Specific acids facilitate umami taste in cheese.

Umami is a basic taste component of many foods. Although monosodium glutamate (MSG) is commonly used to bring out the taste of umami, other compounds, including nucleotides and organic acids, also elicit umami taste.

Umami plays a crucial role in the flavor of many cheese varieties. Scientists at North Carolina State University were able to identify the compounds responsible for umami taste in Cheddar and Swiss cheeses. They selected four Cheddar and four Swiss cheeses--split among low-umami intensity and high-umami intensity from each type--using a trained sensory panel. MSG, disodium 5'-inosine monophosphate (IMP), disodium 5'-guanosine monophosphate (GMP), sodium chloride, lactic acid, propionic acid and succinic acid were quantified in the cheeses.

The investigators determined taste thresholds for each compound in water. The trained descriptive sensory panel used nose clips to eliminate aroma interference. The panel members evaluated each compound in odor-free water across threshold concentrations to confirm the thresholds were based on umami and not some other stimuli.

Model system sensory studies were conducted using whole milk mozzarella cheese, a bland low-flavor, low-umami cheese, and each compound individually or all compounds together. Data were analyzed by analysis of variance with means separation for significant differences.

The researchers found that that IMP and GMP thresholds were 100-fold higher than their concentrations in cheese. All other compounds contributed umami taste within their concentration range in umami cheeses. Analysis of single compound model cheese and N-1 model cheese revealed that glutamic and succinic acids played the largest role in umami perception. Lactic and propionic acids contributed lower intensities. Knowledge of the key compounds associated with umami taste in cheeses will aid in identifying procedures that enhance formation of this desirable taste in cheese.

Further information. Mary Anne Drake, Department of Food Science, North Carolina State University, 236-E Schaub Hall, Campus Box 7624, Raleigh, NC; phone: [phone]; fax: [phone]; email: [e-mail].