Abstract:Objective: some previous works have shown the importance of zinc in nutrition, and even evaluated different zinc sources for food supplementation with this micronutrient. The aim of this work was to evaluate zinc gluconate stabilized with glycine (BZ) as a zinc source for food fortification by employing yogurt as the vehicle and zinc sulfate (SZ) as the standard zinc source. Materials and methods: weaned Sprague Dawley rats were separated in 7 groups of 10 rats each, which were fed with diets according to the scheme: Group 1-2ppm Zn; Groups 2, 3 and 4 -9, 20 and 34 ppm Zn as SO 4 Zn.7H 2 O (SZ) and Groups 5, 6 and 7 -9, 20 and 34 ppm Zn as zinc gluconate stabilized with glycine (BZ) during 21 days. Zinc sources were provided in a vehicle as yogurt, added in the final diet at 10%. Body weight gain, femur weight and femur zinc content were evaluated at the end of the treatments in order to determine zinc bioavailability, as previously described by others. In this way, body weight gain and femur weight were analyzed by a non linear regression according to equation: Y = Ymax (1-e (-kX) ) and femur zinc content was analyzed by a linear regression, all of them as a function of dietary zinc from each source. Results: relative zinc bioavailability of BZ was 0.95; 0.95 and 1.10 according to body weight gain, femur weight and femur zinc content, respectively. Conclusion: zinc gluconate stabilized with glycine may be considered as a suitable source of zinc for food fortification in a yogurt matrix.

Objective: In this study, we evaluated zinc gluconate stabilized with glycine (GZ) and sulfate (SZ) in fermented milk as vehicle. Zinc bioavailability was evaluated in an animal model (Sprague Dawley rats) for both zinc sources in the vehicle with a probiotic (Lactobacillus casei DN114001).Results: For growth parameters, higher weight gain and femur weight values were observed when probiotic and zinc were provided together, independent of the source (weight gain: SZ 81.4g±4.0g; GZ 81.8g±4.0g and 70.2g±12.5g without the probiotic; femur weight: SZ 0.51g ±0.05g; GZ 0.52g±0.05g and 0.42g±0.03g without the probiotic). Femur zinc content was higher for zinc gluconate stabilized with glycine in the presence of the probiotic (97.04ppm±8.40ppm), and the results were similar for zinc sulfate with or without probiotic (84.51ppm±2.44ppm and 84.94ppm±2.28ppm, respectively). Serum antioxidant capacity and immune cellular response were also evaluated by using free radical scavenging assays and a T cell proliferation assay respectively. The free radical scavenging assay showed a tendency to increase with zinc provision, and the highest proliferation index was observed for glycine-stabilized zinc gluconate and the probiotic. Conclusion:The results indicate that the combination of zinc (as glycine-stabilized zinc gluconate) and a probiotic may be beneficial for the evaluated parameters.

The aim of this work was to determine the effects of a new mineral mix combined with a prebiotic on growth, mineral deposit and intestinal microflora using a milk-like vehicle. This study was performed with Sprague Dawley female rats separated into 7 groups. Group 1 was fed with a deficient diet on its mineral content, group 2, 3 and 4 were fed with normal diets on their mineral content during 28 days but group 2 was fed with a diet containing reference Ca, Fe and Zn sources and groups 3 and 4 with diets containing other Ca, Fe and Zn sources that were evaluated. Group 4 received additionally a diet containing a prebiotic. Groups 5, 6 and 7 were submitted to a depletion period of 14 days during which they were fed as group 1 and then to a repletion period of 14 days when they were fed with the same diets as group 2, 3 and 4 respectively. Initial and final body weight, average growth rate, liver and femur weight, iron and zinc liver content as well as calcium and zinc femur content were the parameters evaluated for the growth and mineral deposit analysis. Anaerobes, enterobacteria, lactobacilli and bifidobacteria recount was performed from feces samples collected on different treatment days. Mineral sources under study presented slightly better characteristics than the reference standard ones. Moreover, the combination with a prebiotic may produce some advantages related to mineral absorption and intestinal microflora composition as a bifidogenic effect was confirmed.