Effect of extrusion conditions on lipid quality in puffed food

The lipid quality of puffed food is easy to be changed during the extrusion processing,which affected quality of puffed food.As health and nutrition was concerned,palm oil was chosen to produce the palm oil- based puffed food,and the central composite design( CCD) was adopted to study the influence law of the extrusion processing conditions( moisture content,barrel temperature,screw speed) on its quality( total oxidation value),determining combined experimental conditions of the lowest oxidation content,and the verification test was carried out.The research showed that the order of factors influencing the oil quality of the palm oil- based puffed food during the extrusion processing was as follows: water content > barrel temperature > screw speed. A potential significant interaction between the moisture content and barrel temperature was shown,as when the barrel temperature was low( 100~110 ℃),the total oxidation value decreased with the increase of water content,when the barrel temperature was high( 110~160 ℃),the total oxidation value increased with the increase of water content. Within the scope of experimental conditions,combined various factors of the lowest oxidation content was obtained as the temperature of 124 ℃,the feed moisture of 22%,as well as the screw speed of 250 r / min.Under these conditions,the minimum total oxidation value was 27.15 meq / kg,and its experimental value was( 25.29 ± 0.43) meq / kg.