Nano-encapsulation to fortify banana peels?!

9 min readOct 18, 2021

Now that’s bananas!! 🍌

Contributing authors: Sophia Laird, Heya Desai, Sanvi Laird

This past month I had the pleasure of working Sanvi Rao, Sophia Laird, and Heya Desai on a moonshot challenge hosted by The Knowledge Society! We focussed on aiding malnutrition by using nano-encapsulation to fortify banana peels, to be the base in our creation of an RUTF (Ready-to-use therapeutic food).

The goal of this challenge was to create a project that had the possibility of becoming a company! So… drum roll please… 🥁

Introducing: Alma

Alma is a ready-to-use therapeutic food targeted towards pregnant women! Our mission is to improve the health of the woman to ensure their child has all the right nutrients they need to grow!

Here are the stats:

— Approximately 815 million people are malnourished worldwide

— 40% of pregnant women are malnourished

— Malnourishment is linked to 45% of childhood deaths

In particular, we decided to focus mostly on anemia (subset of malnourishment), but to understand malnutrition as a whole, be sure to check out this article!

Women and Anemia

Women suffer from nutritional deficiencies two times more than men because of their reproductive biology and increased nutritional needs associated with menstruation, pregnancy, and lactation.

A women’s nutritional status has a direct impact on their children's nutrititon: an undernourished pregnant mother is more likely to give birth to a low-birth weight child. The child is then at greater risk of malnutrition during childhood and in later life.

The concept of treating Anemia isn’t a new one. We have bone marrow transplants, blood transfusions, supplements, iron injections, multivitamins and much more! On the more preventative end of the spectrum, there are prenatal vitamins but they’re meant to supplement your diet opposed to being the only source of nutrients.

The Gap/where we come in:

Something is needed with fewer absorption inhibitors
Nothing accounts for chronic loss of hemoglobin, various enzymes and myoglobin which are lost from parasite infections
Most diets around the world are deficient of iodine except where seafood or salt fortified with iodine is available
The regulatation of production and function of hemoglobin, enzymes, myoglobin, thyroid hormone, immune system, many enzymes,

Solution Overview

Alma uses nano encapsulation, specifically micronutrients encapsulated in BMC polymer to fortify a therapeutic product made using irradiated recycled banana peels to treat anemic women, maternal malnutrition and to improve fetal health. Preventing malabsorption and regulating production of hemoglobin, etc.

Current interventions to treat anemia in women, pregnant women and lactating mothers are not affordable and do not account for the multiple deficiencies one may have. Alma Theraputics is using nano-encapsulation, specifically micronutrients encapsulated in BMC polymer, to fortify a therapeutic product. This is made using irradiated recycled banana peels to treat anemic women, maternal malnutrition and to improve fetal health.

The base for Alma Therapeutics’ product are recycled banana peels, which will later be added to a recipe and turned into ready-to-eat individual banana bread portions. The peels themselves are sourced through bioreactor landfills. Along with the rest of the ingredient list consisting of sesame oil, flax-egg and more, these peels enable consumers to increase their antioxidant levels and reap several benefits of the high-protein and content and anti-inflamatorry properties of the recipe.

The Creation Story…

Part 1:

Sourcing Bananas

We’re sourcing the bananas from landfills. You read that right! 🤯

Roughly 30–40% of the food we bring home is thrown away and ends up in the landfill. Much of it could decompose in landfills, but because there is often a lack of oxygen the microbes that break down organic matter can’t do their jobs.
Food waste that decomposes in landfills releases methane, a greenhouse gas that is at least 28 times more potent than carbon dioxide.
We plan to source the bannanas from bioreactor landfills.

Why bioreactor landfills?

We will be sourcing our banana peels from the Municipal solid waste landfills (MSWLFs) that are in control of Bioreactor Landfills.

In these landfills, liquids are added to help bacteria break down the waste, alowwing the organic matter (as mentioned above) to do it’s job. The increase in waste degradation and stabilization is accomplished through the addition of liquid and air to enhance microbial processes.

Cleaning the peel

I don’t know about you, but I don’t want to be consuming a dirty banana peel…

Good news! You don’t have to, because the peels will be cleaned using food irradiation!

What is Food Irradiation?

Approved by the FDA: ✔️

Food irradiation is a technology that reduces or elimates microorganisms and insects. It improves the shelf life and safety of foods by exposing it to doses of ionising energy or radiation. It also doesn’t make the food radioactive so it’s perfectly safe to eat after!

It’s also super affordable! Cost: $0.13 per kilogram (0.5–7 cents per pound)

There are three sources of radiation approved for use on foods:

Gamma rays are emitted from radioactive forms of the element cobalt (Cobalt 60) or of the element cesium (Cesium 137). Gamma radiation is used routinely to sterilize medical, dental, and household products and is also used for the radiation treatment of cancer.
X-rays are produced by reflecting a high-energy stream of electrons off a target substance (usually one of the heavy metals) into food. X-rays are also widely used in medicine and industry to produce images of internal structures
Electron beam (or e-beam) is similar to X-rays and is a stream of high-energy electrons propelled from an electron accelerator into food.

Recipe time

This is the fun part 😎…

The end product is a small piece of banana bread individually packaged. It’s put together by two separate mixtures:

Mixture 1: The banana peel with other ingredients

Mixture 2: The flour with nano-encapselated nutrients.

Recipe and Cost

2 Ripe banana Peels — 7/8 ounces (24 grams) — 0.00144 dollars
Splenda 6 packet — 18 gram (50% less sweet) — 90 cents
Vinegar 2 tablespoons — 28.3 grams — 0.00839149464 dollars
1 2/3 cup of rice flour — 64 grams — $1.1491 (see mixture 2)
1/2 cup of Non-fat milk dry powder — 62.5 grams — $1.190905449
28 grams (1 scoop) Vanilla whey protein hydrolysate — 114 grams → $3.42 ($0.94/ounce)
1/2 cup of Sesame oil — 118.35 grams — $2.40
2 teaspoons of baking soda — 9.6 grams — $0.02
1/4 teaspoon baking powder — 1 gram — $0.01

Cost:

6 servings: $9.09983694364

1 serving: $1.51663949061

Why this recipe?

Rice flour contains more fibre and protein than wheat flour
No water, which reduces exposure to water borne bacteria
Sesame oil is high in antioxidants
Strong anti-inflammatory properties
The polyunsaturated fat in sesame oil is rich in omega 6-fatty acids; which helps prevent the development of plaque in arteries
Gluten free

Mixture 1

In the first mixture, all other ingredients listed above are going to be mixed together, including the ionized banana peel.

Mixture 2: Nanoencapsulation

In this second mixture, nanoencapsulation is going to be used to add nutrients to the flour (once the nutrients are added to the flour, mixture one and two are mixed together).

Nanoencapsulation is the proccess of packaging nanoparticles of solid, liquid or gas (the core/active) within a shell (capsule). The purpose of nano-encapsulation is to ensure the active reaches the stomach without being adversely affected by the environment it passes.

Why use nanoencapsulation?

Nanoparticles have a larger surface area, which results in a higher activity level of the encapsulated ingredients! An increase in surface area may lead to improvement in bioavailability of flavours, which was one of the biggest reasons why regular RUTF’s weren’t as successful as they could have been. The larger surface area also improves the solubility of poorly water soluble ingredients 💧. This is super important because this means our product won’t require any water, limiting exposure to water-borne diseases and bacteria!

Nano-fabrication (Encapsulating the nutrients)

Nano-fabrication is the process used to build and put together structures at the nanoscale.

There a two main approaches used for nano-fabrication: Top-down and bottom up.

Top-down

The top-down technique is essentially like carving a sculpture. You start with a large piece (or relatively small rather) and remove the unnecessary material until you have the desired shape. A technique using this method is called nanolithography. Nanolithography is used for structures under 100nm. The technique etches away the rest of the material after using a mask covering the predetermined structure. Etching can be done chemically or mechanically. Chemically, the technique uses acids and mechanically, ultraviolet light, x-rays or electron beams are used.

Bottom-up

“Started from the bottom, now we here” — Drake 😎

Starting from the bottom is basically how the bottom-up method works. An example is like building a house brick by brick. This method is more intricate, requiring the chip to be assembled atom by atom. Though the tedious steps in this method, it is more flawless then the top-down method. This method is used for biological and chemical purposes.

For our process, we have chosen to use the top-down method, and specifically emulsification which is a technique for the top-down method.

Emulsification Steps

Spray dryers will turn the liquid droplets into a powder. The Sprayed droplets loose the solvent in the drying chamber leading to a solid particle which is subsequently removed from the air stream and collected.
Encapsulate the nanoparticles using a spinning disc atomization system which is used to prepare the overcoated particles, or in other words encapsulate them with BMC. Options for the feed solution include a mixture of BMC, polysorbate that is dissolved in a dichloromethane solvent. While it is not miscible with water, it is polar and miscible with several solvents
The nanoparticles are added to the DCM solution and placed in a sonication bath where sound energy is applied in order to agitate the particles in the solution and evenly disperse the particles in the liquids . It is known to be the most important stage in the process of preparing nanofluids and is carried out through an ultrasonication path, ultrasonic vibrator as well as a mechanical homogenizer. There are several objectives of this step but they include the deagglomeration of nanoparticles, size reduction, and dispersion in the solution. To expand on deaggregation itself, sonication breaks up aggregates of these micron-sized colloid particles. Furthermore, along with the power and frequency of the sonification, the time is one of the most crucial factors to consider in terms of the stability of the formed suspension. For this particular application, they would be placed in the sonication bath for 10 minutes.
The suspension is fed onto a stainless steel custom disc tower
Particles are collected on antistatic plastic that is placed at the bottom of the tower that suppresses initial charges, prevents the build up of static electricity and also enables a very slow rate of decay of static charge from a hundredth of to several seconds.
The products can be collected in a non GMO and aluminum free starch and next it would be sieved to recover the encapsulated micronutrients
In order to remove any residual solution, they should be placed under vacuum for 1 week

BMC Polymer

Above we broke down the nano fabrication steps, and what exactly is being encapsulated. However, now we need to discuss the encapsulation itself, or the “shell” 🐢.

The shell is made out of a BMC polymer which is short for:

(butylmethacrylate-co-(2-dimethylaminoethyl)methacrylate-co-methylmethacrylate) (1:2:1)

Try saying that 10x fast! I can’t even say it once! 🥲

A BMC polymer is an FDA approved material that would protect them from being broken down or interacting with other molecules, and then release them after consumption. BMC ‘s moisture barrier properties is what provides protection against humidity and small-molecule diffusion by acting as a physical barrier between the contents of the particle and environment it is in.

So… why use a BMC polymer shell?

Well, at MIT, Anselmo and colleagues tested 50 polymers and found BMC to be the most ideal! They found that the encapsulated micronutrients were unharmed after being boiled for two hours! The researchers showed that particles broke down in the stomach, as expected, and the cargo travelled to the small intestine, where it could be absorbed.

Joint food and agriculture organization of the United Nations and the WHO expert committee on food additives also yielded a positive response for BMC polymer!

Keep in mind! Everything above about the nanoencapsulation is happening to the flour mixture!

Now that both two mixtures are ready, they will be mixed together and baked into a small bread peice.

Keeping it green 💚

Cornstarch Packaging

For the packaging our product, we have decidee to use cornstartch packaging. Here’s why:

Corn starch packaging is 100% biodegradable; it can be reintegrated as an agricultural fertilizer
Corn starch packaging doesn’t contain harmful toxins such as polyvinyl chloride or dioxin
It releases less greenhouse gas emissions during production
Most companies use polystyrene → which has a bad environmental impact of polystyrene, such as the inability of the material to biodegrade.
If disposed of correctly, packaging material made from cornstarch will break down into carbon dioxide and water within several months.
Corn is the least expensive and most abundant source of commercially available sugar.

Corn starch packaging is sustainable, cheap, and easy to produce.

Why Alma?

Alma stands for “all moms”. We belive that all moms deserve to be healthy, and have the right nutrients without having to break the bank.

Mom’s health → Fetus’ health

In conclusion…

Alma is for all moms. ❤

With love,

Nancy Shnoudeh, Sophia Laird, Sanvi Rao, and Heya Desai