Stock or broth soup for cold days
To bone broth or not?
That may not be the question you were thinking but "Jewish penicillin" for the winter woes may be what you need. Old cook books, CWA household manuals and nursing manuals have recommended beef tea, gels and broth as nourishing fluids for convalescence throughout the ages.
But in this busy world, I was looking for the science behind bone broth to see if my pressure cooker could be the time saver I was looking for. I wanted to be able to quickly make my broth and preserve the nutrients associated with the health benefits of a good broth.
To create a protein rich soup, you need to add heat and water to bones with joint cartilage and meat attached. Bones are about one third collagen proteins and two thirds insoluble mineral crystals deposited amongst the collagen fibres to give them functional strength. Bones are the frame for our muscles so it needs to be strong but flexible so they don’t break easily. A pressure cooker is a wet cooking environment as it is the steam which creates the pressure and increased heat. This quickens the break down of the collagen proteins into the liquid or broth but is it as nutritious?
Why are we so interested in proteins? They are so much more than muscle to move us. Proteins are involved in most aspects of life. From just 20 unique amino acid building blocks your body makes all the varied proteins for the efficient functioning of your body. It is your DNA sequence that provides the instructions for protein synthesis. Proteins are needed for growth and maintenance of your body as well as enzymes for reactions, hormones for messages, antibodies to fight invaders, transport for other molecules such as waxy cholesterol as well as providing us with energy when needed.
Protein production is an all or nothing process just like any other production line you know. If the sequence is moving along and one amino acid is not available, production stops. Eleven of the 20 amino acids can be synthesised by our body if the building blocks are available. When your nutrition is compromised, there are 8 of these amino acids which become conditionally essential meaning you are not able to produce enough of that specific amino acid. There are an additional 9 essential amino acids that need to come from your food.
Animal sources of protein are considered high quality as they contain all the essential amino acids. An incomplete protein source is missing 1-2 essential amino acids and it is why a food habit which excludes animal products needs to be well planned. Ever wondered why traditional vegetarian meals contain beans and grains? Together they complete the set of essential amino acids.
Back to the stock or broth. I tried 2 types of bones- soup bones with a couple of cartilaginous joints which I dry baked in the oven first as I was aiming for a dark colour to the broth; and ox tail which I browned in the pot before adding the water, heat and allowing it to build to pressure and stay there for 45 minutes.
The broth gelled on cooling in both batches which is an indicator of a good broth. The collagen has solubilised and formed a gelatine which is known to be high in conditionally essential amino acids such as glycine and proline. While gelatine is not a complete protein source it is high in these amino acids as they are high in collagen.
It is these amino acids which have been associated with health benefits including improved immune function, gut health and repair of muscle. Glycine in particular is required for synthesis of other amino acids for building proteins used as enzymes, intracellular transporters or signals and muscle building. It would be good to vary the animal bones used- beef, chicken, lamb or pork to change the flavours and potential nutrients as we learn more about these traditional health foods.
To pressure cooker or not? There is no scientific evidence yet to say there are more health benefits from using a simmered broth where the water is at least 85 C for 10 hours over a pressure cooked broth where the water temperature may be as high as 120 C for 120 minutes. This may because each broth batch may be slightly different as you use different bones, vegetables and cooking conditions. I will be using my pressure cooker to create a gelatinous rich broth to be enjoyed over the day, as I need the convenience of the quicker cook time.
How do you enjoy your broth?
Instead of tea or coffee at times,
Add some veggies for a quick soup with flavour or
I may even use it as stock in a stew.
I know when I my children were babies, my grandmother gave me home made brawn to melt into the veggie mash. This gelled meat was like a broth - a protein packed convenience food from the old days!
Let me know who cooks their broth at a simmer and does anyone uses a pressure cooker?
Ref: S. Croxford; E Stirling 2017. Understanding the Science of Food from molecules to mouthfeel. Allen and Unwin. Crows Nest NSW.