High Pressure Based Technologies: Studies on Food Safety, Nutrition, Quality and Food Process Sustainability

<p>NON-TECHNICAL SUMMARY:<br/> Due to increased awareness on the role food plays on the health and wellness, consumers demand natural nutritious food and beverage products with fresh like quality attributes with no or minimal preservatives. The food industry is responding to these demands by investigating application of high pressure based food processing technologies in variety of food processing and preservation scenarios (such as pasteurization, sterilization, thawing among others). The overall objective of the research program is to conduct fundamental and applied research on application of high pressure based hurdle technologies for preserving nutrient and food quality. Impact of high pressure in combination with selected hurdles (electrical resistance heating, homogenization) on food safety, nutrient retention, and product quality will be evaluated using products of
high economic or nutritional value. Models evaluating energy utilization of different components of a high pressure processing will be developed. In summary, the study will help food processors, equipment manufacturers and federal regulators to understand the benefits and limitations of combining elevated pressures with other synergistic hurdles to produce nutritious improved quality foods.
<p>APPROACH:<br/> Pressure-Ohmic Thermal Sterilization (POTS): The overall goal of the proposed research effort is to investigate the efficacy of combined pressure-electric- and thermal effects (simultaneously or sequentially) on safety and quality of selected low-acid food products using a prototype pilot scale POTS equipment. The work will be conducted in collaboration with Prof. Sudhir Sastry. Efforts include development of a pilot scale pressure-ohmic-thermal sterilization system by modifying our existing pilot scale pressure-assisted thermal process equipment and developing a numerical model to examine thermal process uniformity at different process scenarios. POTS (sequential or simultaneous) treatment efficacy on product quality will be evaluated using model vegetable (carrot, broccoli, mushroom), meat (steak) and soup (pasta or vegetable soup) products of high
economic or nutritional value. For example, the food samples may be preheated ohmically to reach certain initial temperature and subsequently subjected to pressure-ohmic thermal combination process. Alternatively, the samples can be pressurized at room temperature (similar to pasteurization treatment). Subsequently the sample temperature can be increased through ohmic heating by taking advantage of the fact that electrical conductivity of food samples increases under elevated pressure conditions. Thermally processed and PATP treated products will serve as relevant controls. Finally consumer acceptance of POTS products will be compared against conventional and PATP treated products. Pressure-ohmic Thawing: Experiments will be conducted to evaluate the use of pressure-ohmic thawing in reducing thawing time and improving quality of frozen foods using pilot scale equipment. Relative
advantages and limitations between pressure-ohmic thawing, pressure thawing, ohmic thawing and conventional thawing food materials will be evaluated. High-pressure Homogenization: The objective of the study is to investigate influence of high-pressure homogenization (HPH) on nutrient retention in model liquid beverage systems during extended storage time. The study will be conducted in collaboration with Prof. Schwartz as well as industrial collaborators. The impact of HPH treatment parameters on model liquid beverages on selected nutrients (such as carotenoids, flavonoids, and vitamin) will be investigated using pilot scale high-pressure homogenization equipment. The benefits and limitations of HPH treatment conditions to produce pasteurized or shelf-stable product in comparison to conventional treatment will be evaluated. Sustainability of high pressure based technologies: The food
industry ranks fourth in energy use after the chemical, mining and paper industry, and uses around 9% of the total energy in the United States with costs ranking third of the overall production costs after raw materials and labor. Any reductions in energy usage will have a significant impact in reducing greenhouse gas emissions and improve long term sustainability. Though high pressure food pasteurization is gaining wide spread acceptance within the food industry, very little known is about the energy efficiency of the process. Research will be conducted to develop models to estimate energy expenses of various components (pump, pressure intensifier, pressure vessel among others) of a high pressure processing system. Equations will be developed based on thermodynamic understanding of the process (such as compressibility and relevant properties) as well as practical pump energy curves.
Such efforts can help equipment vendors to design and develop high pressure systems with improved energy efficiency.