99F-3


Effects of long-term storage on wheat flour packaged in a low oxygen atmosphere

N. M. DICKEY1, D. J. Rose, L. V. Ogden, and O. A. Pike. (1) Nutrition, Dietetics and Food Science, Brigham Young University, S-221 ESC, Provo, UT 84602

There is interest in the long-term storage of food for applications such as space flight, military rations, and disaster relief. Though intact wheat kernels store extremely well, long-term storage of wheat flour has not been extensively studied, especially under modified atmospheres.

The objective of this research was to examine the effects of long-term storage on wheat flour packaged in a low oxygen atmosphere.

Ten samples of wheat flour packaged in No. 10 cans were obtained from donors. Samples ranged in age from 0.5-11 years and were stored at ambient temperatures. Oxygen levels were below 1%, and moisture contents were between 12.0% and 14.3%. Lipid hydrolysis was quantitated using a colorimetric method with oleic acid as the standard. Lipid oxidation was measured by headspace hexanal using GC-FID. A 50-member sensory panel evaluated flour for odor and appearance using a 9-point hedonic scale. Panelists also indicated whether they would use the flour for baking in everyday and emergency situations.

Lipid hydrolysis ranged from 1.74-6.23 mg oleic acid equivalents/g flour, and hexanal ranged from 0.030-0.210 µg/g flour. Using regression analysis, lipid hydrolysis was directly correlated with age and moisture content of the flour. Sensory results indicated that age was not correlated with aroma or appearance; however, moisture content, hexanal, and lipid hydrolysis were good predictors of aroma. Though acceptance of some of the samples was as low as 45% for everyday use, all flour maintained >90% acceptance for use in emergency situations.

Acceptance data indicates that storing wheat flour in the absence of oxygen is a viable option for long-term storage. Because sensory properties and lipid degradation were significantly correlated with moisture content, manufacturers should optimize this parameter when packaging flour for long-term storage.

Session 99F, Quality Assurance: General
2:00 PM - 5:30 PM, Thursday PM Room Hall N-1

2004 IFT Annual Meeting, July 12-16 - Las Vegas, NV