Concentration of nutrients and bioactive compounds in chia (Salvia hispanica l.), protein quality and iron bioavailability in Wistar rats

• Ano de defesa: 2016
• Autor(a) principal: Silva, Bárbara Pereira da
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa
• Palavras-chave em Português: Nutrição; Salvia hispanica - Análise; Vitaminas; Caratenoides; Flavonoides; Ácido fítico; Proteínas
• Link de acesso: http://www.locus.ufv.br/handle/123456789/9247

Chia (Salvia hispanica L.) has been consumed by the world population due to their functional properties and high concentration of essential fatty acids, dietary fiber and protein. However, it is necessary to characterize the nutrient concentration in chia seeds grown in Brazil. The present study aimed to analyze the occurrence and concentration of macro and micronutrients, carotenoids, flavonoids, phytic acid and tannin in chia seeds grown in two different places, as well as evaluating the protein quality and bioavailability of iron in the seeds, since studies in this research field are scarce. Chia seeds used were grown in Catuípe, Rio Grande do Sul (RS) and Jaciara, Mato Grosso (MT). The seeds were ground and stored in polyethylene bags covered with foil in a freezer until the moment of analysis. The concentration of moisture, lipids, proteins, carbohydrates, dietary fiber, minerals and total ash present in chia seeds was determined. The carotenoid investigation (lutein and zeaxanthin), vitamin C (ascorbic acid), flavonoids (3-deoxiantocianidins - 3-DXAs, flavones, flavanones) was performed by high-performance liquid chromatography (HPLC) with detection by diode array, while vitamin E analysis (α, , , δ tocopherols and tocotrienol) was made by HPLC with fluorescence detection. The antioxidant capacity, concentration of total phenolics, phytate and tannins were carried out by spectrophotometry. Furthermore, was available in Wistar mice the protein quality of chia seed and chia flour by feed efficiency ratio (FER), protein efficiency ratio (PER), net protein ratio (NPR) and true digestibility (TD) and iron bioavailability was evaluated using the hemoglobin depletion/ repletion method in animals fed with standard diet and high fat diet. For the analysis of compounds present in chia seeds, we used the t test to compare two samples. For statistical analysis of protein quality, data were submitted to ANOVA. The average test groups were compared by Duncan test. The iron bioavailability experiment, to evaluate the differences between the groups on weight gain, CEA, hemoglobin gain and molecular analysis it were performed ANOVA and the Newman Keulls tests. The significance level for all tests was 5%. Data were analyzed using the statistical software SPSS, version 20.0. There were high lipid (31.2 g.100 g -1 , on average), proteins (18.9 g.100 g -1 , on average) and total dietary fiber (35.3 g.100 g -1 , on average) concentrations in chia seeds. The chia that has grown in RS had a higher (p<0.05) concentration of iron, manganese, boron, lead, aluminum, nitrogen and phosphorus. The concentration of total vitamin E in the chia seeds was high (70γ8.4γ μg.100 g -1 and 7024.59 μg.100 g -1 for the seed grown in RS and MT, respectively), being -tocopherol the major component found (7031.51 ± 1β9.54 μg.100 g -1 , on average). The carotenoids were identified only in the chia grown in RS and the occurrence of vitamin C and 3-DXAS was not observed in the chia seed grown in RS and MT. Similar values of total phenolic compounds and phytic acid were observed in the chia seeds (p>0.05). The concentration of tannins was higher (p<0.05) in the seed grown in Mato Grosso (19.08 ±1.08 eq. catequina/g sample) than in the seed grown in Rio Grande do Sul (14.93 ± 0.24 eq. catequina/g sample). Chia grown in RS showed the highest (p<0.05) antioxidant activity (478.2 ± 0.02 μmol TEAC/g sample) compared to that grown in MT. In the study of protein quality it were used chia seeds and chia flour with and without heat treatment. The values of PER, NPR and DV did not differed (p>0.05) among the animals that were fed with chia and were lower than the control group (casein). The animals fed with tests diets showed lower concentrations of glucose, triacylglycerides (TGL) and very low density lipoprotein (VLDL) and higher concentrations of high-density lipoprotein (HDL) (p<0.05) than the control group. The liver weights of animals that were fed with chia seed and chia flour did not differed (p>0.05) and were lower (p<0.05) than the control group. Crypt depth and thickness of intestinal muscle layers were higher (p<0.05) in groups that were fed with chia seed and chia flour. The iron bioavailability experiment of chia flour showed that the animals fed with high fat diet had similar iron bioavailability of chia compared to animals fed with standard diet. The total consumption and iron intake were lower in animals which received high fat diet (p<0.05). Body weight gain, hemoglobin concentrations, hemoglobin gain, hemoglobin regeneration efficiency (HRE%) and biological value of hemoglobin regeneration efficiency (RBV-HRE) did not differed among the experimental groups (p>0.05). The standard diet + chia (SD + C) group showed lower expression of transferrin when compared to the control group (standard diet + ferrous sulfate) (p<0.05). Ferritin expression was lower (p<0.05) in all experimental groups when compared to the control. The peroxisome proliferator-activated receptor-α (PPAR-α) gene expression in animals fed with SD + C was higher than in the control group (p≤0.05). The mRNA expression of duodenal cytochrome b (DcytB) and divalent metal transporter (DMT- 1) was higher (p<0.05) in the high fat diet + chia (HFD + C) group. However, hephaestin expression was lower (p<0.05) in all experimental groups compared to the control group and the gene expression of ferroportin was lower (p<0.05) in the groups fed with chia flour. In conclusion, chia exhibits high concentration of vitamin E, polyunsaturated fatty acids, dietary fiber, antioxidant activity, iron, calcium, manganese and zinc. Moreover, the consumption of chia showed good protein digestibility, hypoglycemic effect, and improved the lipid profile, reduced fat deposition in the liver of animals in a short period of time (28 days), and also promoted alterations in the intestinal tissue, which increased its functionality. Animals fed with high fat diet showed similar iron bioavailability of chia compared to animals fed with standard diet.