Industrial scale microwave processing of tomato juice using a novel continuous microwave system.

This study evaluated the effect of an industrial scale continuous flow microwave volumetric heating system in comparison to conventional commercial scale pasteurisation for the processing of tomato juice in terms of physicochemical properties, microbial characteristics and antioxidant capacity. The effect against oxidative stress in Caco-2 cells, after in vitro digestion was also investigated. Physicochemical and colour characteristics of juices were very similar between technologies and during storage.

The effect of high hydrostatic pressure on the microbiological quality and safety of carrot juice during refrigerated storage.

The microbial quality of untreated and pressure-treated carrot juice was compared during storage at 4, 8 and 12 °C. High pressure treatment at 500 MPa and 600 MPa (1 min/20 °C) reduced the total counts by approximately 4 log CFU ml⁻¹ and there was very little growth of the survivors during storage at 4 °C for up to 22 days. Total counts increased during storage of pressure-treated juice at 8 °C and 12 °C but took significantly longer to reach maximum levels compared to the untreated juice.

A comparative study of changes in the microbiota of apple juice treated by high hydrostatic pressure (HHP) or high pressure homogenisation (HPH).

The objective of this study was to assess the effect of High Pressure Homogenisation (HPH) compared with High Hydrostatic Pressure (HHP) on the microbiological quality of raw apple juice during storage at ideal (4 °C) and abuse (12 °C) temperatures. In the case of HPH, only low numbers of micro-organisms were detected after treatment at 300 MPa (typically between 2 and 3 log.ml⁻¹).

Solutes determine the temperature windows for microbial survival and growth.

Microbial cells, and ultimately the Earth's biosphere, function within a narrow range of physicochemical conditions. For the majority of ecosystems, productivity is cold-limited, and it is microbes that represent the failure point. This study was carried out to determine if naturally occurring solutes can extend the temperature windows for activity of microorganisms.

Effect of high pressure on the microbiological quality of cooked chicken during storage at normal and abuse refrigeration temperatures.

Vacuum-packaged cooked poultry meat was treated at a range of pressures (400-600 MPa) and hold times (1, 2 and 10 min), followed by storage at 4 degrees , 8 degrees or 12 degrees C for up to 35 days. Weissella viridescens was found to be the dominant microorganism in the pressure-treated meat, constituting 100% of the microflora identified at 500 and 600 MPa. None of the pressure-treated samples had obvious signs of spoilage during the 35 day storage period, even when the Weissella count was >7 log(10) cfu/g.

High pressure-induced inactivation of Qbeta coliphage and c2 phage in oysters and in culture media.

High pressure (HP) treatment inactivates bacteria in shellfish, but its effects on viruses in shellfish have not yet been determined, although viral illness is frequently associated with shellfish consumption. The aim of this study was to investigate the baroresistance of two bacteriophage viruses, Qbeta coliphage and c2 phage, in oysters and in culture media. High numbers (>or=10(7) ml(-1) or g(-1)) of both phages were obtained in culture media and in oysters.

Incidence, radioresistance, and behavior of Psychrobacter spp. in rabbit meat.

The relative incidence of Psychrobacter spp. in rabbit meat, the radioresistance of these bacteria, and the growth of nonirradiated and irradiated psychrobacter isolates, alone and in coculture, during chilled storage of inoculated sterile rabbit meat was investigated. Psychrobacter spp.

Role for compatible solutes glycine betaine and L-carnitine in listerial barotolerance.

Increased listerial barotolerance at elevated osmolarity is attributed, in part, to the presence of accumulated betaine and L-carnitine. The percentage of listerial survival following exposure to 400 MPa for 5 min increased from 0.008 to 0.

Sensitivity of Vegetative Pathogens to High Hydrostatic Pressure Treatment in Phosphate-Buffered Saline and Foods.

The effect of high hydrostatic pressure (up to 700 MPa) at 20°C on the survival of vegetative pathogens was investigated in 10 mM phosphate buffer (pH 7.0), ultra high-temperature-treated (UHT) milk, and poultry meat. In buffer, Yersinia enterocolitica was most sensitive, with a pressure of 275 MPa for 15 min resulting in more than a 10 reduction in numbers of cells.