The effects of different starch levels on the physical quality of high-oil extruded fish feed

Abstract

In this study, the effects of different starch levels (5%, 8% and 11%) on the physical properties of extruded fish feeds with high oil content (22%) were investigated. For this purpose, 3 types of extruded trout feed with different starch levels (S5, S8 and S11) were produced. Physical (moisture, feed diameter, bulk density and pellet durability) and chemical (lipid, starch, water absorption index, water solubility index and water stability) analyses of these feeds were performed in 3 repetitions on the samples taken from the extruder outlet, lubrication outlet and sieve outlet. An increase in the amount of starch in the feed caused an increase in feed diameter and durability of the pellets, while a decrease in bulk density was observed. According to the results of the chemical analysis, it was seen that the increase in the starch ratio had no effect on the crude oil and water solubility index values, the best water absorption index value was in the S8 feed, and the water stability values decreased from S5 to S11.