Quantification and Characterization of Volatiles Evolved during Extrusion of Rice and Soy Flours

Abstract

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.

Extrusion improved the anti‐inflammatory effect of amaranth (Amaranthus hypochondriacus) hydrolysates in LPS‐induced human THP‐1 macrophage‐like and mouse RAW 264.7 macrophages by preventing activation of NF‐κB signaling

“…Pepsin hydrolysates from unprocessed amaranth had higher antioxidant capacity than hydrolysates from extruded amaranth. Extrusion can also lead to interaction between proteins and other macromolecules such as starch and lipids [42,43]. Amaranth grain has high starch content (60-70%) [7], this makes the protein less available as antioxidant.…”

“…Extrusion can also lead to interaction between proteins and other macromolecules such as starch and lipids . Amaranth grain has high starch content (60–70%) , this makes the protein less available as antioxidant.…”