Effect of Moist Heat Treatment on Sensory Qualities of Peanut Kernels

Abstract

Abstract Shelled Florunner cv. peanut kernels adjusted to 12 to 13% moisture were subjected to heat treatments at 60, 90, and 120° C for periods of 1 and 2 hr. Kernels were then dried, oil-roasted, and examined for sensory qualities. Moistened, heated kernels were also inoculated with an aflatoxigenic strain of Aspergillus flavus and analyzed for free fatty acid (FFA) and aflatoxin contents at weekly intervals over a 6-week period of incubation at 30°C. Treatment of moist kernels at 60°C for 1 or 2 hr caused the FFA content to increase from 1.2% (unheated) to 2.2%, whereas treatment at 90 and 120°C for the same periods of time resulted in FFA contents ranging from 10.3 to 13.2%. After 6 weeks, the FFA content of all inoculated and control samples ranged from 11.5 to 14.5%. Sensory panel evaluations of uninoculated, roasted kernels indicated that moist heat treatment at 60°C did not significantly (P ≤ 0.05) alter organoleptic characteristics; treatment at 90°C for 2 hr resulted in significantly lower scores for texture and flavor, whereas treatment at 120°C resulted in a general decrease in all sensory qualities. Kernels heated prior to inoculation with A. flavus did not appear to support growth as well as did unheated kernels early in the 6-week test period.