High Pressure Processing , Hurdle Technology and Irradiation of foods

High Pressure Processing , Hurdle Technology and Irradiation of foods

1. High Pressure Processing High Pressure Processing (HPP) High Pressure Processing is a novel non-thermal process to stop pathogenic spoilage related to food. HPP puts high hydrostatic pressure into food through an internal vessel for a specified period of time to inactivate noxious spoilage microorganisms and enzymes. The pressure range from 100 to 1000 MPa, while the atmospheric is nearly 0.1 to 1 Mpa. This methods’ temperature differs from 0 to 100°C, but lower temperatures are used for sensitive heat products that needed to be preserved. HPP, foods will remain more fresh and desirable than the other thermal processes. HPP does not affect the physical, chemical, and sensory properties of foodstuffs. Preventing microbial and chemical changes in food, it should be treated with processing technologies so the food products would suit the customers’ needs and enhance shelflife.

2. High Pressure Processing High Pressure Processing (HPP) HPP is generated through three ways : Direct compression by dynamic pressure in pistons Indirect compression by static pressure seals Through heating the pressure medium. The foodstuff is put into a vessel and then compressed to the required pressure level and held for the needed time period and after that decompressed. (Procedure almost similar like retort processing). In meat processing usually, products are held at 300 to 600 MPa for 3-5 min. HPP strain vessels are geared up that can be easily used in a short time for loading. HPP process's main factors are pressure, time, temperature, required stress, and decompression time. The product pH, water activity, and packaging material are also important.

3. High Pressure Processing High Pressure Processing (HPP) application in meat processing

4. High Pressure Processing High Pressure Processing (HPP) application to inactivate Microbes

5. High Pressure Processing Beneficial Effect of High Pressure Processing (HPP) HPP eliminates the physiochemical changes, preserving the color, texture, flavor, and freshness. HPP treatment (400 – 600 MPa) on canned fish, meat sausages, minced meat products showed a reduction of FFA content (around 50%) during 6-15 months of the frozen storage period, so HPP's inhibitory effect on lipid hydrolysis has been proved in canned fish. In some meat sausages stability of vitamin C treated with HPP depends on the food matrix, and nearly 90% is retained. HPP processing retention of amino acid were grater, thus increases biological value of meat products. HPP method is effective on inactivation of enzymes and inhibits microbes (except spores; require additinal sterilization) thus no chemical preservatives are needed.

6. High Pressure Processing Beneficial Effect of High Pressure Processing (HPP) It has been generally recognized that HPP is more suitable for preservation of processed meat, rather than raw meat. Raw meat shows some discoluration in HPP. HPP have longer shelflife upto 9-12 months if the product is stored at suitable temperature with proper packaging. HPP Meat products High pressure processing Plant

7. High Pressure Processing High pressure processing equipment

8. Hurdle Processing and Irradiation Hurdle Processing: Hurdle technology (HT) is a new concept in the preservation of meat and meat products. A combination hurdles is applied to inhibit the growth of microorganisms. Some of the hurdles such as temperature (high or low), water activity (aw), preservatives (nitrite, sorbet), competitive microorganisms (lactic acid bacteria) and acidity (pH) have been empirically used for years to stabilize meat, fish, milk and vegetables. Two or more hurdles are preferably used in the system. Intermediate moisture meats and fermented sausages are some of the examples where HT is used. Basic concept of Hurdle technology or processing method has been developed to reduce the usage of preservatives in foods and consists of the combined effect of hurdles to establish an additional antimicrobial effect, thus improving the quality of the food. Various novel hurdles that are being applied in various food products includes Nano-thermo- sonication, ultrahigh pressure, photodynamic inactivation, modified atmosphere packaging of both non-respiring and respiring products, edible coatings, ethanol, milliard reaction products.

9. Hurdle Processing and Irradiation Hurdle Processing: Types or classification of Hurdle Processing methods Types of hurdles Example Physical Aseptic packaging, electromagnetic energy (microwave, radio frequency, pulsed magnetic fields, high electric fields), high temperatures (blanching, pasteurization, sterilization, evaporation, extrusion, baking, frying), ionizing radiation, low temperature (chilling, freezing), modified atmospheres, packaging films (including active packaging, edible coatings), photodynamic inactivation, ultra-high pressures, ultrasonication, ultraviolet radiation Physico-chemical Carbon dioxide, ethanol, lactic acid, lactoperoxidase, low pH, low redox potential, low water activity, Maillard reaction products, organic acids, oxygen, ozone, phenols, phosphates, salt, smoking, sodium nitrite/nitrate, sodium or potassium sulphite, spices and herbs, surface treatment agents Microbial Antibiotics, bacteriocins, competitive flora, protective cultures Miscellaneous Monolaurin, free fatty acids, chitosan and chlorine.

10. Hurdle Processing and Irradiation Hurdle Processing: Principle hurdles used in food preservation Parameter Symbol Application High temperature F Heating Low temperature T Chilling, freezing Reduced water activity a w Drying, curing, conserving Increased acidity pH Acid addition or formation Reduced redox potential E h Removal of oxygen or addition of ascorbate Biopreservatives Competitive flora such as microbial fermentation Other preservatives Sorbates, sulfites, nitrites

11. Hurdle Processing and Irradiation Hurdle Processing: Aspects of hurdle technology: The hurdle technology affects the physiology and growth of microorganisms in food. There are mainly 4 major mechanisms by which hurdle technology affects the growth of microorganisms in foods. Homeostasis Metabolic exhaustion Stress relaxation Multi target preservation of food

12. Hurdle Processing and Irradiation Hurdle Processing: Homeostasis: It is the process that maintains the stability of the living cell’s internal environment in response to the changes in external environment. Some of the examples of homeostasis in the body are regulation of temperature and balance between acidity and alkalinity (pH). These factors are prerequisite feature of living cells and this applies to higher organisms as well as microorganisms. Disturbing the homeostasis of the microorganisms by various hurdles eventually results in the death of the spoilage causing microbes thereby protecting the food product from microbial spoilage.

13. Hurdle Processing and Irradiation Hurdle Processing: Metabolic exhaustion: This aspect of hurdle technology deals with auto sterilization of food. It has been observed that the spore counts in hurdle technology treated food products actually decreases during storage especially at ambient temperature. The microbes in the hurdle treated stable products uses their energy for homeostasis thereby becoming metabolically exhausted. This leads to auto sterilization of food products. Thus, the microbiologically stable product becomes safer for storage at normal room temperatures

14. Hurdle Processing and Irradiation Hurdle Processing: Stress reactions: Some microbes acquire resistance or may become more virulent under stress conditions as they synthesize stress shock proteins. The synthesis of stress shock protein is affected by several factors like pH, water activity, ethanol, heat, etc. The different responses of microbes under stress conditions might hamper the food preservation. Exposure to multiple stresses simultaneously activates the energy utilizing synthesis of several stress shock proteins, in turn making the microbes metabolically weak. Therefore, multi target preservation of foods could be an efficient approach towards reducing the synthesis of stress shock proteins and in food preservation.

15. Hurdle Processing and Irradiation Hurdle Processing: Multi target preservation of food: It is a very important aspect for efficient and effective preservation of targeted food material. Hurdles applied in the targeted food material might not just have effects on microbial stability but they could act synergistically. Synergistic effect could be achieved in the targeted food, if the hurdles affects different targets such as pH, aw, Eh, enzyme systems simultaneously within the microbial cell and thus disturb the homeostasis of the microbes rendering it difficult for the microbes to synthesize different stress shock proteins and to maintain their homeostasis. Therefore the application of several hurdles simultaneously would lead to an optimal microbial stability and effective food preservation.

16. Hurdle Processing and Irradiation Hurdle Processing:

17. Hurdle Processing and Irradiation Irradiation: Radiation is a waves or particals propogating through space or through a medium, carrying energy. The main difference between irradiation and radiation is that the Irradiation; is process by which an object is exposed to radiation. The energy required for sterilization by irradiation is 1/50 that required for heat sterilization and temperature rise is not more than 50°F. Hence this process also called as cold sterilization and comes under non thermal processing. Irradiation is the controlled application of energy from ionizing radiations. A joint FAO / IAEA / WHO Expert Committee of Irradiated Foods approved the use of only the following types of ionizing radiation for food irradiation. i. Gamma rays from radionuclides Cobalt – 60 (Maximum energy 1.17 - 1.3 MeV) or Cesium - 137 (Maximum energy 0.67 MeV). ii. X - rays generated by machines operated at or below an energy level of 5.0 – 7.5 MeV. iii. Electrons produced commercially by machine sources at or below an energy level of 10 MeV

18. Hurdle Processing and Irradiation Irradiation: Units of radiation Radiation energy is measured in terms of rads where 1 rad = 100 ergs of energy absorbed in 1 g of matter. 1 eV = 1.6 X 10-12 erg 1 erg = 10-7 Joule and 1 Joule = 107 erg = 10 M erg A new standard irradiation (SI) unit is known as Gray (Gy). 1 Gray = 100 rads 1 K rad = 1000 rads 1 M rad = 1000 000 rads 1 kGy = 100 000 rads

19. Hurdle Processing and Irradiation Irradiation: Food irradiation is a preservation technique using Ionizing radiation to lengthen shelflife of fresh foods and processed foods. Irradiation postpones or kill microbial spoilage, reduces occurrence of foodborne contamination and prevent infestation by insect. Food irradiation is a process of food preservation in which foods is exposed to ionizing energy radio isotope Cobalt -60 and Cesium -137. High energy electrons are X -rays generated by machines using electricity and incresingly used for food irradiation. ( More econonic so less in use, compare to gamma rays) Radioactive isotopes such as Cobalt-60 and Cesium-137 are needed to produce gamma rays, with sufficient energy to treat foods. Cesium-137 and cobalt-60 were produced from atomic fission representing a major scientific advance that supported the industrial application of food irradiation. Globally Gamma rays are the most common source of food irradiation. Electron beams can not penetrate as for into food as gamma rays(30-120cm) and X-rays, thus they are used primarily for treating Sea foods, meat products, Grains, vegetables etc.

20. Hurdle Processing and Irradiation Irradiation: MECHANISM OF ACTION OF RADIATIONS When ionizing radiations of approved energy levels pass through foods, there are collisions between ionizing radiations and food particles at the molecular levels. Ion pair is produced when the energy from these collision is sufficient to dislodge an electron from an atomic orbit. Molecular changes occur when collisions provide sufficient energy to break chemical bonds between atoms and form free radicals. Irradiation of food helps formation of ion pairs, free radicals, reaction of free radicals with other molecules and recombination of free radicals. Irradiation creates damage in the gentic material of the cell by causing a lesion in the DNA or breaking both strands of DNA. DNA damage prevents multiplication and rondomly inhibits cell functions, resulting in the death of the cell. These mechanisms alter microorganisms and food constituents effecting food preservation.

21. Hurdle Processing and Irradiation Irradiation: MECHANISM OF ACTION OF RADIATIONS Resistance of microorganisms; The most radiation resistant microorganism in foods is Clostridium botulinum . Acid values below pH 4.5, aerobic conditions, extreme dryness in foods and / or, refrigeration below 4 o C prevent growth and toxin formation by this organism. In foods where these conditions do not exist, the food is irradiated with the dosage sufficient to destroy this organism. Food with pH > 4.5, Cl. botulinum is not a problem but other spoilage organisms must be inactivated with lower radiation dosages. Bacterial spores are more resistant to the germicidal action of ionizing radiations than are the vegetative cells.(require sterilization or other hurdle technique along with irradiation.)

22. Hurdle Processing and Irradiation Irradiation: MECHANISM OF ACTION OF RADIATIONS Resistance of enzymes: Most food enzymes are more resistant to ionizing radiations than even the spores of Cl. botulinum . Inactivation of enzymes requires very high doses of the order of 200 kGy (20 M rad). Such a high dosage destroys food constituents and impairs safety of food. For these reasons, irradiation alone is not suitable for food stability. Hence combination of processes is preferred. Enzymes are more easily inactivated by heat (even blanching, Pasteurization, etc) and by certain chemicals.

23. Hurdle Processing and Irradiation Irradiation: Application and Dosage: There are 3 general applications and dose categories when foods are treated with ionizing radiation. They are Radurisation, Radicidation and Radappertisatio. 1. Radurisation: Low doses up to 1 kGy are employed in this process. These low doses substantially reduce the pathogenic and spoilage microorganisms and enhance the keeping quality of meat and meat products. Radurisation is used along with refrigeration to maintain quality. The shelf life of fresh meats in refrigeration at 2 - 4°C is normally 3 days. The shelf life of radurised fresh meats is 5 weeks at the same temperature. Radurisation is helpful if fresh meat is to be transported in chilled condition to the destimation. Radurisation reduces the levels of potential pathogens such as Salmonella spp and spoilage organisms such as P seudomonas spp. Also it causes insect disinfestations and parasite inactivation.

24. Hurdle Processing and Irradiation Irradiation: Application and Dosage: 2. Radicidation: This process involves the application of medium radiation doses of 1 – 10 kGy necessary to reduce the number of viable non - sporing pathogenic and spoilage bacteria. Meat and poultry are frequently contaminated with pathogens such as Salmonella, Campylobacter and Listeria, which are inactivated by this dosage of irradiation. 3. Radappertisation (Cold sterilization): Radappertisation is an alternative to commercial preservation by thermal sterilization, freezing and drying. The doses used are high in the range of 10 - 45 kGy. It is similar to thermal processing of canned meat products. Reduction in numbers of microorganisms will be to the point of commercial sterility. Products subjected to radappertisation should be packed properly to prevent microbial recontamination and the deleterious effects from light, oxygen and moisture. Both metal containers and flexible packages are used under vacuum to prevent rancidity of lipids.

25. Hurdle Processing and Irradiation Irradiation: IRRADIATION IN COMBINATION WITH OTHER TREATMENTS As mentioned in many instances irradiation alone may not be successful in providing safe meat. Combination of different treatments show better results for maintaining the quality of irradiated meat products. The combination treatments have synergistic antimicrobial effect. Incorporation of ascorbic acid and spice powders in to meat products may offset the ill effects of irradiation by minimizing the production of off odors / flavors. Addition of alpha tocopherol / antioxidant in to ground meat and proper packaging retards or limits lipid oxidation in the irradiated meat. Irradiation in combination with vacuum packaging, edible coating film containing natural antimicrobial compounds or modified atmosphere packaging reduced bacterial growth. Irradiation and refrigeration of meat and meat products increased both safety and shelf life of products. High dosage of radiations required for inactivation of enzymes in meat or poultry products is detrimental.

26. Hurdle Processing and Irradiation Irradiation: IRRADIATION IN COMBINATION WITH OTHER TREATMENTS The dosage can be reduced by vacuum packaging in subfreezing temperatures to prepare sterile shelf stable products with excellent sensory properties. Such products have been used extensively by military organizations during space flights and hospitals Benefits: Irradiation can ensure minimum changes in physico – chemical, biochemical and sensory quality attributes and provide better quality meat products. Less food spoilage. Reduce risk of food borne diseases caused by microorganisms such as Salmonella and E. Coli etc. Less need for persticides , preservatives or additives to store or preserve foods. Low cost and high efficiency, longer shelflife and gives assurance to consumer on quality and safety.

27. Hurdle Processing and Irradiation Irradiation