Stories from the Lab: The Grand Finale—My Senior Thesis Project!

All of my training and education during the CIA bachelor’s in culinary science program came together in my Senior Thesis Project. Throughout all my classes, the chefs and instructors taught me the importance of culinary knowledge, food safety, quality assurance, research and development, and food manufacturing.

To begin the process of my project, I had to come up a with a scientific question. My observation was directed towards eggplant. Whenever I would see chefs on TV or physically in the kitchen preparing eggplant, they would often have a different preparation and method. I decided to focus my experiment on salting eggplant before the initial cooking process.

Many people salt eggplant before cooking it. It’s a technique that has been passed down from generation to generation. Some chefs swear by this technique, saying it’s a necessary step for flavor, while others bypass it, claiming it’s unnecessary.

I recognized this when I was working at an Italian restaurant in my home state of New Jersey. While preparing eggplant parmesan, the chef simply cut and roasted the eggplant first, without salting it. When I asked why he did not salt it beforehand, he said he never salts eggplant at all. However, when I was researching eggplant recipes, especially in the CIA’s The Professional Chef cookbook, some of the eggplant recipes required a 30-minute salting period. I decided to test out this theory to see if there were any noticeable changes or differences between salting and not salting before the cooking process and to see which yielded  better results.

The Science Behind It

What does salting really do? Eggplant has a complex structure. Due to the numerous air pockets present in its system, it has a spongy texture. Because of this sponginess, eggplant tends to soak up oil and shrink when they are cooked. To help prevent this from happening, salt concentrations can be added prior to cooking to draw out water into the air pockets, which causes the structure to collapse. Eggplant is mostly composed of water, having upwards of 92.7% concentration levels.

Eggplant also tends to be bitter because of its glycoalkaloids, which help guard against pests and other plant diseases during its growing phase. Most eggplant have higher bitterness qualities that are found in its pulp. Some chefs and culinary experts find this bitterness to be a negative attribute—depending on what they are cooking—and seek ways to isolate it, while others don’t mind the bitter quality at all. Salting the eggplant before cooking is a key way to remove it through osmosis, which draws out any bitter liquids. Osmosis is the net movement of water across a selectively permeable membrane due to the difference in solute concentrations.

To Salt or Not to Salt? That is the Question

To start my research and project, I went around the Hyde Park campus and asked several different chefs whether or not they salt eggplant. The CIA has more certified master chefs than any other culinary school, so I knew that I would get useful information from them. Out of the eight chefs that I asked, three said that they do not salt eggplant, but five said they did.

In the lab, I tested several different methods for my project. I decided to cut the eggplant in ¼-inch circles and salt them with .1 grams of salt for 30 minutes. I took the beginning weight of each eggplant circle sample, salted it, and rinsed it after the 30-minute salting period. After I rinsed it, I vacuumed-packed and sous-vided it for 20 minutes, then weighed the sample again. I then repeated the experiment, but did not salt the eggplant before sous-viding it for 20 minutes.

sous-viding eggplant

After analyzing the results of my experiment, I recommend salting. The eggplant samples were two completely different colors. The appearance of the salted sample was light green/lime-colored with white seeds, while the unsalted sample was dark brown with dark seeds. Even the textures of each sample were different, with the salted variable being spongier than the unsalted variable, which had a denser and firmer texture. I did a colorimeter test on the samples to confirm the color difference. The unsalted sample was found to be darker, redder, and less yellow than the salted sample.

I also did a triangle test around campus to see if panelists could correctly identify the different samples. In a triangle test, two of the samples are the same, while one is different. Because the color differences in the eggplant were somewhat obvious, I added tomato sauce to the samples. Out of 50 panelists, 28 students correctly identified the different sample, while 22 did not, which showed me the samples were significantly different from one another. Some common comments that I received were that the salted sample was salty, smooth, seasoned, and flavorful, while the unsalted sample was said to be bitter, bland, and with a harder skin and different texture.

My classmates also had other interesting Senior Thesis projects, including:

  • Emma Sapiro, who tested whether aquafaba works as an egg replacer in making French meringue
  • Laurie Borden, who tested the cleaning techniques of mushrooms, with the dry towel method vs the water method
  • Yasmin Simpson, who tested the effects of making stabilized whip cream with sheet gelatin versus powdered gelatin

My Senior Thesis project was one of the most challenging activities I’ve done during my time here at the CIA thus far. I spent weeks coming up with potential topics, and then spent many more weeks researching the chemical and biological composition of both the eggplant and salt; then I needed to find a reasonable ratio for the salt on the eggplant and the thickness to cut the slices. Independent projects like this are common when developing recipes, formulas, and products in the field, so it was a great learning experience.

Well, this is my final culinary science blog—but you will still be able to read about my CIA adventure with my double-major Applied Food Studies blogs, which will coming soon! Experiencing this culinary science major has been one of best moments in my life thus far. I personally cannot thank Professor Monaghan, Chef Zearfoss, Chef Lui, and Dean Russin enough for providing an excellent CIA education and for giving me and other classmates the tools to succeed in the industry. I can’t wait to make a meaningful career out of what my instructors taught me and to have a huge impact in the food world and culinary science field. From making $20 fine-dining meals to taking a class trip to Rich’s to fermenting sausages to creating kimchi, I hope you learned from and enjoyed my STORIES FROM THE LAB!

Majestic Lewis-Bryant