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As IFT gears up to celebrate its 75th anniversary at the 2014 annual meeting in New Orleans, this is a unique opportunity to reflect on the technological advances of the past 75 years and explore the food engineering research published in the Journal of Food Science (JFS). During the early 1900's, the technological development of canning by Prescott and Underwood at the MIT paved the way for food engineering research. In the early 20th century, research on thermal processing began its upswing, and was published mostly in National Canners Association (NCA) bulletins. In 1936, the birth of Food Research (predecessor of JFS) provided a platform for food technologists to publish their research findings.

The first issue of JFS, published in 1936, featured an article on pasteurization of Concord grape juice by Carl Pederson of the New York State Agricultural Experiment Station. This study demonstrated that grape juice can be pasteurized successfully at temperatures below 74 °C, which was considerably lower than the temperatures of 88 to 100 °C that were used in the industry and in the home at that time. Pederson obtained the transient temperatures of the juice using a long-stemmed mercury thermometer inserted through a cork at the center of the bottle, and determined the time needed to achieve the desired temperatures. This method of heat penetration has been fundamental to thermal process calculation. Since then, instruments for gathering time-temperature data during processing have become more sophisticated. In subsequent issues of JFS, Tressler and Pederson demonstrated the role of headspace oxygen on the storage quality of pasteurized juice. They showed that juice pasteurized at 73.4 °C for 30 min, when stored with little or no oxygen at 1.1, 8.3, and 22.2 °C, retained excellent flavor and aroma for 3 mo. Another paper in this 1st issue of JFS also highlighted the vacuum desiccator and water displacement methods to determine the vacuum in glass jars. The development of vacuum in food containers sealed hermetically is central to thermal sterilization.

In his seminal paper in the January 1938 issue, Colin O. Ball presented a comprehensive review of advances made in sterilization methods for canned foods. Ball has been recognized for Formula methods, which he developed in 1923 for thermal process calculation. Formula methods were extensively used by the canning industry worldwide for several decades after they were introduced. These process calculation methods are still taught to undergraduates in Thermal Processing courses. Ball's review described food preservation methods used in terms of 2 time periods: before and after Appert developed the canning process. The article described the term ‘commercial sterilization,’ which referred to the term ‘sterilize’ as applied to canned foods. The review covered the development and improvement of thermal processing equipment and the use of the thermocouple in heat penetration studies. The review also explored the relation between processing temperature, heat penetration, and product quality. Ball also emphasized the importance of a faster rate of heat transfer, which prompted the introduction of continuous and agitated retorts. In addition, he advocated high-short sterilization, later referred to as the high-temperature short-time (HTST) process, to improve quality of convection-heated foods. Finally, this seminal article presented a comprehensive review of patents on high-short sterilization and food preservation by other means than heat.

In a fascinating article published in the March 1938 issue, Burton (editor of Food Industries, a McGraw-Hill publication) emphasized the need for trained Food Engineers and the development of the Food Engineering discipline, a branch of engineering related to the industrial production of food and food products. Burton linked Food Engineering to Chemical Engineering, and highlighted the importance of unit operation to the field. At the first Food Technology conference in the U.S., Samuel Cate Prescott, the 1st president of the Institute of Food Technologists (IFT) and founder of Food Research (JFS since 1961), gave the welcome address. In his article in the March 1938 issue, Prescott noted that early work in food chemistry and later, the bacteriology aspects of food preservation led to Food Engineering research and teaching efforts at MIT.

Since then, tremendous progress has been made in the science and technology of thermal processing. This is very well-reflected in the JFS articles published over the last 70 years. These articles present detailed quantitative analyses of heat transfer during thermal processing of solid, liquid, and liquid solid mixtures; thermal process design and optimizations; and the development of sterilization systems and packaging for thermally-processed foods. For example, a 1974 paper by Simpson and Williams presented a rigorous mathematical analysis of high-temperature short-time sterilization in a continuous flow system. Many JFS articles have employed physics-based mechanistic modeling to provide insight into food processes. A recent November 2013 paper presented a comprehensive mathematical model for heating a multicomponent solid-liquid mixture with a continuous Ohmic heater. The mathematical model was validated with experimentally obtained temperatures and microbiological tests. Another article in the same issue applied computational fluid dynamic analysis to simulated fluid flow and heat transfer during thermal processing of olives in brine in a stationary tin can. These studies are particularly relevant to thermal process design and optimization that lead to the production of safe, high-quality products.

By the 1940s, research topics published in JFS included food freezing, food drying, modified atmosphere storage, and various aspects of thermal processing. In the 1950s, scientists at MIT and the National Canners Association laboratories began investigating ionizing radiation to produce preserved foods with natural quality. Early papers on this technology dealt with the irradiation destruction kinetics of spores and spoilage bacteria using X-rays, gamma rays, and cathode rays. In 1957, JFS published a quantitative study of combined heat and irradiation treatment by MIT scientists. During the 1950's, scientists learned about the relationship between vapor pressure of water in food and microbial spoilage in foods. A 1955 JFS paper by Mossel and Kuijk related limiting equilibrium relative humidity values to the growth of broad classes of microorganisms in foods. They utilized modified lithium chloride cells to estimate the equilibrium relative humidity of foods. In the years following these early papers, JFS regularly featured articles on the continued development of irradiation and water activity. From the 1970's to the present, a significant development occurred in thermal and nonthermal food processing technologies, for example, aseptic processing and packaging, baking, extrusion, electrothermal technologies, frying, membrane filtration, high hydrostatic pressure, ultraviolet light, oscillating magnetic fields, and ultrasound. Research on these technologies included equipment development, mathematical modeling of transport processes, and kinetics of microbial and quality changes. JFS frequently published articles on many of these food processing technologies.

Thermal destruction kinetic parameters make up an integral part of thermal process design. In the 1950's, JFS covered topics on kinetic studies of microorganisms, food enzymes, and quality attributes. In 1998, The FDA assigned a contract to IFT to provide scientific and technical review and analysis of emerging and alternative technologies with the potential to enhance food safety and quality. In consultation with academic experts and considering the requirements of other governmental agencies, IFT prepared a report that was published in the November 2000 JFS supplemental issue. This issue featured several papers highlighting the background, scope of study, executive summary, overview of fundamentals of several food technologies, kinetic parameters and models used in food preservation processes to ensure safety, and future research directions.

With continuing progress in the mechanistic understanding of food processes, the need for food properties data became evident. At the same time, the rheological properties of solid and liquid foods were correlated to consumer acceptance. As early as 1937, Evelyn Halliday's editorial review outlined several objective tests for measuring food properties. In 1938, Volodkevich of the Univ. of Karlsruhe published an article on the measurement of the chewing resistance of foods. Volodkevich developed an apparatus to record force as a function of deformation in order to determine the energy required for this deformation. Interestingly, this study used rounded wedges and artificial teeth to compress food samples.

In later years, the JFS section of Food Engineering and Physical Properties regularly featured papers on the rheological properties of liquid, gel, and solid foods, the transport and thermodynamic properties of food, and phase/state transitions in foods. By the 1980s and ‘90s,  JFS published studies using advanced techniques of nuclear magnetic resonance, magnetic resonance imaging, and X-ray microtomography to probe into food properties. These techniques investigated the interactions between water and food solids, food microstructures, temperature mapping, and mass transfer in foods. A recent paper published in September 2013 included image analysis to quantify the particle breakdown in foods as well as the role of food properties in food breakdown during gastric digestion.

Starting with the January 2008 issue of JFS, under the leadership of then Editor-in-Chief Daryl Lund, 3 new sections were added to provide greater visibility of cutting-edge food science research. For example, a section was added on Nanoscale Food Science, Engineering, and Technology (NFSET), with M. Anandha (Andy) Rao as Scientific Editor. This section featured original research on science and the application of nanoscale materials and relevant phenomena. The first paper published in this section appeared in the March 2008 issue, and focused on a production method for nanostructure lipid carriers in food beverage applications. This paper also examined the physical properties and stability of lipid carriers at different temperatures. Since then, this section has regularly featured articles on new methods of producing biocompatible nanoparticles and nanocomposite polymer films with improved functional, physical, and gas barrier properties. An October 2011 paper examined the potential for development of polypropylene and nanoclay composite films with improved thermal, mechanical and gas barrier properties in food applications. Finally, a recent paper in the December 2013 issue investigates the synthesis and characterization of nanoencapsulated particles for antioxidant and antimicrobial applications.

Looking into the future

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  2. Looking into the future

Many recent developments in food science and engineering provide a glimpse into future research directions. During past decades, significant research on advanced thermal and nonthermal food technologies has brought these technologies closer to commercialization. In 2009 and 2010, the FDA approved 3 petitions to preserve low-acid foods using pressure-assisted thermal sterilization and microwave-assisted thermal sterilization systems. Approvals of these petitions were made on a case-by-case basis. The research necessary to commercialize these and other thermal and non-thermal food processing technologies will continue in coming decades. Industrial adaptation of novel food technologies will present new challenges and opportunities related to the development of energy- and water-efficient equipment, automation, and high-performance packaging with reduced environmental impacts. Therefore, future research may take this direction. In the recent past, there have been several foodborne illness outbreaks linked to fresh produce and low-moisture foods. Food engineers will continue making advances in decontamination technologies to enhance microbiological safety of fresh produce and low-moisture foods.

In addition, further research on physics-based mathematical modeling may lead to user-friendly computer simulation tools that allow engineers to significantly speed-up the development of new processes and products analogous to the automobile and aerospace industry. New developments in imaging techniques (such as computed microtomography, magnetic resonance imaging, atomic force microscopy), spectroscopy (for example, Raman, X-ray photoelectron, scanning tunneling, nuclear magnetic resonance, positron annihilation lifetime), and micro and nanoscale structure characterization techniques (small-angle and wide-angle X-ray scattering) will allow us to analyze properties of food, biopolymers and packaging materials at the atomic and molecular levels. In conjunction with bulk properties, molecular and atomic-level food properties may provide a new understanding of transport behavior in heterogeneous and complex food structures during processing and storage. This data on physical properties is also vital to the improvement of food processing technologies. Research will continue to explore the flow and digestion of food after ingestion. Investigation in nanotechnology may provide new ways of designing nanostructures for nutrient delivery and antimicrobial properties of food contact surfaces. Scientific and technological development in processing and packaging technologies may allow the food industry to produce ‘designer food’ according to the desired sensory characteristics and physiological needs of individuals. As we look forward to these and other exciting developments, JFS is poised to provide an excellent platform for dissemination of the science and engineering of food over the next 75 years and beyond.

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Sincerely,

Shyam S. Sablani PhD

Scientific Editor, Food Engineering and Physical Properties; and Nanoscale Food Science, Engineering, and Technology Dept. of Biological Systems Engineering, Washington State Univ.