Comparing Lupin Varieties

Over the past few years, lupins have emerged on the global market. Lupins can be found in products such as marinated bean snacks, granola bars, and more. It is important to note that there are numerous species of lupins, which are all part of the lupinus genus of legumes. The genus lupinus contains annual species (grows for one season and dies) and perennial species (regrows every spring for many years). Most lupin species are herbaceous (think flowers and herbs) although shrub and tree like varieties also exist. As you can see there is a lot of variety and variance within the lupinus genus. Let's take a closer look at some of the popular species grown for agricultural purposes: narrow leaved or blue lupin (L. angustifolius), white lupin (L. albus), yellow lupin (L. luteus), and chocho (L. mutabilis) to see what differentiates these species from one another, and why chocho is the species we have chosen to cultivate and introduce through MIKUNA (cite). 

First, let's look at the history of Lupins. Before 2000 BCE, L. albus or white lupin was domesticated in ancient Greece and Egypt for human and animal consumption and for the creation of cosmetics and medicines. Between 1000 and 800 BCE, L. albus was used as an organic manure in ancient Rome and other Mediterranean countries. Around 700 BCE, people living on the American continent began to domesticate chocho, or L. mutabilis. Flash forward to the late 1900s, and research was done on how to make these seeds more digestible and feasible for widespread human consumption (cite).  Although these little legumes have been around for a very long time, they are still primarily grown for animal feed. Less than 4% of global lupin production is for human consumption (cite)

But what is the difference between them? Part of the difference has to do with how they grow, For example, blue and yellow lupins may be sensitive to alkaline soils. A pH of 7.0 or less is ideal. White lupins on the other hand are more tolerant of alkaline conditions and can grow well at a pH of 7.5. (cite). Chocho grows well in high altitudes. Other differences include the ways in which the lupins reproduce. Mediterranean lupins such as blue lupin, white lupin, and yellow lupin mainly self pollinate. Chocho on the other hand must be cross pollinated, which means that plants have differentiated embryos and endosperms.

 

The nutritional composition between species also varies, as does the nutritional composition between seeds and kernels. Kernels are the center of seeds, or the part that we eat once the outer casing has been removed. When you buy sunflower seeds you have to take out the kernel from the shell, but when you buy shelled sunflower seeds you get just the kernel. The seeds of L. angustifolius are 32% protein, L. albus 36% protein, L. luteus 38% protein, and chocho or L. Mutabilis 44% protein. When the shell is removed and just the kernel is left, the protein percent goes up about 10% for each species. However, research shows that nutritional composition can vary depending on growing conditions, and our calculations put our chocho kernels, L. mutabilis at around 54% protein, making chocho the most protein dense lupin!

In addition to being the most protein dense lupin, chocho also has the highest amino acid profile. The following graph comes from an article on Lupins published in Pulses in May 2020. As you can see in the chart, L. mutabilis AKA chocho contains the highest number of most of the essential amino acids and several conditionally essential amino acids. What's more fascinating is chocho contains several conditionally essential amino acids that all other kinds of lupins lack:  glutamine, glycine, and proline. Glutamine is found in the tissues of your intestine, which uses it as a source of fuel to function well. Glutamine helps to maintain proper barriers within the intestine, and research shows that it may help people with IBS by working to protect the mucous in their digestive tract and may boost immune cell activity in the gut. Glycine is one of three amino acids that your body needs to make glutathione, which is a powerful antioxidant that works to protect cells against oxidative stress and free radicals. Proline helps with protein synthesis and structure, and aids in metabolism, nutrition, wound healing, antioxidant function, and immune responses. It's pretty cool that on top of all the essential amino acids we need, chocho contains extra boots of amino acids to help our bodies function. 


Source: Visvanathan R., Madhujith T., Gamage A., Zhang N. (2020) Lupin. In: Manickavasagan A., Thirunathan P. (eds) Pulses. Springer, Cham. https://doi-org.proxy.library.ucsb.edu:9443/10.1007/978-3-030-41376-7_10

Beyond protein concentration, fat and fiber concentrations also differ. The seeds of L. angustifolius are 6% fat, L. albus is 9% fat, L. luteus is 5% fat, and L. mutabilis is 14% fat. In terms of crude fiber, the kernels of L.angustifolius are 9% fiber, L. albus is 2% fiber, L. luteus is 3% fiber, and L. mutabilis is 10% fiber. L mutabilis is the only species in which fiber goes up when processed from a whole seed to a kernel (cite). As you can see in the kernel graph and the chart of amino acids, Chocho leads in all three nutritional categories and in its amino acid profile, making it the most nutrient dense of all the major Lupin species. 

So, what does this all mean? Well to start we can look at crude protein in the seeds. Chocho has more protein than any other cultivated lupin species, especially when the seeds have been turned into a kernel. Also, Chocho is especially high in fiber and heart healthy fats as compared to other lupin species, which help to keep you satiated and regular. As the lupin market continues to grow, we hope to spearhead a new wave of innovation using chocho as a flour, a protein powder, a base for snack bars, savory meals, and beyond. Chocho is incredibly versatile and is evidently superior as compared to other lupin species, which is why it is the base of all of our products at MIKUNA.   

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