A thesis submitted in partial fulfillment of the requirement for the degree of Master of Engineering, School of Environment, Resources and Development

Thesis (M.Eng.) - Asian Institute of Technology, 1983

A study on processing of partially defatted peanuts by means of pressing, reconstitution and cooking is investigated. The pressing pressure (P), holding time (T) and the original peanut depth (t) are found to have considerable influence on the amounts of oil removed, broken kernels, and over-expansion ability. The amounts of oil removed increase with the increase of strain, and at the strain between 0.3 and 0.7 the correlation is linear, Meanwhile the increase in rate of loading during pressing results in a reduction of the oil yield to some extent, in contrast with the requirement of energy per unit weight of expressed oil is increased. The swelling equilibriums of pressed peanuts with 50 and 70% of oil removed in a 90°C water immersion are attained in 1.5 and 2, 5 minutes, and their corresponding moisture contents are 30 and 40%, respectively. Fried partially defatted peanuts of 70% oil removed with 42% protein contents and low calorie value which can be produced by pressing raw peanuts in the ranges of pressure between 6,800 and 20,400 kPa, holding time between 5 and 30 minutes, and 12.8 cm peanut depth, represent the most acceptable products with respect to sensory parameters. Low fat content of partially defatted peanuts exhibits as twice a long shelf life as the full fat peanuts.