Feeding the World Today and Tomorrow: The Importance of Food Science and Technology: An IFT Scientific Review.

by Philip E. Nelson, 2007 World Food Prize Laureate; Professor Emeritus, Food Science Dept., Purdue Univ. Just as society has evolved over time, our food system has also evolved over centuries into a global system of immense size and complexity. The commitment of food science and technology professionals to advancing the science of food, ensuring a safe and abundant food supply, and contributing to healthier people everywhere is integral to that evolution. Food scientists and technologists are versatile, interdisciplinary, and collaborative practitioners in a profession at the crossroads of scientific and technological developments. As the food system has drastically changed, from one centered around family food production on individual farms and home food preservation to the modern system of today, most people are not connected to their food nor are they familiar with agricultural production and food manufacturing designed for better food safety and quality. The Institute of Food Technologists-a nonprofit scientific society of individual members engaged in food science, food technology, and related professions in industry, academia, and government-has the mission to advance the science of food and the long-range vision to ensure a safe and abundant food supply contributing to healthier people everywhere. IFT convened a task force and called on contributing authors to develop this scientific review to inform the general public about the importance and benefits of food science and technology in IFT's efforts to feed a growing world. The main objective of this review is to serve as a foundational resource for public outreach and education and to address misperceptions and misinformation about processed foods. The intended audience includes those who desire to know more about the application of science and technology to meet society's food needs and those involved in public education and outreach. It is IFT's hope that the reader will gain a better understanding of the goals or purposes for various applications of science and technology in the food system, and an appreciation for the complexity of the modern food supply. Abstract: This Institute of Food Technologists scientific review describes the scientific and technological achievements that made possible the modern production-to-consumption food system capable of feeding nearly 7 billion people, and it also discusses the promising potential of ongoing technological advancements to enhance the food supply even further and to increase the health and wellness of the growing global population. This review begins with a historical perspective that summarizes the parallel developments of agriculture and food technology, from the beginnings of modern society to the present. A section on food manufacturing explains why food is processed and details various food processing methods that ensure food safety and preserve the quality of products. A section about potential solutions to future challenges briefly discusses ways in which scientists, the food industry, and policy makers are striving to improve the food supply for a healthier population and feed the future. Applications of science and technology within the food system have allowed production of foods in adequate quantities to meet the needs of society, as it has evolved. Today, our production-to-consumption food system is complex, and our food is largely safe, tasty, nutritious, abundant, diverse, convenient, and less costly and more readily accessible than ever before. Scientific and technological advancements must be accelerated and applied in developed and developing nations alike, if we are to feed a growing world population.

Effect of water activity on inactivation of Listeria monocytogenes and lactate dehydrogenase during high pressure processing.

The aim of this study was to investigate the effect of water activity (aw) on the inactivation of Listeria monocytogenes and lactate dehydrogenase (LDH) during high pressure processing (HPP). For microbial inactivation lyophilized cells of L. monocytogenes 19,115 were left dry or were suspended in 10 ml of 0.1% peptone water, 10 ml of glycerol, or mixtures of glycerol and peptone water. All samples of various aws were high pressure (HP) processed at ambient temperature at 600 MPa for 300 s. Following HPP, samples were serially diluted in 0.1% peptone and spread-plated on Tryptic Soy agar supplemented with Yeast Extract. For enzyme inactivation, 4.2 mg of lyophilized LDH was suspended in 2 ml of 100 mM phosphate buffer (pH 7.4), 2 ml of peptone water or glycerol, or in 2 ml mixtures of glycerol and peptone water. A lyophilized sample with no added liquid was also included. All enzyme samples were subjected to HPP as described above. After HPP, LDH was diluted to 0.28 microg/ml in 100 mM phosphate buffer (pH 7.4). LDH activity was assessed by measuring the change in concentration of beta-NADH as a function of time. Dynamic light scattering analysis (DLS) was performed to examine the size distribution, polydispersity, and hydrodynamic radius of LDH before and after HPP. No significant difference in CFU/g was observed between lyophilized cells not subjected to HPP and lyophilized cells subjected to 600 MPa for 300 s (P<0.05). However, lyophilized cells that were suspended in 100% to 60% peptone water showed a approximately 7.5-log(10) reduction when subjected to HPP. Survival of L. monocytogenes following HPP significantly increased (P<0.05) when the peptone water concentration was decreased below 60% (aw approximately 0.8). DLS results revealed that LDH suspended in buffer underwent aggregation following HPP (600 MPa, 300 s). Inactivation rate constants obtained using a first-order kinetic model indicated that untreated and HP processed lyophilized LDH had similar activities. When LDH was subject to HPP in solutions containing glycerol, enzyme activity decreased as the water content increased (r2=0.95). Lyophilization completely protected L. monocytogenes and LDH from inactivation by high pressure. Furthermore, enzyme activity and cell survival increased as water activity was decreased. We postulate low aw results in protein stabilization, which prevents protein denaturation and cell death during HPP.

Effect of high-pressure processing on activity and structure of alkaline phosphatase and lactate dehydrogenase in buffer and milk.

Changes in the activity and structure of alkaline phosphatase (ALP) and L-lactate dehydrogenase (LDH) were investigated after high pressure processing (HPP). HPP treatments (206-620 MPa for 6 and 12 min) were applied to ALP and LDH prepared in buffer, fat-free milk, and 2% fat milk. Enzyme activities were measured using enzymatic assays, and changes in structure were investigated using far-ultraviolet circular dichroism (CD) spectroscopy and dynamic light scattetering (DLS). Kinetic data indicated that the activity of ALP was not affected after 6 min of pressure treatments (206-620 MPa), regardless of the medium in which the enzyme was prepared. Increasing the processing time to 12 min did significantly reduce the activity of ALP at 620 MPa (P < 0.001). However, even the lowest HPP treatment of 206 MPa induced a reduction in LDH activity, and the course of reduction increased with HPP treatment until complete inactivation at 482, 515, and 620 MPa. CD data demonstrated a partial change in the secondary structure of ALP at 620 MPa, whereas the structure of LDH showed gradual denaturation after exposure at 206 MPa for 6 min, leading to a random coil structure at both 515 and 620 MPa. DLS results indicated aggregation of ALP only at HPP treatment of 206 MPa and not above and enzyme precipitation as well as aggregation at 345, 415, 482, and 515 MPa. The loss of LDH activity with increasing pressure and time treatment was due to the combined effects of denaturation and aggregation.

Active food packaging technologies.

Active packaging technologies offer new opportunities for the food industry, in the preservation of foods. Important active packaging systems currently known to date, including oxygen scavengers, carbon dioxide emitters/absorbers, moisture absorbers, ethylene absorbers, ethanol emitters, flavor releasing/absorbing systems, time-temperature indicators, and antimicrobial containing films, are reviewed. The principle of operation of each active system is briefly explained. Recent technological advances in active packaging are discussed, and food related applications are presented. The effects of active packaging systems on food quality and safety are cited.