyosin, forming an interlocking troponin-tropomyosin structure – the tropomyosin protein is also bound to the myosin in the thick myofilament.
The last reaction finally binds the troponin I protein from the first reaction to actin in the thin myofilament which then connects with the troponin-tropomyosin structure.
The net effect is myosin proteins are induced to slide along actin proteins, and therefore the entire sarcomere contracts in size – this happens in the A zone and I band regions in the diagram (right).
The H zone is the anchor part of the sarcomere where there are only thick myofilaments – the myosin proteins in the H zone are mostly covered by actin during contraction.
Note both thin and thick myofilaments do not change in size – the sarcomere is shortened because of the lateral movement of the thick myofilaments through the thin myofilaments and the overall range of muscle contraction is multiplied by the number of sarcomeres in the strands of muscle tissue.
The contraction span of any sarcomere is the difference of the A bands and I bands narrowing from their original lengths. The titin protein attached to the thick myofilament is very stretchable, appears to provide additional elasticity to the sarcomere and probably also act as a guidance mechanism for the myosin – as an aside, titin in the largest protein in the human body consisting of 244 folded proteins.

The simple way

So we now know about muscle proteins and how they are organised in the meat we eat. One very simple suggestion to soften such meat therefore would be to use a meat hammer to disrupt the integrity of the sarcomeres as shattering the organised (and tough) protein configurations can only make meat more tender.
And this is exactly why cooks pound meat with jagged-edge mallets. For example, pieces of pork or veal to make schnitzels and chicken breast meat to make chicken steaks.




Grinding and mincing meat would also be another simple way to soften meat; for example, ground pork for meatballs or sausage fillings.
Therefore, at least two simple solutions exist (pounding and mincing) to tenderise meat very quickly. However, disrupting the configuration of meat proteins in such a violent manner also changes the texture emphatically so although I do often pound pieces of meat at home, this can be unsatisfactory after a while as the resulting meat often tastes a little rough.
Also, this pounding technique does not work for all cuts of meat, especially the finer beef cuts which can dry out and roughen during cooking when pounded beforehand.
However, this technique does work to some extent on tough cuts like rectus abdominus (flank), longissimus dorsi (chuck), superficial pectoral (brisket), et cetera – as long as the meat is cut initially into thin (around 1cm) slices. Pound hard and sensibly, as you need to disrupt the tough sarcomere structures significantly (but not to the point of destruction and mushiness) – and cook quickly.
Regardless, my opinion is that if time and conditions permit, many people would probably, and at least occasionally, prefer to eat properly aged beef steak. Please note that there are interesting techniques to considerably accelerate the ageing of meat – more on this later.

The ageing of beef

Traditionally, beef is aged by hanging the carcass in a cold room or resting the meat on a slab of salt in a chiller for between 28 to up to 459 days – yes, you can get served beef that has been aged over a year and a quarter in the United States, though in Europe the most extreme beef is usually only aged half a year or so.
Such severely aged beef is always from grain-fed cattle as it needs the extra fat marbling in the flesh to prevent drying out prematurely – and this is why commercial beef is usually aged in vacuum-sealed bags to retain the moisture (and minimise weight loss) of lesser quality meat.
Personally, I draw the aged beef line at around 55 to perhaps 70 days as beef older than this tends to freak out my taste buds in much the same way as well-hung game birds make me slightly nauseous – there is no need to dwell on the peculiar aspects of eating flesh that is significantly on the road to putrefaction, despite enthusiasts predicating about its “sensation overload”, “flavour complexity”, “chemical astringency”, et cetera.
Beef ages due to enzymatic activity on muscle fibres followed by the bacterial breakdown of proteins and fats. The main chemical processes involved are proteolysis, lipolysis, and oxidation.
Proteins are basically structures made up of amino acids and proteolysis is the decomposition of the elastic rope-like muscle fibre proteins into more basic amino acids and polypeptides (amino acids held together by peptide bonds).
Left alone, proteins take a long time to break down and therefore proteolysis needs to be catalysed by several enzymes (known as proteases) within the flesh itself – there will be much more about these interesting enzymes later.
Lipolysis is the term used to define the breaking down of fats into glycerol and free fatty acids and is initiated by other enzymes such as lipases within the meat – lipolysis is then further promoted by bacterial action.
The compounds formed by ageing eventually react with oxygen in air in a process called oxidation – this can add further taste complexities and aromas, though oxidation can degrade meaty flavour compounds such as 2-Methyl-3-Furanthiol (MFT) and also form carbonyls (eg. ketones, carboxylic acid) which tend to be rather icky-tasting molecules. As an aside, MFT is also produced commercially and used to enhance the meaty flavour of processed foods.

Part 2 reviews the science behind how to tenderise beef by ageing beef faster and also describes the results of a few experiments with beef at home.

http://www.star2.com/food/food-news/2017/08/13/tender-moment-part-1/