Stability studies of vitamins in three food reference materials

Summary Stability in storage and shipment of retinol, -tocopherol, vitamins B₁, B₂ and C in three foods was studied to assess the feasibility of certifying the vitamin content of three food RMs, whole milk powder (CRM 380), pork muscle (CRM 384) and freeze-dried haricot beans (CRM 383); these were recently certified for major dietary components and major elements. Interpretation of the long-term stability data was complicated by a dominant analytical variability over the measurement period. The long-term stability study (24 months) gave evidence of deterioration of vitamin B₂ in pork muscle. The other vitamins studied seemed to be acceptably stable at –18°C and +4°C. Additional studies showed stability of retinol in milk powder for 34 months and of vitamin C in haricot beans for 31 months at –18°C and +4°C. Long-term storage seems to be possible at a temperature not higher than +4°C except for vitamin B₂. A short-term stability study at +25°C and +30°C for 6 weeks showed acceptable stability of retinol and -tocopherol in milk powder (CRM 380) and of vitamin C in haricot beans (CRM 383). However, storage at +42°C induces degradation of retinol, -tocopherol and vitamin C.