PHYSICO-CHEMICAL CHARACTERIZATION AND BIOLOGICAL ACTIVITY OF DAUCUS CAROTA CULTIVARS INDIGENOUS TO PAKISTAN

Abstract

In view of escalating awareness and demand for natural products, having antioxidants in the form of vegetables to get foods with medicinal properties, the research on natural antioxidants has achieved remarkable momentum. Daucus carota is among the emerging vegetables with high economic value, due to craving taste and health promoting attributes. It is extensively acknowledged that cultivar and genotype can affect the physico-chemical characteristics and biological activities in fruits and vegetables. The present project was designed to evaluate compositional variations in newly developed cultivars of carrot indigenous to Pakistan. Investigated cultivars proved to be good source of protein, carbohydrates, oil, crude fiber and minerals with significant (ρ < 0.05) variation. The investigated carrot cultivars showed considerable amounts of phenolic acids and carotenoids with remarkable total antioxidant activity, DPPH scavenging capacity, super radical scavenging capacity and hydroxyl radical scavenging capacity. The composition of individual phenolics and sugars compounds was determined using high performance chromatography (HPLC) with diode array and refractive index detectors, respectively. Among phenolic compounds, 5-caffeoylquinic acid was the major hydroxylcinnamic acid, ranging from 6.98 to 33.23 mg/100g of total phenolic compounds. The total amount of phenolic compounds in DCP cultivar was 54.62 mg/100g, where as the corresponding values in other cultivars ranged from 12.8 to 20.29 mg/100g. Maltose was the predominant sugar in all the seven cultivars of D. carota (1.886-2.463 g/100g), followed by fructose (1.103-2.09 g/100g), glucose (0.963-1.395g/100g). The concentration of maltodextrin and maltotriose ranged from 0.166-0.583 g/100g and 0.004-0.058g/100g respectively in all cultivars of D. carota. A pilot study was conducted to evaluate the effect of consuming 250mL carrot juice for one month on cardiovascular risk markers, body mass index (BMI), blood pressure, blood chemistry, blood cells, lipid profile and antioxidant status in industrial workers of different age groups. Drinking carrot juice showed positive effects on blood chemistry, decreased systolic blood pressure and increased plasma antioxidant activity. Overall, the present study explored that investigated carrot cultivars indigenous to Pakistan are the potent source of 16 minerals, carotenoids, natural sugars and phenolic acids with significant biological activities. It is concluded that all the genotyipical different cultivars with compositional variation, having functional and nutraceutical attributes may be beneficial for health conscious consumers.