Effect of Blanching on Peanut Shelf-Life1

Abstract

Blanching, seed coat removal, is often a processing step in peanut manufacturing but the general peanut industry consensus is that shelf-life reduction occurs as a result of the process. In order to examine the effects of blanching on shelf-life, runner-type peanuts were blanched using total heating time and final temperature in a 3 X 3 factorial experiment. In each of nine treat ments, heating began at 32 C and increased incremen tally through six heating zones over a total time of30,45, : The use of trade names in this publication does not imply endorsement by the U.S. Corresponding author.or 60 min to a final temperature of either 76.7, 87.8, or 98.9 C. Blanched peanuts from each treatment and nonblanched control samples were stored at 26 ± 1C and ambient RH and were sampled over a 28-wk period. Peroxide value (PV) and oxidative stability index (OSI) of blanched and nonblanched peanuts were similar indi cating no meaningful shelf-life differences. Descriptive sensory analysis of peanuts roasted when taken from storage indicated no significant differences in intensity of painty and cardboardy descriptors between blanched and nonblanched peanuts. Mean separations of at tributes, including roast peanutty, for which significant differences were noted revealed only a weak, inconsis tent relationship between descriptor intensities and final blanching temperature.

Impact of Microwave Blanching on the Flavor of Roasted Peanuts

“…1990). This decrease in positive flavor attribute intensity with increase in temperature was also observed in blanching with traditional techniques (Sanders et al . 1999).…”

“…The effect of blanching on lipid oxidation is not yet known, as some studies showed an increase in lipid oxidation after blanching (Ory et al . 1992), while a study by Sanders et al . (1999) showed no practical detrimental effects of blanching on oxidative stability.…”

Flavor of roasted peanuts ( Arachis hypogaea ) — Part II: Correlation of volatile compounds to sensory characteristics

“…The peanuts were dry blanched to remove the testa at approximately 85°C for 30 min, (Sanders, Adelsberg, Hendrix, & McMichael, 1999) followed by mechanical abrasion (Steinweg-Handelsveem BV, Oosterhout, NL), and kept at −15°C until further processed, generally within less than 6 months. The blanched seeds were consequently processed according to a fractional factorial design, and 134 roasted peanut samples were obtained (Table 1), ensuring that the final moisture content for all treatments was between 2 and 2.7% w/w.…”

Microwave Irradiation for Dry-Roasting of Hazelnuts and Evaluation of Microwave Treatment on Hazelnuts Peeling and Fatty Acid Oxidation

“…As reported for peanuts, oven roasting reduced oxidative activity of lipase and lipoxygenase (Adelsberg & Sanders, 1997;Schirack et al, 2006). In another work (Sanders et al, 1999), the same process was reported to slightly increase these enzymatic activities with little impact on shelf life.…”