Optimized Bioresource Valorization: Geopedological Mapping of High-Value Glucomannan and Anti-Nutritional Cyanide in Amorphophallus muelleri Blume Across Southeast Sulawesi, Indonesia

The escalating global demand for functional ingredients necessitates the strategic optimization of high-value biopolymer sources, such as glucomannan derived from porang (Amorphophallus muelleri Blume). This study conducted a comprehensive comparative analysis of a single porang landrace harvested from seven distinct agroecological districts (P1–P7) across Southeast Sulawesi, Indonesia, to identify the optimal cultivation zone for industrial-quality tubers. Proximate, carbohydrate (NFE, starch), glucomannan, and anti-nutritional cyanide (HCN) contents were determined. Results revealed significant environmental sensitivity, particularly in the primary commercial and safety determinants. The concentration of the target biopolymer, glucomannan, exhibited high variability (51.47% to 69.09%), peaking decisively in the P6 district (69.09%). This superior yield was critically associated with the latosol/lithosol soil type found in a hill zone (120 m elevation), suggesting that well-drained, moderately stressed pedological conditions favor maximal polysaccharide synthesis. Concurrently, while anti-nutritional HCN content varied (32.17 ppm to 86.12 ppm), the level in the P6 sample (42.86 ppm) remains easily mitigated by standard processing, with the economic benefit of the high glucomannan content overwhelmingly justifying the minor detoxification cost. Furthermore, P7 yielded the highest structural components, recording peak crude protein (8.85%) and ash (7.57%), demonstrating the region's diverse capacity for producing nutritionally dense tubers. This research confirms that specific geopedological characteristics of the P6 district offer a robust ecological niche for maximizing the industrial quality of porang, providing an empirical basis for targeted agricultural investment and sustainable policy recommendations to enhance Indonesia's global commodity competitiveness.