Synergistic oxalate-phosphate complex inhibits blue stain and preserves freshness of postharvest lotus rhizomes
Year: 2025
Type: article
Abstract: Lotus rhizome is valued for its nutritional benefits but often suffers from non-enzymatic blue stain, which deters consumers. To combat this, we developed a blue stain inhibitor (BSI) complex containing 10 g/kg oxalic acid, 10 g/kg NaH 2 PO 4 , 5 g/kg ascorbic acid, 10 g/kg tea saponin and 10 g/kg polyethylene glycol (PEG-400). This study examined the effects of BSI on the preservation and prevention of blue stain in lotus rhizomes. Compared to the control group (CK1), BSI significantly slowed the reduction in L * and b * values and the increase in ΔE ( p <0.05). After 60 d storage, it significantly slowed down the decrease in total phenolic content (0.56 ± 0.011 g/kg, p < 0.05 vs. CK1). Additionally, BSI reduced electrolyte leakage and inhibited the growth of bacteria, molds and yeasts, demonstrating improved preservation performance. HPLC analysis showed that after 60 d of storage, the BSI-treated lotus rhizomes (G2 group) had 1.2 to 2.2 times higher levels of L-dopa (8.92 mg/g DW), gallocatechin (6.60 mg/g DW), and epigallocatechin (7.88 mg/g DW) compared to CK1 ( p < 0.05). This suggests that BSI treatment lessened polyphenol leakage and oxidation. Furthermore, the content of iron ions (Fe 3+ ) decreased significantly, likely due to the formation of (FePO 4 ·Fe 2 (C 2 O 4 ) 3 ) precipitates with C 2 O 4 2- and H 2 PO 4 - and Fe 3+ , reducing polyphenol-iron chelate formation and inhibiting blue staining. In summary, this study offers new strategies for preventing blue stain and preserving lotus rhizomes.
Source: LWT
Institutions: Huazhong Agricultural University, University of Bakhtalruda
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: gold
Estimated APC paid: $3,240
Funder: Huazhong Agricultural University
Award: G2529897379
OpenAlex ID: W4413617645