Plenty to Process

Food processing equipment displayed at the Food Expo evolves slowly, so developments are rarely dramatic. Nonetheless, there are enough exhibitors to generate piles of literature and consume several days of walking the floor.

Because of some recent interest in fruit and vegetable processing, I was intrigued with presses and a pasteurizer offered by Goodnature, Orchard Park, N.Y. The presses produce juices at rates of 1.25–8 tons/hr, depending on the model and various features, such as auto loading. They work by squeezing pulp held in cloths between plates and then discharging press cake by rotating the plates and dumping the cake. Other juice press designs require more manual labor to load and unload.

From the Show Floor
• Small-Scale Equipment. In addition to MicroThermics, Raleigh, N.C., and Armfield, Hampshire, UK, and Jackson, N.J.—both suppliers of a wide line of mini-production and demonstration equipment—there were other suppliers of small-scale equipment on hand. MicroThermics offers a microwave processor module, while Armfield was featuring a batch processing unit for high-viscosity materials such as jams and confections.

Bottom Line Process Technologies Inc., Largo, Fla., showed equipment designed to produce and package beverages in bottles, including a small batch bottle pasteurizer. OMVE Netherlands B.V., Schalkwijk, The Netherlands, showed a line of carbonization, heat treatment, and aseptic filling equipment intended to be integrated for small-scale production.

• Encapsulation. Encapsulated ingredients are increasingly common, often from firms that have proprietary technology that may or may not be available for custom manufacturing. Weishi, Zhejiang, China, and Hightstown, N.J, offers a line of nutrient ingredients in microcapsules, including various vitamins and nutrient fatty acids.

• Morishita Jintan Co. Ltd., Osaka, Japan, offers contract manufacturing of many different types of capsules, including some with multiple layers. Southwest Research Institute, San Antonio, Texas, developed many of the technologies used to form very small capsules and offers custom manufacturing and licensing.

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• Containers. Several versions of stainless steel intermediate bulk containers were shown by Automationstechnik USA LLC, Woodinville, Wash., which cooperates with CCR, a French manufacturer and leasing company with more than 300 types of containers. If a stock container is not suitable, a custom-made one can be designed. Most containers have capacities up to about 1,000 L, but larger ones are also made.

• Mixing. A division of AZO Incorporated, Memphis, Tenn., Amixon showed vertical shaft mixers with nice, sanitary finishes. The company manufactures vessels up to 1,800 cu ft. It also makes continuous mixers for liquids, solids, and viscous materials. The twin-shaft mixer is intended for materials requiring gentle treatment.

American Process Systems, Gurnee, Ill., claims that its Optima-Blend fluidizing paddle blenders can shorten normal mix times because the paddles provide more surface area than does a ribbon blender of comparable capacity. Mixing theory says that mixing occurs in the space behind the moving agitator, so an agitator with greater surface area has more active mixing volume.

Littleford Day, Florence, Ky., showed a model of its Ploughshare Mixer that had a large side access door for easy cleaning. Laboratory-size mixers are available in working capacities of 0.11–2.7 cu ft and standard sizes from 6–533 cu ft working capacity.

• Separations. Best known for its ion exchange resins and for owning Morton Salt, Rohm and Haas, Philadelphia, Pa., offers a special absorption resin that selectively absorbs polyphenolics, of interest as functional ingredients from fruits. The polyphenols are first non-selectively extracted by water and solvents, then the crude extracts are purified over the FPX resin and desorbed by eluting. The resin is said to be regenerated and capable of reuse hundreds of times.

Artisan Industries Inc., Waltham, Mass., offers a line of evaporator/strippers based on its Rototherm heat exchanger, a wiped-film device. Artisan also offers disk and tube internals for strippers and a steam-jet chiller that cools water by evaporation under vacuum.

LCI Corporation, Charlotte, N.C., (formerly Luwa) offers a line of wiped-film evaporators, many acquired from other manufacturers, such as Blaw Knox, Turba-Film,and Cherry Burrell. Evaporators can be linked to dryers to produce a powder from a slurry in one pass

Microdyn Technologies Inc., Raleigh, N.C., supplies the membranes for micro-, ultra-, and nano-filtration systems used to concentrate and clarify foods. The company’s membranes are often provided in systems built by other companies and can be used for replacement when needed.

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• High Pressure. One of four Food Expo Innovation Award winners, NC Hyperbaric, Burgos, Spain, was recognized for its Wave 6000/420 high hydrostatic pressure processor, which differs from others in the volume and number of chambers and pressure intensifiers. (See full story on Food Expo Innovation Awards on page 62.) Some have a volume of 420 L and a diameter of 380 mm. Most chambers are 300 L and 300 mm in diameter and have 1–8 intensifiers. The more intensifiers, the shorter the pressurizing cycle, and thus the higher the production rate. Ready-to-eat meats are treated after packaging to eliminate potential Listeria contamination.

Several poultry processors are using high pressure for such products as sliced turkey and chicken strips. Ohio State University, Columbus, Ohio, recently installed a high-pressure system from Stanstead Corp., an English firm; the system is available for small-scale runs, up to 5 L.

Uhde High Pressure Technologies GmbH, Hagen, Germany, also offers high-pressure processing systems as well as supercritical fluid contacting systems. Supercritical fluid extraction is appealing in many applications because the solvent is selective, is easily removed from extract by reducing pressure, and if carbon dioxide is the supercritical fluid, it is nontoxic and nonexplosive, in contrast to other common solvents.

Asoyia, Iowa City, Iowa, a small firm commercializing a special, ultra-low-linolenic-acid soybean oil, uses supercritical carbon dioxide instead of hexane to extract soybean oil from its specially bred seeds so that the oil qualifies as organic.

• Drying and Extrusion. The big news was the continued consolidation of the equipment industry as Aeroglide, Cary, N.C., itself an assembly of three previously separate companies—Aeroglide, National Dryer, and FEC, was acquired by Buhler, Minneapolis, Minn., a manufacturer of extruders and other grain-processing equipment. Aeroglide was showing a rotary dryer for fruit pomace. A rotary dryer is somewhat less complex than the typical conveyor dryer made by Aeroglide and its competitors.

Wenger Manufacturing Inc., Sabetha, Kan., makes single- and twin-screw extruders as well as dryers, often used after the company’s extruders for pet foods, cereals, and snacks. The Magnum ST extruder is designed to deliver high levels of specific mechanical energy (SME), which often correlates favorably with low product bulk density, small cell structure, and a higher degree of cook in starch-based products.

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One of the more eye-catching exhibits was by Coperion Holding GmbH, Stuttgart, Germany, demonstrating dense-phase pneumatic conveying of rice in a transparent tubing system with several of the company’s rotary feeders and valves. Several models are designed so that the rotor can be easily pulled out for maintenance and cleaning.

Oregon Freeze Dry, Albany, Ore., received FDA approval to freeze dry bulk pharmaceuticals (active pharmaceutical ingredients or API), which president Herb Aschkenasy described as one of the more-challenging exercises in his long career. One of the company’s first assignments is biscalcitrate, an antibiotic that is prescribed for some stomach ulcers.

• Instruments. An in-line spectrometer to measure any property measurable by optical spectroscopy, including near-infrared, infrared, Raman, fluorescence, ultraviolet, and visible, was on display by Ometric Corporation, Columbia, S.C. Examples include moisture, composition, fat, protein, and color.

• Spraying. Wheaton, Ill.-based Spraying Systems Co. showed a system for spraying an antimicrobial solution on meats, which included controls that were triggered by appearance of a piece, precise application of the spray, and accurate documentation so that the system could function as a critical control point in a HACCP plan.

Technical Sessions
One of the more creative sessions in the extensive program was organized by Ashim Datta and A. Halder of Cornell University to give as many as 40 attendees hands-on experience with a user-friendly predictive tool for food safety. The tool, developed at Cornell and the University of Tennessee, is a computer program that embeds the intimidating equations for heat transfer and biochemical kinetics, along with known kinetic and physical parameters, so that a user, in theory, need only specify the food of interest and the proposed process—cooking, frying, baking, or another thermal process—and the program will estimate the reduction in most pathogens of interest. The complexity of the task was illustrated by P.M. Davidson of the University of Tennessee, who mentioned that in the U.S. Department of Agriculture database, there are 7,500 distinct foods. These were collected into 17 groups, but still choices had to be made concerning what pathogens were of interest, initial doses, and the kinetic parameters as a function of temperature and other conditions. Datta pointed out that complex processes could take considerable time (several hours) for calculations, but that processes in which lumped parameters were appropriate took only seconds.

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Ilenys Perez-Diaz of USDA Agriculture Research Service South Atlantic Area Food Science Research Unit presented a poster (with R.F. McFeeters) on salt-free preservation of non-fermented cucumbers with acetic acid and sodium benzoate. The significance of this work is that FDA has not previously allowed inclusion of preservatives such as benzoate in filings for acidified foods even though they acknowledge that such preservatives inhibit the growth of acid-tolerant pathogens. The work in this poster demonstrated that pathogens die off in about 24 hr at pH of 3.5 and in the presence of acetic acid and sodium benzoate. Sorbates were less effective. Bulk-packed acidified foods often cannot be hot filled nor can post packaging be sterilized because the containers are too large or cannot stand high heat. Previous research in McFeeters’ group has shown reductions in pathogens in acidified food models (pickle brines) at pH below 3.3 over relatively short periods—24–48 hr. This and related research recently published in the Journal of Food Science could provide scientific support for filings for acidified foods at pH above 3.3.

Jose Miguel Aguilera of the Pontifical Universidad Catolica de Chile gave the Food Engineering Division lecture and the required report on the Marcel Loncin Research Award by discussing his research on quantifying and controlling food microstructure. He first discussed the challenge of properly sampling a surface that is examined microscopically. In the case of a loaf of bread, where the intent was to characterize the foam structure, nearly an entire slice had to be examined to get a representative distribution of bubble sizes at each distance through the loaf. For other foams, the spatial distribution is as important as the size distribution. Aguilera used a Euler characteristic to quantify foam structure. Finally, he described how physical structure of starch affected digestibility and found that various methods of gelatinization gave different results. His overall point was a plea to pay attention to the size domain in between the macro scale and the currently fashionable nano scale.

Thinking About a Second or Third Career?

YourEncore, Indianapolis, Ind., was a first-time exhibitor. The company promotes the use of retired or independent consultants to various industrial clients, acting as a virtual consulting firm and adding a fee of its own to whatever the individual wants to charge. YourEncore has relationship managers at key accounts, such as General Mills, Eli Lilly, and Boeing, which were the original users of the service. More food companies are being added. There are thousands of consultants in the database, and it is easy to join, with no cost or obligation. Potential assignments are discussed with what seem to be appropriate candidates, and scope and cost are submitted to clients.

Speaking of second or third careers, another is writing. Elsevier/Academic Press, New York, N.Y., was one of four publishing companies displaying books of interest to the food industry. (The others are Springer, New York, N.Y.; Wiley/Blackwell, Ames, Iowa; and CRC Press-Taylor & Francis, Boca Raton, Fla.) Forgive my shameless self-promotion, but Elsevier was showing page proofs of my new book, Practical Design, Construction and Operation of Food Facilities, and said they sold two. (More information is available at http://elsevierdirect.com/9780123742049; the long number is the ISBN number.) Seeing page proofs is like viewing the ultrasound image of your yet-to-be-born—promising but fuzzy. By the time this issue appears, the book should be officially out. Next year, at Springer’s booth, should be my next, Case Studies in Food Engineering: Learning from Experience.

by J. Peter Clark is Contributing Editor, Food Technology ( [email protected] ).