Objective:
The cork used in the manufacture of natural cork stoppers or technical stoppers must meet a number of conditions, including being free of certain anomalies. The use of NIRS (near infrared spectroscopy) technology has proven to be a valid technique for detecting yellow stain and corkbark, which are defects that must be avoided due to their harmful effects on the properties of the cork.
Context:
The manufacture of natural and technical cork stoppers requires the use of cork free of certain anomalies to prevent the cork from acquiring unwanted characteristics. Two of those anomalies are ‘yellow stain’ and ‘corkbark’. Yellow stain produces a yellow discoloration in the stoppers and confers a mould-like taste due to the TCA biosynthesis it causes. Corkbark changes the density of the cork, affecting the mechanical behaviour of the stoppers. Quality control for such anomalies is only standardized for cork stoppers. Such techniques cannot be applied to raw cork due to the high cost and high variability of the material; hence cork planks are currently assessed visually.
Contacts:
David Pérez-Terrazas, david.perez.terrazas@alumnos.upm.es, www.upm.es
José Ramón González-Adrados, joseramon.gonzalez.adrados@upm.es, www.upm.es
Mariola Sánchez-González, msanchez@inia.es, www.inia.es
Further information:
Pérez-Terrazas, D., González-Adrados, J. R., & Sánchez-González, M. (2020). Qualitative and quantitative assessment of cork anomalies using near infrared spectroscopy (NIRS). Food Packaging and Shelf Life, 24, 100490.