15D-26 |
Effect of microwave energy on blanchability and shelf-life of peanuts |
T. D. RAUSCH, Dept. of Food Science, North Carolina State University, Box 7624, Raleigh, NC 27695-7624, J. M. Drozd, Industrial Microwave Systems Inc., 3000 Perimeter Park Dr., Bldg. I, Morrisville, NC 27560, and T. H. Sanders, USDA/ARS, Box 7624, Raleigh, NC 27695-7624. Novel microwave technology that creates a uniform distribution of microwave energy was utilized to examine the effect of microwave energy on blanchability of peanuts. Preliminary studies indicated that the time for reduction of peanut moisture content by approximately 2 percentage points was less than 6 min utilizing microwave energy compared to 60 min for conventional blanching technology with heated air. Raw, runner type, peanuts at 6.49% moisture content were subjected to a total of 9 treatment combinations of 5, 7.5, or 10 kW of microwave power for 1.47, 2.85, 4.2 or 5.78 min duration. After treatment, samples were examined for total moisture content, single seed moisture distribution, and blanchability before being stored at 30 C for 28 wk. Samples were taken at variable intervals during the storage period and peroxide value, oxidative stability index, hexanal, and pentanal were determined as measures of shelf-life of the treated samples. Treatments resulting in final moisture content of 5.1-6.0% moisture content provided the best blanchability and longest shelf-life. The 2 treatments which optimized shelf-life parameters and blanchability were 5 kW for 5.78 min and 10 kW for 1.47 min. The 5 kW treatment reduced moisture content to 5.6% and resulted in over 85% blanchability and the 10 kW treatment reduced moisture content to 5.9% with a similar percent blanchability. These data suggest strong potential for advancements in peanut moisture removal technology using this novel microwave technology.
Session 15D, Food Engineering: Processing Technologies
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