Postharvest sour rot control in lemon fruit by natamycin and an Allium extract

Int J Food Microbiol. 2022 Mar 1;368:109605. doi: 10.1016/j.ijfoodmicro.2022.109605. Online ahead of print.ABSTRACTCitrus sour rot caused by Geotrichum citri-aurantii is one of the most important postharvest diseases in citrus fruit, causing huge economic losses. Traditionally, it has been controlled by the postharvest application of guazatine and propiconazole fungicides, but restrictions in their use make it urgent to find an alternative for sour rot management. Natamycin, a common food preservative, and the organosulfuric compounds extracted from Allium species are safe food additives that control different foodborne pathogens. In the present study, the curative activities of commercial formulations of natamycin (Fruitgard Nat 20) and an Allium extract (PTSO: propyl thiosulfinate oxide; Proallium FRD®), were evaluated for the control of G. citri-aurantii in artificially inoculated lemon fruit. Trials in laboratory and in commercial conditions were carried out to explore the feasibility of including both compounds as part of a safe postharvest sour rot disease control strategy. Under controlled laboratory conditions, sour rot was significatively reduced by 500 mg L-1 of natamycin, 580 mL L-1 of PTSO and 290 mL L-1 of PTSO + 4% of a food coat, applied by immersion. Nevertheless, the maximum dose of PTSO (580 mL L-1) caused phytotoxicity on the fruit rind. In commercial drenching conditions, 290 mL L-1 of PTSO + 4% of a food coat reduced sour rot incidence similar to convent...
Source: International Journal of Food Microbiology - Category: Food Science Authors: Source Type: research