High Temperature and Humidity Effect on Biochemical Characteristics of Organically-Grown Parsnip Roots Compared to Garlic Bulbs

Functional food with high concentrations of monosaccharides and antioxidants is important for quick replenishment of energy reserves and rehabilitation after intensive oxidant stress. The effect of high temperature and humidity for manufacturing such products from parsnip roots of three cultivars (Zemchug, Krugly, Bely aist) compared to garlic bulbs from cultivar Demidovsky was investigated. The processed parsnip demonstrated higher antioxidant activity than 'black garlic': phenolics (22.6 compared to 13.3 mg-GAE/g d.w.), total antioxidant activity (26.1 compared to 18.1 mg-GAE/g d.w.) and radical scavenging activity (0.24 compared to 0.18 mcM TE/g d.w.). Monosaccharides concentration in parsnip roots increased from 6.5-8.0 to 36.2-42.5 g/100 g d.w., the latter range including the value relevant to the processed garlic (37.4 g/100 g d.w.). Parsnip roots showed concurrent monosaccharides increase and disaccharides decrease (from 33.75-37.2 to 1.25-6.72 g/100 g), whereas garlic displayed the enhancement of both mono- and disaccharide biosynthesis. Total acidity level in processed parsnip also increased by 3 to 5 times and was highly correlated with monosaccharides content (r = 0.99 at P <= 0.01). Thanks to its higher mineral content, 'black parsnip' proved to be suitable for quick energy and antioxidant replenishment after strong physical and/or oxidant stress.