Progress 01/01/01 to 12/31/01
Outputs
We concluded data analysis of trends in food acceptability and intake during a closed diet study. In this study, 16 subjects ate a vegan diet appropriate for a bioregenerative space life support system for 30 days (3 10-day cycles). At each meal we recorded food intake (by weight) and acceptability score (on a 9 point hedonic scale) for each food consumed. Acceptability scores were stable over the study except for dinner foods, where scores rose in the second cycle, then dropped cycle 1 ratings. ANOVA was performed to see if the initial acceptability score (high, medium, or low ) would influence the stability of acceptability ratings. No effects were observed. However, when ANOVA was applied to the intake of foods rather than to ratings, significant trends were noted. Intake increased markedly at breakfast and with borderline significance at lunch, while dinner and snack intake were stable. Intake of medium and high acceptability foods increased significantly over the
study. These results indicate that the higher food intake in cycles 2 and 3 was consumed chiefly during breakfast and lunch and consisted mainly of medium- and high-acceptability foods. Breakfast and lunch foods and snacks, were consumed significantly more on weekends than on weekdays. On weekends, subjects ate more of high-acceptability foods and less of low acceptability foods than on weekdays. It appears that weekend eating was less constrained by environment than weekday eating, hence more controlled by subjects' preferences and appetite. Strawberry and melon were the only fruits offered during the study. They were among the most highly preferred foods and the subjects, offered foods ad libitum, consumed large amounts especially on weekends. We are preparing a report for NASA Ames Research Center on the potential of microbial and chemically synthesized foods from Mars in-situ resources to become part of the ALS food system. Feedstocks for food production would be C1 and C2
hydrocarbons and oxygenates with primary uses as Mars Rover fuel and rocket propellant. The best schemes appear to be microbial lipids and cellular protein from ethanol, extracellular polysaccharides and cellular protein from methanol, and sugars from formaldehyde via the formose reaction using a more selective catalyst. 4 papers were submitted for publication and a conference paper was presented (IFT)
Impacts
This project has extended the minimum-cost diet concept from its roots in livestock diet formulation to a form useful for design of human diets and menus. It has also demonstrated that omnivores can switch to a plant-based diet without major changes in body weight, mood or enjoyment of food - an encouraging result for nutritionists trying to persuade Americans to include more plant-based foods in their diet.
Publications
- Greenwalt, C.J. and Hunter, J.B. 2001 Edible Oil Processing Options for ALS. Life Support and Biosphere Science 7:233-242 Greenwalt, C.J. Hunter, J.B. Lin, S. McKenzie, S. and A. Denvir, 2001Ozonation and Alkaline Peroxide Pretreatment of Wheat Straw for Cryptococcus curvatus Fermentation. Life Support and Biosphere Science 7: 243-250
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Progress 01/01/00 to 12/31/00
Outputs
In calendar year 2000, the acceptability of previously developed and tested plant-based foods was assessed in a closed 30 day diet study consisting of 3 similar ten-day menu cycles. A weekly mood questionnaire was administered to the 16 study subjects and to a control group. Subjects' weights, their intake of all foods, and their food acceptability ratings were monitored. Correlation earlier taste session acceptability scores and the 30 day study food intake was 64%, and between the 30 day study acceptability and the study's food intake was 67%, but between taste session scores and in-study scores, only 43%, indicating that intake of a food is reasonably well predicted by acceptability ratings despite the environmental and experience factors responsible for variations in acceptability ratings. The study revealed significant differences among pre-study, in-study and post-study mood scores but these differences were paralleled in controls, hence not attributed to the
diet. Subjects lost a statistically significant amount of weight, on average 3.75 lbs, stabilizing toward the end of the study. No monotony effect was noted. The nutritional profile of the diet met NASA standards except for the low calcium and high fiber level. Videotape analysis is a work measurement tool used in the manufacturing industry. Videotape data of food preparation by an experienced cook was analyzed to construct a model of labor requirements for food preparation. Up to 500 individual tasks per recipe were identified from the videotapes, timed and entered in a database. An initial analysis, based on 19 recipes, indicated that task labor times have a roughly exponential distribution and do not scale uniformly with the quantity of food processed. This disappointing result was attributed to an overly detailed task classification scheme. An optimized schedule for food preparation tasks for a predetermined menu was accomplished using fewer, broader, recipe-specific task
classifications; this approach appears promising for a food preparation scaling model as well. Design of a crop production system based on an optimized diet was concluded in collaboration with researchers from University of Guelph. A review of vegetable oil processing methods for bioregenerative life support systems was prepared for Johnson Space Center. An optimized schedule for food processing operations was demonstrated using data from the Rutgers crop production model and a cost optimized menu cycle as inputs. This nonlinear problem, which includes thousands of binary decision variables, is more complex than the diet optimization. Papers were submitted to Journal of Life Support and Biosphere Sciences and Advances in Space Research, and eight conference papers were presented. Project funding terminated in September, 2000.
Impacts
This project has extended the minimum-cost diet concept from its historical roots in livestock diet formulation to a form useful for design of human diets and menus. It has also demonstrated that omnivores can switch to a plant-based diet without major changes in body weight, mood or enjoyment of food. An encouraging result for nutritionists and public health officials trying to persuade Americans to include more plant-based foods in their diet.
Publications
- A. A. Olabi, J. B. Hunter, and D. A. Levitsky. 2000. Optimization of the crew diet for a bioregenerative space life support system. Proceedings of the 2000 Cornell Nutrition Conference for Feed Manufacturers, pp. 270-280 Olabi, Ammar Ahmad. 2000. The optimization of a bioregenerative life support space diet. Doctoral dissertation, Cornell University. Greenwalt, Cheryl Jean. 2000. Utilization of crop residue and production of edible single cell oil for an advanced life support system. Doctoral dissertation, Cornell University.
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Progress 01/01/99 to 12/31/99
Outputs
Between December 1998 and December 1999, we finished acceptability testing of 90 additional foods on two panels of 24 subjects each. Nutritional analyses were computed for all tested recipes using the Nutritionist IV r software package. We continued work on modeling labor requirements for food preparation by videotaping preparation of the recipes for a work factor analysis of meal preparation and by coding data for a number of the recipes. The labor cost estimates for the overall food subsystem were updated and included in overall cost estimates. The optimization work was expanded to generate 7- and 10-day menu cycles which included the entire suite of 210 foods as inputs. Using sensitivity analysis, we explored the role of food variety and food acceptability to the overall cost of a completely bioregenerative diet. A feasibility study of a "dynamic" menu optimization was completed successfully, showing that our diet optimization procedure could design nutritionally
compliant diets around a menu in which up to 30% of the foods were preselected on a weekly basis by crewmembers. Since a truly optimized food system has optimal production practices as well as an optimal diet, we completed the first phase of designing an optimization procedure for food processing operations. In this study, crop growth models from other researchers were used as inputs for availability of raw crops, and the optimized diet cycle was considered the demand to be met. Preliminary results using ingredient inventory as the objective function to be minimized, showed that the frequency of processing depended on the cost of labor. This project brought to light the need for an in-depth study of ingredient processing waste and food preparation waste. We have updated the spreadsheet models developed last year to estimate equivalent system mass (ESM) costs for food crops and processed food ingredients produced on a lunar or planetary colony. The revisions are based on numbers
generated by A.E. Drysdale (Boeing, Inc) for the Biomass Production Chamber at Kennedy Space Center. The food production cost model was updated to account specifically for processing losses. In addition, a study of food preparation losses (waste generated by trimming crops "as-purchased" to the edible portion only) was completed for all Mars-produced ingredients and for 17 vegetable crops. In fall 1999 we finished designing the 30-day feeding study described in the original proposal, recruited subjects, and began preparation of the foods to be served. The goal of the 30-day study was to test the acceptability of the foods, and the food intake of the subjects, over a 30-day period in which subjects consumed only those foods supplied by the project. To reduce labor requirements for food preparation during the study itself, we tested many of the foods on the menu after frozen storage and produced the acceptable ones in bulk. The feeding study is planned for early 2000.
Impacts
(N/A)
Publications
- Engineering Concepts for Food Processing in Bioregenerative Life Support Systems. J.B. Hunter. Journal of Life Support and Biosphere Science, 6(1), 53-60 (1999)
- Cost and Quality in a "Bioregenerative" Crew Diet. A. A. Olabi and J. B. Hunter. SAE Technical Paper 1999-01-2077. (1999)
- Work Measurement Videotaping Technique as a Means for Estimating Food Preparation Time of a Bioregenerative Diet. A.A. Olabi, P. Jackson, J.B. Hunter, M. Segal and thirteen undergraduate students. SAE Technical Paper 1999-01-2075 (1999)
- Evaluation of Space-Compatible Biomass Pretreatment Methods Jean Hunter, Cheryl Greenwalt, Scott McKenzie and Adrian Denvir. SAE Technical Paper 1999-01-2076
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Progress 01/01/98 to 12/31/98
Outputs
During 1998 we finished acceptability testing of the first 120 foods on two panels of 24 subjects each. Nutritional analyses were computed for all tested recipes using the Nutritionist IV r software package. We have developed a new series of recipes for panel testing in calendar year 1999. The emphasis in the new recipe series is on easy-to-prepare foods based on the most cost-effective crops from the ALS crop list: white potato, sweet potato, and wheat . A statistical analysis of our two 24-subject panels shows good block-to-block correspondence. Though acceptability scores from the second panel are slightly lower on average than those from the first panel, the rank order of the dishes in any testing session is generally consistent between the two panels. We have also observed a gradual upward trend in food acceptability ratings by both panels as testing proceeds, which may reflect panelists' adaptation to the new cuisine. This hypothesis will be tested during the
1999 evaluations. We have also verified that the panels' overall responses are consistent from week to week, through use of anchor foods such as bread or crackers which are presented at every panel session. We have developed spreadsheet models to estimate equivalent system mass (ESM) costs for food crops and processed food ingredients produced on a lunar or planetary colony. The crop model is based on data for PPF, photoperiod, canopy height and nutrient pool depth, cropping cycle, biomass productivity, and harvest index as plant parameters; assumptions on design of crop lighting, nutrient delivery system and treatment of water and agricultural wastes, and labor requirements for seeding and harvest. Model assumptions are specifically identified and tracked to allow updating. ESM resource costs are based on numbers generated by A.E. Drysdale (Boeing, Inc) for the Mars reference mission. The food production cost model is based on food processes previously identified, standard food
processing equipment envisioned for the Advanced Life Support Systems Integrated Test Bed (Bio-Plex) now under construction, and estimates of the energy, resupply, water and labor resource utilization for each food processing operation. In fall 1998 we began a work factor analysis for food preparation, with a goal of modeling and predicting food prep labor requirements for Bio-Plex or a future Lunar or Martian station. The project chef is videotaped while preparing food for the panel tastings, then individual cooking tasks and transits are identified and timed from the videotape. Statistical analysis of the time/task data identifies average times for individual tasks, or linear regression models for tasks performed on different amounts of materials, allowing preparation time to be predicted for larger and smaller preparation scale (crew size) and for work areas of different design. Since the crew of a Lunar or Martian planetary station will be busy, food preparation labor is expected
to be an important cost factor in the food system, and perhaps even a constraint on the foods selected.
Impacts
(N/A)
Publications
- No publications reported this period
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Progress 01/01/97 to 12/31/97
Outputs
We have identified160 recipes for development and testing. A questionnaire for panel testing of foods, including an overall assessment and assessment of important food qualities (e.g. aroma, texture), attributes (e.g. sweetness, saltiness) and a series of open-ended questions was developed. Using a spreadsheet for bioregenerative crop cost estimation in equivalent system mass (ESM) units, developed in cooperation with Alan Drysdale of Boeing, Inc. and an algorithm, crop and food estimates are directily calculated from ESM costs of basic resources such as power, pressurized volume, equipment mass, ressuply mass and labor, which change as mission scenarios and life support technologies change. A FileMaker Pro database will supply recipe, nutritional analysis, production cost, and sensory test data to a linear programming optimization program which will select the lowest cost diet for a given menu cycle length, subject to constraints on nutrient content, labor
availability, and dietary diversity. A process for seitan, a form of wheat gluten used as a meat alternative, has been developed. We have succeeded in producing tempeh (a fungal-cultured soybean product, used as a meat replacer) from okara, the solid residue of soymilk production. Amazake, a starch-hydrolysate sweetener, was developed based on wheat starch rather than white rice as the starchy substrate. A process for direct hydrolysis of wheat starch using amylases is under development.
Impacts
(N/A)
Publications
- LIN, SHUWEI, 1997. Bench Scale Process Development: Single Cell Oil Production from Wheat Straw by Cryptococcus curvatus ATCC 20509. Master's thesis. Cornell University, Department of Agricultural and
- YAU, JOAN C. 1997. A Study of Amazake Production Using Different Substrates. Master's Thesis. Cornell University, Department of Food
- HUNTER, J.B., S. LIN, A.E. DRYSDALE, Y. VODOVOTZ. 1997. Prospects for Single-Cell Oil Productionin a Lunar Life Support System. Presented at 27th International conference on Environmental Systems, Lake Tahoe, NV. SAE Technical Paper 97236
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