Quality characteristics of cheese whey from Kenyan dairy processors and their suitability for downstream valorisation

Whey streams from sixteen cheese processors across Kenya were examined to determine their suitability for downstream valorisation in a circular bioeconomy context. Samples were analysed for pH, total solids, moisture, fat, crude protein, ash and minerals, and lactose using standard AOAC methods, atomic absorption spectroscopy, and titration. Moisture ranged from 93.5 to 94.0%, total solids 6.0-6.5% (w/w), fat 0.4-1.0%, protein 0.3-1.0%, ash 0.5-0.6%, and pH 4.2 to 5.6. Mineral contents were calcium 0.016–0.019% (w/w), sodium 0.037–0.042% (w/w), potassium 0.09–0.13% (w/w), and chloride 0.037–0.039% (w/w). Lactose content ranged from 3.9 to 5.7% (w/w) across samples, with significant differences observed among whey types (p < 0.05). One-way ANOVA revealed no significant differences in overall mean composition across processors (p = 1.00), indicating broad consistency despite variations in cheese types and processing scales. However, significant differences existed among whey types for lactose, fat, protein, ash, calcium, and potassium (p < 0.05), reflecting coagulation methods (rennet vs. acid). The composition of Kenyan whey aligns with global benchmarks. It contains valuable fermentable components, especially lactose and residual proteins, making it suitable for microbial fermentation, animal feed, and other value-added applications. Standardized quality assessment and targeted pre-treatments can enhance valorisation, reducing environmental impact from disposal and supporting Kenya’s growing dairy sector, while opening new opportunities in the circular bioeconomy.