Thermal Resistance of Bacillus coagulans in Double Concentrated Tomato Paste

Abstract

Thermal resistance was determined on a strain of Bacillus couguluns in double concentrated tomato paste (a," = 0.95 at 23"C, pH=4.0, 30.3"Brix, 70.1% moisture and acidity 1.30 g/lOOg citric acid. A microsyringe method was used with an inoculum of 1.3 x lo4 spores/ mL. Values of D,,= 3.5 min and z = 9.5C" were obtained.

Alicyclobacillus Contamination in the Production Line of Kiwi Products in China

“…The D 80°C of Bacillus coagulans is 40 min in a double concentrated tomato paste media according to Sandoval et al [38], and Bacillus fumarioli grows optimally at pH 5.5 and 50°C [39], while Bacillus ginsengihumi can also grow in acid media at temperature up to 50°C [40]. These reports proved that these Bacillus can be an interference to the detection of Alicyclobacillus from samples and cause false positive results, although there are no reports relating them with spoilage of juice products and guaiacol production.…”

Thermal Inactivation Kinetics of Bacillus coagulans Spores in Tomato Juice

“…The thermal resistance of test microorganisms was determined by thermal death time tests and reflected by D-and zvalues. Since the thermal destruction of B. coagulans generally follows a first-order reaction based on most published data (14,17,19), the D-values of B. coagulans spores were obtained by taking the negative reciprocal of the slope from linear regression of the survivor curves. The z-value was estimated by plotting the log Dvalues versus heating temperatures and taking the negative reciprocal of the slope from linear regression.…”

“…The practice of acidification of canned tomato juice to a pH lower than 4.5 before treatment prevents the outgrowth of spores surviving heat treatment, particularly spores of C. botulinum (11). Although the heat resistance of B. coagulans spores in tomatoes has been studied at acid pH (8,14,16,17,23), information about heat resistance at different acidic pH levels between 4.0 and 4.5 (the commonly controlled pH range for canned tomato products) is still limited, especially under high temperatures. Since the thermal resistance of B. coagulans spores is strain dependent, three strains of this microorganism (ATCC 8038, ATCC 7050, and 185A) were investigated in this study, although the first two strains have been used more frequently in previously published work (10,15,16,22,23).…”

“…This is the single organism most frequently isolated from spoiled canned vegetables acidified to pH 4.0 to 4.5 and has been considered the primary cause of economically important spoilage in thermally processed tomatoes and tomato products (8,19). It results in a type of spoilage commonly referred to as flat sour in tomato-based products (14,17,19,23). Although B. coagulans is a nonpathogenic microor ganism, it may cause a food safety hazard due to its ability to increase the pH of acidic foods, processed with a reduced treatment, to a level that can allow the germination of surviving Clostridium botulinum spores (1,2).…”

“…Most published data related to the inactivation of B. coagulans spores in food media are based on studies performed with moderate heat only (17,23) or by combining heat treatment with other technologies, such as high pressure (5,12,21). For high-temperature heating, Palop et al (13,14) studied heat resistance in food medium (pH 4 and 7) between 105 and 130°C, using a strain isolated from canned asparagus, and Mallidis et al (8) obtained the z-value (z-value is defined as the change in temperature required for a 10-fold reduction of the D-value, which is defined as the time required at a certain temperature for a 1-log reduction of the target microorgan isms) of B. coagulans spores in tomato serum (pH 4.24) at temperatures in a narrow range (95 to 105°C).…”