BAOBAB

ENGR 493 Fall 2009

Alice Cheng Katie Kirsch

Rachel Lower Alex Lubchansky

Introduction

The baobab tree (Adansonia

digitata) is found in equatorial

sub-Saharan Africa and

Madagascar (Nirvana). It is

referred to by some as the

“upside-down” tree due to its

many thin branches and large

The Baobab Tree (Mahr) trunk. Because the areas in which

the baobab grows are very dry, the large trunk is able to store water (Mahr). It can grow up to

80 feet tall and 40 feet in diameter. Adansonia digitata is the only species that produces

flowers, and these flowers give rise to the baobab fruit, on which this project is based.

The fruit of the baobab has a hard shell with pulp and seeds inside. It is comparable to a

coconut, but the inside pulp is dry and fibrous with small, hard seeds similar in shape to a

kidney bean but about half the size of one.

(From left to right): The whole baobab fruit, baobab fruit split open, close-up of baobab seed encased in pulp and fiber

Baobab seeds are used as a coffee-type drink and also used as feed for livestock. Although

covered with a hard shell, baobab seed endocarp is rich in protein and nutrients. Locally,

baobab pulp is used for a tart drink similar to lemonade, and also medicinally as a cure for

fevers and diarrhea (Mahr). However, baobab pulp has recently been discovered and

approved by the FDA for use in foods in the United States (Addy). It is high in Vitamins C,

A, B1/2/6, Calcium, Iron, Potassium, and many amino and fatty acids (Manfredini). The

pulp has also been used to make cream of tartar and is high in carbohydrates such as pectin

(Mahr). Baobab has been coined by some as the “New Superfruit” and products have already

hit shelves in the United Kingdom with baobab. The seeds are also being used cosmetically in

oils and lotions (Baobab Pulp).

The purpose of our project was to find an easier method to process the baobab and also to

experiment with different uses of the baobab. Because Africa is still a developing continent,

finding uses for baobab and an easier decortications method will help the African economy

by providing an export. Baobab trees are very plentiful, but the use for the fruit has been

lacking until just recently. We divided our project into three aspects:

1.) Separating pulp and fiber from seeds

2.) Separating seed endocarp from shell

3.) Pectin extraction from pulp

We worked as a team of leaders as well as with outside parties. We have provided our

experimental procedures, data and results in the following report in hopes that it will

someday benefit Africa and accelerate the use of baobab.

Separation Of Pulp And Fiber

The first step in using the baobab fruit is opening the shell and separating the seeds from

the dry pulp. In industry, this has been done partly mechanically and partly with human labor.

Our goal in this aspect of the project is to minimize manual labor and mechanize the process.

Because energy and resources are scarce in Africa, we wanted to incorporate sustainability

into our design to make it feasible for anyone to use our machine. We were not able to build a

fully functional model of our design due to lack of time and materials, but we have provided

a rough prototype of the machine. The separation of the pulp from the seeds is completely

mechanized. The energy generation will be provided by a bicycle. The pedals will be ideally

pushed by a human, but it is also possible to attach n engine to power the machine.

Parts of the machine include:

• Gears

• Sifting Screens ( gauge 10, 12, 20)

• Rollers

• Shafts

• Wooden Frame

These are the results of testing the pulp and seed separation by using screens. The sifters

were used to mimic the screen shelves of the actual design.

Gear assembly

Roller

Prototype Pictures

Separation of Seed Endocarp and Shell

Although seeds can be eaten by livestock, the outer shell of the seed is too hard for

humans to consume raw. However, the seed endocarp, similar to a nut, is rich in protein and

fatty acids. These proteins and fatty acids are hard to come by in Africa, where resources are

scarce and meat is expensive. Since baobab fruits are very plentiful in poor regions of Africa,

finding a way to extract protein from the seed could lead to a better nourished population that

is self-sustainable. We got in contact with Mark Wyatt of baobab-fruit.com, an affiliate of

Baobab Company in Senegal. He generously donated two whole baobab fruits as well as a

sample of the company’s extracted seed endocarp, using a mechanized micronization process

(Wyatt).

Our first experiment was soaking the seeds in vinegar. The report from students doing

this project last year concluded that acids worked the best in softening the seeds, and boiling

the seeds was even more helpful. Since the amount of resources needed to start a fire and boil

seeds in water is high, we decided to try a more feasible way of softening the seeds by

soaking them in vinegar, a weak acid. Our hypothesis was that soaking the seeds in vinegar

would soften the seeds, and human labor would be able to the peel the shell.

We set up 7 jars of 6 different types of vinegar and one standard with water. We soaked

baobab seeds in each jar overnight and over the period of a week.

Types of Vinegar and Percent Acidity (from left to right in order of decreasing acidity): Pompeian Balsamic Vinegar (6%), Heinz Apple Cider Vinegar (5%), Heinz Distilled White Vinegar (5%), Star Red Wine Vinegar (5%), Nakano Rice Vinegar Mizkan Natural (4.2%), Koon Chun Diluted Red Vinegar (2.47%)

Our results were surprising. We found that soaking the baobab seeds overnight in the

vinegars or water produced no visible signs of softening the seeds. After a week, the seeds

were slightly softer but still not able to peel. After a week, many of the seeds were also

bloated with liquid, and we feared that the nutrients in the endocarp may have been

compromised by the long soaking time. Also, the water seemed to work just as well as the

vinegar in terms of softening the seeds.

After our unsuccessful attempt with the vinegars, we tried boiling the seeds in water and

vinegar to see if there was a difference. Boiling the seeds in vinegar produced faster results,

but the concern about the leak in nutrients due to the acid was still present. Our conclusion

was that water was sufficient in softening the seeds, but still had a lot of downfalls. The seeds

may have nutrients and were still not able to be peeled.

Finally, we tried roasting the seeds. Since the seeds could be roasted and used as a coffee

substitute (Mahr), we wanted to see if roasting the seeds would make them any easier to open.

We spread seeds on a cookie sheet and sprinkled them with a little vegetable oil, then baked

them at 350 degrees Fahrenheit for 15 minutes. After removing the seeds from the oven and

letting them cool down, we discovered that although we were not able to peel them with our

fingers, we could easily put the seeds in our mouths and break them open with our teeth. This

was a big improvement on the raw seeds, which could hardly be opened even after soaking.

Roasting the seeds, however,

takes a lot of energy. We decided to

rely on the hot, dry climate of Africa

and built a sustainable solar cooker

with poster paper and aluminum foil

(CooKit). With a solar cooker, the

baobab seeds can be roasted without

the additional cost of energy that would normally be associated with heating.

With this new discovery, we decided to pursue the separation of the endocarp from the

seed by density differences. We put the roasted seeds in a plastic bag and smashed them with

a hammer until they cracked. Then we dumped the seeds in a container of water. Our

hypothesis was that the density difference between the shell and the endocarp would lead the

shell to float (lower density) and the endocarp to sink (higher density due to proteins).

Unfortunately, everything sank after we poured the cracked seeds in the container. We tried

the experiment again with vegetable oil as the solvent, but again, to no avail.

The problem with our density experiment was that our seeds had been cracked

excessively by the hammer, and so every piece was very fine. With such small particles,

perhaps the density was not a big enough factor in separating the endocarp from the shell. In

the future, one might try to crack the seeds less. The problem with cracking the seeds is that

the seeds are kidney shaped, and therefore cracking the seeds in half or fourths would not

help, since the endocarp would cling tightly to the curvy shell. We also did not have

information about the density of the shell or the endocarp, but based the experiment on our

knowledge of proteins and nutrients in the endocarp, which are larger than carbohydrates that

compose the shell (Port).

Another idea was to have a machine peel the seeds through a series of cheese grating like

methods. Similar to what is used in industry to peel potatoes, a cylinder of fine zesting or

shaving metal would rotate around a screw augur. As gravity and the augur moved the seeds

down the rotating shaver metal would chip away at the shell. At the bottom you would get

just the endocarp. This method was not extensively tested, but after looking at patents for

machines, like an automated chestnut peeler, this may be a very successful design. It could be

used on both baked and unbaked seeds.

Pectin Extraction

Since cream of tartar has been attributed to baobab pulp (Mahr), we decided to try and

extract pectin from the pulp. Our procedure (Joyea) was as follows:

Heat 600 mL distilled water on Bunsen Burner

Add 41 grams of baobab pulp with seeds to hot water

Add 1 tbsp acetic acid

Boil mixture for 15 minutes

Filter mixture through Whatman 12.5 cm glass microfiber filter

Add 250 mL of 95% ethanol to filter

Pump mixture through filter and save liquid pectin contents

Filtering pulp and seeds

Extraction after boiling and filtering pulp Adding 95% Ethanol

(Above^) Alcohol precipitation of pectin

(<Left) Mixing in the alcohol

(Both Below) Filtering pectin

With the successfully extracted pectin, we made jam and cookies. The extracted pectin

worked wonderfully well in baking and could very possibly be a vegan substitute for eggs.

The recipe we used for sugar cookies (E Cheryl) substituted two tablespoons of pectin for

every egg:

2 large eggs (2 tablespoons extracted pectin)

2/3 cup vegetable oil

2 teaspoons vanilla extract

3/4 cup white sugar

2 cups white flour

2 teaspoons baking powder

1/2 teaspoon salt

Mix ingredients and bake at 400 degrees Fahrenheit for 7 minutes

To compare the amount of pectin in baobab pulp to regular pulp, we made jam. We first

experimentally made jam with equal parts baobab pulp, water and double the amount of sugar.

The jam was a bit runny but held after refrigeration overnight. We compared our raw baobab

pulp in the baobab jam to strawberry jam made (30 Minutes) with store-bought pectin. The

results of the different jams were comparable, which verified that baobab pulp has a large

amount of pectin.

The results of our experiment showed that baobab pulp is rich in pectin. Extraction of the

pectin was easy and could be used to make vegan cookies. The vegan market is a popular and

quickly expanding market in the United States (Ginsberg), so the use of pectin from baobab

may lead to a sustainable export from Africa.

Leadership

Earlier in the semester, each member of our group took the Kiersey Personality Test and

our results were divided between Artisan and Guardian:

Alice Cheng – Artisan

Katie Kirsch – Artisan

Rachel Lower – Guardian

Alex Lubchansky – Guardian

Alice and Katie proved to be Artisans in their own ways. Alice enjoyed being creative

with different experiments and recipes with the baobab. Katie brought many innovative ideas

to the table when designing the pulp and seed separation machine. Rachel and Alex also

exhibited qualities of a Guardian. Rachel took initiative to build a solar cooker by herself

during Thanksgiving break. Alex oversaw many of the projects and gave much needed

support, as well as organized much of the work.

One obstacle we faced as a group was deciding what to do with a (former) group member

that was nice meeting expectations. We were divided on whether we wanted to keep him in

the group and give him a chance to prove himself, or letting him go. We waited for a few

weeks with no response from the member and finally decided to tell him that he would no

longer be able to participate in our group, since he would not be able to catch up with our

schedule. Alex really showed his Guardian side when he was able to communicate with this

group member and resolve the issue without wreaking havoc on the rest of the group.

Although we had different personalities, we worked together well and successfully

completed this project. Taking the personality tests was important because we each learned

about each other before the project began and we came in to the project knowing about the

traits of the other members. It also helped that certain members carried certain strengths, such

as communication, perseverance or creativity. All of these characteristics benefitted our group

throughout the semester and cumulated in a successful project.

Technology was also crucial for this project. YouTube, Google Patents, and various other

online sources provided a wealth of knowledge on the area we were designing this for and

what else has been done. Having this background knowledge gave us a competitive

advantage and saved us much time on failing and learning. Communication amongst the

group was also aided by technology. Social networking sites, Video conferencing, e-mail, and

cell phones were commonly used to update each other on the status of our project and set up

meetings. 3-D modeling software was used to design parts of the seed separation machine

without having to use resources to physically create them to convey the concept.

The importance of a global perspective and understanding was stressed in ENGR 408.

This project was designed to give students the opportunity to thing morally and help make the

lives of people thousands of miles away better. The team was able to use their knowledge to

create solutions that would significantly help the people of Benin. Freeing up the time women

spent meticulously peeling the seeds, fetching sticks and water to fuel the fires and boil the

seeds, and the overall Baobab processing time. Reducing the amount of manual labor would

allow them to do other productive things. Also providing a method for this region to process

this plant would allow them to sell the nutrient rich parts at a premium instead of shipping out

bulky whole fruits.

Conclusion

The group split into two teams to tackle the mechanical and chemical parts of the baobab

project. The chemical part consisted of understanding the nutritional and molecular qualities

of the baobab. Knowing the properties would help future teams decide how to market the

baobab properly. The mechanical team focused on creating processing machines to separate

the desired parts of the baobab, without requiring lots of time, fuel, or water. The chemical

team found that baobab pulp is a significant source of pectin and can replace more expensive

sources like apple pectin. They also found that roasting the seeds make them brittle and easier

to crack open. Other techniques to soften the shell, such as soaking in vinegar and water,

seemed to be fruitless. The mechanical team built a prototype of a machine to separate the

pulp from the seed. They also offered ideas to get the seed shell from the nut. The overall

team had many opportunities to show leadership through, global awareness, dealing with

delinquent group members, and using technology.

Works Cited

1. " 30 Minutes To Homemade SURE.JELL Strawberry Freezer Jam." Sure-Jell. 30 Nov

2009. Kraft Foods, Web. 30 Nov 2009.

<http://brands.kraftfoods.com/surejell/main.aspx?s=recipe&m=recipe/knet_recipe_d

isplay&recipe_id=50137>.

2. Addy, Rod. "Baobab fruit approved as food ingredient in US." Nutra Ingredients USA. 11

Sept 2009. Decision News Media, Web. 29 Nov 2009.

<http://www.nutraingredients-usa.com/content/view/print/259574>.

3. "Baobab Pulp." Baobab Fruit Company Senegal. 2009. BFCS, Web. 29 Nov 2009.

<http://www.baobabfruitco.com/ENG/Products/index.html>.

4. "CooKit." Solar Cooking. Web. 17 Nov. 2009.

<http://solarcooking.wikia.com/wiki/CooKit>.

5. "Egg Substitute." The Daily Dish Recipes. 23 Jun 2008. Cook With Me, Web. 30 Nov

2009. <http://cookwithme.today.com/2008/06/23/egg-substitute/>.

6. E, Cheryl. "Grandma's Soft Sugar Cookies." RecipeZaar. 3 Sept 2001. Scripps Networks,

Web. 30 Nov 2009.

<http://www.recipezaar.com/Grandmas-Soft-Sugar-Cookies-11345>.

7. Ginsberg, Caryn, and Alissa Ostrowski. "The Market for Vegetarian Foods." The

Vegetarian Resource Group. Vegetarian Resource Group, Web. 30 Nov 2009.

<http://www.vrg.org/nutshell/market.htm>.

8. Joyea, D. D., and G. A. Luzio. "Process for Selective Extraction of Pectins from Plant

Material by Differential pH." Carbohydrate Polymers (200): 337-42. Elsevier. Web.

1 Nov. 2009. <www.elsevier.com/locate/carbpol>.

9. Mahr, Dan & Susan. Baobab Trees. University of Wisconsin, 24 Nov. 2009. Web. 29

Nov. 2009

<http://www.hort.wisc.edu/mastergardener/features/indoor-tenderplants/baobabs/bao

bab.htm>.

10. Manfredini, Stefano. "Baobab Fruit Pulp 100% Native Dried." Baobab Fruit. 1 Jul

2008. BFCS, Web. 29 Nov 2009.

<http://www.baobab-fruit.com/BaobabFruitPulp_DS_2008NA.pdf>.

11. Nirvana, H. Baobab. Blue Planet Biomes, 7 Nov. 2006. Web. 29 Nov. 2009

<http://www.blueplanetbiomes.org/baobab.htm>.

12. Port, Tami. "What Are Organic Molecules? Carbohydrates, Proteins, Lipids and Nucleic

Acids." Suite 101. 15 Oct 2007. Suite 101, Web. 29 Nov 2009.

<http://organic-chemistry.suite101.com/article.cfm/what_are_organic_molecules>.

13. Wyatt, Mark. "Alice from Penn State." Message to Alice Cheng. 6 Nov 2009. E-mail.

Special Thanks

We would like to give thanks to the following people who contributed greatly to the success of

our project:

Dr. Lisa Steinberg, our advisor throughout the semester

Dr. Richard Schuhmann, our professor, for providing an ongoing baobab project

Mark Wyatt of the Baobab Company Senegal, who generously provided baobab fruit and

seed endocarp