Progress 07/01/23 to 06/30/24
Outputs
Target Audience:Industry groups and entrepreneurs interested in manufacturing frozen desserts were given real life demonstration of the system in our lab. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?One post-doctoral associate, one food science graduate and one scientist were trained in dense carbon dioxide-based cryogenic freezing system evaluation. How have the results been disseminated to communities of interest?The Project Director presented the progress and key findings of the project to date at the following meetings during the past year Design and Development of Novel Processes for Better Quality Foods. Department of Food and Nutritional Sciences, University of Reading, London, July 2, 2024 Engineering Processes for Novel Foods, China Agricultural University, Beijing, , June 21, 2024 Innovative Engineering Processes for Novel Foods, Chinese Academy of Agricultural Science, IFST-CAAS, Beijing, June 4, 2024. Engineering Processes for Foods Innovation, Food Science Advisory Council Meeting, April 18, 2024. Nutritionally Superior Extruded Foods from Agricultural Waste Streams. Food and Agriculture Research Foundation Webinar, April 16, 2024. Novel Food Processing Technologies. Entrepreneurship at Cornell, Ithaca, NY, April 11, 2024 Design and Delivery of Superior Dairy Foods with End-user & Environmental Benefits. Northeast Dairy Foods Research Center Annual Meeting. Cornell University, April 04, 2024 Engineering Processes for Dairy Foods Innovation. National Dairy Research Institute, Karnal, India, December 21, 2023 Engineering Processes for Food Innovation. Indian Institute of Technology, Delhi, December 18, 2023 Strategies for Novel Food Development and Innovations in Food Value Addition. Food & Agribusiness Management Program, Ithaca, NY, June 14, 2023 What do you plan to do during the next reporting period to accomplish the goals?Develop scale-up criteria,design and build a larger unit with capacity to generate larger frozen quantity of the product. Analysersthe carbon footprint reduction and recycling of used carbon dioxide to improve the efficiency and economy of the process will be undertaken. It is anticipated to open up new avenues for freezing of liquid foods, pharmaceutical and biological materials of industrial utility.
Impacts
What was accomplished under these goals?
The feasibility to manufacture clean, on-demand, and point-of-use ice cream using our previously developed flash freezing system was investigated. Buttermilk powder was used as a source of milk phospholipid to replace commercial emulsifier from the ice cream formulation. Results suggested that the draw temperature attained for flash-frozen clean label ice cream (-9.7°C) was like that of the flash-frozen regular ice cream (-9.8°C) and commercial ice cream produced by the conventional method (-10.5°C). It had an overrun and a melting rate of 15.3% and 0.63 g.min-1, respectively. In comparison, regular flash frozen and conventionally manufactured commercial ice creams yielded overrun values of 21.8% and 26.3%, along with melting rates of 0.59 g.min-1 and 0.42 g.min-1 respectively. Clean label flash-frozen ice cream exhibited greater fat aggregate particle size (5079 nm) compared to regular flash-frozen (4913 nm) and commercial ice cream produced by the conventional method (4747 nm). The higher fat destabilization (45.8%) in flash frozen ice cream also reduced the hardness (14.0N) and resulted in a softer texture compared to the conventionally manufactured commercial ice cream (21.3N). The flash-freezing technology with carbon dioxide is a good fit for manufacturing clean label ice cream and its on-demand and point of use characteristics helps to eliminate the need for cold chain distribution, storage to the store, and thus ensuring energy efficient and a low carbon footprint technology for the industries to adopt. The flash freezing system was further modified for better performance and scale-up. As a critical component of the system, the nozzle design was observed to significantly impacts the performance and efficiency of a flash freezing system operating with high pressure CO2. A new nozzle designed with a larger throat diameter (2.5 mm) exhibited superior performance compared to the nozzles with a throat diameter of 1.5 mm by minimizing the nozzle back pressure from 2174.3 kPa to 780.1 kPa, which allowed for greater gas expansion, higher kinetic energy, and improved overall efficiency. The lower back pressure also reduced the energy losses caused by the normal shock wave of the high-pressure CO2 and allowed for better energy conversion, as evidenced by the higher Mach number (0.079 vs. 0.064) and greater freezing efficiency (49.1% vs. 42.9%). This design enhancement led to a 30.6% increase in production rate and a slight improvement in product quality evidenced by higher ice cream overrun values (17.8±0.6%) compared to previously reported average values of 15.3±0.6%. Despite the higher volumetric flow rate of liquids to be frozen, the newer nozzle maintained almost similar final product temperature (-9.8oC vs.8.6oC), demonstrating its effectiveness in maintaining freezing efficiency. The system's overall energy consumption was also observed to be low, with high product recovery rate(97.9%) and a coefficient of performance (COP) of 1.31 (conventional 1.0-1.2), indicating that this design can replace traditional freezing technologies with improved sustainability and efficiency.
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Progress 07/01/22 to 06/30/23
Outputs
Target Audience:Several individuals and industry groups interested in manufacturing frozen desserts were given real life demonstration of the system in our lab. Changes/Problems:A one-year, no-cost extension was requested we experienced severe disruptions in research activities due to COVID-19. The PI's lab was closed for several months, and research activities were largely suspended. The difficult situation of the lockdown and restrictions imposed by the pandemic disrupted our ability to conduct lab-based research work more significantly than other types of undertakings. In particular, the experimental work for this project depended heavily on acquisition of new items and designing new systems. During this time it became extremely difficult to recruit and hire technical personnel with appropriate training. We faced extremely hard time to get individuals with the right credentials. This along with supply chain delays brought about several effects on the performance of planned activities and our team was not able to complete experimental work in a planned and timely fashion. Although we have made substantial progress to catch up in the past years, we will still need extra time (1 year) to bring our planned research to a successful culmination. What opportunities for training and professional development has the project provided?One post-doctoral associate, one chemical engineering graduate and one undergraduate students were trained in supercriticalfluid-based cryogenic freezing system evaluation. How have the results been disseminated to communities of interest?The Project Director presented the key findings of the project to date at the following meetings during the past year. Emerging Perspectives for Product Design; Engineering Processes, Sustainable Protein Forum, AOCS Ann. Mtg. Chicago, IL, October 4-6, 2022. Engineering Processes for Dairy Foods Innovation. Northeast Dairy Foods Research Center Annual Meeting. Cornell University, April 03, 2023. On-demand Production of Cream. Artisan Ice Cream Short Course, Cornell University, April 18, 2023. What do you plan to do during the next reporting period to accomplish the goals?Further development and potential scale-up of the system along with recycling of used carbon dioxide to improve the efficiency and economy of the process will be undertaken. It will open up new avenues for freezing of liquid foods, pharmaceutical and biological materials of industrial utility.
Impacts
What was accomplished under these goals?
A flash freezing system was designed and built using a novel eductor-nozzle assembly. It provided the means for both suctioning fluids and cooling/freezing the feed stream. High-pressure carbon dioxide was supplied to the nozzle inlet and directed through the nozzle such that the low pressure, high velocity jet served as motivation for suctioning via the Bernoulli effect and provided the motivation for cooling/freezing the suctioned liquid via the Joule-Thompson effect. The pressure and temperature were set so that when the fluid throttled out of the nozzle the expanded gas was adiabatically cooled to -78°C and performed the cryogenic cooling/freezing process. The fluid to be frozen was designed to enter the eductor tangentially and accelerate around the nozzle to high linear and rotational velocities before mixing with the CO2 stream. After the liquid accelerated around the nozzle, it entered the mixing zone, where feed liquid was mixed with the high velocity CO2 jet. The high velocity nature of the process prevented the final product from sticking and blocking the passageway, while also directed the frozen product directly into the collection chamber. Excess CO2 from this process was vented, which in a larger industrial system may be recycled. Nozzles of different throat diameters and the same convergent length were 3-D printed, and their performance was evaluated. Freezing efficiency of the unit was determined by measuring the draw temperature and overrun of ice cream of different formulations. The Computational Fluid Dynamic (CFD) was used to model CO2 expansion. To validate the CFD simulation, numerical predictions were compared with experimental data. Numerical simulations of flow of carbon dioxide at 7.2 MPa and 35 °C at the nozzle inlet were successfully carried out in a two-dimensional computational domain to predict the velocity, temperature, and pressure contours of the flow for three different nozzle geometries. The numerical predictions were found to be in reasonably good agreement with the experimentally measured values. A higher turbulence intensity close to the vena contract of the nozzle with larger throat diameter provides better mixing between fluids and maximized the freezing efficiency. The system was tested at many different sets of operating conditions to determine its coefficient of performance (COP), freezing efficiency, and energy costs. The COP was found to reach a maximum value of 4.3 under specific conditions, which is greater than the COP of a conventional mechanical refrigeration system. The maximum freezing efficiency achieved by the flash freezing unit was 95%, which implies very good mixing and heat transfer within the system. Using a standard ice cream mix, the combined effect of temperature (15, 20, 25 & 30 °C) and run time (1.5, 2.0 & 2.5 sec.) of SC-CO2 on the overrun, melting behavior, draw temperature, quantity and crystal size of the resultant ice cream was evaluated. The results showed the overrun to range from 8-20% and a melt rate of 0.1-0.8g/min. as compared to the premium quality commercial ice cream, which had an overrun and melt rate of 16.4 % and 0.2 g/min., respectively. The novel flash freezing system provides quick freezing, is more energy efficient than currently implemented freezing systems and thus requires less energy input.
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Progress 07/01/21 to 06/30/22
Outputs
Target Audience:Frozen and chilled food processors and distributors. Changes/Problems:Research work was delayed because of the COVID-19 epidemic and lab closure. Now the work is progressing well. What opportunities for training and professional development has the project provided?One post-doctoral associateand one chemical engineering undergraduate were trained in supercritical fluid-based cryogenic freezing system evaluation. How have the results been disseminated to communities of interest?A manuscript is in progress and will be submitted for publication in a peer reviewed journal. What do you plan to do during the next reporting period to accomplish the goals?Further work to determine theflow of two fluid streams (CO2and feed liquids), coefficient of performance compared to conventional vapor-compression system and scale up criteria along with consumer acceptability of ice cream products are planned for the coming year.
Impacts
What was accomplished under these goals?
A flash freezing system was designed and built using a novel eductor-nozzle assembly. It provided the means for both suctioning fluids and cooling/freezing the feed stream. High-pressure carbon dioxide was supplied to the nozzle inlet and directed through the nozzle such that the low pressure, high velocity jet served as motivation for suctioning via the Bernoulli effect and provided the motivation for cooling/freezing the suctioned liquid via the Joule-Thompson effect. The pressure and temperature were set so that when the gas exited out of the nozzle the expanded gas was adiabatically cooled to -78°C and performed the cryogenic process. The fluid to be frozen was designed to enter the eductor tangentially and accelerate around the nozzle to high linear and rotational velocities before mixing with the CO2stream. After the liquid accelerated around the nozzle, it entered the mixing zone, where feed liquid was mixed with the high velocity CO2jet. The mixture then emerged the eductor in cold/frozen state. The high velocity nature of the process prevented the final product from sticking and blocking the passageway, while also directed the frozen product directly into the collection chamber. Excess CO2from this process was vented, which in a larger industrial system may be recycled. Three nozzles of different throat diameters and the same convergent length were 3-D printed, and their performance was evaluated. Freezing efficiency of the unit was determined by measuring the draw temperature and overrun of ice cream of different formulations. The Computational Fluid Dynamic (CFD) was used to model CO2expansion. To validate the CFD simulation, numerical predictions were compared with experimental data. Numerical simulations of flow of carbon dioxide at 7.2 MPa and 35 °C at the nozzle inlet were successfully carried out in a two-dimensional computational domain incorporating pressure-based solver with k-ω SST turbulence model to predict the velocity, temperature and pressure contours of the flow for the three different nozzle geometries. The numerical predictions were found to be in reasonably good agreement with the experimentally measured values. The throat diameter and shape of converging section of nozzle were found to impact the nozzle performance significantly. The exit pressure of nozzle with the smallest throat diameter (N1) was lower than the other two nozzles, basically because of the internal shock wave formation near the throat region of this nozzle. The flow behavior of nozzle N1 was also observed in the field flow velocimetry to give the critical pressure drop. An enhancement in thrust was observed for the nozzle with uniform throat to exits diameter (N3) when compared with the other two nozzles (N1 and N2). However, higher turbulence intensity close to the vena contracta of the nozzle with larger throat diameter (N3) provides better mixing between fluids and maximized the freezing efficiency. Experimental results showed that nozzle N3 gave the highest overrun and lowest draw temperature ice cream compared to the other two nozzles. Based on both experimental and numerical results, nozzle N3 was found to be the better nozzle for maximization of mixing behavior and freezing efficiency of the tested liquid ice cream mixes.
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Progress 07/01/20 to 06/30/21
Outputs
Target Audience:Frozen and chilled food processors and distributors Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?One post-doctoral associate, oneand one chemical engineering undergraduate were trained in supercritical fluid-based cryogenic freezing system evaluation. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?To design and build a sanitary flash-freezing system with cleaning features and test its performance for freezing both water and ice cream mix, additional configurations for a lid assembly will be designed and fabricated. One of the objectives of this study was to conduct experimental analysis on different nozzle geometries and determine the effect of geometrical parameters and shapes on nozzle performance to maximize the freezing efficiency. Autodesk Inventor Professional was used to design 3-D models of nozzles and 3-D printed models were tested. Additional nozzle configurations will be built to identify the optimum nozzle geometry. To develop criteria for a system, scale up for larger manufacturing capacity, a numerical model will be used to study the flow field characteristics of supercritical CO2 and the mixing behavior of the cryogenic freezing. For doing so, formulas of the density, viscosity, and thermal conductivity of CO2 will be verified for a supercritical state, and they will be embedded in a CFD model. Subsequently, the reliability of the numerical model will be validated in experiments that monitor the pressure and temperature of SC-CO2.
Impacts
What was accomplished under these goals?
Based on the preliminary setup, improved cryogenic freezing setup was built, and to increase the freezing efficiency and minimize the spreading out of flash-frozen liquids, a new collection chamber with a different design was fabricated and tested. Additionally, stainless-steel tube assembly as straight, cone, inverted cone, and elbow-shaped were evaluated to reduce the fluid velocity coming from the eductor and nozzle and the cone design was observed to work better than the other designs due to higher drag reduction. Sample collection bowls were modified to enhance the collection efficiency of the frozen mass of different liquids. After several tests, the bowl dimensions were optimized for the system to help collect more frozen mass. Autodesk Inventor Professional was used to design 3-D models of cone-shaped tubes and collection bowls. Models were 3-D printed by using the Selective Laser Sintering (SLS) process using Nylon-12. Testing with the new components was observed to yield frozen products 1 to 2°C lower in temperature and 5-7% lower in entrainment losses. A range of parameters including nozzle pressure, blast time, and quantity of initial liquid were tested experimentally to evaluate the performance of cryogenic freezing. Several experimental measurements were done with water and carbon dioxide-ice clathrate as the primary product. An ice cream mix of the standard composition was obtained from the Cornell Dairy Plant. The result demonstrates that at a nozzle pressure of 1200 psi and a blast time of 2.5 s, the overrun increased to 20-21% and the temperature of frozen mass declined to -8.5 to -9°C. To minimize the remaining quantity in suctioned feeding containers and preventing the extra spreading of flash-frozen liquids, the quantity of the initial liquid worked best at 68 g. The amount of time between each blast was determined by the time the nozzle backpressure gets pressurized to 1150 psi while working consecutively, this was approximately 1 to 1.5 min. Subsequently, the impact of different temperatures (10, 20, and 30°C) on viscosity was compared in the carbonated ice cream and commercial ice cream. To simplify the exhaust process of excess CO2 from the collection bowl, 3-D models of the lid with different gaps were designed using Autodesk Inventor Professional. A 3-D printed model with a 2.5 mm gap has shown lower entrainment loss. To minimize accumulated frozen mass coming from the eductor and nozzle, a 3-D model for the top collection chamber plate was designed and tested. A 3-D printed plate designed to slide in the eductor to make it completely sealed. Moreover, the mechanical energy of compressed springs was used to apply force to the bottom of the collection chamber causing it to be tightly sealed. For the sake of straightforwardness, a 3-D model of a door assembly with a bowl holder for the collection chamber was designed and fabricated.
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