S0022029921000741jra 468..474

The work reported in this paper addresses the iodine nutritional deficiency that still affects a large number of people. For this purpose, we analyzed the possibility to use, as iodine vehicle, a hard typical ewe cheese, called Canestrato d’Abruzzo, derived from milk of ewes fed with an iodine-fortified diet. Both in the milk and the cheese of these animals, the iodine level was higher than that measured in sheep with a normal diet. An increase in the lactoferrin and iron content was evident in the whey derived from milk of the iodine group. Furthermore, in derived cheese, the caseins seemed more efficiently transformed in small peptides making the product more digestible and, for this reason, particularly suitable for feeding the elderly. In conclusion, the dairy products obtained from ewes fed with iodine diet contain more bioactive compounds so that they represent a useful food to prevent iodine and iron deficiency in lamb and humans. Iodine is an essential constituent in the synthesis of thyroid hormones triiodothyronine (T3) and thyroxine (T4) which regulate cellular metabolic processes, playing a vital role in organ development including the brain (Zimmermann, 2011). Consequently, any dietary deficiency of this microelement is a public health problem (WHO, 2004). Newborns are more at risk (Nazeri et al., 2015) and since breast milk is the only source of iodine for them, the maternal deficiency of this element in the postpartum period could affect the neonatal neuro-psycho-intellectual development (Chan et al., 2004). The adult human body contains 10–20 mg of iodine, mainly in organic form, the steady state of which derives from dietary intake. Iodine is easily absorbed in the small intestine and transported, in iodide form, to tissues, mainly the thyroid gland. The recommended daily intake of this micronutrient is 150 μg for adolescents and adults and 250 μg for pregnant and lactating mothers (Koukkou et al., 2017). Iodine is differently distributed in the soil and therefore in foods. In many areas, especially mountainous regions, the ingestion levels of this trace element are not sufficient to prevent signs of deficiency in the population. In addition, the consumption of particular diets (including a vegetarian diet) can lead to deficiencies of iodine, even in areas where fishery products normally account for the recommended daily intake of this element (Katagiri et al., 2015; Trøan et al., 2015; Elorinne et al., 2016). Seafood, together with milk and dairy products, account for 80% of the daily requirement of iodine and the dairy contribution reaches an average 55–70% of the daily iodine intake particularly in inland areas in which the consumption of fish products is often lower (Trøan et al., 2015). This high percentage derives also from the possibility to reinforce cattle feed with iodide that exhibits a high transfer from the diet to the milk. The milk iodine content is influenced by various factors, primarily iodine intake by the animal (Franke et al., 2009) but seasonality, lactation stage and milk yield as well as post-harvest milk processing all play an important role (Norouzian, 2011; Flachowsky et al., 2014). Although not as well studied as in humans, iodine deficiency is also dangerous for animal health and welfare (Hetzel and Mano, 1989) impairing their reproductive performance and affecting perinatal mortality of offspring (Ferri et al., 2003). Sheep have been used for extensive studies on iodine deficiency because they are convenient models for the study of maternal −fetal function (Ferri et al., 2003) and, as reported by Potter et al. (1982), iodine deficiency in sheep feed affects the development of the sheep fetus. The first estimate of the amount of iodine required for farm animals dates back to 1937. This work served as the basis for the study published by Underwood and Shuttle (1999), which defined the minimum quantity of iodine, in food dry matter, for feeding farm animals. For pigs, poultry and sheep the daily requirement of this element is between 0.05 and 0.10 mg per kg of body weight. Iodine enrichment of animal feed represents a method successfully tested in Scandinavia for both animal and human prevention of iodine deficiency (Hetzel and Welby, 1997). The aim of the present study was to ascertain whether the feeding of lactating ewes with an iodine enriched diet would modify the chemical and biochemical composition of milk and/or dairy products, and in particular their protein profile. We conducted a two-month study on two flocks of ewes. The first received a traditional feed while the second a diet enriched of iodine. During the experimental period the pooled milks were tested. Then we analyzed the compositional evolution during ripening of a hard typical ewe cheese called Canestrato d’Abruzzo derived from both groups. We investigated the diet effect on iron content and on the antibacterial protein lactoferrin in the ewes and finally we studied the casein proteolysis process in fresh and ripening cheeses. Materials and methods.