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.
PKU is usually diagnosed through newborn screening testing that is done shortly after birth on a blood sample (heel stick). However, PKU should be considered at any age in a person who has developmental delays or mental retardation. This is because, rarely, infants are missed by newborn screening programs.