University of Houston • University of Houston-Clear Lake • ISSO Annual Report Y2002—pp. 61-65

Design of a Food Service and Food Processing System for Long-Duration Missions in a Closed Environment

Clint L. Rappole (UH), Michele Perchonok (NSBRI and Baylor University), and Stephen J. French (UH)

Abstract
In order to provide food to crewmembers on a long duration mission, the Advanced Food System (AFS) must evaluate current commercial technologies, develop new technologies, and determine appropriate food handling protocols. Staple crops such as soybean and wheat will provide a significant portion of nutrients in crewmember diets while on a planetary surface. The soymilk, tofu, okara and whey (STOW) processor prototype is the first piece of equipment to be developed by the AFS. Bread making technologies and methodologies are being evaluated for their use in the AFS.

Since its delivery to Johnson Space Center in May, 2001, the STOW has been researched for its use in NASA’s AFS. This research has resulted in a complete remanufacture of the equipment as well as an investigation into microbiological control methods. It has produced JSC publications including a hazard analysis, standard operating procedure manual, and an evaluation document.

Bread making technology evaluation has shown a wide range of results. Four bread makers, representing different mixing mechanisms, were assessed for their impact on equivalent system mass (ESM) and loaf characteristics across a wide range of processing conditions. Two of the four technologies evaluated show promise as possible candidates for further evaluation at technology readiness level (TRL) five (5) testing.

NASA’S ADVANCED FOOD SYSTEM (AFS) MUST PROVIDE crewmembers palatable menu items on long duration space missions. Improving menus must address issues relevant to the environment and mission scenario. In response, the AFS is evaluating technologies and food delivery protocols for use in transit vehicle and planetary surface environments. The soymilk, tofu, okara and whey (STOW) processor prototype and different bread making technologies are being evaluated and used to develop methods for providing menu items. Prior to mission launch, tests of the closed environment life support system (CELSS) will take place to evaluate technology readiness.

STOW Project
The initial deliverable technology, designated as the soymilk, tofu, okara, and whey processor prototype, was manufactured from plexiglass and polycarbonate composites. While this material provided certain advantages, the equipment proved too unreliable for research purposes. This prompted researchers to rebuild the equipment using a more durable material, stainless steel, capable of withstanding the rigors of research.

Following its redesign and rebuilding, the STOW was able to undergo evaluation for its processing capabilities. The STOW technology is designed to provide soymilk and firm style tofu. Because of the current design, the STOW is unable to produce silken style tofu. From an engineering perspective, new knowledge has enabled researchers to determine the different types of materials that should be used and the types of improvements that would benefit the manufacture of food products and the amounts of material that can be processed in the STOW. Further development of soybean processing equipment may implement new designs generated from this evaluation to ensure a viable system for CELSS testing.

Bread Project
Methods and Materials
Whole wheat bread loaves were baked using four different bread makers. Each of these bread makers represented a unique mixing mechanism (Table 1).

Sixteen loaves of bread were baked using each of the bread makers. Formulations and cycling times varied throughout the study to gather information regarding consistency. Two loaves were made for each variation. Variations in formulas and cycling times included:

• 60 or 90 minute rise time instead of the 43 minute standard
• 10 or 20 percent addition of soymilk
• 10 or 20 percent addition of okara
• Large (average 1700-850 m) bran inclusion instead of smaller (average 425-355 m) bran

Commercial sources provided hard red spring wheat and hard red spring wheat flour (Cargill Flour Milling, Albany, NY). The hard red spring wheat grain was milled using a Brabender Quadramat, Jr. II mill. The hard red spring wheat flour was milled using an outside bran source (Wholefoods Inc.). Researchers added protein by adding to the mix store-bought whole-wheat gluten (75-80% protein) (Bob’s Red Mill, Milwaukie, OR).

Soymilk and okara were processed using a blender at a water-to-bean ratio of 4:1. Beans were ground for 15 seconds using the puree setting. Soymilk was filtered using a 200-mesh filter while the okara was processed through a juicer to standardize moisture content. Soymilk total solids were measured using a refractometer. Soymilk and okara were added by weight with direct addition of okara and the substitution of water with soymilk taking into account total solids content.

Loaf volume was measured using the seed displacement method; dough and loaf texture were measured using a TA-XT2 texture analyzer. Extensibility was measured using a Kieffer Dough and Gluten Extensibility Rig (Texture Technologies, Scarsdale, NY). A measurement of force in tension was conducted using a pre-test speed of 2.0 mm/sec, test speed of 3.3 mm/s, post-test speed of 10 mm/sec, and distance of 75 mm. Measurements were performed in triplicate. Loaf hardness was measured using a 25 mm perspex cylindrical probe. Testing measured two compressions to 40 percent strain with a pre-test speed of 2.0 mm/s. The hardness of three slices from each of two loaves was measured.

Results
Different aspects of a bread making technology may be used to evaluate its suitability for use in a CELSS habitat. Characterization like equivalent system mass (ESM), functionality, durability, human factors, and environment specific factors will be used for such an evaluation.

Four components factor into an ESM value. Mass and volume components are calculated after which a penalty for infrastructure support is added. Infrastructure support in the case of bread makers would include energy requirements. A final component to an ESM value is crew involvement time. A correction to the ESM value is made for crew time required to operate and maintain the system. While seeming to be an insignificant amount of time, total involvement with the system must be counted. In the case of bread makers, an accounting might include time required to weigh ingredients and add the ingredients to the system.

A final ESM value has not been calculated for the evaluated bread maker technologies. This will depend upon penalty value for crew involvement time presently unknown. However, values necessary to do so are provided in Table 3. Once unknown values are provided, an appropriate ESM value may be assigned.

Table 3. Weight, Volume, and Kilowatt/hr Values for Four Different Bread Makers

An arbitrary value (10 minutes) has been given as a standard time required to weigh ingredients. A larger value of 15 minutes was assigned to the Bready prototype to account for time needed to interface the mixing bag with the equipment. The Bready prototype inputs processing parameters by scanning a barcode attached to the mixing bag. Currently, time is needed to create the barcode and attach it to the mixing bag.

From the perspective of functionality, each of the commercial technologies possessed an approximately equal number of products able to be manufactured. Models TR2200C and TR3000 allowed for additional alteration of loaf size between 1, 1.5, and 2 pounds. Available products from each of the commercial technologies included white, wheat, and French breads having light, medium and dark crusts, jams, cakes, and doughs. The Bready prototype technology did not possess the same range of possible products. However, research is being conducted by the developing company to extend functionality to these products.

From an ergonomic perspective, the Breadman model TR3000 technology was the easiest to operate. Unique to this technology, a touch-screen LCD is incorporated into the form factor allowing for more visual based operation. This visual interface removes the need to remember particular key sequences necessary to perform a specific operation. For example, to manually input cycling times, model BBCC-V20 requires that the operator follow the steps listed below:

1. Select "Home Made" using the Select Course key.
2. Press the Cycle key.
3. Change the time for the displayed cycle by pressing the Time key followed by the Cycle key to move to the next process cycle.

While these steps are not difficult, they are less intuitive than the visual interaction used with the Breadman model TR3000.

The TR3000 requires the operator to touch the screen key sequence: personal baker followed by process. The operator is next provided a list of all possible cycles and may change times by pressing arrows provided on screen. The Bready prototype technology required interaction with the operator through computer Graphical User Interface (GUI). This feature adds the benefit of allowing remote control over process operation; however, lack of direct control could prove inconvenient.

Considering environmental factors, the Martian environment (approximately one-third gravity) could affect the mixing and rising of bread doughs. Aphenomena could occur in which the bread doughs migrate upward along the mixing shaft. The Bready prototype would effectively remove this effect as bread doughs are contained within a mixing bag. This design-specific advantage could become a major proponent for use in such a technology.

Soymilk and okara addition move significantly away from the control, in opposite directions, in dough strength values. Soymilk significantly increased (P value = 0.0199) dough strength while okara significantly decreased (P value = 0.0042) dough strength. However, dough strengths did not differ significantly between addition levels (10% and 20%) of soymilk (P value = 0.2119) and okara (Pvalue = 0.1816). Dough elasticity showed no significant differences when soymilk or okara were added at either level. With the exception of loaves generated using the TR2200C breadmaker, volumes for loaves did not statistically differ between the control (0%) and the 10% and 20% addition of soymilk or okara. The statistical outliers for loaves from the TR2200C originated from a 36% decrease in volume from the control to 10% soymilk addition and a 24% decrease when 20% okara was added. This would indicate that changes in dough strength values attributed to the addition soymilk or okara do not manifest in altered dough volume.

Researchers encountered difficulty in comparing data sets because three of the four bread makers were unable to produce loaves using large particle size bran incorporation. This result shows that milling equipment will need to be developed that can produce bran-containing flour having a particle size smaller than 850 m at the level of inclusion (31%) used in our formulation.

Discussion
Results from this work indicate that two bread making technologies, models TR3000 and the Bready prototype, performed well in the determined evaluative aspects. It may be that each technology alone or a fusion of the two technologies will provide a suitable technology for TRL five (5) testing. Using these technologies, it may also be feasible to incorporate waste products from soybean utilization. This will greatly benefit the Equivalent System Mass (ESM) for the Advanced Food System (AFS).

Publications
Clubbs, E., E. Vittadini, T. H. Shellhammer, and Y. Vodovotz. "Extending the Shelf-Life of Corn Tortillas: Effects of High Pressure Processing and Added Glycerol," 33rd International Conference on Environmental Systems (ICES), Vancouver, B.C., Canada, July 7-10, 2003.
French, S. J. "Standard Operating Procedure Manual for the Soymilk, Tofu, Okara and Whey (STOW) Processor Prototype," NASA document. (In process.)
French, S. J. and M. H. Perchonok. "Bread Making for Long Duration Space Missions: Bran and Protein Content Effects on Loaf Characteristics." (In process.)
French, S. J., M. H. Perchonok, and J. L. Greene. "Bread Making for Long Duration Space Missions: Soy Product Incorporation." (In process.)
French, S. J. and M. H. Perchonok. "Bread Making for Long-Duration Space Missions: Equipment Assessment." (In process.)
Vittadini, E., Y. Vodovotz. "Comparison of Physio-Chemical Properties of Wheat and Soy Containing Breads During Storage as Studied by Thermal Analyses," J. Food Science. (Submitted.)
Vittadini, E., E. Clubbs, J. Sachleben, and Y. Vodovotz. "Effects of High Pressure Treatment and Glycerol on the Physio-Chemical Properties of Corn Tortillas," J. Cereal Science. (In preparation.)

Presentations
Clubbs, E., T. H. Shellhammer, and Y. Vodovotz. "Effects of Glycerol and Salt on the Physio-Chemical Properties of Corn Tortillas," poster presentation, IFT Annual Meeting and Food Expo, Anaheim, CA, June 15-19, 2002.
Clubbs, E., E. Vittadini, T. H. Shellhammer, and Y. Vodovotz. "Extending the Shelf-Life of Corn Tortillas: Effects of High Pressure Processing and Added Glycerol," 33rd International Conference on Environmental Systems (ICES), Vancouver, B.C., Canada, July 7-10, 2003. (Accepted.)
French, S. J. "Bread Making for Long Duration Space Missions" 33rd International Conference on Environmental Systems (ICES), Vancouver, B.C., Canada, July 7-10, 2003.
French, S. J. "Current Food-Related NASA Funded Research Projects," IFT Annual Meeting and Food Expo, Chicago, IL, July 12-16, 2003.
French, S. J. "Soy in the NASA Space Program to Planet Mars," National Soy Research Laboratory, Champaign, IL, 2003.
Vittadini, E., E. Clubbs, J. R. Sachleben, and Y.Vodovotz. "Effect of High Pressure Treatment and Glycerol on the Physio-Chemical Properties of Corn Tortillas," 6th International Conference on Applications of Magnetic Resonance in Food Science, Paris, France, Sept. 4-6, 2002.
Zhang, Y. C., E. Vittadini, J. R. Sachleben, and Y. Vodovotz. "Changes in Water State and Distribution in Soy Containing Bread During Storage," IFT Annual Meeting and Food Expo, Chicago, IL, July 12-16, 2003. (Accepted.)
Zhang, Y. C., E. Vittadini, J. R. Sachleben, and Y. Vodovotz. "Effects of Soy on Bread’s Physio-Chemical Properties During Storage," IFT Annual Meeting and Food Expo, Anaheim, CA, June 15-19, 2002.

Funding and proposals
French, S., M. Perchonok, and C. Rappole. A Continuation of the Project "Prediction of Processing Parameters of Wheat- Based Food Products with Varying Composition." Center Director’s Discretionary Fund Program, FY2002, $50,000.
Vodovotz, Y. (Ohio State University) "Model System for Functional Foods: Tomato Products Containing Soy." Co-PI: S. J. Schwartz, M. Failla, S. K. Clinton, J. Bomser, N. H. Hooker, D. Francis, and J. Delwiche; USDA Initiative for Future Agriculture and Food Systems Program, 2001-2003, $1,275,000.

Classroom Instruction
"Food Service Systems In Space: A Challenge For The 21st Century." Course designed in 1997 for instruction by aerospace fellows. Instructors have been Dr. Yael Vodovotz (1997-1999), Dr. Elena Vittadini (2000), and Dr. Stephen French (2002).
"Living, Working and Playing In Space," taught by Dr. Charles Bourland and Dr. Clinton L. Rappole, Spring 2001, 2002, 2003.

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Institute for Space Systems Operations - Y2002 Annual Report
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