Black Pepper

Environmental & Science Education, STEM, Nature of Science, Miscellaneous

Ed Hessler

Another puzzle in the spice trade has been solved. It is reported on by Stephen Carmichael of the Mayo Clinic, MN in his regular column, Carmichael's Concise Review, for MicroscopyToday, January 2023.

Ground-up, dried fruits of black pepper (Piper nigrum)  is a commonly used spice -- it is one of my favorites which includes the sound and feel of grinding the fruits. Carmichael begins by wondering about the first people to taste pepper seeds and their experience of it. Once in the mouth, he writes, "a pain receptor that is also stimulated by...capsaicin. Stimulation of that receptor is at the heart of a centuries-old spice trade that is still flourishing today."

The cause of pepper's pungency is due to the chemical piperine "in combination with a blend of naturally occurring organic chemicals." Two questions have long remained about piperine, "its cellular localization and complete biosynthetic pathway." One of these has been solved by a research team at the Leibniz Institute of Plant Biochemistry and the results published in The Plant Journal. 

The research question was whether piperine is produced in one place and then stored in another or whether production and storage occur in the same location.

I was immediately struck by the number of techniques the research encompassed, "including," as Carmichael writes, "but not limited to, purification of the native enzyme, immunolocalization, fluorescence microscopy,and electron microscopy that produced "experimental evidence that...the synthesis and storage of piperine occur in the same location."  However, "there remain several unanswered questions about the biosynthesis and storage of piperine and related compounds."

The technical paper referred to above may be found here. While it is for specialists there are parts you may find helpful, e.g., some of the abstract and introduction and the illustrations in which are included many images providing the case for their finding. One of these, much enlarged, is included in Carmichael's reporting. The paper includes a listing of the contributions made by each author which emphasizes the various skills each brings. 

At the top of one of the pages from the Leibniz Institute of Plant Biochemistry I found this statement on what the Leibniz Association regards as Good Scientific Practice: "The basis for scientific work is the honesty of scientists towards themselves and others. This is the ethical standard and the basis for the rules of good scientific practice. Validating and applying these rules in practice is a key task for the sciences." 

 

Denoting "in practice" focuses on the people and places where research is done.