Internalization ofSalmonella typhimuriuminto mango pulp and prevention of fruit pulp contamination by chlorine and copper ions

Abstract

Outbreaks of Salmonella infections associated with fresh mango consumption have occurred in recent years. The study's objective was to assess the effectiveness of chlorine and copper ions to reduce Salmonella typhimurium from hydro-cooling water and prevent fruit pulp contamination of heat-treated mangos. Mature green Tommy Atkins' mangos were immersed in water at 46.1 degrees C for 100 min. Heat-treated mangos were then introduced, during 30 min, in 25 degrees C water containing 6 Log(10) CFU/ml of Salmonella with or without disinfectants (5 and 8 mg/l of either chlorine or copper ions). Chlorine at 5 and 8 mg/l reduced 6 Log(10) CFU/ml of Salmonella. Copper ions at 5 and 8 mg/l reduced 3.26 and 4.3 Log(10) CFU/ml, respectively. 2 Log(10) of Salmonella penetrated into mango pulp when disinfectants were not applied to 25 degrees C water. Both chlorine and copper ions were effective in preventing fruit pulp contamination by Salmonella typhimurium. Of residual chlorine, 2.37 and 3.54 mg/kg were detected in mango pulp after the treatment of 5 and 8 mg/l, respectively. Copper ions at 5 and 8 mg/l showed a residual content of 0.1 and 0.6 mg/kg on mango pulp, respectively. The chloride and copper residual levels in the pulp did not exceed the daily ingestion rates recommended by the National Academy of Sciences. Salmonella entered mango pulp by vascular elements and lenticels, both natural structures measuring an average diameter of 21 and 112 microm, respectively. The results illustrate the potential for pathogen penetration if heat-treated mangos are cooled in non-disinfected water. Also, appropriate chlorine or copper ion concentration prevents fruit pulp contamination.

Efficacy of Chlorine, Chlorine Dioxide, and Peroxyacetic Acid in Reducing Salmonella Contamination in Wash Water and on Mangoes Under Simulated Mango Packinghouse Washing Operations

“…Therefore, by controlling Salmonella in wash water and preventing pathogen contamination on mangoes, chlorine, and PAA were able to inhibit Salmonella internalization into the pulp of intact fruit. Similar reduction in Salmonella populations in wash water and mango pulp was reported by Soto et al (2007) following the incorporation of chlorine (8 mg/L) in the hydrocooling water.…”

“…This rapid transition of warm fruit to a cooler environment has been shown to favor pathogen internalization in produce including mangoes, tomatoes, apples and oranges (Bartz and Showalter, 1980;Buchanan et al, 1999;Eblen et al, 2004;Penteado et al, 2004;Bordini et al, 2007). As previously reported, ∼2.3 log CFU/g of internalized Salmonella was recovered from the pulp of hot water treated mangoes that were hydrocooled in contaminated wash water in the absence of a disinfectant (Bordini et al, 2007;Soto et al, 2007). Treatment with 5 ppm chlorine dioxide particularly in the presence of organic matter did not result in any significant reduction in internalized Salmonella populations when compared to the control.…”

“…Therefore, it is critical to prevent contamination on the fruit surface in order to avert pathogen internalization (Nieto-Montenegro and Almanza, 2014). Toward this end, research has demonstrated that incorporation of effective disinfectants in wash water could control pathogens in water and thereby prevent internalization (Penteado et al, 2004;Soto et al, 2007). Hence, the present study was undertaken to test the efficacy of commonly used disinfectants in promoting the microbial safety of mangoes under simulated packing house washing operations.…”

Salmonella and Tomatoes

“…The exemption for citrus fruit was based on the relative low risk that microorganisms will become internalized within the fruit. With apples, internalization has been well documented in the literature Eblen et al, 2004;Merker et al, 1999;Soto et al, 2007). However, with citrus fruit, NACMCF determined that although internalization could occur, it was unlikely that such an event would occur, particularly with sound, tree-picked fruits.…”

Estudo da ação da radiação Gama de 60Co sobre Salmonella spp, Escherichia coli ATCC 8739 e Alicyclobacillus acidoterrestris em polpa de manga congelada

“…Casos como esse de Petrolina, fazem com que aumentem as barreiras dificultando a exportação de alimentos produzidos por países em desenvolvimento, afetando ainda mais suas economias (GERMANO & GERMANO, 2003;BRANDÃO et al, 2003;PENTEADO, 2003;SOTO et al, 2007).…”