Indigenous knowledge in the Kithul (Caryota urens L.) industry of Sri Lanka and its scientific basis

Exploitation of the kithul palm (Caryota urens L. Arecaceae) is an ancient industry in Sri Lanka, yet it is neither commercialized nor cultivated. Naturally established palms in the agroforestry systems or in the wild are used to produce food, beverage, timber, and traditional medicines. As kithul cultivation is not commercialized, the related production systems are not mechanized, products are not standardized, or value added. Each step related to kithul products has specific sets of methods learnt through experience, disseminated from one generation to the next. Diverse kithul products are used in diets, in industry and some of its products are integrated with Ayurvedic medicine. The scientific research findings corroborate some beneficial properties of kithul products such as floral sap, treacle, jaggery, toddy, vinegar and flour, claimed by ayurvedic physicians. Kithul products have many potential uses in the food industry, pharmaceuticals, bioremediation, energy production, and structural engineering. This review compiles the indigenous knowledge system behind the kithul industry in Sri Lanka and the scientific findings justifying the practices in the industry and properties of the products. We highlight the need to scientifically explore certain components in the industry such as the seasoning mixtures used for tapping the sap to develop more effective commercial products, develop innovative tapping and processing technology, and improved cultivars and establishment of plantations. We have also shown the scientific basis of the medicinal value of kithul-based products already used in local Ayurvedic medicine.