Abstract

In this study, collagen peptide products (SFC) were prepared using solid-state fermentation of chrome tanned leather shavings (CTLS) by Serratia marcescens G and compared with alkali extracted collagen peptide products (AEC) and acid extracted collagen peptide products (ADC). SDS-PAGE electrophoresis revealed a wide relative molecular weight distribution for SFC and ADC, while AEC exhibited a concentration around 200 and 160 kDa. Scanning electron microscopy depicted a multi-layer sheet-like structure for SFC and ADC, contrasting with the dense block-like structure of AEC. X-ray diffraction indicated the formation of amorphous structures in products produced through acid or solid-state fermentation. Chromium content analysis through ICP experiments revealed levels in the order ADC > SFC > AEC. Thermal stability assessment using a rotational viscometer ranked the products as AEC > SFC > ADC. Measurement of pH effects on solubility determined the isoelectric points of SFC and AEC as pH = 6, while those of ADC were pH = 4. Experimental results on oil absorption, water absorption, water holding capacity, and emulsifying capacity showed that SFC exhibited the highest oil absorption capacity, ADC had the highest water absorption capacity, SFC and AEC demonstrated better water holding capacity, and SFC and ADC exhibited superior emulsifying capacity.