Contribution of ultrasound and slightly acid electrolytic water combination on inactivating Rhizopus stolonifer in sweet potato

• Published in: Ultrasonics sonochemistry Vol. 73; p. 105528
• Main Authors: Li, Lulu, Mu, Tai-Hua, Zhang, Miao
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.05.2021; Elsevier
• Subjects: Combination; Original; Rhizopus stolonifer; Slightly acidic electrolyzed water; Sweet potato; Ultrasound; Slightly acidic electrolyzed water; Sweet potato; Rhizopus stolonifer; Ultrasound; Combination
• ISSN: 1350-4177; 1873-2828
• DOI: 10.1016/j.ultsonch.2021.105528

•Ultrasound (US) and slightly acidic electrolyzed water (SAEW) were combined.•US + SAEW treatment inhibited mycelial growth and spore germination of R. stolonifer.•US + SAEW treatment disrupted the cell membranes and caused the leakage of cytoplasm.•US500 + SAEW50 at 40 and 55 °C increased cell membrane permeability and decreased MMP.•US500 + SAEW50 at 40 °C and US300 + SAEW50 at 55 °C controlled soft rot decay in TRs. Effects of ultrasound (US, 300, 400, and 500 W) and slightly acidic electrolyzed water (SAEW, 10, 30, and 50 mg/L) combination on inactivating Rhizopus stolonifer in sweet potato tuberous roots (TRs) were investigated. US at 300, 400, and 500 W simultaneous SAEW with available chlorine concentration of 50 mg/L at 40 and 55 °C for 10 min significantly inhibited colony diameters (from 90.00 to 6.00–71.62 mm) and spores germination (p < 0.05). US + SAEW treatment could destroy cell membrane integrity and lead to the leakage of nucleic acids and proteins (p < 0.05). Scanning and transmission electron microscopy results showed that US + SAEW treatment could damage ultrastructure of R. stolonifer, resulted in severe cell-wall pitting, completely disrupted into debris, apparent separation of plasma wall, massive vacuoles space, and indistinct intracellular organelles. US500 + SAEW50 treatment at 40 and 55 °C increased cell membrane permeability, and decreased mitochondrial membrane potential of R. stolonifer. In addition, US500 + SAEW50 at 40 °C and US300 + SAEW50 at 55 °C controlled R. stolonifer growth in sweet potato TRs during 20 days of storage, suggesting effective inhibition on the infection of R. stolonifer. Therefore, US + SAEW treatment could be a new efficient alternative method for storing and preserving sweet potato TRs.