Recipient Organization
INVENTHERM, L.L.C.
6117 SHAKESPEARE DR
BATON ROUGE,LA 708172920
Performing Department
(N/A)
Non Technical Summary
Improperly cleaned soft serve ice cream machines are a known significant contributor to foodborne illnesses worldwide. Studies indicate that from 12% to over 50% of soft serve ice cream machines are contaminated with unsatisfactory levels of bacteria. Contamination issues are due to the complex and costly disassembly, cleaning, and sanitizing (DCS) process required for all machines currently on the market. The DCS process can cost businesses well over $6300 for each machine per year in wasted product, labor, and supplies. In addition, significant potential revenue is lost when the machine is out of service for cleaning.Inventherm is developing commercial soft serve ice cream and slush machines (SSMs) that virtually eliminates the DCS process, produces aseptic or sterile products, and slashes operating costs by several thousand dollars per machine, annually. Inventherm's breakthrough technology containes the product mix in consumable packaging. From liquid mix through dispensing the product never touches any part of the machine. While not the focus of the current development, Inventherm's technology can also be applied for producing sterile saline slush, which is used in surgical procedures for reducing tissue damage.Soft serve products (e.g., ice cream, frozen yogurt), and frozen beverages (e.g., slushes, daiquiris) represent distinct market segments. Of these, soft serve presents the most technical challenges. Producing soft serve with the desired smooth and creamy mouthfeel, requires that ice crystal size be kept small (i.e., less than 50 microns) and that air is mixed in with the frozen product. The latter is referred to as overrun. The DCS costs are also greater for soft serve products due to their tendency to spoil, form biofilms, and leave calcium and magnesium deposits (i.e., milk-stone) on surfaces.This Phase II SBIR project aims to advance the technology from the early state prototype developed during Phase I to a late stage asceptic SSM on the verge of commercialization.
Animal Health Component
50%
Research Effort Categories
Basic
0%
Applied
50%
Developmental
50%
Goals / Objectives
This USDA-NIFA SBIR Phase II project seeks to develop aseptic soft serve and slush machines (SSM). The project goal is to be on the cusp of commercializing the technology at the end of the project. Phase III work will shift from a research and development focus to a focus on design for manufacturing and final product development tasks.Technical Objective 1: Perform the research needed to advance the asceptic SSM from Phase I early-stage laboratory prototype to a late-stage advanced prototype on a clear path to manufacturability and commercialization. For Phase I, all technical objectives were met, and the team was able to advance Inventherm's SSM to a technology readiness level (TRL) of 4 to 4.5 (i.e., prototype demonstration in a laboratory environment). Inventherm is confident that during Phase II it will overcome the remaining technical hurdles and advance the SSM to a TRL of 7+ (i.e., field operable late-stage prototype). The team will then be well positioned to advance the technology to commercialization in Phase III (TRL 9). Key technical areas to be addressed during Phase II include:Advance the SSM design so that maximum soft serve quality is achieved while minimizing stress on the consumables that contain the product mix.Achieve freeze times, product throughput, and energy efficiency equal to or better than conventional machines of the same size.Develop the processes and technologies required to fully automate machine operation.Demonstrate adequate reliability of machine components.Conduct quality assessments of the soft serve product using ice cream sensory evaluation experts and consumer (i.e., layperson) testing.Technical Objective 2: Quantify the food safety benefits of Inventherm's SSM through microbial testing and develop a risk mitigation plan to address any deficiencies.
Project Methods
The following tasks will be performed to achieve project objectives: Task 1 - SSM freeze section: A 2nd generation SSM freeze section with improvements from the 1st generation design including increased rigidity of components was constructed. These improvements address deficiencies found in Phase I of the project. One challenge encountered during Phase I testing was the inability to easily see what was happening inside the SSM freeze section during the freezing process. Visualization of flow as well as the behavior of other components is very beneficial for understanding and improving the design. A glass-front freezer has been purchased for housing the 2nd generation SSM freeze section. This will permit a less obstructed view of internal components during operation.The 1st generation SSM used a direct expansion (DX) vapor compression refrigeration system, where the evaporator tubing made direct contact the freeze section. While this is a potentially viable option for commercialization Phase II experiments will be performed with various other methods of cooling the freeze section. Potential options include:Secondary coolant loopDirect air impingementAir impingement with heat pipesThermoelectric assisted coolingThe goal of the previously described testing is to determine the cooling method that provides the best balance of cooling performance, compact form factor, ease of loading, high reliability, and ease of periodic maintenance.Computer based modeling and analysis techniques will be performed on the freeze section during development as needed to facilitate reaching development objectives. Lumped parameter modeling, finite element analysis (FEA), and computational fluid dynamics (CFD) will be used as needed to address unknowns that cannot be more quickly resolved with experimental work. It is expected that as development continues and the technology becomes more refined, that more analysis will be needed to compliment the experimental work. The RPHE is a complex system involving fluid dynamics, heat transfer, dynamics, and tribology.Task 2 - Consumable Packaging and Equipment Development: Task 2 involves development of the consumable packaging used in the SSM. This includes developing packaging that is amenable to manufacturing on automated machinery.Task 3 - Prototype System Development: An initial prototype (1st Gen) SSM was constructed during Phase I. The Phase I prototype was suitable for demonstrating laboratory proof-of-concept. Significant research remains to advance the technology toward commercialization. The list below shows prototype SSM R&D tasks that will be addressed during Phase II.Filling automation: A method for automatically filling the freeze section with liquid mix from the reservoir section with the correct amount of product mix and air has not been developed thus far. Reliable and consistent filling of the requires accurate sensing of the freeze section contents at all phases of operation.Freeze section automation: Freeze section automation refers to cycling of the refrigeration system and freeze section churning action. The 1st generation SSM had the capability to shut down the refrigeration system based on the evaporator temperature and shut down the churner based on motor current. This was a first step in the automation process, but substantial work remains to perfect this process. In general, the refrigeration system and churner are on when the mix is freezing and should cycle off when the product is ready to dispense. The churner needs to turn back on for dispensing and both the churner and refrigeration system will come on to maintain product consistency and for freezing makeup mix. This must be done while avoiding over-churning, which can cause the cream in the mix to turn into butter, especially with high-fat, premium mixes. In addition to meeting the basic requirement of achieving proper product consistency and temperature, the process should be optimized to limit stress on freeze section components.Rapid freezing and throughput: The 1st generation SSM takes about 45 minutes to complete initial product freezing. This compares to 20 to 30 minutes for most conventional machines. The objective is to be on par with conventional machines. Based on Phase I analysis, this should be possible. It is estimated that about half of the improvement needed will come from simple fixes of known deficiencies. For example, the 1st generation SSM was difficult to properly insulate. This led to substantial heat leakage and air infiltration. While the cold plate was cooled to about -20 °C the air surrounding the freeze remained at about 18 °C. Air infiltration puts a substantial latent load on the refrigeration system while the associated frosting reduces evaporator heat transfer. The refrigeration system was also undersized, which was a cost consideration. The other half of the improvement needed is expected to come from improved thermal design of the RPHE and freeze bag. Improving thermal contact between the freeze bag and cold plate as well as testing thinner bag films are two areas where improvements are expected.Product temperature: The desired temperature of dispensed product from conventional machines ranges from about -4 °C to -9 °C. The 1st generation SSM struggles with product at very high viscosities and, therefore, product was usually cooled to about -6 °C. This limitation was largely related to the 1st generation freeze section components being insufficiently stiff. Phase II development will address this issue. R&D efforts in this area will focus on obtaining the necessary strength and stiffness for RPHE components while minimizing its overall thermal mass, which impacts initial freeze times.Other areas of prototype development during Phase II include, improved dispensing speed and consistency, machine loading efficiency, and reliability testing.Task 4 - Sensory Evaluation: Sensory evaluation is the field of science associated with measuring and analyzing human responses to the composition of food and drink. A dairy sensory evaluation expert has joined the team as a consultant.Task 5 - Microbial Contamination Risk Assessment and Testing: Task 5 seeks to quantify the food safety benefit of the asceptic SSM technology and to establish safe operating procedures. While the food safety benefits of the SSM are obvious, there is a need to establish safe operating procedures for the machine. For example, as with conventional machines the dispensing nozzle is exposed to ambient air and, therefore, is a potential source for microbial contamination. Inventherm has patent pending technology designed to sanitize the nozzle area, which will maximize the time that product can safely be stored in the machine. If this technology is implemented, it will be necessary to demonstrate its effectiveness. It will also be desirable to compare the microbial contamination levels in a conventional machine to those in Inventherm's SSM. An experienced food safety scientist has joined the project to lead this effort.