Physicochemical Analysis of Adlay ( Coix lacryma-jobi ) and Mung Bean ( Vigna radiata ) Rice Analogue

Introduction: Indonesia's heavy reliance on rice as a staple food has raised concerns regarding food security amid declining domestic production. To address this issue, developing rice analogues from underutilized crops offers a sustainable approach to diversifying staple food options while maintaining nutritional adequacy. This study aimed to formulate rice analogues using adlay (Coix lacryma-jobi L.) and mung bean (Vigna radiata), two nutrient-dense and underutilized crops with high potential to improve food security. Methods: Various formulations with different adlay and mung bean flour ratios were prepared through extrusion cooking, and their physicochemical properties were evaluated in comparison to conventional rice. Key parameters assessed included moisture content, crude protein, color, texture (hardness), bulk density, Water Absorption Index (WAI), Water Solubility Index (WSI), Water Absorption Ratio (WAR), cooking loss, and cooking time. Results: Among the tested formulations, the 70:20 adlay-to-mung bean ratio showed the most comparable characteristics to regular rice, with 16.18% crude protein, a whiteness level of 76.11, hardness of 9.48 kgf, bulk density of 0.734 g/mL, WAI of 2.42 g/g, WSI of 3.86%, WAR of 185.61, cooking loss of 1.59%, and cooking time of 28.5 minutes. Discussion: The inclusion of mung beans improved protein content, although excessive levels negatively affected texture. While the current formulation shows promise, further optimization is needed to improve cooking efficiency and reduce solubility and loss. Conclusion: This study highlights the potential of adlay and mung bean-based rice analogues as viable rice substitutes, contributing to both food security and agricultural sustainability in Indonesia.