A combined treatment of UV-assisted TiO2 photocatalysis and high hydrostatic pressure to inactivate internalized murine norovirus

ABSTRACT We have studied inactivation of four strains each ofEscherichia coli and Listeria innocua in milk by the combined use of high hydrostatic pressure and the lactoperoxidase-thiocyanate-hydrogen peroxide system as a potential mild food preservation method. The lactoperoxidase system alone exerted a bacteriostatic effect on both species for at least 24 h at room temperature, but none of the strains was inactivated. Upon high-pressure treatment in the presence of the lactoperoxidase system, different results were obtained for E. coli and L. innocua. For none of the E. coli strains did the lactoperoxidase system increase the inactivation compared to a treatment with high pressure alone. However, a strong synergistic interaction of both treatments was observed for L. innocua. Inactivation exceeding 7 decades was achieved for all strains with a mild treatment (400 MPa, 15 min, 20°C), which in the absence of the lactoperoxidase system caused only 2 to 5 decades of inactivation depending on the strain. Milk as a substrate was found to have a considerable effect protecting E. coli and L. innocua against pressure inactivation and reducing the effectiveness of the lactoperoxidase system under pressure on L. innocua. Time course experiments showed that L. innocua counts continued to decrease in the first hours after pressure treatment in the presence of the lactoperoxidase system.E. coli counts remained constant for at least 24 h, except after treatment at the highest pressure level (600 MPa, 15 min, 20°C), in which case, in the presence of the lactoperoxidase system, a transient decrease was observed, indicating sublethal injury rather than true inactivation.

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Synergetic Inactivation Mechanism of Protocatechuic Acid and High Hydrostatic Pressure against Escherichia coli O157:H7

Foods ◽

10.3390/foods10123053 ◽

2021 ◽

Vol 10 (12) ◽

pp. 3053

Author(s):

Jingyi Hao ◽

Yuqing Lei ◽

Zhilin Gan ◽

Wanbin Zhao ◽

Junyan Shi ◽

...

Keyword(s):

Escherichia Coli ◽

Hydrostatic Pressure ◽

High Hydrostatic Pressure ◽

Protocatechuic Acid ◽

Combined Treatment ◽

Membrane Integrity ◽

Escherichia Coli O157 ◽

Safety Issues ◽

Bactericidal Effects ◽

The Individual

With the wide application of high hydrostatic pressure (HHP) technology in the food industry, safety issues regarding food products, resulting in potential food safety hazards, have arisen. To address such problems, this study explored the synergetic bactericidal effects and mechanisms of protocatechuic acid (PCA) and HHP against Escherichia coli O157:H7. At greater than 200 MPa, PCA (1.25 mg/mL for 60 min) plus HHP treatments had significant synergetic bactericidal effects that positively correlated with pressure. After a combined treatment at 500 MPa for 5 min, an approximate 9.0 log CFU/mL colony decline occurred, whereas the individual HHP and PCA treatments caused 4.48 and 1.06 log CFU/mL colony decreases, respectively. Mechanistically, membrane integrity and morphology were damaged, and the permeability increased when E. coli O157: H7 was exposed to the synergetic stress of PCA plus HHP. Inside cells, the synergetic treatment additionally targeted the activities of enzymes such as superoxide dismutase, catalase and ATPase, which were inhibited significantly (p ≤ 0.05) when exposed to high pressure. Moreover, an analysis of circular dichroism spectra indicated that the synergetic treatment caused a change in DNA structure, which was expressed as the redshift of the characteristic absorption peak. Thus, the synergetic treatment of PCA plus HHP may be used as a decontamination method owing to the good bactericidal effects on multiple targets.

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Effects of High Hydrostatic Pressure Combined with Vacuum-Freeze Drying on the Aroma-Active Compounds in Blended Pumpkin, Mango, and Jujube Juice

Foods ◽

10.3390/foods10123151 ◽

2021 ◽

Vol 10 (12) ◽

pp. 3151

Author(s):

Lin Yuan ◽

Xujuan Liang ◽

Xin Pan ◽

Fei Lao ◽

Yong Shi ◽

...

Keyword(s):

Hydrostatic Pressure ◽

Thermal Processing ◽

High Hydrostatic Pressure ◽

Volatile Compound ◽

Freeze Drying ◽

Combined Treatment ◽

Flavor Quality ◽

Untreated Sample ◽

Combination Process ◽

Gas Chromatography Olfactometry

A combination process of completely non-thermal processing methods involving high hydrostatic pressure (HHP) and vacuum-freeze drying (VFD) for producing a new snack from fruit and vegetable blends was developed, and the effect of the process on flavor quality was investigated. The HHP–VFD treatment did not significantly reduce volatile compound contents compared to single HHP or VFD. Gas chromatography–olfactometry showed that HHP–VFD raised the contents of floral-like volatile compounds (e.g., β-ionone) compared to the untreated sample. Sensory evaluation analysis confirmed that the overall liking was unchanged after the HHP–VFD treatment. The HHP–VFD combined treatment is effective in maintaining the flavor and extending shelf life, and is convenient for the portability and transportation of ready-to-drink juice.

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Effects of UV-C in a Teflon-Coil and High Hydrostatic Pressure Combined Treatment for Maintenance of the Characteristic Quality of Dongchimi (Watery Radish Kimchi) during Room Temperature Storage

Journal of Food Processing and Preservation ◽

10.1111/jfpp.13057 ◽

2016 ◽

Vol 41 (4) ◽

pp. e13057 ◽

Cited By ~ 2

Author(s):

H.M. Shahbaz ◽

H. Ryoo ◽

J.U. Kim ◽

S. Kim ◽

D.U. Lee ◽

...

Keyword(s):

Hydrostatic Pressure ◽

High Hydrostatic Pressure ◽

Room Temperature ◽

Combined Treatment ◽

Room Temperature Storage ◽

Uv C ◽

Temperature Storage

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Application of high hydrostatic pressure for the inactivation of norovirus and quality stability in fresh sea squirt (Halocynthia roretzi)

Food Science and Technology International ◽

10.1177/1082013219842439 ◽

2019 ◽

Vol 25 (7) ◽

pp. 573-578 ◽

Cited By ~ 1

Author(s):

Shin Young Park ◽

Yeoun Joong Jung ◽

Ji Young Kwon ◽

Seh Eun Kim ◽

Myeong-In Jeong ◽

...

Keyword(s):

Hydrostatic Pressure ◽

High Hydrostatic Pressure ◽

Room Temperature ◽

Murine Norovirus ◽

Halocynthia Roretzi ◽

Human Norovirus ◽

Initial Inoculum ◽

Sea Squirt ◽

Quality Stability ◽

Sea Squirts

Sea squirt ( Halocynthia roretzi) is considered a potential cause of human norovirus in Korea. This study investigated the effect of high hydrostatic pressure at 100–500 MPa for 5 min at room temperature (23 ± 2 ℃) on the inactivation of murine norovirus-1 (initial inoculum of 6–7 log10 plaque forming units/ml) as a human norovirus surrogate in fresh sea squirt. The effects of high hydrostatic pressure on the Hunter colors and pH were also examined as the main indices of quality. No reductions in murine norovirus-1 titers were observed in sea squirt treated at 100–400 MPa. However, murine norovirus-1 in sea squirt was completely inactivated by 500 MPa of high hydrostatic pressure. Furthermore, the Hunter colors (“L,” “a,” and “b”) and pH values (6.10–6.19) were not significantly ( P > 0.05) different between non-high hydrostatic pressure-treated sea squirts and all high hydrostatic pressure-treated sea squirts. Therefore, 500 MPa of high hydrostatic pressure at room temperature may be an optimal treatment for Tunicata meat without altering the food quality (color and pH).

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Pasteurization of Fruit Juices of Different pH Values by Combined High Hydrostatic Pressure and Carbon Dioxide

Journal of Food Protection ◽

10.4315/0362-028x.jfp-12-127 ◽

2012 ◽

Vol 75 (10) ◽

pp. 1873-1877 ◽

Cited By ~ 8

Author(s):

LI WANG ◽

JIAN PAN ◽

HUIMING XIE ◽

YI YANG ◽

DIANFEI ZHOU ◽

...

Keyword(s):

Hydrostatic Pressure ◽

Orange Juice ◽

High Hydrostatic Pressure ◽

Combined Treatment ◽

Physiological Saline ◽

Fruit Juices ◽

E Coli ◽

Sublethal Injury ◽

Pressure Resistance ◽

Low Pressures

The inactivation of the selected vegetative bacteria Escherichia coli, Listeria innocua, and Lactobacillus plantarum by high hydrostatic pressure (HHP) in physiological saline (PS) and in four fruit juices with pHs ranging from 3.4 to 6.3, with or without dissolved CO2, was investigated. The inactivation effect of HHP on the bacteria was greatly enhanced by dissolved CO2. Effective inactivation (>7 log) was achieved at 250 MPa for E. coli and 350 MPa for L. innocua and L. plantarum in the presence of 0.2 M CO2 at room temperature for 15 min in PS, with additional inactivation of more than 4 log for all three bacteria species compared with the results with HHP treatment alone. The combined inactivation by HHP and CO2 in tomato juice of pH 4.2 and carrot juice of pH 6.3 showed minor differences compared with that in PS. By comparison, the combined effect in orange juice of pH 3.8 was considerably promoted, while the HHP inactivation was enhanced only to a limited extent. In another orange juice with a pH of 3.4, all three strains lost their pressure resistance. HHP alone completely inactivated E. coli at relatively mild pressures of 200 MPa and L. innocua and L. plantarum at 300 MPa. Observations of the survival of the bacteria in treated juices also showed that the combined treatment caused more sublethal injury, which increased further inactivation at a relatively mild pH of 4.2 during storage. The results indicated that the combined treatment of HHP with dissolved CO2 may provide an effective method for the preservation of low- or medium-acid fruit and vegetable juices at relatively low pressures. HHP alone inactivated bacteria effectively in high-acid fruit juice.

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