Sensory Science in the SAT

We were excited to learn that early work on umami taste by our very own Prof. Michael O’Mahony and Dr. Rie Ishii was recently featured in an SAT question — the standardized test used for admission to U.S. universities.

It’s not every day that sensory science shows up in a college entrance exam!

𝗧𝗲𝘅𝘁 𝟭

Soy sauce, made from fermented soybeans, is noted for its umami flavor. Umami—one of the five basic tastes along with sweet, bitter, salty, and sour—was formally classified when its taste receptors were discovered in the 2000s. In 2007, to define the pure umami flavor scientists Rie Ishii and Michael O'Mahony used broths made from shiitake mushrooms and kombu seaweed, and two panels of Japanese and US judges closely agreed on a description of the taste.

𝗧𝗲𝘅𝘁 𝟮

A 2022 experiment by Manon Jünger et al. led to a greater understanding of soy sauce's flavor profile. The team initially presented a mixture of compounds with low molecular weights to taste testers who found it was not as salty or bitter as real soy sauce. Further analysis of soy sauce identified proteins, including dipeptides, that enhanced umami flavor and also contributed to saltiness. The team then made a mix of 50 chemical compounds that re-created soy sauce's flavor.

𝗕𝗮𝘀𝗲𝗱 𝗼𝗻 𝘁𝗵𝗲 𝘁𝗲𝘅𝘁𝘀, 𝗶𝗳 𝗜𝘀𝗵𝗶𝗶 𝗮𝗻𝗱 𝗢'𝗠𝗮𝗵𝗼𝗻𝘆 (𝗧𝗲𝘅𝘁 𝟭) 𝗮𝗻𝗱 𝗝𝘂𝗻𝗴𝗲𝗿 𝗲𝘁 𝗮𝗹. (𝗧𝗲𝘅𝘁 𝟮) 𝘄𝗲𝗿𝗲 𝗮𝘄𝗮𝗿𝗲 𝗼𝗳 𝘁𝗵𝗲 𝗳𝗶𝗻𝗱𝗶𝗻𝗴𝘀 𝗼𝗳 𝗯𝗼𝘁𝗵 𝗲𝘅𝗽𝗲𝗿𝗶𝗺𝗲𝗻𝘁𝘀, 𝘁𝗵𝗲𝘆 𝘄𝗼𝘂𝗹𝗱 𝗺𝗼𝘀𝘁 𝗹𝗶𝗸𝗲𝗹𝘆 𝗮𝗴𝗿𝗲𝗲 𝘄𝗶𝘁𝗵 𝘄𝗵𝗶𝗰𝗵 𝘀𝘁𝗮𝘁𝗲𝗺𝗲𝗻𝘁?

𝗔. The broths in the 2007 experiment most likely did not have a substantial amount of the dipeptides that played a key part in the 2022 experiment.

𝗕. On average, the diets of people in the United States tend to have fewer foods that contain certain dipeptides than the diets of people in Japan have.

𝗖. Chemical compounds that activate both the umami and salty taste receptors tend to have a higher molecular weight than those that only activate umami taste receptors.

𝗗. Fermentation introduces proteins responsible for the increase of umami flavor in soy sauce, and those proteins also increase the perception of saltiness.

𝗘𝘅𝗽𝗹𝗮𝗻𝗮𝘁𝗶𝗼𝗻

𝗖𝗵𝗼𝗶𝗰𝗲 𝗔. This is the best choice. Ishii and O'Mahony were trying to isolate the pure umami flavor, while Jünger was trying to recreate soy sauce, which has a mix of flavors that includes umami. Accordingly, the broths from Text 1 are not described as having any soy sauce in them—just "shiitake mushrooms and kombu seaweed". So they probably don't have as much of the dipeptides described in Text 2, which were found to be a key part of soy sauce's umami-ness and its saltiness.

𝗖𝗵𝗼𝗶𝗰𝗲 𝗕. Neither text supports this. Neither text gets into the diets of people in the United States, nor the diets of people in Japan.

𝗖𝗵𝗼𝗶𝗰𝗲 𝗖. Neither text supports this. Text 2 does talk about the molecular weights of chemical compounds, but there isn't enough information provided about molecular weights in Text 1 to make an inference about what the scientists in Text 1 would say.

𝗖𝗵𝗼𝗶𝗰𝗲 𝗗. Neither text supports this. Text 1 briefly mentions that soy sauce is "made from fermented soybeans", but it never claims that fermentation is responsible for its flavor in any way. And Text 2 never mentions fermentation at all.