Store peeled onions in the freezer. Chop your onions and place them in a flat layer on a cookie sheet and freeze. After they are frozen, remove the onions from the sheet and store them in Ziploc bags or storage containers in the freezer. One of the down sides of this option is limited storage space.hop your onions and place them in a flat layer on a cookie sheet and freeze. After they are frozen, remove the onions from the sheet and store them in Ziploc bags or storage containers in the freezer. One of the down sides of this option is limited storage space.
Newborns with phenylketonuria initially don't have any symptoms. Without treatment, babies usually develop signs of PKU within a few months. PKU symptoms can be mild or severe and may include: 1  Intellectual disability (formerly called mental retardation). 2  Delayed development. 3  Behavioral, emotional and social problems.
Why It Is Done. A phenylketonuria (PKU) screening test is done to see whether a newborn baby has the enzyme needed to use phenylalanine in his or her body. If this test shows that your baby has a phenylalanine problem, the doctor will do further testing to check whether your baby has PKU.