Characterization of Essential Element Profiles in Red Sorghum Hydrolysis under Multivariate Conditions of Enzyme Level, pH, and Time

Abstract Red sorghum ( Sorghum bicolor L. Moench) is a nutrient-dense cereal containing essential macro- and micro-minerals vital for human health. Enzymatic hydrolysis is essential in breaking down the complex matrix of sorghum, releasing valuable constituents. This study aimed to profile the release of essential element during enzymatic hydrolysis of red sorghum using papain under varying processing conditions using chemometric approach. Hydrolysis was performed with three enzyme concentrations (w/w: 0.1%, 0.3%, and 0.5%), pH levels (7, 8, and 9), and incubation times (2, 4, and 6 hours). To quantify the release of macro-micro essential elements, Elementomic analysis was conducted using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Chemometric methods, including Principal Component Analysis (PCA) and Partial Least Squares Discriminant Analysis (PLSDA),-were employed to assess treatment effects and identify optimal hydrolysis conditions. The findings showed that hydrolysis facilitated the release of essential metals, with 80–98% recovery observed for Mg, P, K, Fe, Zn, Mn, and Se across most treatments relative to raw sorghum. Notably, treatments 5 and 6—both using 0.5% papain at pH 8 for 2 and 6 hours, respectively—yielded the highest release and enrichment of key elements, particularly Mn, Fe, K, Mo, Se, and Zn. The findings from PCA and PLS-DA revealed that the treatment groups were more distinctly clustered based on enzyme concentration and pH levels rather than hydrolysis duration. Furthermore, the variable importance in projection (VIP) analysis highlighted phosphorus (P), potassium (K), and magnesium (Mg) as major discriminating variables contributing to group separation. These findings demonstrate that optimized enzymatic hydrolysis can significantly enhance the bioavailability of essential minerals in red sorghum, providing valuable insights for developing mineral-rich functional food ingredients.