Colour variations and distribution of quinones in samples of teak wood from various regions of Kerala

Teak (Tectona grandis Linn.) exhibits notable colour and chemical variability across Kerala’s diverse ecological regions, yet the links between heartwood colour parameters and quinonoid composition remain insufficiently understood. This study aims to examine the colour variation and distribution of quinones and relative extractives in teak heartwood collected from seven localities of Kerala. Heartwood samples from 40-42 year old trees were analyzed using the CIE Lab and Munsell colour systems, while GC-MS was used to identify and quantify key quinones (including tectoquinone, tectol, lapachol, and isodesoxylapachol) and sualene. Statistical analysis, including ANOVA and Pearson’s correlations, were performed to determine inter-regional differences and metabolic relationships. Nilambur showed the lowest lightness values (L = 49.39±2.86) and the highest quinone concentrations, particularly tectoquinone (0.29%), whereas Kanjiramkulam exhibited higher lightness (L = 56.33±2.93) and lower extractives levels. Strong correlations were observed between hue angle and chroma (r = 0.91, p < 0.001), indicating a coordinated biosynthetic pattern influencing colour development. The work is novel in integrating colourimetric data with quantitative extractive profiling across multiple localities, revealing how eco-physiological conditions drive metabolic variability in teak. The findings provide practical value for locality-based grading, durability prediction, and future breeding strategies targeting superior-quality teak. This work is novel in integrating colourimetric data with quantitative extractive profiling across multiple provenances, revealing how eco-physiological conditions drive metabolic variability in teak. The findings provide practical value for provenance-based grading, durability prediction, and future breeding strategies targeting superior-quality teak.