In order to be able to save a scanned image as JPEG, you cannot set the [Scan Mode] to "Black and White".

If you select [Black and White] or [Black and White (OCR)] as the [Scan Mode], JPEG Exif is no longer available under [Save as Type].

If your desired [Save as Type} format is "JPEG", you may only select one of the "color" options available in the [Scan Mode] (i.e. Grayscale, Color, Color (Magazine)).