"HIGH PRESSURE" TECHNOLOGY-EXTENDING LIFE OF AVOCADO PRODUCTS

Pathogenic microorganisms like Salmonella, Listeria and virulent strains of E.coli are causing enormous damage to processed foods in spite of fast advances made by food technology. The recent E.coli poisoning episode in Europe, claiming almost 50 lives and causing health damage to thousands is a classical example of what these organisms can do in harming humans through their foods. Though gamma radiation is considered efficient in destroying these pathogens, this technology has not yet become the industry standard due to consumer apprehension regarding the safety of irradiated foods. It is against such a background one has to appreciate the arrival of High Pressure Processing (HPP) technology which achieves "cold sterilization" without use of chemical preservatives or high temperatures. Introduced commercially in the US during 1990's HPP has come to be established as a reliable technology world over though its high investment cost is a damper to its wide scale use. New Zealand, which has a substantial production base for Avocados is the latest to acquire HPP for extending the life of the fruit from 30 days to more than 60 days that is expected to boost its exports dramatically in the coming years.

"The Kiwi avocado industry has secured a multi-million dollar export deal with Japan thanks to its new food processing technology. The food preserving technology, introduced earlier this year, dramatically extends the shelf life of avocados without the use of any chemicals or other additives. The Ultra High Pressure (UHP) processing technology, which is also known as cold pasteurization, uses pressures of up to 87,000 psi to shock and kill bacteria in food products. Kiwi owned Fressure Foods, a grower-owned company, imported the technology last year, establishing its plant in Pukekohe and creating 40 jobs. Fressure Foods CEO, Vern Dark, says with its ability to extend the shelf-life of avocados and deliver them in a convenient ready to use pack the industry is capable of boosting the country's annual exports by 20 million dollars. "Avocados usually last around 30 days but now we're able to extend this to 60 days. We imagine this extended shelf life will open many new markets. With this technology we are able to add significant value to a commodity product which was too perishable for some of the countries we wanted to export to." One of the first products to receive the UHP treatment is the Fressure Foods Guacamole with significant orders being delivered to Japan and Singapore. Export negotiations are also well advanced in Australia and the products have recently launched in New Zealand supermarkets. Dark says ultra high pressure treatment has driven up total consumption of avocados in the United States, something he is hoping will be repeated here".

It is a fact that the high investment HPP technology is most popular in the US and majority of the 100 plus plants are located in that country. Subjecting products to high hydrostatic pressure causes irreversible denaturation of proteins including bio-active enzymes, fortifies hydrogen bonds, disrupts non-covalent bonds while leaving the covalent bonds unaffected. The texture is maintained while bacteria are made innocuous. It is notable that cold sterilization can be achieved within 3 minutes while traditional thermal processing can take as much as 10-45 minutes. On the limitation side spores are not destroyed unless there is a reduction in the pH of the system while some foods need refrigeration to prevent deterioration due to some enzymes not inactivated during the process. Some of the products commercially being processed by HPP include fish, meat, salad dressings. rice cake, yogurts and Avocado derived guacamole. Considering that food products that cannot be processed at high temperatures need sterilization to ensure consumer safety, HPP is considered the most appropriate technology at present.

V.H.POTTY
http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com

HIGH PRESSURE PROCESSING TECHNOLOGY-COMING OF AGE

It is the constant endeavor of food technologists to evolve processes that can be carried out at ambient conditions and the High Pressure Pasteurization technology now available to the industry for commercial level adoption offers such a clean process. Under high hydrostatic pressure contaminating microorganisms are susceptible to destruction while the quality of food remains unaltered. According to present information available, HPP process may revolutionize the food processing practices in the coming years though all foods cannot be subjected to this technology. One of the main advantages is that the products can be in-package sterilized, requiring no further exposure of the contents to the atmosphere that could cause re-contamination.

"High Pressure Pasteurization is an all-natural, environmentally friendly, cutting-edge technology that uses intense hydrostatic pressure to deactivate and destroy pathogenic bacteria and microbiological contaminant flora. An ideal solution for pre-packaged RTE products including meats, soups, wet salads, sauces, fruit smoothies, shellfish and seafood, Safe Pac's HPP process allows food manufacturers to offer safely packaged, minimally altered chemical-and-preservative-free goods to retailers, with minimal fear of recall due to bacterial contamination. According to Guy Giordano, President of Safe Pac Pasteurization, LLC, "By applying up to 87,000 pounds of hydraulic pressure per square inch to ready-to-eat food products in their final packaging, our HPP Process completely eradicates harmful bacteria, eliminating the need for chemicals and preservatives, without compromising the taste or texture of the treated products." Best with moist foods without internal air pockets, HPP places pre-packaged products in flexible containers (i.e. pouches, plastic bottles) into a high-pressure chamber, which is then flooded with cold water and pressurized for a short time period, usually 3-5 minutes. As pressure is applied uniformly around and throughout the product, reaching all parts of the product simultaneously, treated foods retain their original shape and texture. Unlike competitive heat-based processes, the quality of HPP processed foods is similar to fresh food products, because pressure has little to no effect on low molecular weight components such as color, flavor and vitamin content. Because it protects naturally, preserving foods with water pressure, HPP meets Organic standards, processing products without impacting their USDA Organic designation. "By denaturing the cells of food borne pathogens without using chemicals, we're setting a standard and sending a message," says Giordano. "At Safe Pac, we help customers reduce or eliminate preservatives, cut costs, and offer the all-natural and organic products today's consumers are looking for."

Though the processing cost is considered very low, the initial cost of investment on the equipment can be substantial. Besides only moist foods, not requiring the structural integrity to be maintained, are suitable candidates for this technology. Hydrostatic pressure to a limited extent is employed by the food industry for in-pack thermal sterilization using steam to attain sterilization temperatures in flexible pouches and there are hundreds of such products in the market readily accepted by the consumers. Most of the Indian culinary preparations are preserved for long-haul markets using the retort pouch technology. Probably these products may be suitable for processing using HPP technology.

V.H.POTTY
http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com

HIGH PRESSURE PROCESSING-A CLEAN TECHNOLOGY

Preservation of food is a vital necessity of mankind as such a course of action can ensure food security all the time. As most foods are seasonal in nature, excess production needs to saved away for future needs when production is not possible due to season and weather conditions. For the last 200 years man has been continuously striving to reduce food wastage through better technologies and the vast strides made by food technology have provided food industry with a wide range of choices vis-à-vis food preservation. One of the most elegant process evolved relatively in recent times makes use of the principle that when food is subjected to high hydrostatic pressure all living things in it are totally destroyed. Pressures as high as 50000 pounds per square inch can make inactive bacteria, molds and yeasts in less than 15 minutes. Many enzymes are also inactivated because of the susceptibility of protein to denaturation at the pressure employed. The 17th Century scientist Blaise Pascal who is the pioneer in high pressure processing (HPP)would not have imagined that the process named after him as "Pascalization" has such a high potential for saving foods from spoilage to day.

"High pressure in the food industry, as a new non-thermal method, is applied in many phases of food processing. This new non-thermal technology was developed in the 1990s. The main advantages of high-pressure processing are in the short time of processing which is between a few seconds and 30 minutes. Processing of solid or liquid food products with or without packaging happens in the temperature interval 5 – 90 °C, and pressures 50 – 1000 MPa. The driving pressure is distributed uniformly through the whole product independently of its quantity and shape. These processing characteristics combined with improved food microbiological safety, less energy expenditure, low concentration of waste products and longer shelf life make high-pressure processing a very promising novel food technology. Combined with lower cost of treatment (but unfortunately higher initial cost of equipment) compared to traditional processing technologies, it is also economically profitable. The main purpose of such treated food products are in preservation of sensory, nutritive and textural properties. As the temperature increase is very low, there are no significant changes in sensory properties, in contrast to conventional thermal processing (sterilization, pasteurization). However, with the combination of heating or cooling and high pressure, modification of existing and creation of new food products is possible. Today, high pressure is used for the treatment of meat products (inactivation of microorganisms), freezing and defrosting of foodstuffs, production of fruit juices (pasteurization), processing of oysters, modification".

It was left to Japan to recognize the merits of HPP first and products like juices, jams and jellies became the first commercial products marketed by using this process. To day a wide range of foods like fish, meat, salad dressings, rice cakes, yogurts etc are shelf-stabilized using HPP. Only limitation for this process is that some enzymes are not inactivated leading to possible quality deterioration during extended storage. Similarly some spores are not affected, especially under low acidic environment, calling for combining HPP with other techniques for complete sterility. HPP works extremely well under acidic conditions where proteins get denatured, hydrogen bonds are fortified, non-covalent bonds are disrupted and nutrients are unaffected. High investment need for setting up the plant will naturally reflect on the cost of processing and products from HPP line are bound to be more expensive to the consumer. Probably fish and meat may remain the most suitable candidate for HPP technology because of their high value.

V.H.POTTY
http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com