Assessment of Soaking Solutions for Oxalate Reduction in Locally Known “Galyang” Collected from Cauayan City, Philippines

Abstract

This study examined the effects of household processing methods on the oxalate content of a locally sourced “Galyang,” a taro-type plant collected from Barangay Marabulig I, Cauayan City, Isabela. The study was anchored on the principle of oxidation-reduction reactions used in permanganometric titration for oxalate determination. A two-factor Completely Randomized Design (CRD) with subsampling was employed to evaluate oxalate reduction between raw and processed samples. Young leaves, stalks, and corms of Galyang were subjected to different immersion treatments, including water, 10% salt solution, 10% vinegar solution, and a combined 10% salt and 10% vinegar solution. Oxalate content was determined through permanganometric titration using standardized 0.05 N KMnO₄ solution, while statistical analysis was performed using the Linear Mixed Model through jamovi version 2.6.23.0. The findings revealed that the leaves exhibited the highest oxalate content, followed by the stalks, while the corms had the lowest oxalate level, with a significant difference observed between the leaves and corms. Significant differences were also observed among immersion treatments. The control treatment recorded the highest oxalate content, while the combined salt and vinegar treatment showed the lowest oxalate level. Soaking in salt solution and salt-vinegar solution effectively reduced oxalate content compared to untreated samples, whereas soaking in plain water was less effective. The reduction in oxalate levels was attributed to the leaching of soluble oxalates into the soaking medium. The study concluded that simple household immersion methods may improve the safety and potential utilization of Galyang as a food source and for possible product development. Future studies are recommended to investigate additional processing techniques, nutrient retention, sensory properties, and specific oxalate forms in Galyang. The study aligns with SDG 2 (Zero Hunger), SDG 3 (Good Health and Well-Being), and SDG 12 (Responsible Consumption and Production) through the promotion of food safety, improved utilization of underutilized crops, and practical household processing methods. The findings contribute to socio-economic, nutritional, and public health sustainability by encouraging accessible food processing techniques and safer dietary practices.