Biothermokinetic characterization and evaluation on the quality of Colla corii asini

Colla corii asini (CCA) is a widely used animal-derived traditional medicine and nutritional supplement in China that has a variety of bioactive effects, especially anti-anaemic effects. To date, the effective substances in CCA are still unclear, thus limiting the evaluation of the quality and consistency of CCA. In this study, a microcalorimetry-based bioassay method was established to assess the quality of CCA by investigating its effects on the growth and metabolism of Escherichia coli, and ten biothermodynamic parameters were employed to characterize the biothermal changes. A principal component analysis (PCA) of these parameters showed that CCA significantly promotes the heat production of E. coli compared to that in the control group, and CCA showed an obvious dose–effect relationship from 0.625 to 20 mg mL−1. Then, the effects of 12 batches of CCA from three different manufacturers were studied at a concentration of 5 mg mL−1, which had a good effect and showed good intraday and daytime reproducibility. The results revealed distinctive characteristics among different manufacturers and good consistency within the same manufacturer according to the scores of the first principal component. In summary, the method based on microcalorimetric has good prospects in the evaluation of the quality of CCA.