Bacterial inactivation mechanism of SC-CD and TEO combinations in watermelon and melon juices

Abstract

Inactivation mechanism of supercritical carbon dioxide (SC-CD) combination with Thymbra spicata essential oil (TEO) treatments on bacteria in tryptone soy broth (TSB) and juices was investigated. Salmonella Typhimurium was significantly inactivated by 3.45 and 5.55 logs after SC-CD+TEO treatment of TBS for 35 min at 7.6 and 10.13 MPa respectively. Klebsiella pneumoniae showed higher resistance to treatments than other two bacteria and Escherichia coli showed higher resistance to treatments than S. Typhimurium. Approximately 5.27, 4.68 and 3.82 logs inactivation of S. Typhimurium, E. coli and K. pneumoniae were obtained in the treatment of watermelon juice with SC-CD+TEO at 10.13 MPa after 35 min, while 6.89, 4.82 and 4.55 logs inactivated, respectively, were observed in melon juice. Research indicated that the inactivation mechanism involves inducing cell damage, increasing membrane permeability, increasing cell rupture, precipitation of cytoplasmic contents, extracting cellular substances and lysing cells. Different sensitivities of Gram-negative bacteria to the treatments may be attributed to the differences in the cell structure, compositions of membrane and presence of capsule, pressure level and exposure time. pH, total soluble solid and browning degree of juice did not significantly change after treatments and during 7 days of storage.

A hami melon flavor creation

“…Usually, ripe Hami melon can be eaten fresh or made into refreshing drinks. As a kind of delicious dessert fruit, melon is enjoyed worldwide and is one of the most consumed fruit in the world (Erkmen, 2021;Perry et al, 2009). It has always been loved by the people in China.…”

Antimicrobial effects of Cinnamomum verum essential oil against Enterococcus faecalis and Staphylococcus aureus in mulberry and carrot juices

“…Measurements of the pH values of juices (control) were performed using a Corning pH meter (EM78X, Fisher, Pittsburgh, USA) equipped with a glass electrode at 25 °C (Erkmen, 2022a). A refractometer (Index Instruments, PTR 46 X, Florida, USA) was used to measure the Brix values of juices (control).…”

“…Barks of Cinnamomum vera were obtained from shops. Barks were broken into small sticks, and 200 g of sticks were placed into a Clevenger's vessel (1 L) containing double distilled water in a 1:2 ratio (material: water) and hydrodistilled (at 100 °C) for 3 h using special laboratory hydro-distillation Clevenger apparatus (InterLab, Adana, Turkey) for 3 h (Erkmen, 2022a). Before using CEO, it was filtered through filter paper (0.45 lm pore size) using sterile analytical glass vacuum filter units (Sartorius, Kazakhstan street no:5/14 Ankara, Turkey).…”

Modelling of inactivation of microorganisms in the process of sterilization using high pressure supercritical fluids

“…High-pressure technology stops the chemical activity of microorganisms. In the last decade, the technology of its use in the food industry has also expanded (Erkmen, 2021). The effect of high pressures on the inactivation of microorganisms has been known since the beginning of the twentieth century.…”