Household soybean processing, protein content, and caregiver acceptability of complementary porridges in rural Malawi

Child undernutrition remains a major public health challenge in Malawi, where inadequate dietary protein contributes to persistent stunting and poor child health outcomes. Soybean (Glycine max) is a locally cultivable and protein-rich crop with potential to strengthen complementary feeding in resource-constrained rural settings. However, the nutritional and practical effectiveness of soybean-based complementary foods depends on household-level processing methods and caregiver acceptability.

A community-based experimental study was conducted in Dowa District, Central Malawi, in July 2025. Four locally cultivated soybean varieties were subjected to five household-level processing methods: untreated (control), soaked, roasted, dehulled, and dehulled-and-roasted. Protein content was determined using the Kjeldahl method with triplicate laboratory analyses. Caregiver sensory evaluation was conducted among 60 caregivers attending under-five clinics using structured tasting sessions assessing aroma, flavour, texture, and overall acceptability on a 10-point Likert scale. Data were analyzed using Kruskal-Wallis H tests, Mann-Whitney U tests, repeated-measures ANOVA, and bootstrap resampling to estimate 95% confidence intervals.

Measured protein content differed significantly across soybean processing methods (H = 12.68, df = 4, p = 0.013). Dehulled soybean flour demonstrated the highest measured protein content (21.26% ± 0.12; 95% CI: 21.12–21.40), while soaked soybean flour demonstrated the lowest (11.85% ± 0.11; 95% CI: 11.73–11.97). Caregiver sensory evaluation additionally differed significantly across processing methods (p < 0.05). Dehulled-and-roasted soybean porridge achieved the highest overall acceptability score (8.2 ± 0.2), followed by dehulled soybean porridge (7.8 ± 0.4). Integrated assessment demonstrated that dehulled and dehulled-and-roasted soybean processing methods produced the most favorable combined nutritional and caregiver acceptability outcomes.

Household soybean processing methods substantially influence both measured protein content and caregiver sensory acceptability of soybean porridge in rural complementary feeding contexts. Dehulling, with or without roasting, represents a locally feasible household processing strategy with potential to strengthen soybean-based complementary feeding using existing agricultural resources. The findings highlight the importance of integrating nutritional quality with caregiver acceptability in the development of sustainable community-based child nutrition interventions in low-resource settings.