Quantification and characterization of volatiles evolved during extrusion of rice and soy flours.

NASA-Johnson Space Center is designing and building a habitat (Bioregenerative Planetary Life Support Systems Test Complex, BIO-Plex) intended for evaluating advanced life support systems developed for long-duration missions to the Moon or Mars where all consumables will be recycled and reused. A food system based on raw products obtained from higher plants (such as soybeans, rice, and wheat) may be a central feature of a biologically based Advanced Life Support System. To convert raw crops to edible ingredients or food items, multipurpose processing equipment such as an extruder is ideal. Volatile compounds evolved during the manufacturing of these food products may accumulate and reach toxic levels. Additionally, off-odors often dissipated in open-air environments without consequence may cause significant discomfort in the BIO-Plex. Rice and defatted soy flours were adjusted to 16% moisture, and triplicate samples were extruded using a tabletop single-screw extruder. The extrudate was collected in specially designed Tedlar bags from which air samples could be extracted. The samples were analyzed by GC-MS with special emphasis on compounds with Spacecraft Maximum Allowable Concentrations (SMACs). Results showed a combination of alcohols, aldehydes, ketones, and carbonyl compounds in the different flours. Each compound and its SMAC value, as well as its impact on the air revitalization system, was discussed.

Critical path plan for food and nutrition research required for planetary exploration missions.

In preparation for future planetary exploration, NASA-Johnson Space Center has developed a critical path plan for food and nutrition research needs. The plan highlights the risk factors pertaining to food and nutrition associated with exposure to the space flight environment as well as the possible consequences if no corrective measures are implemented. Included in the plan are the initiating events such as microgravity, remote environment and mission duration, which obviously impact the risk factors. The plan includes points of intervention where mitigating factors can be implemented to avoid outcomes such as malnutrition and unsafe foods. Physiological changes induced by lack of gravity, as well as increased exposure to radiation, may alter nutrient bio-availability, and/or nutrient requirements. An inadequate food system, whether due to technical limitations or nutritional shortcomings, can result in serious consequences. Additionally, microbial and chemical food contamination or psychological factors such as depression may lead to insufficient food intake. Critical questions define areas where further research is required to eliminate or ameliorate the risk from each of those factors. These questions delineate priorities for NASA food and nutrition research for planetary exploration missions.

Food systems for space travel.

Space food systems have evolved from tubes and cubes to Earth-like food being planned for the International Space Station. The weight, volume, and oxygen-enriched atmosphere constraints of earlier spacecraft severely limited the type of food that could be used. Food systems improved as spacecraft conditions became more habitable. Space food systems have traditionally been based upon the water supply. This presentation summarizes the food development activities from Mercury through Shuttle, Shuttle/Mir, and plans for the International Space Station. Food development lessons learned from the long-duration missions with astronauts on the Mir station are also discussed. Nutritional requirements for long-duration missions in microgravity and problems associated with meeting these requirements for Mir will be elucidated. The psychological importance of food and the implications for food development activities are summarized.

Advances in food systems for space flight.

Food for space has evolved from cubes and tubes to normal Earth-like food consumed with common utensils. U.S. space food systems have traditionally been based upon the water supply. When on-board water was abundant (e.g., Apollo and Shuttle fuel cells produced water) then dehydrated food was used extensively. The International Space Station will have limited water available for food rehydration so there is little advantage for using dehydrated foods. Experience from Skylab and the Russian Mir space station emphasizes that food variety and quality are important elements in the design of food for closed systems. The evolution of space food has accentuated Earth-like foods, which should be a model for closed environment food systems.

Characterization of rco-1 of Neurospora crassa, a pleiotropic gene affecting growth and development that encodes a homolog of Tup1 of Saccharomyces cerevisiae.

The filamentous fungus Neurospora crassa undergoes a well-defined developmental program, conidiation, that culminates in the production of numerous asexual spores, conidia. Several cloned genes, including con-10, are expressed during conidiation but not during mycelial growth. Using a previously described selection strategy, we isolated mutants that express con-10 during mycelial growth. Selection was based on expression of an integrated DNA fragment containing the con-10 promoter-regulatory region followed by the initial segment of the con-10 open reading frame fused in frame with the bacterial hygromycin B phosphotransferase structural gene (con10'-'hph). Resistance to hygromycin results from mutational alterations that allow mycelial expression of the con-10'-'hph gene fusion. A set of drug-resistant mutants were isolated; several of these had abnormal conidiation phenotypes and were trans-acting, i.e., they allowed mycelial expression of the endogenous con-10 gene. Four of these had alterations at a single locus, designated rco-1 (regulation of conidiation). Strains with the rco-1 mutant alleles were aconidial, female sterile, had reduced growth rates, and formed hyphae that coiled in a counterclockwise direction, opposite that of the wild type. The four rco-1 mutants had distinct conidiation morphologies, suggesting that conidiation was blocked at different stages. Wild-type rco-1 was cloned by a novel procedure employing heterokaryon-assisted transformation and ligation-mediated PCR. The predicted RCO1 polypeptide is a homolog of Tup1 of Saccharomyces cerevisiae, a multidomain protein that mediates transcriptional repression of genes concerned with a variety of processes. Like tup1 mutants, null mutants of rco-1 are viable and pleiotropic. A promoter element was identified that could be responsible for RCO1-mediated vegetative repression of con-10 and other conidiation genes.

Nutrition in space: lessons from the past applied to the future.

From the basic impact of nutrient intake on health maintenance to the psychosocial benefits of mealtime, the role of nutrition in space is evident. In this discussion, dietary intake data from three space programs, Apollo, Space Shuttle, and Skylab, are presented. Data examination reveals that energy and fluid intakes are almost always lower than predicted. Nutrition in space has many areas of impact, including provision of required nutrients and maintenance of endocrine, immune, and musculoskeletal systems. Long-duration missions will require quantitation of nutrient requirements for maintenance of health and protection against the effects of microgravity. Psychosocial aspects of nutrition will also be important for more productive missions and crew morale. Realization of the full role of nutrition during spaceflight is critical for the success of extended-duration missions. Research conducted to determine the impact of spaceflight on human physiology and subsequent nutritional requirements will also have direct and indirect applications in Earth-based nutrition research.

Selection of human consumables for future space missions.

Consumables for human spaceflight include oxygen, water, food and food packaging, personal hygiene items, and clothing. This paper deals with the requirements for food and water, and their impact on waste product generation. Just as urbanization of society has been made possible by improved food processing and packaging, manned spaceflight has benefitted from this technology. The downside of this technology is increased food package waste product. Since consumables make up a major portion of the vehicle onboard stowage and generate most of the waste products, selection of consumables is a very critical process. Food and package waste comprise the majority of the trash generated on the current shuttle orbiter missions. Plans for future missions must include accurate assessment of the waste products to be generated, and the methods for processing and disposing of these wastes.

Food system for Space Shuttle Columbia.

The Space Shuttle's food system consists of food products preserved by dehydration, thermostabilization, irradiation, and moisture control. A preassembled standard menu is provided for each crew member. This is supplemented with a pantry food supply. In case of emergency, the pantry is a contingency food source, but on a nominal mission it can be used to supplement meals, and pantry items can be exchanged with standard meal items to accommodate individual food preferences. Shelf life, storage temperature, volume, and weight have been the primary factors considered in the development of the Shuttle food system.

Space Shuttle Food Processing and Packaging.

A new space food system will be introduced on the fifth Shuttle mission. The change includes redesign of the package for rehydratable foods and a new galley. The package will be an injection molded base with a thermoformed flexible lid and a needle-septum concept for rehydration. One package will be used for both rehydratable foods and beverages. Automated production and more readily available materials reduce the cost of space food packaging. The galley system has a food preparation area, a semi-automatic rehydration unit and a convection oven. The time required to add water to the packages has been reduced to 3-5 min. Foods for space flight are purchased in lots and held at 40 F until 1 to 2 months before a scheduled flight. Most of the safety and quality testing are done while the foods are in storage. Foods which pass the tests, i.e. microbiological, sensory, rehydration, storage, and oxygen headspace, are transferred to flight packages in a Class 10,000 clean booth, using clean room techniques. The menu for the Shuttle food system is derived from a variety of foods that are preserved by dehydration, thermostabilization, irradiation and moisture control.

Microbiological testing of Skylab foods.

The Skylab manned space flight program presented unique food microbiology problems. This challenge was successfully met by careful evaluation of the total Skylab food system by considering the nature of Skylab foods, their processing and handling, and Skylab food safety requirements. Some of the unique problems encountered with the Skylab foods involved: extended storage times, variations in storage temperatures, no opportunity to resupply or charge foods after launch of the Skylab Workshop, first use of frozen foods in space, first use of a food-warming device in weightlessness, relatively small size of production lots requiring statistically valid sampling plans, and use of the food as an accurately controlled segment of sophisticated life science experiments. Consideration of all of these situations generated the need for definitive microbiological tests and test limits. These tests are described in this paper along with the rationale for their selection. Test results are reported which show successful compliance with the test limits.