Isotopic and biochemical fingerprinting of Auricularia heimuer grown on agricultural substrates: A multivariate approach to nutritional traceability

This study aimed to evaluate how different lignocellulosic substrates – hardwood sawdust, sugarcane bagasse, and cottonseed shell – affect the isotopic and biochemical composition of Auricularia heimuer . Stable isotope ratio mass spectrometry (IRMS), high-performance liquid chromatography (HPLC), and multivariate statistical analysis (PCA, PLS-DA) were used to investigate substrate-dependent variations. The results showed clear isotopic differentiation among mushrooms grown on the three substrates, with δ 13 C, δ 15 N, and δ 2 H emerging as reliable biomarkers of substrate origin. Substrate chemistry, particularly C/N ratio and elemental content, strongly influenced nutrient assimilation and amino acid metabolism. Bagasse promoted higher protein and polysaccharide levels, cottonseed shell enhanced amino acid and mineral accumulation, and sawdust increased crude fiber. Progressive increases in amino acid and protein contents across harvest tides reflected improved nitrogen utilization over time. Correlation and multivariate analyses confirmed strong links between substrate properties, isotopic fingerprints, and nutritional outcomes. Collectively, these findings demonstrate that isotopic and biochemical fingerprinting provides a practical framework for optimizing substrate use, enhancing nutritional quality, and enabling traceability in sustainable mushroom production. • Combined isotope and biochemical profiling reveals substrate effects. • δ 13 C, δ 15 N, and δ 2 H serve as biomarkers of substrate origin. • Bagasse boosts protein yield; cottonseed enhances amino acids. • Amino acids and proteins rise across successive harvest tides. • Isotopic-nutritional data enable traceability and quality control.