Elimination ofEscherichia coliO157:H7 from Fermented Dry Sausages at an Organoleptically Acceptable Level of Microencapsulated Allyl Isothiocyanate

Abstract

Four sausage batters (17.59% beef, 60.67% pork, and 17.59% pork fat) were inoculated with two commercial starter culture organisms (>7 log 10 CFU/g Pediococcus pentosaceus and 6 log 10 CFU/g Staphylococcus carnosus) and a five-strain cocktail of nonpathogenic variants of Escherichia coli O157:H7 to yield 6 to 7 log 10 CFU/g. Microencapsulated allyl isothiocyanate (AIT) was added to three batters at 500, 750, or 1,000 ppm to determine its antimicrobial effects. For sensory analysis, separate batches with starter cultures and 0, 500, or 750 ppm microencapsulated AIT were produced. Sausages were fermented at <26°C and 88% relative humidity (RH) for 72 h. Subsequently sausages were dried at 75% RH and 13°C for at least 25 days. The water activity (a w ), pH, and levels of starter cultures, E. coli O157:H7, and total bacteria were monitored during fermentation and drying. All sausages showed changes in the initial pH from 5.57 to 4.89 and in a w from 0.96 to 0.89 by the end of fermentation and drying, respectively. Starter culture numbers were reduced during sausage maturation, but there was no effect of AIT on meat pH reduction. E. coli O157:H7 was reduced by 6.5 log 10 CFU/g in sausages containing 750 and 1,000 ppm AIT after 21 and 16 days of processing, respectively. E. coli O157:H7 numbers were reduced by 4.75 log 10 CFU/g after 28 days of processing in treatments with 500 ppm AIT, and the organism was not recovered from this treatment beyond 40 days. During sensory evaluation, sausages containing 500 ppm AIT were considered acceptable although slightly spicy by panelists.

Survival of E. coli O157:H7 during manufacture of dry‐cured Westphalian ham surface‐treated with allyl isothiocyanate or hot mustard powder

“…19 In order to reduce volatility and improve stability of AIT and pHBIT, these compounds have been microencapsulated within starch matrices. Chacon et al 20 added microencapsulated AIT to dry fermented sausage batter contaminated with E. coli O157 : H7 and found AIT at 750 and 500 µg kg −1 reduced E. coli O157 : H7 by 6.5 and 4.8 log 10 CFU g −1 after 28 days, respectively. In other work it was found that 350 µg kg −1 microencapsulated pHBIT reduced numbers of E. coli in broth >6 log 10 CFU mL −1 after 5 days.…”

“…22 Sensory analysis of these antimicrobial treatments previously found that 500 µg kg −1 microencapsulated AIT and 50 or 100 g kg −1 mustard powder mixed into dry sausage and ground beef, respectively, were noticeable but acceptable. 20,22 The objectives of the present study were to apply 200, 300 and 400 µg kg −1 microencapsulated AIT or 60 g kg −1 hot mustard powder as surface treatments for…”

Health and Safety Considerations of Fermented Sausages

“…The addition of various compounds with antibacterial effects has been evaluated as ingredients in DFS for improved safety. Microencapsulated allyl isothiocyanate (AIT) at 500 ppm gave 4.75-log reductions of E. coli O157:H7 in DFS 28 days after processing, >3 log more than control DFS [261]. Deodorized mustard powder, containing AIT as an antimicrobial ingredient, provided 5-log reduction of E. coli O157:H7 28 days after processing when used at 4% in DFS [262][263][264][265][266].…”

Effect of the oriental and yellow mustard flours as natural preservative against aflatoxins B1, B2, G1 and G2 production in wheat tortillas

“…In particular, it has been demonstrated that allyl ITC (AITC), which is formed from sinigrin (2-propenyl glucosinolate), effectively inhibits a variety of pathogenic microorganisms, even at low concentrations (Lin et al 2000;Luciano and Holley 2009). The potential of AITC as a natural antimicrobial has been shown in different foods, including chicken breast (Shin et al 2010), ground beef (Chacon et al 2006a;Nadarajah et al 2005), dry-cured ham (Graumann and Holley 2007), fermented dry sausages (Chacon et al 2006b) and tuna meat (Hasegawa et al 1999). The goals of this study were to study a) the qualiquantitative GLCs composition of yellow and oriental mustard flours and b) the reduction of AFs production by A. parasiticus in wheat tortilla treated with ITCs generated from mustard flours.…”