In our study, a colorimetric method previously applied in trace detection of polyols [27, 28] was developed and
optimized for the high throughput assay of sugar alcohols (Additional file 1: Fig. S1). d-arabitol was selected
as a standard for the method construction because it is the main sugar alcohol product of P. anomala. By optimizing
the reaction system, the standardized assay demonstrated a linear detection range of d-arabitol from 0
to 12 g/L. Although the linear relation was noticeably altered at 20 g/L sugar alcohol, the colorimetric curve
was positively related with the sugar alcohol concentration and could be applied in the preliminary screening
(Fig. 1a, b). To analyze effects of the substrate and by-products on sugar alcohol screening, an interference
experiment was performed at different concentrations of glucose and ethanol (2–30 g/L). The results showed that
glucose and ethanol had no interference in the quantitative analysis of sugar alcohols by the colorimetric method
(Fig. 1a), which indicated that the developed assay is highly efficient for the determination of the content of
sugar alcohol in biological samples. To gain a further understanding of the accuracy, the reference HPLC and
the proposed colorimetric methods were applied to analyze sugar alcohol at different concentration levels. The
results showed that the data measured by the colorimetric procedure agree with those determined by the reference
HPLC method, and a regression line with an R2 of 0.9673 was obtained (Fig. 1c; Additional file 1: Fig. S1).