Total Phenolic and Starch Content of Arrowroot Tuber in The Agroforestry System

Abstract

Indonesia's tropical forest management faces several challenges owing to the growing demand for forest resources and increasing population. The forestry sector plays a significant role in supporting food security programs by harnessing the potential of forest resources. One solution to sustainable forest management and optimal forest land use is agroforestry techniques. Arrowroot (Maranta arundinacea) is tolerant to heavy shade and is a promising functional food crop that can contribute to food security programs. Starch content in arrowroot tuber plays an important role in meeting nutritional requirements and overcoming several health problems. Arrowroot tubers also contain phenolic compounds, the largest group of compounds that act as natural antioxidants in plants. This study aimed to analyze the total phenolic and starch contents of arrowroot tubers cultivated in agroforestry systems. We used a Randomized Complete Block Design with a planting pattern as treatment for the species combinations of Falcataria moluccana + arrowroot (FA), F. moluccana + arrowroot + Amomum cardamomum (FAC), and monoculture arrowroot (MA) with three blocks/replications. The arrowroot tubers were harvested from nine-month-old plants and composite samples representing each treatment were analyzed for total phenolic and starch contents. The total phenolic content in the arrowroot tubers was determined using the Folin-Ciocalteu reagent. Starch content was measured using the Modified Somogyi method, which involves preparing reagents, followed by hydrolysis and the reducing sugar determination methods. The results revealed that the planting pattern significantly affected starch content. The highest starch content was observed in the MA pattern of 23.99%, followed by the FAC and FA planting patterns of 22.75% and 18.44%, respectively. The planting pattern did not significantly affect phenolic content. The MA, FAC, and FA patterns yielded the highest to lowest phenolic contents of 218.02, 212.62, and 210.04 µg/g, respectively. Furthermore, the planting pattern significantly affected the total phenolic of tuber yield per plant, with the highest value of 214.48 mg yielded by MA pattern. Thus, agroforestry practices can maintain the phenolic and starch content of arrowroot tubers. The development of arrowroot in agroforestry system will be prospective not only for meeting food demand, but also for supporting forestry multi-business and social forestry programs to achieve sustainable forest management.