This vector graphic was probably made with the shapes tool to create a circle and the leaves.They may have manipulated the stroke with the pen tool or width tool to get uneven wavy lines in the circle, the curves in the leaves and the individual slices of the orange.
They may have also used the rotate tool to create the different slices and then manipulated them later with the pen tool to be varying shapes to give a more realistic look of an orange.
The background most likely used the pen tool to create the different waves and a gradient to get the variation in color from the top and bottom. Since the lines are faint opacity was probably kicked back as well to achieve a more faded background that doesn’t distract from the image.
The little seeds or textures in the center could have been made with a thick line and the width tool although there are several ways to get the shapes.