Export Artboards to PDF - Images with Low Quality

When I use the export artboards to PDF, even if I select the maximum quality in JPG, the images are still compressed with a huge loss of quality. The comparison below shows the difference in quality when exporting the same document with artboarts to pdf and when using save as pdf, is there any way to solve this? The document I need to save contains around 13 artboards and I don't care about the file size that much, just the quality.