You can try saving (or writing) the Buffered Image with the changes you made and then opening it as an Image.
EDIT:
try {
// Retrieve Image
BufferedImage buffer = ImageIO.read(new File("old.png"));;
// Here you can rotate your image as you want (making your magic)
File outputfile = new File("saved.png");
ImageIO.write(buffer, "png", outputfile); // Write the Buffered Image into an output file
Image image = ImageIO.read(new File("saved.png")); // Opening again as an Image
} catch (IOException e) {
...
}