Yacon (Smallanthus sonchifolius) stores water and a sugar called fructooligosaccharides in its roots (often referred as tubers).
The ‘sugar’ or Fructooligosaccharides (known as FOS) is made up of a longer chain of sugars. With up to around 5 sugars linked together it is much longer than mono or di-saccharides but not a long chain sugar like Inulin. Inulin with ~10-11 chains can be broken down into FOS.
FOS is about 30-50% as sweet as sugar and has a much lower caloric value than simple sugars. Our bodies treat it more like a fibre than a sugar and it comes into play in our colon where it is fermented by anaerobic bacteria. As such FOS is a prebiotic, feeding the ‘good bacteria’ in our large intestine and is reported to increase the overall health of our gastrointestinal tract. Some studies suggest that it is an effective treatment for yeast infections.
Yacon has been instrumental in the recovery of my digestive health. I suffer from a motility disorder in my stomach (stomach/intestines don’t move) which means I rely on healthy flora in my digestive system to break down and get nutrients from the food I eat and fibre to keep everything moving through.
As a by-product of having yacon in my diet on a daily basis I am no longer plagued with yeast infections. So for me at least the science seems to stack up. We are all different and what works for one person may not for the next, it really is about finding what works for you, yourself.
Extracts, Links and References from Wikipedia (https://en.wikipedia.org/wiki/Fructooligosaccharide )
The Jerusalem artichoke and its relative yacón together with the Blue Agave plant have been found to have the highest concentrations of FOS of cultured plants.
Because of the configuration of their glycosidic bonds, fructooligosaccharides resist hydrolysis by salivary and intestinal digestive enzymes. In the colon they are fermented by anaerobic bacteria. In other words, they have a lower caloric value, while contributing to the dietary fiber fraction of the diet.
FOS serves as a substrate for microflora in the large intestine, increasing the overall gastrointestinal tract (GI Tract) health. It has also been proposed as a supplement for treating yeast infections.
- ^Severian Dumitriu (2005). Polysaccharides: Structural Diversity And Functional Versatility. CRC Press. p. 855. ISBN 978-0-8247-5480-8. Retrieved 13 June2012.
8.^ V. Rousseau, J.P. Lepargneur, C. Roques, M. Remaud-Simeon, F. Paul; Lepargneur; Roques; Remaud-Simeon; Paul (2005). “Prebiotic effects of oligosaccharides on selected vaginal lactobacilli and pathogenic microorganisms”. Anaerobe. 11 (3): 145–153. doi:10.1016/j.anaerobe.2004.12.002. PMID 16701545.
We are always asked what is the best way to keep high FOS (fructo-oligo-saccharide) yacon in our diet..and the answer is fresh and raw!
However, it is a bit more complicated than that. In most growing areas in NZ you have to lift the Yacon to store, where-upon the FOS immediately starts breaking down to more simple sugars. This is why yacon becomes sweeter over time.
For a perpetual supply we keep some yacon in the ground year round where we have good drainage, mild winters and to insulate it from the cold we also cover it with a thick layer of mulch. Technically our yacon is fresh and raw when harvested from the ground. Even so the roots in the ground do break down to more simple sugars when the plant dies off so the FOS is compromised.
This ‘pineapple yacon’ is a good example of yacon left in the ground which has become more sweet over time, the colour of the flesh often goes more yellow/gold as it breaks down, rather than a translucent white when optimum FOS can be found.
To lock in the FOS you must first deactivate the enzyme responsible for breaking it down, we do this through heating, reducing the PH and the water content in the yacon.
We have found the two best ways to lock in the FOS for us are:
- To juice, add lemon juice (alters the PH) and simmer to evaporate the water off, which is making it into yacon syrup (our e-guide on how to grow and preserve yacon gives you more details on the process and can be purchased here https://mygreens.nz/collections/yacon )
- To slice, add to a bath of water and lemon, dry then dehydrate the yacon.
This really needs to be done the first chance you can after lifting your yacon because the sugar begins to break down straight away.
Yacon syrup can be used in smoothies, beverages and on cereal, yoghurt, ice cream or pancakes.
Dried yacon can be eaten as a snack, in scroggin, chopped up and put in muesli or anywhere you would use dried fruit.
Here are some tips on getting your yacon crowns through winter, the method you use will very much depend on how severe your winters are.
Things to consider are how hard your frosts are and how good your drainage is.
If you have good drainage and few frosts you can leave your yacon in the ground and harvest them as and when you are ready, replanting your crowns in at least tennis ball sized clusters as you go. We still recommend a layer of mulch and lodging the stalks rather than cutting back like we’ve done here. This shows the yacon emerging in the spring.
If you have good drainage and moderate frosts (like we did in Waikato) you can replant and mulch heavily (20-30cm thick mulch). You can also use clamps or underground root cellars/boxes.
If you don’t have good drainage and few frosts your tubers are likely to rot in the ground and this can effect the crowns as well. You will need to lift and store your Yacon crowns.
Yacon crowns pictured here in amongst their South American cousins are stored temporarily to harden off in egg cartons and a large chilly bin outside.
We keep smaller crowns that have come away from the cluster or cut off from one that has rot in here. This is simply to be able to monitor them more closely and make sure their wounds heal over (rather than rot away). Please note this is not reccomended for long term storage as like the sunchokes (jerusalem artichokes) and Oca (NZ Yam) they may dry and shrivel away over time and are best stored in the ground.
If you have ample frosts or ground freeze you will need to lift and store your crowns. Methods of storage are:
- Create a free draining stock bed, we build a temporary raised bed underneath a canopy to heel the yacon in over winter. This is later mulched or covered with thick coffee sacks to protect from the cold.
- Store in pots or baskets in seed raising (has less microbes, is more porous) under eaves or in a garden shed away from frosts. Keep misted or wrap in plastic bag with few holes to maintain moisture content (else they shrivel up).
When Yacon flower in the autumn it is a signal that you can harvest, but what if they don’t flower?
Flowering is just one of the signs that the Yacon is almost ready to harvest. Another signal is a change to colder temperatures. Just like a few of its South American cousins Oca (NZ Yam) and Jerusalem Artichokes or Sunchokes the change to cooler temperatures, and particularly frosts trigger the plant to store – making the tubers grow at a more rapid rate.
Some of our facebook community have commented that their yacon doesn’t flower. Our yacon has flowered in Northland and Waikato. In Waikato it is a race between the flowers and the frosts and is very dependent on how quickly it turns colder.
Either way 2wks to 6wks from flowering or frosts your yacon should be ready to harvest. If you are in a colder climate it would be at the 2wk end of the scale, most will be a month and in some areas it can be left in the ground to winter over.
Even though frosts are rare in Northland a colder patch will blacken off the leaves. The two photos above are only 3 weeks apart and you can see the colour of the leaf changing. In a frost the leaves and the stalks will go quite black before dropping off or turning to mush.
Our next post will be on caring for your yacon as winter sets in and what you can do to store the yacon for spring.
The slaters have found the perfect place to hide from the birds -in our Yacon plants!
Thats the stalk or a dead yacon cane on the horizontal out to the left, the slaters have used the cane as a portal travel into the heart of the growing crowns and tubers and are quite happy here munching away on the yacon and staying hidden from the birds inside the cane.
We wont be leaving the stalks to poke above the mulch next year, my idea was to leave them as markers when the plants had died down so I knew where they were hiding under the mulch. Lesson learnt!
We unearthed this monstrous 1kg yacon tuber today! You can see its mature by the rot creeping in and the caramel/yellow colouring of some of its flesh… this means the FOS has broken down into a more simple sugar, its sweeter and slightly less juicy.
Did you know you can use Yacon like a fruit? we use it like pineapple in a fruit salad, clean (the mud comes off easy as!), peel, dice and soak for a few minutes in water with a little lemon juice to stop it browning before adding to your fruit salad.
We’ve added this to pepinos, bananas and oranges, all ripe and seasonal fruit grown right here in our forest garden!
I want to share a really good question that came in today about Yacon (Yakon) … with Yacon is crop rotation necessary?
We’ve been growing yacon both commercially and for our own use for well over 10 years…when the yacon is lifted and all tubers (the edible bit) are harvested you can replant the crown/rhizomes (growing bit) in the same spot year-on-year.
However if you leave the mature tubers and plant to winter over and sprout again the next season we have noticed that the decomposing mature tubers can effect, cause rot, in the new tubers as they grow.
Heres an example of rotting,
and the effect on a new tuber (the black on the end is not typical of yacon!)
That being said we use Yacon as a pioneer plant, it improves the soil (the worms and microbes love the decaying tubers), lift and move them on in the spring where they can do their work on another patch.
Its super easy to grow your own yacon.
We have clusters of the growing crowns available. These are harvested from the food forest floor and here in Northland are just starting to shoot up again.
Single clusters (approx tennis ball sized) are NZ$15 incl p&p to anywhere in NZ only (sorry we cant send these overseas) and a double sized cluster is NZ$25 incl p&p – once again to anywhere in NZ only.
Email us on firstname.lastname@example.org to place an order or ask any questions.
Here is the journey your yacon crowns go on… after rain we fossick about in the forest garden to find and lift a yacon plant which has been dormant over the winter…
One plant will give us a bucket of crowns, a few immature edible tubers (the mature ones have decomposed and feed the plant, soil and microbes over the winter). Tubers are hanging down, and you can see the crowns just sprouting in the picture below.
From this bucket of crowns only 3-6 make the final cut, some have been damaged by slugs and bugs while others when separated fall apart into crowns that are too small to plant on their own. We plant fist/tennis ball sized clusters of crowns because they are less susceptible at this size to damage and they will give a good first year yield.
Heres some weve sent recently in orders (on the right) and a tennis and golf ball to get a size comparison. The young tubers are on the left, they are edible at this stage but yields in the spring are light. They should be harvested in the Autumn.
Dayna has already started to make Christmas cookies like these Gingerbread people… we use Yacon Syrup to replace the treacle and it can be used instead of golden syrup in recipes too for a lower sugar alternative.
We are always trying to replace sugar with yacon syrup and over the years have developed several recipes, heres our Teriyaki Yacon Sauce recipe.
You will need a bottle or glass jar (approx 250ml) and the following ingredients:
- 1/2 cup Yacon Syrup
- 1/2 cup Soy Sauce (we use dark soy)
- 1/2 cup Sake or Sherry (we use medium sweet sherry)
- 2 tsp Sesame Oil
- 3 tsp Ginger, finely grated
- (optional) Chilli flakes/seeds to taste.
Put all ingredients into a saucepan and boil gently for 10 minutes. Leave to cool the pour into glass jar/bottle and store in the refrigerator. Will keep for months!
We love using teriyaki yacon sauce on asian slaws, as a marinade or as a bake (check out Annabel Langbein’s Fish and Mushroom bake, yum yum!).