Oscillatory High Pressure Processing Applied to Mechanically Recovered Poultry Meat for Bacterial Inactivation

Inactivating Food Microbes by High-Pressure Processing and Combined Nonthermal and Thermal Treatment: A Review

High-pressure processing (HPP) is a mild technology alternative to thermal pasteurization and sterilization of different food products. HPP has emerged to provide enormous benefits to consumers, i.e., mildly processed food and additive-free food. It effectively retains bioactive compounds and extends the shelf life of food commodities by inactivating bacteria, yeast, mold, and virus. The limitation of HPP in inactivating spores can be overcome by using other thermal and nonthermal processing sequentially or simultaneously with HPP. This review summarizes the applications of HPP in the fruits and vegetables, dairy, meat, fish, and poultry sector. It also emphasizes microbial food safety and the effectiveness of HPP in the load reduction of microorganisms. Comprehensive information about the synergistic effect of HPP with different techniques and their effectiveness in ensuring food safety is reported. The summarized data would be handy to interested researchers and industry personnel.

Frozen-Phase High-Pressure Destruction Kinetics of Escherichia coli as Influenced by Application Mode, Substrate, and Enrichment Medium

The synergistic effect of frozen-phase high pressure (HP) on the inactivation of E. coli ATCC 25922 cultures in suspension medium, Chinese bayberry juice (pH 3.0), and carrot juice (pH 6.5) was evaluated. The survivor count of E. coli remained at 3.36 log CFU/mL on a nonselective brain heart infusion (BHIA) medium, while no survivor was detected on a selective violet red bile agar (VRBA) medium after a 5 min hold pressure at 250 MPa in a frozen culture suspension. BHIA was suitable for safe testing of the injured E coli cells after HP treatment in frozen state. Frozen Chinese bayberry juice showed higher sensitivity to HP treatment for its matrix property with high sterilizing efficiency at 170 MPa. Two pulses exhibited a significant inactivation effect in frozen samples compared with one pulse, especially for the Chinese bayberry juice with different pressure levels. The destruction kinetics of HP pulse mode followed the first-order rate kinetics with a Zp value of 267 MPa in frozen carrot juice. Our results evaluated the influenced factors of frozen HP destruction effects, including the medium, substrate, and application mode. The frozen HP destruction kinetics of pulses afford us better understanding of the technology application in the food industry.

Multi-Pulsed High Hydrostatic Pressure Treatment of Foods

Multi-pulsed high hydrostatic pressure (mpHHP) treatment of foods has been investigated for more than two decades. It was reported that the mpHHP treatment, with few exceptions, is more effective than the classical or single-pulsed HHP (spHHP) treatment for inactivation of microorganisms in fruit juice, dairy products, liquid whole egg, meat products, and sea foods. Moreover, the mpHHP treatment could be also used to inactivate enzymes in foods and to increase the shelf-life of foods. The effects of the mpHHP treatment of foods are summarized and the differences between the mpHHP and spHHP are also emphasized.

Decontamination technologies for meat products

Consumers demand high quality, natural, nutritious, fresh appearance and convenient meat products with natural flavour and taste and an extended shelf-life. To match all these demands without compromising safety, in the last decades alternative non-thermal preservation technologies such as HHP, irradiation, light pulses, natural biopreservatives together with active packaging have been proposed and further investigated. They are efficient to inactivate the vegetative microorganisms, most commonly related to food-borne diseases, but not spores. The combination of several non-thermal and thermal preservation technologies under the so-called hurdle concept has also been investigated in order to increase their efficiency. Quick thermal technologies such as microwave and radiofrequency tunnels or steam pasteurization bring new possibilities to the pasteurization of meat products especially in ready to eat meals. Their application after final packaging will prevent further cross-contamination during post-processing handling. The benefits of these new technologies and their limitations in an industrial application will be presented and discussed.

A review of aerobic and psychrotrophic plate count procedures for fresh meat and poultry products

This is a review of reports that employed aerobic plate counts on fresh meat and poultry products since 1985; it lists synopses of 100 applications. A total of 15 different plating media were used, with 48 (48%) being either plate count agar (PCA) or tryptone glucose yeast extract agar. The temperature-time relations ranged from a low temperature of 20 degrees C for 120 h to 37 degrees C for 24 h. Some 29 different temperature-time combinations were used among the total of 109, with 21 (19.3%) being 35 degrees C/48 h, followed by 12 (11.0%) at 32 degrees C/48 h, 11 (10.1%) at 25 degrees C/48 h, and 9 (8.3%) at 25 degrees C/72 h. Fifty-four (49.5%) plate count applications employed incubation temperatures of 30 degrees C and below. From the 26 reports that employed psychrotrophic counts, 16 (61.5%) used PCA; 18 different temperature-time combinations were used, with 7 degrees C/10 d employed by only four. Twenty-one (80.8%) employed an incubation temperature at or <10 degrees C, and five employed an incubation temperature >10 degrees C. There is a serious need for some consensus on methodologies for aerobic and psychrotrophic counts on fresh meat and poultry products.