Vitamin C in Blanched Vegetables: Effect of Chlorine Dioxide and Peracetic Acid Used as Disinfectants during Cooling

摘要

The production of frozen vegetables generally includes a heat treatment (a blanching)nto denaturate cellular enzymes. The water used for cooling after this blanchingnis disinfected to prevent microbial growth and to ensure a microbiologicallynqualitative end product. In this study, the possible influence of the disinfectantsnchlorine dioxide (ClO2) and peracetic acid (PAA) on the vitamin C content of thenprocessed vegetables was investigated. The vitamin C content was measured usingna high-performance liquid chromatography (HPLC) technique coupled with anfluorescence detector. Besides a decrease, resulting from the blanching of the vegetables,na concentration-dependent effect was seen with PAA. This effect was notnnoticed when using lower concentrations, e.g., 30 parts per million (ppm) of PAAnor 3 ppm chlorine dioxide. The major conclusion of our work is about spinachnand we can conclude that it makes no sense to use concentrations higher thann40 ppm of PAA in the cooling water of the blancher since this only results in ansupplementary decrease of the vitamin C content and this without a substantialnadditional antimicrobial effect.