Synergistic Effect of High Hydrostatic Pressure and Natural Antimicrobials on Inactivation Kinetics ofBacillus cereusin a Liquid Whole Egg and Skim Milk Mixed Beverage

Abstract

An in-depth study was conducted in order to extend the storage life of a liquid whole egg-skim milk (LWE-SM) mixed beverage to enhance its safety and the safety of related beverages. Bacillus cereus vegetative cells (1 x 10(8) colony-forming units [CFU]/mL) were inoculated in LWE-SM beverages with or without natural antimicrobial supplements: flavonol rich-cocoa powder (cocoanOX 12%, CCX) (700 ppm), vanillin (700 ppm), anise (700 ppm), and cinnamon (700 ppm). B. cereus cells were maintained at 10 degrees C for 10 days in the different beverages to test the bacteriostatic or inhibitory effect of the aforementioned ingredients. Beverages were treated with high hydrostatic pressure (HHP) technology and stored at 10 degrees C for 15 days after treatment. All natural antimicrobials reduced the micro(max) values and increased the lag phase time of B. cereus, and Gompertz growth curves showed different inhibitory effects depending on the substance. The maximum inhibitory effect (1.330 log cycle reduction) was achieved in LWE-SM-cinnamon-supplemented beverage. The maximum inactivation achieved by HHP in LWE-SM beverage was a reduction of around 3.89 +/- 0.25 log cycles at 300 MPa for 12 minutes. When supplemented beverages were treated under the same conditions, enhanced inactivation levels were achieved. This increased inactivation can be attributed to a synergistic effect when the LWE-SM was supplemented with flavonol-rich cocoa powder, cinnamon, and vanillin. The maximum synergistic effect was observed in LWE-SM-CCX-supplemented beverage. During the refrigerated storage of B. cereus HHP-treated cells in beverages to which antimicrobials had been added, the inhibitory effect was dependent on the previously applied pressure level.

Effects of High Hydrostatic Pressure Processing on Hen Egg Compounds and Egg Products

“…Since egg yolk solutions are sensitive to thermal treatments, high pressure treatment is an approved and effective alternative to eliminate micro‐organisms in food products (Anton and other , ). To circumvent the limitation of conventional pasteurization, HHP has been applied as a nonthermal technique for egg pasteurization (Anton and others , ; Pina‐Pérez and others ; Monfort and others ). The application of N 2 gas at a pressure of 13.7 MPa and 35 °C for 2 h has also been studied; however, it was shown that the combined application of HHP and N 2 was not effective in killing bacteria added to egg yolk (Wei and others ).…”

“…It has been demonstrated that microbial growth can also be inhibited by adding plant‐based antimicrobial compounds (Pina‐Pérez and others ). The combined effects of antimicrobials and HHP treatments were investigated to assess the possibility of reducing the pressure or the amount of antimicrobial compounds required to inactivate microorganisms (Ross and others ).…”

“…Several natural antimicrobial ingredients have been considered safe, including cinnamon, anise, vanilla, and cocoa powder. These compounds have been examined as antimicrobial additives combined with HHP processing to inactivate B. cereus cells in a liquid whole egg (20% v/v) and skim milk (80% v/v) mixed beverage (Pina‐Pérez and others ). The maximum inactivation level of B. cereus occurred at 300 MPa for 12 min, with and without antimicrobial additives.…”

“…The maximum inactivation level of B. cereus occurred at 300 MPa for 12 min, with and without antimicrobial additives. The microbial inactivation obtained in supplemented beverages was related to the synergistic effect of the hurdle technology (Pina‐Pérez and others ). Hydrogen peroxide (H 2 O 2 ) is another antimicrobial agent approved by the FDA and it has been used in egg products combined with HHP processing (Işiker and others ).…”

Addition of thiamine dilaurylsulfate to reduce the intensity of hydrostatic pressure treatment for microbial safety of Korean Jogaejeot-muchim (salted-fermented-seasoned short-neck clam)

“…Various studies of the combinations of HP treatment with an antimicrobial addition for food safety have been reported in rice pudding, cooked chicken, beverages, and fermented sausages (Corbo et al 2009;Pina-Pérez et al 2009;Ananou et al 2010;Patterson et al 2011;Pulido et al 2012). Pina-Pérez et al (2011) researched HP treatment with the addition of various antimicrobials in beverages, and they reported that additive or synergistic effects were observed depending on the antimicrobial.…”