ARS | Publication request: The Effect of Moisture Content on Storage Quality and Sensory Attributes of Oil Roasted Peanuts

Submitted to: Institute of Food Technologists
Publication Type: Abstract Only
Publication Acceptance Date: June 6, 2009
Publication Date: N/A

Technical Abstract: Physical characteristics of peanuts may interact with processing conditions to impact quality. This study, examined the effects of preroast moisture content on the chemical and sensory characteristics of oil roasted peanuts. Virginia type peanuts were sequentially dried in-shell to obtain extra large kernel grade size peanuts of 4.2%, 4.5%, 5.8% and 6.6% moisture content. Peanuts were oil roasted with a standard protocol, stored in glass jars at 30 C and sampled at eight timepoints over one year. MC and Aw after roasting were 0.93/0.10, 1.00/0.10, 1.26/0.13, 1.53/0.15 respectively and did not change significantly (P<0.05) over the storage period. After roasting, OSI increased the most (11.1 to 16.2 H) in the low moisture samples compared to the high moisture samples (10.3 to 10.7 H) but OSI decreased with time in all samples. Lower pre-roast MC resulted in lower PV (3.37 meq/kg) through 12 months compared to the higher MC (4l83 mequ/kg). High MC pre-roast samples had higher FFA than low moisture samples, both before (0.228%, 0.102% respectively) and after roasting (0.238% and 0.142%, respectively). Descriptive sensory analysis indicated that off flavors appeared with storage time. Cardboard and painty intensities began to appear in all samples at 4 months, with higher intensities in higher pre-roast MC. Pre-roast moisture content affected sensory and shelf life characteristics of oil roasted peanuts and strongly suggests the need for consistent incoming moisture content in the peanut oil roasting industry.