The impact of thermal and non-thermal processing on the phytochemical characteristics and nutritional value of Daucus carota (carrots)

Carrots (Daucus carota L.) are rich in vitamins, minerals, and other essential nutrients playing an important role in the human diet contributing both nutritive and functional properties to enhance health. The current study evaluated the phytochemical characteristics and nutritional content of carrots that have been exposed to various thermal and non thermal processing methods. Various processing methods, inclusive of cooking, steaming, and freezing, were applied to the carrots after which they were analyzed for primary and secondary metabolites, vitamins C, B9 and B12 content, photosynthetic pigments, carotenoids, antioxidant capacity, and other nutrients present. The results revealed that carbohydrate levels within the carrots was reduced, especially in fresh refrigerated samples (15.65 mg/mL). The levels of phenolic compounds within the carrots however remained consistent. The levels of vitamin C, B12 and B9 declined in the boiled carrot samples (0.20, 21.70, 21.61 mg/mL, respectively), but remained consistent in the fresh carrots (0.37, 35.84, 32.38 mg/mL). There was an observed increase in the carotenoid content of boiled and frozen carrots (0.06, 0.14 mg/mL), whereas fresh carrots contained lower levels of carotenoids. No significant changes were observed in the total mineral content of carrots that were subject to further processing. Fresh and steamed carrot samples (59.37, 90.62 %) exhibited higher antioxidant properties as compared to carrots that were subjected to further thermal processing. Low temperature preservation (cold storage and freezing) appears to be more effective in preserving the nutritional composition of carrots as compared to thermal processing. Of the processing methods investigated, steaming demonstrated superior efficacy in maintaining antioxidant properties and minimizing vitamin and carbohydrate loss. Further research is required to further evaluate other non-thermal processing methods and their potential impact on the overall nutritional quality of carrots and other vegetables.