Effects of roasting on vitamin E content, color, microstructure and moisture of peanuts, and vitamin E content in peanut oils prepared from the roasted peanuts were investigated. Runner-type peanuts were roasted at 140, 150, and 160ºC for 10-20 min. As roasting temperature and time increased, the CIELAB L* value of peanuts decreased while a* and b* values increased, resulting in formation of the golden brown color of roasted peanuts. Moisture ratio (M/Mo) and color b* value of peanuts roasted at 140 to 160ºC showed a correlation of b* = 21.61 (M/Mo)2 – 40.62 (M/Mo) + 34.12 (R2 = 0.9123). Overall changes in the tocopherol contents of peanuts and peanut oils were significantly affected by roasting temperature and time (p<0.05). Roasting at 140ºC caused a slight increase in the levels of tocopherols of peanuts over roasting time up to 20 min (p<0.05). There was no significant change in the tocopherol levels of peanuts during roasting at 150 ºC for 20 min (p>0.05). At 160ºC, the levels of tocopherols significantly decreased during the initial 10 min of roasting (p<0.05) while there was no extended loss after 10 min, resulting in about 5, 12, 20, and 10% losses of α-, β-, γ- and δ-T, respectively. After 20 min, total tocopherols decreased by 18%. However, tocopherol contents of pressed peanut oils significantly decreased at all roasting temperatures (p<0.05). After roasting peanuts at 160ºC for 20 min, about 84% of initial α-T in peanut oils was retained. α-T was the most stable to roasting while γ-T was the least. Swollen epidermal cells on the inner surface and broken cell walls of parenchyma tissue of peanut cotyledon were observed in peanuts after roasting at 160ºC for 15 min. Severe changes in microstructure of peanut by roasting would contribute to vitamin E stability because of exposure of oil droplets in peanuts to oxygen.

ABSTRACT
 I. INTRODUCTION
 II. Materials and Methods
  2.1 Sample preparation
  2.2 Color measurement
  2.3 Vitamin E extraction
  2.4 HPLC analysis
  2.5 Fixation and sample preparation for scanningelectron microscopy (SEM)
  2.6 Statistics
 III. Results and Discussion
  3.1 Moisture content of peanuts
  3.2 Color of peanuts
  3.3 Tocopherol contents in peanuts
  3.4 Tocopherol contents in peanut oils
  3.5 Microstructure of peanuts
 IV. Conclusions
 ≫ Literature cited

• Ronald R Eitenmiller(Dept. of Food Sci. and Technol., University of Georgia)
• Sung-Gil Choi(Dept. of Appl. Life Sci., Gyeongsang National Univ.(Insti. of Agric. Life Sci.))
• Jiyeon Chun(Dept. of Food Sci. and Technol., Sunchon National University) Corresponding author