Friday, February 27, 2009

Touch of Africa; Spring Class on African Food and Culture

It's been hectic for me lately. Last Saturday night was Penn State's annual Touch of Africa celebration sponsored by the African Students' Association. As usual, it was a sold-out event (500 tickets) and a cultural extravaganza that gave the students and the community an opportunity to taste unfamiliar foods and experience the music, fashion, story-telling and energy of Africa, largely normally unavailable to central Pennsylvanians. I was brought in late in the game to oversee the preparation of the food with the The Penn Stater's professional cooking staff and some student volunteers. I don't generally do quantity cooking, so it was a challenge, but the team managed to pull it off with help from The Penn Stater's chef Ken Stout and his staff. A few (very few--I was too busy to take pictures) photos from the event are up on my BETUMI account on flickr. The menu included several West African dishes, representing the heavily West African ASA membership (efo stew with greens and beef and smoked fish and smoked ground shrimp and palm oil), egusi (a.k.a agushi, a fabulous melon seed and one of the so-called "lost crops of Africa") soup, puff puff (a Nigerian doughnut), chicken jollof rice, fried ripe plantains, hot and mild versions of Ghanaian-style tomato gravy, and bissap (hibiscus chilled tea with lemon grass and pineapple juice), as well as North African-style couscous, East African coconut basmati rice and Somali sombosas, roasted chicken, tilapia with sauce, and all-Africa tropical fruit salad with flaked coconut.

Sore Shields of The African Market and I coordinated a silent auction to raise money for 2 charities in Africa, and Kunmi Oluleye of Flavors of Africa generously donated copies of her cooking dvd of Nigerian, Kenyan, and South African cooking (first in a series of 17 planned). Thank you to everyone who helped and bid on the items.

Now, I need to get ready to teach a five-week African cooking (and culture) course beginning March 18. . . Never a dull moment.

Wednesday, February 11, 2009

Food Science of African Tastes: comminution and the asanka

Anyone familiar with African cuisines knows that grinding and pounding are important cooking techniques, and texture matters. She or he also knows that while an electric blender is a lot faster and easier than a mortar and pestle or a grinding stone or bowl, it comes at a cost: a deterioration of flavor.

Prof. Sefa-Dedeh, Professor of Food Science and Technology, and Dean of the Faculty of Engineering Sciences at the University of Ghana, talked to me about why these taste differences occur.

I asked why a blender gives such different results, than say, the Ghanaian asanka pictured above. Asankas are ubiquitous in Ghanaian kitchens: they are clay grinding/mashing bowls with ridged surfaces and are used with a wooden masher. I keep several in my Pennsylvania kitchen, especially for making fresh pepper sauces.

He explained to me that there are several reasons for the differences and began by mentioning there are "attrition" and "impact" forces. First, you begin with a solid material like ginger or tomato or chili peppers or garden eggs (similar to a small eggplant), cooked or uncooked, which you want to shred. Each ingredient has cells in it with a structure, and in the cells are all the taste and flavors. For example, when you break a piece of ginger you begin to smell it because you have broken down the cells and some of the compounds begin to interact.

When you use an asanka as your "size reduction equipment," the amount of force you apply to the ingredients is much less than you get from a blender. With something like a pepper, you generally don't want a lot of impact, you're more interested in shearing and tearing the structure, but not completely. In the blender you are "comminuting" (pulverizing) all the ingredients together so you may actually lose some of the flavor. Ghana's traditional mashing bowl conserves the flavor because of the way it separates the particles.

Finally, when you eat a product, different particle sizes will likely give different tastes even though the ingredients may be the same. For example, some people may cook a soup with a whole pepper in it. If you're eating the soup and you bite into certain peppers, a single bite of the pepper releases the compounds that interact with your tongue and palate and gives you a certain sensation in your mouth (the flavor chemistry).

So, the differences are partly due to the equipment used for the size reduction to give you a certain product. When you put that product in your mouth a certain reaction takes place. To summarize, when you put food into a blender to blend it you have virtually broken all the tissues into one mass, and the effect in your mouth is not the same as when you pound or mash the ingredients.

I guess I intuitively knew this, but still it was nice to have Prof. Sefa-Dedeh explain it. Soon I'll share his insight about fermentation and answer to my question about why I have not yet succeeded in souring dried corn to make an authentic corn dough for Ghanaian-style kenkey.

Footnote: Last week I mentioned that BETUMIBlog had been selected as one of the "100 Best Blogs for Learning About Africa." This week I was informed that it is on another list: this time as one of the "Top 50 Blogs for Studying Africa." I'm not sure who "University Reviews Online" actually is, but thought I'd mention it for what it's worth.