Preliminary Evidences of Biofortification with Iodine of “Carota di Polignano”, An Italian Carrot Landrace

Abstract

The “Carota di Polignano” (Polignano Carrot – PC, Daucus carota L.) is a multi-colored landrace, cultivated in the Southern Italy, whose colors range from yellow to purple. Iodine is an essential micronutrient for humans, since it is a key component of thyroid hormones, which regulate the growth and development of the human body. The main source for iodine assumption is represented by diet, but its concentration in the vegetables is usually limited with respect to human needs. To this purpose, two experimental trials (in open field and in greenhouse with a soil-less system) were carried out to enrich PC with iodine. Three levels of iodine (control treatment, C – 0 mg·L−1; low, L – 50 mg·L−1; and high, H – 500 mg·L−1), distributed with foliar spray fertilizations (in both open field and greenhouse) or with nutrient solution (in greenhouse, at the level of 50 mg·L−1) in the form of KIO3 were compared. In open field, the H treatment showed a biofortification that was double and triple respect to L and C treatments, respectively, without influencing color and biometric parameters, such as the fresh and dry weight of roots and DM percentage. In greenhouse, the biofortification done with foliar spray fertilization followed the same trend of open field, while the biofortification by means of nutrient solution was more effective but reached very high levels that had toxic effects on the plants and could be too high for human nutrition. However, the concentrations of iodine into biofortified carrots in open field can allow to satisfy the recommended daily allowance (RDA) by consuming 100 and 200 g of fresh product for the treatment H and L, respectively. Regarding the greenhouse biofortification, the RDA would be satisfied by consuming 200 g of fresh carrots (with the high level of foliar fertilization).

Hydroponic Production of Reduced-Potassium Swiss Chard and Spinach: A Feasible Agronomic Approach to Tailoring Vegetables for Chronic Kidney Disease Patients

“…A novel challenge in agriculture is the production of tailored foods, i.e., foods specifically suitable for target groups of people with particular nutritional needs. In fact, in recent years, a number of studies have highlighted the possibility of producing vegetables for specific physiological conditions, such as biofortified vegetables, with the aim of counteracting different nutritional deficits [1][2][3][4][5][6][7][8]. In general, these authors reported evidence on the use of specific growing protocols aimed to increase the content of specific nutrients in plant tissues, such as iodine (I), silicon (Si), calcium (Ca), selenium (Se), zinc (Zn), and iron (Fe).…”

Phytochemical Analysis and Antioxidant Properties in Colored Tiggiano Carrots

“…Several Apulian varieties are included in the list of vegetables at risk of genetic erosion [9], which constitutes an issue for the loss of the genetic traits important for the biodiversity and nutritional quality of the varieties [8][9][10]. In the Apulia region, three main ecotypes of colored carrots have been reported, whose names are strictly related to the production areas: Polignano (province of Bari, [11]), Zapponeta, (province of Foggia), and Tiggiano (which also includes Tricase and Specchia villages, in the province of Lecce [12]). Tiggiano carrot cultivation is strongly related to the popular cult of the Saint Ippazio, protector of male virility.…”

Agronomic biofortification as a means of enriching plant foodstuffs with iodine

“…These, in turn, can affect the properties of foodstuffs, its durability and stability [17]. There is also a risk that the concentrations of the substance introduced into the fortified foodstuff will be too high or even potentially harmful [14].…”

“…They show considerable homology to methyltransferases involved in responses to salinity or glucosinolate metabolism, suggesting that methyl iodide production may be a defence mechanism in plants [28]. Literature research indicates that there is no single pattern according to which chemical forms of iodine affect plants [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. Each species will react in a different way, depending on the method of cultivation and application of iodine.…”

“…Iodine doses should be strictly optimized. A high dose of iodine can disturb the normal growth of plants, especially those grown in a soil-less system and pose a threat to human health [14]. Therefore, it is important to find ways to enrich plants with iodine so that they will become a widely consumed and accessible source of iodine in food.…”