Bacterial Spore Inhibition and Inactivation in Foods by Pressure, Chemical Preservatives, and Mild Heat

Abstract

Sucrose laurates, sucrose palmitate, sucrose stearates, and monolaurin (Lauricidin) were evaluated for inhibitory effects against spores of Bacillus sp., Clostridium sporogenes PA3679, and Alicyclobacillus sp. in a model agar system. The combined treatment of sucrose laurate, high hydrostatic pressure, and mild heat was evaluated on spores of Bacillus and Alicyclobacillus in foods. The minimum inhibitory concentrations of the sucrose esters were higher than that of Lauricidin for all spores tested in the model agar system, but Lauricidin was not the most readily suspended in the test media. The sucrose laurates and sucrose palmitate were more effective and more readily suspended than the sucrose stearates. A combined treatment of sucrose laurate (<1.0%), 392 megaPascals (MPa) at 45 degrees C for 10 to 15 min provided 3- to 5.5-log10 CFU/ml reductions from initial populations of 10(6) CFU/ml for Bacillus subtilis 168 in milk, Bacillus cereus 14579 in beef, Bacillus coagulans 7050 in tomato juice (pH 4.5), Alicyclobacillus sp. N1089 in tomato juice (pH 4.5), and Alicyclobacillus sp. N1098 in apple juice. The most notable change in the appearance of the products was temporary foaming during mixing of the sucrose laurate in the foods. The effect of sucrose laurate appeared to be inhibitory rather than lethal to the spores. The inhibitory effects observed on Bacillus and Alicyclobacillus spores by the combined treatment of pressure, mild heat, and sucrose laurate appear promising for food applications where alternatives to high heat processing are desired.

Effect of Lactose Monolaurate on Pathogenic and Nonpathogenic Bacteria

“…Smith et al (11) synthesized various carbohydrate esters and found that the carbohydrate moiety can markedly influence the microbial inhibitory activity of the fatty acid. The activity of sugar esters has been suggested to be antimicrobial (2), while others have suggested they have just bacteriostatic activity (10). All published studies investigating the activity of sugar esters only provide the MICs; there are no publications that determined the minimal bactericidal concentrations (MBCs) of sugar esters.…”

Lethality enhancement of pressure-assisted thermal processing against Bacillus amyloliquefaciens spores in low-acid media using antimicrobial compounds

“…For example, Chaibi et al (1998) reported a significant reduction in the heat resistance of Bacillus cereus spores treated at 91e97 C (0.1 MPa) in phosphate buffer in the presence of 0.005 mol L À1 monolaurin. Shearer et al (2000) also reported a 3.0-log reduction of Bacillus subtilis spores in milk treated at 392 MPa and 45 C for 10 min in the presence of monolaurin added at a concentration as low as 0.001%. No significant spore inactivation (P > 0.05) was achieved by a 2-min PATP treatment in the absence of antimicrobial compounds at pH 7.0 (only a 0.4 log reduction) (Fig.…”

“…and C. sporogenes spores in a model agar system (monolaurin); enhanced high-pressure inactivation of B. subtilis spores in milk (monolaurin) Chaibi, Ababouch, and Busta (1996); Chaibi et al (1998); Shearer et al (2000) Preservative salts Sodium benzoate (0.5 g L À1 ) and sodium nitrite (2 g L À1 )…”

“…Although most of the compounds studied showed inhibitory effects (prevention of microbial outgrowth and recovery during storage), some including monolaurin and nisin and certain phenolic compounds from plant and fruit sources have been capable of enhancing process lethality against bacterial spores (Chaibi, Ababouch, Ghouila, & Busta, 1998;Gao & Ju, 2008;Komitopoulou, Boziaris, Davies, Delves-Broughton, & Adams, 1999;Shearer, Dunne, Sikes, & Hoover, 2000;Shin et al, 2008). This study was conducted to evaluate the possibility of enhancing PATP lethality against B. amyloliquefaciens spores by sensitizing the spores with selected antimicrobial compounds in a buffer system as well as in selected low-acid foods.…”

Modeling the inactivation of psychrotrophic Bacillus cereus spores in beef slurry by 600 MPa HPP combined with 38–70 °C: Comparing with thermal processing and estimating the energy requirements

“…nisin and sucrose laurate), or an additional control hurdle (e.g. olive powder) to inactivate B. cereus spores has been investigated (Aoyama et al, 2005;Arroyo et al, 1997;Evelyn and Silva, 2015b;Fornari et al, 1995;Gola et al, 1996;Ju et al, 2008;Lopez-Pedemonte et al, 2003;Luu-Thi et al, 2014;Marco et al, 2011;McClements et al, 2001;Meyer, 2000;Raso et al, 1998;Robertson et al, 2008;Rovere et al, 1998;Scurrah et al, 2006;Shearer et al, 2000;Shigeta et al, 2007;van Opstal et al, 2004). B. cereus spore log reductions between 1 and ≥ 7 were achieved, depending on the conditions applied and the spore resistance.…”