phlegmy sounding while eating baby food?

Hey ladies. So we just got the ok to start solids. We tried 1oz of puréed apple sauce last night and she almost ate the whole thing. But after she coughed and it sounded phlegmy. And my first thought was "oh no! Are you getting sick" but then she was fine and was fine all day today until she ate the apples again. Once again she coughed a few times and it sounded phlegmy. Any idea why? Anyone else notice this?