The radically diminished cook times are achieved by the vigorous and thorough mixing of the food contents, enabling rapid heat transfer through the containers and through the basket holding them.
Conventional retort processes are time- and energy-intensive. A thousand cans of food in a large steel pressure cooker may be heated to 250°F. Food near the container walls will sterilize relatively quickly, but heat penetration to the interior of the can may take hours. The container will not be sterile until every microorganism in the middle is destroyed. The extended sterilizing time of food within the container accounts for the “overcooked” flavor of many canned foods.
The Shaka process stirs the contents in the package in a manner that allows heat to penetrate to the center of the container and sterilize the contents very quickly.
“The equipment looks like an ordinary retort, a pressure vessel with a door,” says Emanuel. “But there’s a motor and an actuator going through a port in the pressure vessel. It shakes the basket holding the containers about 150 times per minute. We found that shaking the product slowly hardly makes a difference, but if you shake it harder, the process speeds up tremendously and eliminates the overcooking found with a normal retort.”
More on the web
FMC FoodTech has seven Food Processing and Technology Centers that allow processors to test-run new technologies and equipment, refine applications or experiment with new ones. They’re located in Madera, Calif.; Lakeland, Fla.; Sandusky, Ohio; St. Niklaas, Belgium; Helsingborg, Sweden; and Araraquara, Brazil. Check them out at: www.fmctechnologies.com/FoodTech/AboutUs/OurInnovations/Labs.aspx.
Heat and Control has a technical library with technical articles, brochures and equipment videos, as well as a downloaded unit conversion utility, which converts everything from international standards to velocity, mass, force, pressure, density, temperatures, fuel consumption, etc. See:
The rapid process works effectively with products packed in cans, glass, retort pouches and other containers.
“At first I thought our biggest advantage was energy – taking minutes instead of hours to sterilize and cook product,” says Emanuel. “But the real advantage is in food quality. The result is product closer to freshly cooked or chilled food.” But with very long shelf life at ambient conditions.
Chilled prepared foods have a shelf-life ranging from five to 20 days. They also require energy for chilled storage, which adds cost. In Europe, chilled products generally sell at two to four times the cost of canned food, and much of that product goes to waste, Emanuel notes.
Three leading retort manufacturing companies -- including Allpax Products in Covington, La., and Steriflow in France -- make Shaka process retorts under license from Zinetec Ltd. Utek Europe is advising Zinetec on commercialization.
The Shaka process is not suitable for solids, according to Emanuel. But it shines when applied to soups, sauces, baby food, soya-based drinks, dips, cheese sauces, chopped vegetables, milk-based drinks and pet foods. Product has a long shelf life at ambient temperatures. Like the usual array of heat processed foods, product will last for years.
“It produces high-quality foods that taste fresher, with better flavor, texture and color,” says Emanuel. “People want long shelf-life, good-tasting, convenient foods.”
Combo systems and energy improvements
Fast-food operators aren’t the only ones asking if you’d like “a combo.”
More and more of today’s processors are incorporating multiple types of thermal processing equipment into a processing system. Branders, searers, ovens and fryers are often combined to deliver custom products having unique taste and consumer appeal. Some hybrid heating/cooking systems also use continuous microwave ovens to increase throughput and garner significant energy savings.
“We’re seeing more add-on components added to the front, middle or back of a system,” says Heat and Control’s Giles. “Processing systems for prepared foods such as boneless breaded chicken breasts traditionally have been simple sequences of applying batter and breading, frying and finishing in an oven. Today it’s more common for processors to also use steam chambers, infrared ovens and other devices to more efficiently transfer heat the product, improve the energy efficiency of the process and increase output capacity.”
That microwave addition may boost yield 3-15 percent and increase capacity 15-50 percent. “A 10 percent increase in throughput can be very efficient,” says Giles. “The microwave might be 20 feet long and cost a quarter million dollars, but that can be peanuts in the scope of things.”
Oven-microwave combos can improve the efficiency of poultry products, nuggets, sausage toppings, bacon bits and strips, patties, meatballs, hot pockets, potato products and snacks.
A “totally different frying concept” called HeatWave from Heat and Control claims energy, cost and quality advantages over conventional “submerge-in-oil” frying.
The system conveys product through curtains of hot oil that descend from overhead weirs. The system was developed for meat, poultry and seafood but also works on nuts and some other snack products.
The freshness of the oil is a critical factor in any frying operation. “The best fryer is the fryer that has the least amount of oil volume in the system to produce the product capacity you desire,” says Giles. “Faster oil turnover rate generally translates into higher quality product. A major advantage with HeatWave is that it has roughly 50 percent of the system oil volume of a typical submersion fryer.”
The Stein GCO-II GyroCompact spiral oven from FMC FoodTech incorporates multiple cooking processes to produce more moist and tender meat products.
The oven consists of two distinct cooking processes: an initial phase using steam condensation and a convection phase of superheated steam-air mixture for quick cooking. The combination helps maintain uniformity and quality across the belt width. Timing the right mode of heat transfer at the appropriate time in the cooking process delivers products that are more moist and tender with better appearance and flavor as well.
The company offers the system as an alternative to conventional microwave ovens to bacon processors, claiming higher yields and throughput, better steam containment, improved mesh belt design and enhanced vertical air flow.
“Average yield is the primary measurement, not temperature, in bacon processing,” says Ramesh Gunawardena, manager of technology and process development for Chicago-based FMC FoodTech (www.fmcfoodtech.com). “The variability in temperature control leads to inconsistent quality. The superior cross-belt temperature control of the GCO-II allows production at a lower standard temperature deviation. That produces more consistent and superior overall product quality.”
A supplementary impingement section gives processors more flexibility and higher output with significantly lower maintenance costs.