STABILITY STUDIES OF VITAMINS IN 3 FOOD REFERENCE MATERIALS

Stability in storage and shipment of retinol, alpha-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 (CRM384) 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-degrees-C and +4-degrees-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-degrees-C and +4-degrees-C. Long-term storage seems to be possible at a temperature not higher than + 4-degrees-C except for vitamin B2. A short-term stability study at +25-degrees-C and +30-degrees-C for 6 weeks showed acceptable stability of retinol and alpha-tocopherol in milk powder (CRM 380) and of vitamin C in haricot beans (CRM 383). However, storage at +42-degrees-C induces degradation of retinol, alpha-tocopherol and vitamin C.