Dietary intake, clinical-nutritional status, and homocysteine in hemodialysis subjects: the mediating role of inflammation (NUGE-HD study).

The aim of the present study was to test the hypothesis that inflammation mediates the associations among food intake, clinical-nutritional status, and plasma homocysteine (Hcys) in hemodialysis (HD) subjects. This was a cross-sectional analysis of data on 129 subjects undergoing HD (58.9% male, 61.8 ± 15.5 years of age) from the cohort Nutrition and Genetics on HD outcomes (NUGE-HD study). Sociodemographic, anthropometric, and metabolic data were collected, and food intake was assessed using a quantitative food frequency questionnaire. Plasma C-reactive protein (CRP) was used as an inflammatory marker. Data were analyzed by structural equation modeling. Regarding the direct effects, complex B vitamin intake was negatively associated with body mass index, and diabetes mellitus was positively associated with CRP. Plasma CRP also showed a negative association with Hcys, and the ratio of saturated and polyunsaturated fatty acids intake showed a positive association with Hcys. Regarding indirect effects, the results showed that the relationship between the presence of diabetes mellitus and Hcys is mediated by plasma CRP. In conclusion, the ratio of saturated and polyunsaturated fatty acids had a direct effect on plasma Hcys, whereas inflammation had a direct and mediating effect on the relationship between Hcys and diabetes mellitus in HD subjects. Novelty In end-stage renal disease, CRP influences plasma Hcys directly and also indirectly through its mediating effect. The quantity and quality of dietary fatty acids influence plasma Hcys concentrations in HD subjects.

Effect of a Nutritional Intervention, Based on Transtheoretical Model, on Metabolic Markers and Food Consumption of Individuals Undergoing Hemodialysis.

OBJECTIVE: This study aimed to evaluate the effect of a nutritional intervention, based on the transtheoretical model, on the metabolic markers and dietary intake of individuals undergoing hemodialysis (HD). METHODS: Intervention study at a nephrology clinic includes 83 individuals undergoing HD, over a period of 4 months. The nutritional intervention based on the transtheoretical model was composed of two group meetings and three individual ones, with delivery of personalized food plans and nutritional education activities. Anthropometry, dietary intake, metabolic markers, and stage of behavior change were evaluated before and after nutritional intervention. RESULTS: There was a significant change from the stage of contemplation to the stage of action, after the intervention (P < .001). There was a significant reduction in serum concentrations of creatinine and predialysis and postdialysis urea (P < .001). Hyperphosphataemia and hyperkalemia in the group were also significantly reduced as were markers related to bone metabolism (P < .001). The markers of iron metabolism (P < .001), protein (P = .042), and globulin (P < .001) showed a significant increase. Regarding food consumption, the caloric intakes (P = .034), cholesterol (P = .034), protein, and lipid as well as intake of iron, phosphorus, potassium, copper, and vitamin C (P < .001) were significantly higher after intervention. CONCLUSIONS: The nutritional intervention based on the transtheoretical model promoted a change in the behavior of individuals undergoing HD, with an important improvement in their metabolic control. This can be explained by the significant change in the intake of calories, macronutrients, and micronutrients, as well as adequate use of phosphorus binders, indicating the crucial role of nutrition in this group.

Processed and ultra-processed food consumption are related to metabolic markers in hemodialysis subjects / Consumo de alimentos processados e ultraprocessados está relacionado a marcadores metabólicos em indivíduos em hemodiálise

ABSTRACT Objective To investigate the consumption of processed and ultra-processed foods and evaluate its relationship with the nutritional and metabolic status of hemodialysis patients in a single center in Brazil. Methods This cross-sectional study enrolled 73 individuals in hemodialysis (50 men and 23 women, 21-87 years-old). Clinical and lifestyle variables were assessed by a semi-structured questionnaire and dietary data by food frequency questionnaire. Anthropometric and metabolic data are collected from medical records. Results Processed and ultra-processed foods represented 11.0% of daily caloric intake, 53.0% of trans fatty acid, and 12.5% of salt consumed in the study sample. Individuals who had high intake of this food group (≥128.4g/day, median intake) had higher serum phosphorus and pre-dialysis urea values (p=0.038; p=0.013, respectively). Also, individual with higher consumption of processed meat, sausages and ready prepared food had higher pre-dialysis serum urea (p=0.021), while serum potassium was higher among the subjects who consumed more sauces and salt-based seasonings (p=0.002). Conclusion Higher consumption of processed and ultra-processed foods was associated with important biomarkers of metabolic control for hemodialysis subjects, probably due to non-health dietary composition. Nutritional guidelines and intervention strategies must be promoted to reduce consumption of these food-group in thisspecific population.

RESUMO Objetivo Investigar o consumo de alimentos processados e ultraprocessados e avaliar sua relação com o estado nutricional e metabólico de pacientes em hemodiálise em um único centro brasileiro. Métodos Este é um estudo transversal com 73 indivíduos em hemodiálise (50 homens e 23 mulheres, 21-87 anos de idade). As variáveis clínicas e de estilo de vida foram avaliados por um questionário semi-estruturado, bem como dados dietéticos por questionário de frequência alimentar. Dados antropométricos e metabólicos foram coletados de registros médicos. Resultados Os alimentos processados e ultraprocessados representaram 11,0% das calorias diárias, 53,0% dos ácidos graxos trans e 12,5% de sódio consumido na amostra estudada. Os indivíduos que tiveram alta ingestão deste grupo alimentar (≥128,4 g/dia, ingestão mediana) apresentaram maiores valores de fósforo sérico e uréia pré-diálise (p=0,038; p=0,013, respectivamente). Também, indivíduos com maior consumo de carne processada, embutidos e refeições prontas apresentaram maior ureia sérica pré-diálise (p=0,021), enquanto o potássio sérico foi maior entre os indivíduos que consumiram mais molhos e temperos á base de sal (p=0,002). Conclusão O maior consumo de alimentos processados e ultraprocessados foi associado a importantes biomarcadores de controle metabólico para indivíduos em hemodiálise, provavelmente devido à composição dietética não saudável. Orientações nutricionais e estratégias de intervenção devem ser promovidas para reduzir o consumo desses alimentos nessa população específica.

Processed and ultra-processed food consumption are related to metabolic markers in hemodialysis subjects / Consumo de alimentos processados e ultraprocessados está relacionado a marcadores metabólicos em indivíduos em hemodiálise

ABSTRACT Objective To investigate the consumption of processed and ultra-processed foods and evaluate its relationship with the nutritional and metabolic status of hemodialysis patients in a single center in Brazil. Methods This cross-sectional study enrolled 73 individuals in hemodialysis (50 men and 23 women, 21-87 years-old). Clinical and lifestyle variables were assessed by a semi-structured questionnaire and dietary data by food frequency questionnaire. Anthropometric and metabolic data are collected from medical records. Results Processed and ultra-processed foods represented 11.0% of daily caloric intake, 53.0% of trans fatty acid, and 12.5% of salt consumed in the study sample. Individuals who had high intake of this food group (≥128.4g/day, median intake) had higher serum phosphorus and pre-dialysis urea values (p=0.038; p=0.013, respectively). Also, individual with higher consumption of processed meat, sausages and ready prepared food had higher pre-dialysis serum urea (p=0.021), while serum potassium was higher among the subjects who consumed more sauces and salt-based seasonings (p=0.002). Conclusion Higher consumption of processed and ultra-processed foods was associated with important biomarkers of metabolic control for hemodialysis subjects, probably due to non-health dietary composition. Nutritional guidelines and intervention strategies must be promoted to reduce consumption of these food-group in thisspecific population.

RESUMO Objetivo Investigar o consumo de alimentos processados e ultraprocessados e avaliar sua relação com o estado nutricional e metabólico de pacientes em hemodiálise em um único centro brasileiro. Métodos Este é um estudo transversal com 73 indivíduos em hemodiálise (50 homens e 23 mulheres, 21-87 anos de idade). As variáveis clínicas e de estilo de vida foram avaliados por um questionário semi-estruturado, bem como dados dietéticos por questionário de frequência alimentar. Dados antropométricos e metabólicos foram coletados de registros médicos. Resultados Os alimentos processados e ultraprocessados representaram 11,0% das calorias diárias, 53,0% dos ácidos graxos trans e 12,5% de sódio consumido na amostra estudada. Os indivíduos que tiveram alta ingestão deste grupo alimentar (≥128,4 g/dia, ingestão mediana) apresentaram maiores valores de fósforo sérico e uréia pré-diálise (p=0,038; p=0,013, respectivamente). Também, indivíduos com maior consumo de carne processada, embutidos e refeições prontas apresentaram maior ureia sérica pré-diálise (p=0,021), enquanto o potássio sérico foi maior entre os indivíduos que consumiram mais molhos e temperos á base de sal (p=0,002). Conclusão O maior consumo de alimentos processados e ultraprocessados foi associado a importantes biomarcadores de controle metabólico para indivíduos em hemodiálise, provavelmente devido à composição dietética não saudável. Orientações nutricionais e estratégias de intervenção devem ser promovidas para reduzir o consumo desses alimentos nessa população específica.

Dietary intake as a predictor for all-cause mortality in hemodialysis subjects (NUGE-HD study).

This study aimed to identify the factors capable of mortality prediction in patients on hemodialysis, using a prospective cohort with three years of follow-up. We hypothesized that lack of clinical-metabolic control, impairment of nutritional status, and inadequate food consumption are risk factors for mortality in this population. This is a longitudinal study on a non-probabilistic sample of 85 adults and elderly patients undergoing hemodialysis, aged ≥ 18 years (66.0% male, 61.6±13.7 years). Data on anthropometric, biomarkers, body composition and food intake were obtained. Predictors of mortality were evaluated using Cox regression analysis. During the three years follow-up, 16 patients (18.8%) died. We observed that age (HR = 1.319, CI 95% = 1.131-1.538), calcium-phosphorus product (HR = 1.114, CI 95% = 1.031-1.205), ferritin (HR = 1.001, CI 95% = 1.001-1.002), nitric oxide (HR = 1.082, CI 95% = 1.006-1.164), and vitamin C intake (HR = 1.005, CI 95% = 1.001-1.009) were positively associated with mortality. Serum iron (HR = 0.717, CI 95% = 0.567-0.907), triceps skinfold thickness (HR = 0.704, CI 95% = 0.519-0.954), lean mass (HR = 0.863, CI 95% = 0.787-0.945), and the ratio of dietary monounsaturated/polyunsaturated fat (HR = 0.022, CI 95% = 0.001-0.549) were independent negative predictors of mortality. Our results suggest that dietary intake is also a predictor of mortality in patients on hemodialysis, besides nutritional status, body composition, oxidative stress, inflammation, and bone metabolism, indicating the importance of evaluation of these factors altogether for better prognosis.

Modulation of intestinal microbiota, control of nitrogen products and inflammation by pre/probiotics in chronic kidney disease: a systematic review.

Dysbiosis may favor the occurrence of inflammation and oxidative stress in chronic kidney disease (CKD). It has been suggested that the intake of pre/probiotics may control the progression of chronic kidney disease. Thus, the objective of this study was to systematically review the literature on the effects of pre/probiotic intake on the intestinal microbiota, control of nitrogen products, oxidative stress, and inflammation in CKD patients.The literature search was conducted on MEDLINE, LILACS, Cochrane Library of Clinical Trials, and Science Direct. After careful evaluation by the reviewers, ten potentially relevant articles were selected for this study. Based on previous studies, intake of prebiotics appears to have the following effects: increased bifidobacteria and lactobacillus counts; reduced formation of uremic toxin, p-cresol, and its serum concentrations; improved lipid profiles; reduced systemic inflammatory state and concentrations of oxidative stress markers. Similarly, consumption of probiotics can reduce blood urea and serum phosphate concentrations. Furthermore, an increase in fecal volume and intestinal Bifidobacteriumand a reduction in p-cresol serum and blood urea concentrations were observed in response to symbiotic intake. These results suggest that consumption of pre/probiotics may modulate the intestinal microbiota, and promote the growth and metabolism of anaerobic bacteria by decreasing the production of uremic solutes, further causing oxidative stress and systemic inflammation in CKD patients.

Polymorphism related to cardiovascular risk in hemodialysis subjects: a systematic review.

Cardiovascular disease (CVD) is one of the leading causes of mortality in hemodialysis (HD) subjects. In addition to the traditional risk factors that are common in these individuals, genetic factors are also involved, with emphasis on single nucleotide polymorphs (SNPs). In this context, the present study aims to systematically review the studies that investigated the polymorphisms associated with cardiovascular risk in this population. In general, the SNPs present in HD individuals are those of genes related to inflammation, oxidative stress and vascular calcification, also able of interfering in the cardiovascular risk of this population. In addition, polymorphisms in genes related to recognized risk factors for CVD, such as dyslipidemia, arterial hypertension and left ventricular hypertrophy, also influence cardiovascular morbidity and mortality.

Modulation of intestinal microbiota, control of nitrogen products and inflammation by pre/probiotics in chronic kidney disease: a systematic review / Modulación de microbiota intestinal, control de productos de nitrógeno e inflamación por pre/probióticos en la enfermedad renal crónica: una revisión sistemática

Dysbiosis may favor the occurrence of inflammation and oxidative stress in chronic kidney disease (CKD). It has been suggested that the intake of pre/probiotics may control the progression of chronic kidney disease. Thus, the objective of this study was to systematically review the literature on the effects of pre/probiotic intake on the intestinal microbiota, control of nitrogen products, oxidative stress, and inflammation in CKD patients.The literature search was conducted on MEDLINE, LILACS, Cochrane Library of Clinical Trials, and Science Direct. After careful evaluation by the reviewers, ten potentially relevant articles were selected for this study. Based on previous studies, intake of prebiotics appears to have the following effects: increased bifidobacteria and lactobacillus counts; reduced formation of uremic toxin, p-cresol, and its serum concentrations; improved lipid profiles; reduced systemic inflammatory state and concentrations of oxidative stress markers. Similarly, consumption of probiotics can reduce blood urea and serum phosphate concentrations. Furthermore, an increase in fecal volume and intestinal Bifidobacteriumand a reduction in p-cresol serum and blood urea concentrations were observed in response to symbiotic intake. These results suggest that consumption of pre/probiotics may modulate the intestinal microbiota, and promote the growth and metabolism of anaerobic bacteria by decreasing the production of uremic solutes, further causing oxidative stress and systemic inflammation in CKD patients

La disbiosis puede favorecer la incidencia de inflamación y de estrés oxidativo en enfermedades renales crónicas. Se ha sugerido que el consumo de prebióticos y probióticos puede controlar la progresión de enfermedades renales crónicas. De este modo, el objetivo de este estudio es revisar sistemáticamente la literatura sobre los efectos del consumo de prebióticos y probióticos en la microbiota intestinal, el control de los productos de nitrógeno, el estrés oxidativo y la inflamación en enfermedades renales crónicas. La búsqueda bibliográfica fue realizada por medio de MEDLINE, LILACS, Cochrane Library of Clinical Trials y Science Direct. Diez artículos fueron incluidos en este estudio. Los prebióticos parecen aumentar las bifidobacterias y el recuento de lactobacillus, reducir la formación de toxina urémica, p-cresol y su concentración sérica; mejorar los perfiles lipídicos y reducir el estado de inflamación sistémica y la concentración de indicadores de estrés oxidativo. El consumo de probióticos puede reducir la urea en sangre y la concentración de fosfato sérico. Se verificó el aumento del volumen fecal y de las bifidobacterias intestinales y la reducción de la concentración sérica de p-cresol y de urea en sangre en respuesta a la ingesta de simbióticos. Estos resultados indican que los prebióticos y probióticos modulan la microbiota intestinal y promueven el crecimiento del metabolismo de bacterias anaerobias, disminuyendo la producción de solutos urémicos y la incidencia de estrés oxidativo e inflamación sistémica en pacientes portadores de enfermedades renales crónicas

Polymorphism related to cardiovascular risk in hemodialysis subjects: a systematic review / Polimorfismos associados ao risco cardiovascular em indivíduos em hemodiálise: uma revisão sistemática

ABSTRACT Cardiovascular disease (CVD) is one of the leading causes of mortality in hemodialysis (HD) subjects. In addition to the traditional risk factors that are common in these individuals, genetic factors are also involved, with emphasis on single nucleotide polymorphs (SNPs). In this context, the present study aims to systematically review the studies that investigated the polymorphisms associated with cardiovascular risk in this population. In general, the SNPs present in HD individuals are those of genes related to inflammation, oxidative stress and vascular calcification, also able of interfering in the cardiovascular risk of this population. In addition, polymorphisms in genes related to recognized risk factors for CVD, such as dyslipidemia, arterial hypertension and left ventricular hypertrophy, also influence cardiovascular morbidity and mortality.

RESUMO A doença cardiovascular (DCV) é uma das principais causas de mortalidade de indivíduos em hemodiálise (HD). Além dos fatores de risco tradicionais, que são frequentes nesses indivíduos, também estão envolvidos fatores genéticos, com destaque para os polimorfismos de nucleotídeo único (do inglês, single nucleotide polymorphism, SNP). O presente trabalho tem como objetivo revisar sistematicamente os estudos que investigaram os polimorfismos associados ao risco cardiovascular nessa população. De modo geral, os SNPs presentes em indivíduos em HD são aqueles de genes relacionados à inflamação, estresse oxidativo e calcificação vascular, também capazes de interferir no risco cardiovascular dos pacientes. Polimorfismos em genes relacionados a fatores de risco reconhecidos para DCV, como dislipidemia, hipertensão arterial e hipertrofia ventricular esquerda, também influenciam a morbidade e mortalidade cardiovascular.

Clinical-nutritional, inflammatory and oxidative stress predictors in hemodialysis mortality: a review.

The evaluation of clinical-nutrition status is essential to increase life quality and improve clinical outcomes of patients in hemodialysis (HD). In the absence of a gold standard, the goal of this integrative review was to present and discuss the latest scientific literature on the ability of clinical-nutritional indicators and inflammatory and oxidative stress markers to predict morbidity and mortality in HD. In this context, the lean and fat mass indexes have become good predictors of mortality in HD individuals, regardless of BMI. Subjective scoring systems have been more sensitive to malnutrition, and altogether anthropometric indicators may result in an early detection of mortality risk in this population. On the other hand, inflammation in HD, as assessed by C-reactive protein, is not only related to cardiometabolic alterations, but it is also one of the key-points in the development of malnutrition, exacerbated by the state of oxidative stress, which has been identified in this group by the increase of the serum levels of gamma-glutamyl transferase and malondialdehyde.

Metabolic, inflammatory and oxidative stress markers in the nitric oxide variation of hemodialysis subjects.

INTRODUCTION: Oxidative stress markers such as nitric oxide (NO) have been investigated in hemodialysis (HD). OBJECTIVE: Evaluate the association of NO variation with adiposity indicators, metabolic, inflammatory and oxidative stress markers in individuals to HD. METHODS: Cross-sectional study with 85 subjects on HD treatment (≥ 18 years). The clinical-nutritional status was evaluated through subjective global assessment modified (SGAm), anthropometric measurements and body composition. Dietary intake was evaluated using a food frequency questionnaire. Metabolic markers were obtained from medical records. Inflammatory markers (IL-6 and IL-10) and oxidative stress, (TACs), (SOD), (GST), (MDA) and NO were determined using standardized protocols. RESULTS: Those individuals with a high concentration of NO (> 4.32 µmol/L) had lower values for SGAm score (p = 0.012) and higher iron values (p = 0.050), Fe saturation (p = 0.037) and triacylglycerol (p = 0.003). The same subjects still had lower consumption of copper (p = 0.026), manganese (p = 0.035), vitamin E (p = 0.050), ω3 (p = 0.021) and ω6 (p = 0.020). In a multiple regression model, concentrations of ferritin, triacylglycerol, IL6 and SOD contributed to a 54.8% increase in NO concentrations, whereas triacylglycerol and SOD concentrations were independent factors for NO variation (p < 0.001). CONCLUSIONS: The clinical and nutritional status as well as intake of nutrients with antioxidant properties (Cu, Zn, Mn, vitamin C and ω3) appears to modulate the variation of NO in this population.

Metabolic, inflammatory and oxidative stress markers in the nitric oxide variation of hemodialysis subjects / Marcadores de estrés metabólico, inflamatorio y oxidativo en la variación del óxido nítrico de los individuos de hemodiálisis

Introduction: Oxidative stress markers such as nitric oxide (NO) have been investigated in hemodialysis (HD). Objective: Evaluate the association of NO variation with adiposity indicators, metabolic, inflammatory and oxidative stress markers in individuals to HD. Methods: Cross-sectional study with 85 subjects on HD treatment (≥ 18 years). The clinical-nutritional status was evaluated through subjective global assessment modified (SGAm), anthropometric measurements and body composition. Dietary intake was evaluated using a food frequency questionnaire. Metabolic markers were obtained from medical records. Inflammatory markers (IL-6 and IL-10) and oxidative stress, (TACs), (SOD), (GST), (MDA) and NO were determined using standardized protocols. Results: Those individuals with a high concentration of NO (> 4.32 μmol/L) had lower values for SGAm score (p = 0.012) and higher iron values (p = 0.050), Fe saturation (p = 0.037) and triacylglycerol (p = 0.003). The same subjects still had lower consumption of copper (p = 0.026), manganese (p = 0.035), vitamin E (p = 0.050), ω3 (p = 0.021) and ω6 (p = 0.020). In a multiple regression model, concentrations of ferritin, triacylglycerol, IL6 and SOD contributed to a 54.8% increase in NO concentrations, whereas triacylglycerol and SOD concentrations were independent factors for NO variation (p < 0.001). Conclusions: The clinical and nutritional status as well as intake of nutrients with antioxidant properties (Cu, Zn, Mn, vitamin C and ω3) appears to modulate the variation of NO in this population (AU)

Introducción: se han investigado marcadores de estrés oxidativo como el óxido nítrico (NO) en hemodiálisis (HD). Objetivo: evaluar la asociación de la variación del NO con los indicadores de adiposidad, los marcadores metabólicos, inflamatorios y de estrés oxidativo en individuos a HD. Métodos: estudio transversal con 85 sujetos en tratamiento HD (≥ 18 años). El estado clínico-nutricional se evaluó a través de la evaluación global subjetiva modificada (SGAm), medidas antropometricas y composición corporal. La ingesta dietética se evaluó mediante un cuestionario de frecuencia alimentaria. Marcadores metabólicos se obtuvieron de los registros médicos. Se determinaron marcadores inflamatorios (IL-6 e IL-10) y estrés oxidativo (TAC), (SOD), (GST), (MDA) y NO mediante protocolos estandarizados. Resultados: los individuos con una alta concentración de NO (> 4,32 μmol/L) tuvieron valores más bajos de puntuación de SGAm (p = 0,012) y mayores valores de hierro (p = 0,050), saturación de Fe (p = 0,037) y triacilglicerol (p = 0,003). Los mismos sujetos tuvieron un menor consumo de cobre (p = 0.026), manganeso (p = 0,035), vitamina E (p = 0,050), ω3 (p = 0,021) y ω6 (p = 0,020). En un modelo de regresión múltiple, las concentraciones de ferritina, triacilglicerol, IL6 y SOD contribuyeron a un aumento de 54,8% en las concentraciones de NO, mientras que las concentraciones de triacilglicerol y SOD fueron factores independientes para la variación del NO (p < 0,001). Conclusiones: el estado clínico y nutricional así como la ingesta de nutrientes con propiedades antioxidantes (Cu, Zn, Mn, vitamina C y ω3) parecen modular la variación del NO en esta población (AU)

Avaliação da estabilidade da capacidade antioxidante e de parâmetros físico-químicos de néctares de frutas caseiros / Assessment of the antioxidant capacity and of the physicalchemicalsparameters stability in homemade fruit nectars

Este estudo avaliou a capacidade antioxidante e os indicadores físico-químicos de néctares caseirosde laranja, manga e maracujá, mantidos sob refrigeração (5 ± 2 oC) por 24 horas. Os néctaresforam preparados em laboratório e mantidos sob refrigeração, simulando as condições domésticas.As análises foram realizadas após o preparo (T0) e durante o acondicionamento sob refrigeração(1 h, 4 h e 24 h). Os sólidos solúveis, pH e cor foram determinados respectivamente por refratometria,potenciometria e colorimetria. Carotenoides e ácido ascórbico foram analisados por cromatografialíquida de alta eficiência; a concentração de compostos fenólicos foi determinada utilizando-seo reagente de Folin Ciocalteau e a atividade antioxidante pelo teste do DPPH. Ácido ascórbico,β-caroteno e compostos fenólicos foram identificados em todos os néctares. Foram encontradosα-caroteno e β-criptoxantina no néctar de laranja e licopeno no néctar de manga. Durante 24 horasde refrigeração, os compostos analisados e a atividade antioxidante mantiveram-se estáveis. De formageral, os parâmetros físico-químicos também se mantiveram estáveis durante o período avaliado.Em conclusão, sob as condições utilizadas no presente estudo, os néctares não apresentaramalteração da capacidade antioxidante, podendo ser considerados fontes de carotenoides e vitamina C,mesmo se consumidos após 24 horas de preparo.

The objective of the study was to evaluate the antioxidant capacity and the physical-chemicalindicators of homemade nectars of orange, mango and passion fruit, kept under refrigeration(5 ± 2 °C) for 24 hours. The nectars were prepared in laboratory and kept under refrigerationsimulating the domestic conditions. The samples analyses were performed after their preparations(T0) and during the refrigerated storage (1 h, 4 h and 24 h). Soluble solids, pH and color weredetermined by refractometry, colorimetry and potentiometry, respectively. Carotenoids andascorbic acid were analyzed by high performance liquid chromatography, the concentrationof phenolic compounds were determined by using Folin Ciocalteau reagent, and the antioxidantactivity by the DPPH test. Ascorbic acid, β-carotene and phenolic compounds were identified inall of the analyzed nectars samples. The α-carotene and β-cryptoxanthin were found in orangenectar and the lycopene in mango nectar samples. During the refrigeration for 24 hours,the analyzed compounds and the antioxidant activity remained stable. In general, thephysical-chemicals parameters also remained stable during the storage for 24 hours. In conclusion,under the conditions used in this study, the nectars might be considered as antioxidant sources,even if consumed after being prepared 24 hours before.

Avaliação da estabilidade da capacidade antioxidante e de parâmetros físico-químicos de néctares de frutas caseiros / Assessment of the antioxidant capacity and of the physicalchemicals parameters stability in homemade fruit nectars

Este estudo avaliou a capacidade antioxidante e os indicadores físico-químicos de néctares caseiros de laranja, manga e maracujá, mantidos sob refrigeração (5 ± 2 o C) por 24 horas. Os néctares foram preparados em laboratório e mantidos sob refrigeração, simulando as condições domésticas. As análises foram realizadas após o preparo (T0) e durante o acondicionamento sob refrigeração (1 h, 4 h e 24 h). Os sólidos solúveis, pH e cor foram determinados respectivamente por refratometria, potenciometria e colorimetria. Carotenoides e ácido ascórbico foram analisados por cromatografia líquida de alta eficiência; a concentração de compostos fenólicos foi determinada utilizando-se o reagente de Folin Ciocalteau e a atividade antioxidante pelo teste do DPPH. Ácido ascórbico, β-caroteno e compostos fenólicos foram identificados em todos os néctares. Foram encontrados α-caroteno e β-criptoxantina no néctar de laranja e licopeno no néctar de manga. Durante 24 horas de refrigeração, os compostos analisados e a atividade antioxidante mantiveram-se estáveis. De forma geral, os parâmetros físico-químicos também se mantiveram estáveis durante o período avaliado. Em conclusão, sob as condições utilizadas no presente estudo, os néctares não apresentaram alteração da capacidade antioxidante, podendo ser considerados fontes de carotenoides e vitamina C, mesmo se consumidos após 24 horas de preparo.

The objective of the study was to evaluate the antioxidant capacity and the physical-chemical indicators of homemade nectars of orange, mango and passion fruit, kept under refrigeration (5 ± 2 °C) for 24 hours. The nectars were prepared in laboratory and kept under refrigeration simulating the domestic conditions. The samples analyses were performed after their preparations (T0) and during the refrigerated storage (1 h, 4 h and 24 h). Soluble solids, pH and color were determined by refractometry, colorimetry and potentiometry, respectively. Carotenoids and ascorbic acid were analyzed by high performance liquid chromatography, the concentration of phenolic compounds were determined by using Folin Ciocalteau reagent, and the antioxidant activity by the DPPH test. Ascorbic acid, β-carotene and phenolic compounds were identified in all of the analyzed nectars samples. The α-carotene and β-cryptoxanthin were found in orange nectar and the lycopene in mango nectar samples. During the refrigeration for 24 hours, the analyzed compounds and the antioxidant activity remained stable. In general, the physical-chemicals parameters also remained stable during the storage for 24 hours. In conclusion, under the conditions used in this study, the nectars might be considered as antioxidant sources, even if consumed after being prepared 24 hours before.