Genotypic variation and the effects of nitric oxide and 1-methylcyclopropene on mitigating blackspot bruise enzymatic browning in potatoes

Authors: YADAV, PANKAJ - University Of Idaho; PAYTOSH, SAMUEL - University Of Idaho; SMITH, JESSICA - University Of Idaho; OLSEN, NORA - University Of Idaho; Dogramaci, Munevver; TEIXEIRA, GUSTAVO - University Of Idaho

Submitted to: Postharvest Biology and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/2/2026
Publication Date: 8/28/2026
Citation: Yadav, P., Paytosh, S., Smith, J., Olsen, N., Dogramaci, M., Teixeira, G. 2026. Genotypic variation and the effects of nitric oxide and 1-methylcyclopropene on mitigating blackspot bruise enzymatic browning in potatoes. Postharvest Biology and Technology. 69. Article 175. https://doi.org/10.1007/s11540-026-10121-z.
DOI: https://doi.org/10.1007/s11540-026-10121-z

Interpretive Summary: Blackspot bruise is a common defect caused by mechanical injury in potato tubers that triggers internal enzymatic browning, leading to significant postharvest losses. Therefore, reducing the development of the internal discoloration has enormous benefits for the industry. Thus, the objective of this study was to evaluate the efficacy of chemical treatments in controlling blackspot enzymatic browning using agronomically important three potato cultivars. Tubers from these cultivars were treated with two different chemicals in addition to an untreated control group. After the application of these treatments, half of the tubers were stored at industry standards for potatoes (7.2 °C and 95% relative humidity) for 14 days. The remaining half of the tubers were mechanically injured to induce blackspot bruising, and then held for 24 h at different conditions (23 °C and 65% relative humidity) to allow browning symptoms to develop. Both chemical treatments used in this research significantly reduced blackspot enzymatic browning score as compared to the untreated control. Further, ascorbic acid and flavonoid levels were better preserved in treated tubers, highlighting their protective role against oxidative discoloration. This study provides novel approaches to minimize bruise-associated discoloration in potatoes with the potential to reduce postharvest losses and enhance the marketable value of fresh potatoes.

Technical Abstract: Blackspot bruise is a common defect caused by physical injury of potato tubers that triggers internal enzymatic browning, leading to significant postharvest losses. Reducing the development of internal discolouration has enormous benefits for the industry. The objective of this study was to evaluate the efficacy of nitric oxide (NO) and 1-methylcyclopropene (1-MCP) in controlling blackspot enzymatic browning in Clearwater Russet, Russet Burbank, and Russet Norkotah potato cultivars. Tubers from these three cultivars were treated with NO (98 mL L-1; 5 h) and 1-MCP (0.139 mL L-1; 24 h), in addition to the untreated control. After the application of these treatments, half of the tubers were stored at 7.2 °C and 95% relative humidity (RH) for 14 days. The remaining half of the tubers were injured to induce blackspot bruising and then held for 24 h at 23 °C and 65% RH to allow browning symptoms to develop. 1-MCP and NO treatments significantly reduced blackspot enzymatic browning score to 1.3 and 1.1, respectively, compared to the untreated control (1.8) on a scale from 1 (lightest) to 4 (darkest). Treated tubers maintained higher lightness (L*) value of bruise area after peeling 70.47 in 1-MCP and 69.35 in NO, compared to the control, 66.67. Biochemical profile does not show any significant changes with treatment. This study provides preliminary proof of approaches to minimise bruise-associated discolouration in potatoes, with the potential to reduce postharvest losses and enhance the marketable value of fresh potatoes, which needs further verification to see its further implications.