Photo Credit: Catie Baumer Schwalb (Pitchfork Diaries) “Suprême” refers to the classic culinary technique of removing the flesh of citrus from the pith, or the white spongy layer in between citrus segments composed mainly of pectin and cellulose. Removing the pith, which is characterized by a distinctly bitter flavor, enhances the perceived sweetness in citrus fruit [1]. Though “suprême” may sound like a fancy-schmancy technique reserved for the finest of dining, citrus suprême can be found in common everyday foods such as mandarin orange slices on salads and garnishes in cocktails. Classic citrus suprême is made by cutting off the top and bottom of the fruit, removing the pith with a knife, and cutting each segment out from between the membrane. However, this produces a lot of waste, as it is not possible to completely clean the pith of the fruit. It is also not efficient for large-scale industrial processing. Solution: pectinase.
Figure 1: The leftover pith waste from citrus supreme. Photo Credit: The Cherry Share Pectinase is a general term for an enzyme that breaks down pectin, or the polysaccharide contained in plant tissue [2]. I set out to test the efficacy of pectinase in my own kitchen. I used the pectinase Pectinex Ultra SP-L, a polygalacturonase that is derived from the fungus Aspergillus Aculeatus [3]. Using a recipe from Chef Steps, I proceeded with the following protocol: Recipe for Citrus Suprême [3]: 250g Citrus (About ½ pound citrus, or about 2 tangerines) 250g Water (About 1 cup water) 2.5g Pectinex Ultra SP-L (About ½ teaspoon)