Flavor Stability of Butter Prints during Frozen and Refrigerated Storage

Butter from each of two factories was stored for 12 mo at -18°C to determine flavor stability, particularly on the surface, of butter in 10 different wrappers; five wrappers were based on polyethylene, the others on paper; including a paper-foil laminate.Butter remained Canada First Grade in the interior for the 12-mo period.There was no evidence of serious oxidation on the surface with any wrappers as evidenced by increased peroxides or by description by an expert panel of off-flavors as oxidized.Three wrappers imparted slight off-flavors described variously as cardboard, box, paper, or wrapper.In this experiment, frozen storage for I yr of high quality butter in suitable wrappers resulted in high quality products.The same butter remained high in quality in the interior during storage at 5°C for 14 wk.The surface also remained high in quality with most wrappers.Peroxides did not increase on the surface with any wrappers.However, four paperbased wrappers tended to develop offflavors on the surface, two in particular.These off-flavors were "paper-related", the same as observed after frozen storage, but were more intense; assessments by the graders were sometimes Canada Second Grade.