Application of Low Dose Irradiation to a Fresh Bread System for Space Flights

Abstract

Irradiation pasteurization of flour and bread at 50,000 rads markedly reduced their microflora. Irradiation pasteurization of bread in combination with the irradiated flour extended the period of freedom or low incidence of mold growth when stored at 21–25°C improving the use of fresh bread for flights having several weeks duration. The irradiation process reduced the presence of the mold genera Aspergillus and Penicillium, which suggests an advantage when considering potential toxic metabolites that may result from mold growth. Chemical measurements, involving TBA value, gas chromatography of bread volatiles, and infrared scanning of the bread lipids, did not show any major influences due to the irradiation process. Irradiated white bread samples after short term storage contained a new carbonyl group identified in the infrared scan that was not noted in the control white bread. This same compound, tentatively identified as propionaldehyde, appeared after 12 wk in non‐irradiated white bread. Panel evaluations were unable to distinguish aroma, appearance, flavor, texture or freshness differences attributable to the irradiation process used in this study. Within the type of bread specified by NASA, no general detrimental quality changes were observed due to the irradiation treatments used. Overall the results support the application of low dose irradiation in the extension of mold‐free fresh bread for space flights.

The potential of some spice essential oils in the control of A. parasiticus CFR 223 and aflatoxin production

“…However, only a few of them have been tested against toxigenic Aspergillus spp. with majority of the tests being in artificial synthetic media and only Hartung et al (1973) reported that raisin bread containing cinnamon did not support growth and aflatoxin production by A. parasiticus. Similarly, Montes-Belmont and Carvajal (1998) investigated the effect of eleven plant essential oils for maize protection against A. flavus and found out that essential oils of cinnamon (C. zeylanicum), peppermint (Mentha piperita), basil (Ocimum basilicum), thyme (Thymus vulgaris), origanum (Origanum vulgare), flavouring herb epazote (Teloxys ambrosiodes), clove (Syzygium aromaticum) caused a total inhibition of fungal development on maize kernels.…”

“…The use of spices in preserving food products has been traditional and they are cultivated in many countries such as India, Japan and Russia (Hartung, Bullerman, Arnold, & Heidelbagh, 1973). Spices occupy a prominent place in the traditional culinary practices and are indispensable part of daily diets of millions of people all over the world.…”

Irradiation of cereal grains and cereal grain products

“…By applying a 50-krad dose of irradiation to flour and subsequently to bread, Hartung et al (1973) showed a significant reduction in the visible and total mold count, as well as in bacterial count, on bread stored for up to 20 weeks.…”

“…Hartung et al (1973) reported that the total detectable aerobic bacteria per gram of flour was 600 and 2,400 for irradiated and nonir radiated flour, respectively. The predominant bacteria type was Gram-positive cocci (88%), most of which were Staphylococcus epidermidis.…”

“…Low levels of irradiation do not sterilize food products but rather reduce the microbial population and thereby extend storage life. This application of irradiation was employed by Hartung et al (1973) to extend the shelf life of bread used in food systems for manned space flight missions.…”