Archivos Latinoamericanos de Nutrición

Evolución de los precios de los alimentos y nutrimentos en México entre 1973 Y 2004

El objetivo del estudio fue conocer los cambios en los precios de los alimentos y ciertos nutrimentos en México durante las últimas tres décadas. Para ello, se analizaron los datos del Índice Nacional de Precios al Consumidor de 1973 a 2003, así como las cotizaciones de los alimentos que se utilizan para su cálculo en los años 1990, 1995, 2000 y 2004. Se estimó el costo de 100 kcal, 10 g de grasa saturada, 100 mg de colesterol, 10 g de fibra y 1 mg de hierro. Mediante modelos de regresión se analizó la asociación del costo de los nutrimentos y la energía con las densidades nutrimental y energética. Los resultados permiten inferir que, en México, la estructura de precios de los alimentos en la década de los ochentas fue diferente a la de los noventas, de modo tal que en la primera las verduras y los productos derivados de maíz y trigo fueron los alimentos que tuvieron menos incrementos en su precio; pero en la siguiente década fueron de los productos que experimentaron mayor aumento de su valor. Por otro lado, las carnes de res y puerco y los pescados y mariscos frescos durante la década de los ochentas tuvieron incrementos importantes de su costo, pero durante los noventas han sido cada vez más económicos. Dentro de los cárnicos existieron diferencias de precios que tienen relación con la densidad energética y nutrimental ya que los cortes magros fueron más caros que los que tienen mayor cantidad de grasa y, por tanto, de energía y colesterol. Los pescados (atún y sardina) en lata, el huevo y la carne de ave comenzaron a ser más económicos desde la década de los ochentas. La mayoría de los aceites y grasas han tenido incrementos de sus precios por debajo de la inflación del grupo de alimentos en general. Los alimentos industrializados o procesados han comenzado a ser más económicos que los que se expenden frescos. En un análisis de correlación se observó que la densidad energética de los alimentos se asociaba negativamente con su costo. Finalmente, se comentan las implicaciones de los resultados en términos de políticas públicas.

The aim of this study was to know the price changes of foods and nutriments in México during the last three decades. To this end, two sets of data were analyzed: the National Consumer Prices Index for 1973 to 2003, and quotations of food prices for 1990, 1995, 2000 and 2004. Cost estimates were calculated for 100 kcal, 10 g of saturated fat, 100 mg of cholesterol, 10 g of fiber and 1 mg of iron. Regression models were used to analyze the association between nutrient and energys costs and energetic and nutrimental densities. Our results lead to infer that that in México, the structure of foods prices differed between the eighties and the nineties decades. In the former, vegetables and corn and wheat derived foods had the lowest price increment, whereas their price had the largest increment in the following decade. On the other hand, the prices of fresh meat of cattle and pig, and of fish and seafood rose during the eighties but became cheaper during the nineties. The differences in prices of the meat are inversely related to their energy density and nutrimental value: lean meat became more expensive that those with more fat (i.e. more energy and cholesterol). Canned fish (tuna and sardine), eggs and poultry became cheaper at the turn of the eighties. The prices of the majority of oils and fats have increased less than the inflation of the group of food. Processed and industrialized foods became cheaper than the fresh ones. The energy density of the foods is negatively correlated to their cost. The implications of our results are discussed in terms of public policies.

Relación entre medidas antropométricas y valores de la presión arterial en estudiantes brasileños

La verificación de la presión arterial y de las medidas antropométricas son importantes en la evaluación de la salud de niños y adolescentes, puesto que cada vez son más frecuentes las alteraciones cardiovasculares en esta población. El objetivo fue analizar la correlación entre las medidas antropométricas y los valores de la presión arterial considerando el sexo, la edad y la práctica de ejercicios físicos. Estudio transversal desarrollado en una escuela de la ciudad de Fortaleza-Ceará / Brasil, con 122 estudiantes de 6 a 18 años. Los datos fueron recolectados en formulario específico que incluyó datos socio-demográficos, evaluación antropométrica, verificación de la presión arterial y la práctica de actividad física. Fueron realizadas tres medidas para cada variable antropométrica y para la presión arterial y calculadas sus respectivas medias. Los datos fueron procesados y analizados con auxilio del Software SPSS versión 13.0. El nivel de significancia adoptado fue del 5% (p<0,05). Se identificó correlación entre la presión arterial y el pliegue tricipital. No se encontraron diferencias de media de las medidas antropométricas en la presencia de presión arterial alta. El Índice de Masa Corporal presentó correlación con los pliegues abdominal y subescapular, con circunferencia de la cintura y de la cadera. La actividad física no tuvo influencia sobre las medidas antropométricas. El sexo femenino presentó media de pliegues tricipital e abdominal más altas que el masculino. El estudio confirma la influencia de las variables sexo y edad sobre las medidas antropométricas obtenidas. El pliegue tricipital estuvo especialmente correlacionado a la presión arterial sistólica.

The evaluation of blood pressure and anthropometric measurements is important for evaluating the health of children and teenagers, since cardiovascular abnormalities are becoming more and more common in this population. The objective of this study was to analyze the correlation between anthropometric measurements and arterial pressure taking gender, age and the practice of physical activities into consideration. A cross sectional study was carried out in a school in the city of Fortaleza, Ceará, Brazil, in a sample of 122 students of 6-18 years of age. Data was collected on a specific form and included sociodemographic data, anthropometric evaluation, measurement of arterial pressure and the practice of physical activity. Three measurements were taken of each anthropometric variable and arterial pressure, and the respective means were calculated. Data were processed and analyzed using the SPSS software program, version 13.0. Significance was established at 5% (p<0.05). A correlation was identified between arterial pressure and tricipital skinfold thickness. No statistically significant differences were found between the mean anthropometric measurements and the presence of high blood pressure. A correlation was found between body mass index and abdominal and subscapular skinfold thickness and between body mass index and waist and hip circumference. Physical activity had no effect on anthropometric measurements. Females had a higher mean tricipital and abdominal skinfold thickness than males. This study confirms the influence of the variables of gender and age on the anthropometric measurements evaluated. In particular, tricipital skinfold thickness was correlated with systolic arterial pressure.

Validez del índice energía/proteína en la identificación de la malnutrición por exceso en preescolares venezolanos de bajo estrato socioeconómico

Se evaluó la validez del índice energía-proteína (IEP) en la identificación de la malnutrición por exceso en 163 niños entre 4 y 6 años, de bajo estrato socioeconómico en la ciudad de Valencia, Estado Carabobo, Venezuela. Se tomó peso, talla, brazo y pliegues subcutáneos. Se calculó el Peso para la Talla (P/T), área grasa (AG) e IEP. Se consideró en déficit a todo sujeto con P/T £ p10, normalidad P/T >p10 y £ p90 y en exceso aquel con P/T y AG >p90. Se calculó la distribución percentilar del IEP por edad y género, considerando bajo la norma £ p10, normal >p10 y £ p90 y sobre la norma >p90. Su validez se analizó a través de la sensibilidad, especificidad y razón de verosimilitud positiva (RV+) y negativa (RV-). Las pruebas de t de Student y ANOVA se utilizaron para comparaciones de grupos (p< 0,05). Según el diagnóstico nutricional, un 27,60% de los niños presentaron déficit, 66,88% normalidad y 5,52% exceso. El IEP reportó un 7,36% en bajo la norma, 82,20% normal y 10,44% sobre la norma. El IEP disminuyó con la edad en los varones y presenta diferencias por género en el grupo de 6 años, siendo significativamente mayor en las niñas. Para identificar el exceso, la sensibilidad fue del 77% y la especificidad del 93%, con una RV+ de 11. Finalmente, un IEP sobre la norma fue 11 veces más probable en un sujeto con exceso que en otro en normalidad. Para el déficit, las pruebas no cumplieron los requisitos de utilidad.

The validity of the energy/protein index (EPI) in the detection of overweight was assessed in 163 low income children (four to six years old) from Valencia, Venezuela. Weight, height, arm circumference, and skinfolds were taken. Weight for height (W/H), limb fat area (LFA), and EPI were calculated. All subjects with W/H £ p10 were considered deficient, with W/H between >p10 and £ p90 normal, and with W/H and LFA >p90 in excess. Percentile distribution of EPI for age and gender was calculated, regarding below the norm all subjects £ p10, normal those > p10 and £ p90, and above the norm those >p90. Validity was assessed through sensibility, specificity, and likelihood ratio. Student´s t test and ANOVA were used for group comparisons (p< 0.05). According to the nutritional diagnosis, 27.60% of the children were deficient, 66.88% normal, and 15.52% in excess. According to the EPI, 7.36% of the sample was considered below the norm, 82.20% normal, and 10.44% above the norm. The EPI decreased with age in boys, and in the 6 years old group was significantly higher for girls. Lastly, an EPI above the norm is eleven times more likely to occur in a subject considered in excess than in subjects considered normal. For deficiency, the tests did not meet the expected values.

Prevalência e fatores associados à anemia e deficiência de ferro em crianças de 18 a 24 meses

Foi realizado um estudo transversal com 101 lactentes de 18 a 24 meses atendidos em serviços públicos de saúde da cidade de Viçosa, MG, Brasil. Objetivou-se verificar a prevalência e os fatores associados à anemia e deficiência de ferro entre lactentes. As informações foram obtidas através de entrevista aos pais ou responsáveis pelas crianças, realizadas nos domicílios. Foram feitas análises da hemoglobina e ferritina, por um contador automático e pelo método de doseamento imunométrico, respectivamente. As amostras de fezes foram analisadas pelos métodos de Hoffman, Faust e Ritchie. Caracterizou-se anemia através da concentração de hemoglobina e a deficiência de ferro através da ferritina. Na avaliação da prática alimentar utilizou-se o recordatório de 24 horas. Foram feitas análises de regressão linear e logística para avaliar as variáveis associadas à hemoglobina e a deficiência de ferro, respectivamente. As prevalências de anemia, deficiência de ferro e parasitoses intestinais foram de 30,1; 38,4 e 21%, respectivamente. O número de moradores na casa, idade de introdução de sucos e/ou frutas, escolaridade materna e tempo de aleitamento materno total associaram-se aos níveis plasmáticos de hemoglobina. Para a deficiência de ferro as variáveis associadas foram consumo de leite próximo das refeições e número de moradores na casa.

A transversal study was carried out with 101 18-to 24-month old infants, attended at public health services in Viçosa, MG, Brazil, The objective of this study was to verify the prevalence and factors associated to anemia and iron deficiency among infants. Data were obtained by interviews of the infants parents or guardians at their households. Hemoglobin and ferritin analyses were peformed using an automatic counter and the immunometric dosage method, respectively. Feces samples were analyzed by the Hoffman, Faust and Ritchie methods. Anemia was characterized by hemoglobin concentration and iron deficiency by ferritin. For dietary practice, the 24-hour recall was used. Linear regression and logistics analyses were conducted to evaluate the variables associated to hemoglobin and iron deficiency, respectively. Anemia, iron deficiency and intestinal parasite prevalences were 30.1; 38.4, and 21%, respectively. The number of household members, age infants were introduced to juices/or fruit, mothers level of instruction, and total breastfeeding period were associated to the levels of hemoglobin plasma. The associated variables for iron deficiency were milk consumption near meals and number of household members.

Ingesta de calcio y proteínas: relación con marcadores bioquímicos óseos en mujeres pre y posmenopáusicas de Comodoro Rivadavia (Argentina)

Se estudió la relación de la ingesta de calcio y de proteínas con algunos marcadores de recambio óseo en 50 mujeres, 28 premenopáusicas (Pre) y 22 posmenopáusicas (Pos), de Comodoro Rivadavia (Argentina) con densidad mineral ósea (DMO) normal. Las ingestas de calcio (ICa) y de proteínas (IPr) se calcularon por encuesta de 7 días y frecuencia de consumo de alimentos. En orina de 24 h se determinaron: calcio (Ca), creatinina (Crea) y deoxipiridinolina (Dpir); en suero: fosfatasa alcalina ósea (BAPh). Los resultados (promedio ± DE, mínimo y máximo) fueron, para Pre y Pos, respectivamente: ICa (mg/d): 694 ± 411 (190 - 2.117); 918 ± 304 (471 - 1.740) (p<0,01); IPr (g/d): 64,6 ± 25,4 (33,5 - 136); 63,7 ± 17,6 (41,5 - 95,2); calciuria (mg/d): 123 ± 85 (20 - 369); 114 ± 66 (17 - 252); Ca/crea (mg/mg): 0,124 ± 0,086 (0,014 - 0,372); 0,131 ± 0,077 (0,020 - 0,338); Dpir/crea (nM/mM): 5,5 ± 1,5 (3,4 - 10,3); 7,1 ± 2,3 (3,9 - 14,5) (p<0,01); BAPh (UI/l): 58 ± 12 (28 - 94); 70 ± 20 (32 - 99) (p<0,01). La ICa fue inferior a la Ingesta Adecuada para la edad en el 86 % de Pre y en el 82 % de Pos. Los indicadores bioquímicos no correlacionaron significativamente con ICa ni con IPr. Estos resultados sugieren que en estas mujeres, sin pérdida de masa ósea, existiría adaptación a un amplio rango de ICa y que la masa ósea se mantendría mediante un equilibrio entre el incremento de la formación ósea y el de la resorción.

Healthy premenopausal women (Pre n=28) and posmenopausal (Pos n=22), living in Comodoro Rivadavia (Argentina), with normal femoral neck and lumbar spine bone mineral density (BMD) were studied. Usual daily calcium intake (CaI) and protein intake (PrI) were calculated according to an special questionaire and the National Food Composition Tables. Fasting blood samples and 24 h urine were collected. Laboratory measurements were: in urine (U): calcium (Ca), creatinine (Crea) and deoxypiridinoline (Dpyr); in serum: Bone Alkaline Phosphatase (BAPh). The results presented the following media ± SD (minimum - maximum) in Pre and Pos, respectively: CaI (mg/d): 694 ± 411 (190 - 2,117); 918 ± 304 (471 - 1,740) (p<0.01); PrI (g/d): 64.6 ± 25.4 (33.5 - 136); 63.7 ± 17.6 (41.5 - 95.2); daily UCa (mg/d): 123 ± 85 (20 - 369); 114 ± 66 (17 - 252); Ca/crea (mg/mg): 0.124 ± 0.086 (0.014 - 0.372); 0.131 ± 0.077 (0.020 - 0.338); Dpyr/crea (nM/mM): 5.5 ± 1.5 (3.4 - 10.3); 7.1 ± 2.3 (3.9 - 14.5) (p<0.01); BAPh (UI/l): 58 ± 12 (28 - 94); 70 ± 20 (32 - 99) (p<0.01). CaI was lower than the Adequate Dietary calcium intake in 86 % and 82 % of the Pre and Pos women, respectively. There was no correlation between CaI, PrI and the biochemical indicators. Conclusions: in these healthy women, without bone mass loss and with wide range of CaI, although usually low, markers of bone turnover, would be a balance between the increase of bone formation and resorption.

Blood pressure and obesity of children and adolescents - association with body mass index and waist circumference

The objective of this work was to evaluate the association between the average levels of blood pressure of 706 children in Porto Alegre with their nutritional state - body mass index (BMI), body fat percentage, waist circumference - and with their social-economic state. A prevalence of 12.3% (n=87) of high blood pressure was found. According to the BMI, 11% of the sample was obese. 47.7% belonged to the social class with an income less than two monthly minimum salaries. All of the correlations of the SBP (systolic blood pressure) and DBP (diastolic blood pressure) with variables in the nutritional state showed to be significant (p<0.001). What ended up having a stronger association was the BMI and waist circumference with SBP (R=0.27). This study made it possible to notice that the anthropometric indicator that best is related to the existence of high BP is the BMI along with the waist circumference. This seems to be an easy method that is noninvasive and of low cost to detect the risk of high BP in children and adolescents.

O objetivo deste trabalho foi avaliar a associação entre os valores médios de pressão arterial de 706 crianças de Porto Alegre com seu estado nutricional - índice de massa corporal (IMC), percentual de gordura corporal e circunferência da cintura -, com o estado sócio-econômico. Foi encontrada uma prevalência de 12.3% (n=87) de pressão arterial alta. De acordo com o IMC, 11% das crianças da amostra eram obesas e 47,7% pertenciam à classe social com renda menor que dois salários mínimos mensais. Todas as correlações da PAS (pressão arterial sistólica) e PAD (pressão arterial diastólica) com variáveis do estado nutricional mostraram-se significativas (p<0,001). A que se manteve como uma associação mais forte foi o IMC e circunferência da cintura com PAS (R= 0,27). Este estudo possibilitou verificar que o indicador antropométrico que melhor relaciona-se com a existência de PA alta, é o IMC juntamente com a circunferência da cintura. Mostrando-se um método fácil, não invasivo e de baixo custo para detecção do risco de PA alta em crianças e adolescentes.

Prevalencia de sobrepeso y obesidad en el noroeste de México por tres referencias de índice de masa corporal: diferencias en la clasificación

El objetivo del estudio fue determinar y comparar la prevalencia de sobrepeso en escolares de una región del noroeste de México por tres criterios de índice de masa corporal para la edad (IMC/edad). Un total de 604 niños de 6 a 10 años fueron evaluados en 17 municipios del estado de Sonora, México durante el año 2002. Se determinó la prevalencia de obesidad usando tres referencias de IMC/edad; la nueva versión del Centro de Control y Prevención de Enfermedades de EU (US. CDC/NCHS Growth Charts 2000); el método avalado por la Comisión Internacional sobre la Obesidad (IOTF) y la referencia recomendada por la Organización Mundial de la Salud (WHO) en 1995 para niños mayores de 10 años y utilizada en México por la Encuesta Nacional de Nutrición en 1999 para escolares. No se encontraron diferencias en los valores de sobrepeso y obesidad entre niños y niñas (p>0.5), ni tampoco entre zonas urbanas y rurales. El criterio WHO sobrestimó la prevalencia de sobrepeso y obesidad (39%) en comparación con el método del CDC/NCHS (20%) y IOTF (17%). Las dos últimas referencias mostraron mejor equivalencia (kappa>80). En conclusión, el uso de distintos criterios de referencia de IMC/edad genera variaciones en la estimación de la prevalencia de sobrepeso y obesidad. El estándar WHO puede sobrestimar la prevalencia de obesidad, por tanto el uso de las 3 referencias debe ser considerado en niños mexicanos para comparaciones posteriores.

The objective of this study was to compare the prevalence of overweight and obesity in children from northwest of Mexico based on BMI/age and three criteria of growth reference standards. Six hundred and four children, 6 to 10 years of age, from 17 municipalities of the state of Sonora were measured for weight and height and age established from birth certificate school records. The prevalence of overweight and obesity was determined by the new version of the US Centers for Disease Control and Prevention (CDC/NCHS), the International Obesity Task Force (IOTF) and the values proposed by The World Health Organization (WHO) that was utilized in the National Nutrition Survey of 1999 in Mexico (ENN). Using the WHO reference, prevalence of overweight and obesity was 39%. This was higher than the CDC/NCHS (20%) and IOTF (17%) references, respectively. Prevalence of overweight and obesity by CDC/NCHS and IOTF criteria, showed the best agreement (Kappa >80); this was not the case when prevalence from CDC/NCHS and IOTF were compared to the WHO criteria (Kappa <40). For overweight and obesity frequencies, no sex or urban-rural differences were observed (p>0.05). In conclusion, the use of these 3 reference values systems using BMI/age did not show the same prevalence estimates of overweight and obesity. The use of the WHO method can overestimate the prevalence of obesity in children, therefore the use of these 3 references should be considered for future comparisons.

**Evaluación de la técnica de inmunoseparación magnética para recuperación de Escherichia coli O157:H7 en cremas de leche**

The utility of immunomagnetic separation (IMS) for the recovery of Escherichia coli O157:H7 in milk creams was evaluated. The efficiency of different pre-enrichments broths previous to ISM was determined and different agars were analyzed (differential and/or selective) for plating of the inmunobeads. Portions of 25 g from milk creams were inoculated with pathogen low levels (50, 10 and 1 cell/g) and then, were enriched in buffered peptone water with vancomycin (BPW-V), buffered peptone water with vancomycin and cefixime (BPW-VC) and triptone soya broth with vancomycin, cefixime and tellurite (TSB-VCT) being incubated 35ºC/18 hours. Then, IMS was applied and immunobeads were plated onto sorbitol MacConkey agar (SMA), sorbitol MacConkey agar with cefixime and tellurite (SMA-CT) and chromogenic agar with tellurite and cefixime (CRGA-TC). It was observed significant differences (p<0,05) in the recovery percentages according to the pre-enrichment broth used, being obtained the biggest recovery rates with the use of TSB-VCT for the three inocula levels. The recovery rates did not vary significantly (p<0,05) among the utilized agars, while the number of inoculated cells impacts the recovery percentages, being bigger as it increases the inocula. In conclusion, IMS is a sensitive method for the recovery of Escherichia coli O157:H7 in milk creams, recommending for isolation of this pathogen, the enrichment in TSB-VCT, application of IMS, and plating of immunobeads onto nonselective agar (SMA) and selective agar (SMA-TC or CRGA-TC).

Efecto sinergistico y cuantificación de los 5´-ribonucleótidos en una sopa de pollo

La normativa nacional e internacional permite adicionar a las mezclas deshidratadas para caldos y sopas resaltadores del sabor tales como glutamato monosódico (GMS) y los ácidos inosínico y guanílico o sus sales fosfatadas (IMF y GMF, respectivamente), solos o combinados para lograr un efecto sinergístico. Los objetivos de este estudio fueron: 1) determinar mediante un panel sensorial, el efecto sinergístico en el sabor de una sopa de pollo deshidratada cuando se usa mezcla de resaltadores y 2) cuantificar los 5´-ribonucleótidos en dicha matriz. La intensidad del sabor a pollo se determinó empleando un panel de 6 personas previamente entrenadas. Los 5´-ribonucleótidos se cuantificaron empleando HPLC. Los resultados con el panel entrenado comprobaron que la combinación utilizada de GMS, IMF y GMF potencia significativamente (p<0,05) el sabor de la sopa de pollo deshidratada. El análisis químico de los 5´-ribonucleótidos reflejó un porcentaje de recuperación de 93,6% para GMF y 90,5% para IMF.

The international and national regulation permits the addition of flavour enhancers such as monosodium glutamate (MSG) and inosinic and guanilic acids and their fosfated salts (IMP or GMP, respectively) alone or combined to dehydrated mixtures of broths and soups in order to obtain a synergistic. The objectives of this study were: 1) to determine, through a sensorial panel, the synergistic effect on the flavour of a dehydrated chicken soup to which flavour enhancers were added and 2) quantify the 5´-ribonucleotides in such matrix. The intensity of the chicken flavour was determined using a previously trained 6-member panel. The 5´-ribonucleótidos were determined using the HPLC technique. The results using the panel demonstrated that the combination of GMS, IMF and GMF used potentiates significantly (p<0.05) the flavour of the dehydrated chicken soup, which allows the use of less quantity of them to obtain the same effect on the flavour. The chemical analysis of the 5´-ribonucleótidos in the dehydrated chicken soup reflected a percentage of recovery of 93.6% for MSG and 90.5% for IMF.

Barra de cereais de elevado teor protéico e vitamínico: estabilidade enzimática e das vitaminas c e e durante armazenamento

Produtos a base de cereais vêm se tornando um excelente veículo para se incluir ingredientes com alegação funcional no mercado consumidor. Uma tendência emergente são os produtos formulados com proteína de soja, por providenciarem benefícios à saúde. Devido ao grande potencial destes produtos, foi considerado de interesse determinar a estabilidade de barra de cereais à base de proteína de soja, gérmen de trigo e aveia, suplementada de vitamina C (ácido ascórbico) e fortificada de vitamina E (acetato de a -tocoferol 50%), durante o armazenamento. Três filmes (A: PET/PEBD; B: PETMET/PEBD; C: PET/PEBD/AL/PEBD) foram utilizados como embalagens e as barras de cereais foram estocadas em condições de temperatura (25±2°C) e umidade relativa (56%) ambiente por um período de 180 dias. A estabilidade da vitamina C, vitamina E, e a atividade de lipase e peroxidase foram verificadas. Durante o estudo, as barras de cereais embaladas nos três filmes testados apresentaram uma retenção de vitamina C menor que 50%. No entanto, a embalagem estruturada com folha de alumínio (C), proporcionou menor velocidade de reação ao longo do período de armazenagem, k=0,00473 (-dia), e maior tempo de meia vida (146 dias). Os teores de vitamina E (acetato de a -tocoferol) nas barras de cereais apresentaram pequenas variações durante o armazenamento. Houve um aumento significativo (p£0,05) na atividade de peroxidase aos 90 dias de estocagem nas embalagens testadas, enquanto que a atividade de lipase não demonstrou aumento significativo durante o período estudado.

Cereal-based products have become an excellent vehicle for delivering tasty functional food ingredients to busy consumers. One emerging trends is food products formulates with soy protein because of its proven health benefits. Because of the potential usefulness of these products, it was considered of interest to determine the stability of cereal bars based on soy protein, wheat germ and oat, enriched with vitamin C (ascorbic acid) and E (acetate of a-tocopherol 50%), during the storage. Three films with different properties of barrier (A: PET/PEBD; B: PETMET/PEBD; C: PET/PEBD/AL/PEBD) were used as packing and the cereal bars were stored at temperature (25±2°C) and relative humidity ambient (56%) for six months. The stability of vitamin C, vitamin E and, its lipase and peroxidase activity was verified. During the study, the cereal bars packed in three tested films presented retention in the vitamin C lesser that 50%. However, packing structuralized with aluminum (C) leaf provided to minor speed of reaction during the storage, k=0,00437 (-day), and greater time of half-life (146 days). The vitamin E (acetate of a-tocopherol) in the cereal bars presented a little variation during the storage. It had a significant (p£ 0,05) increase in the peroxidase activity at 90 days of storage in the packages tested, while that the lipase activity demonstrated no significant increase during the period studied.

Migração de minerais de panelas brasileiras de aço inoxidável, ferro fundido e pedra-sabão (esteatito) para preparações culinárias

Os utensílios culinários podem liberar alguns elementos inorgânicos durante a cocção de alimentos. A migração destes pode ser interessante desde que ocorra em quantidades adequadas às necessidades nutricionais do usuário ou não tenham implicações toxicológicas. O presente estudo avaliou a migração de minerais (Fe, Mg, Mn, Cr, Ni e Ca) durante sete cocções seqüenciais para duas preparações alimentares (arroz polido e molho de tomate comercial, este último como alimento ácido) efetuadas em panelas brasileiras de vários materiais novas de aço inoxidável, ferro fundido e pedra-sabão, utilizando o vidro refratário como branco. O teor dos minerais foi quantificado por espectrometria de emissão óptica por plasma indutivamente acoplado (ICP OES). Os utensílios estudados apresentaram quantidades e comportamento de migração distintos e susceptíveis à variação, conforme o tipo de alimento a ser cozido. Análise de regressão dos dados revelou que, em função do uso, as panelas de ferro apresentam acréscimo da migração de ferro quando cozido o molho de tomate (y = 70,763x + 276,75; R² = 0,77). As panelas de pedra-sabão liberaram concentrações médias de cálcio (35 e 26mg/kg), magnésio (25 e 15mg/kg) e para o molho de tomate comercial e arroz polido cozidos, respectivamente. O molho de tomate comercial cozido em panelas de pedra-sabão apresentou migração de manganês (3,9 mg/kg) e níquel (1,0mg/kg), este último indesejavelmente por ser tóxico. As panelas de inox apresentaram migração menor de níquel, com tendência decrescente em função do número de cocções do molho de tomate, liberando ainda ferro e cromo para as preparações. Os utensílios de materiais distintos devem ter seu uso selecionado em função da preparação a ser realizada, visando à saúde do consumidor. Conclui-se que apesar de os utensílios de ferro fundido e vidro serem os mais adequados para a saúde nutricional do consumidor, as panelas de aço inox e esteatito podem ser utilizadas com risco relativamente baixo, desde que o preparo rotineiro de alimentos ácidos seja evitado.

Culinary utensils may release some inorganic elements during food preparation. Mineral migration can be beneficial for as long as it occurs in amounts adequate to the needs of the consumer or no toxicological implications are involved. In this study, the migrations of Fe, Mg, Mn, Cr, Ni and Ca, along seven cooking cycles were evaluated for two food preparations (polished rice and commercial tomato sauce, the latter as an acid food), performed in unused stainless steel, cast iron and soapstone pans, taking refractory glass as a blank. Minerals were determined by inductively coupled plasma optical emission spectrometry (ICP OES). The utensils studied exhibited different rates, patterns and variability of migration depending on the type of food. Regression analysis of the data revealed that, as a function of the number of cycles, the iron pans released increasing amounts of iron when tomato sauce was cooked (y = 70.76x + 276.75; R² = 0.77). The soapstone pans released calcium (35 and 26mg/kg), magnesium (25 and 15mg/kg) into the tomato sauce and rice preparations, respectively. Additionally, the commercial tomato sauce drew manganese (3.9 and 0.6mg/kg) and some undesirable nickel (1.0mg/kg) from the soapstone material, whereas the stainless steel pans released nickel at a lower rate than steatite and in a diminishing fashion with the number o cooking cycles, while still transferring some iron and chromium to the food. We conclude that while cast iron and glass could be best for the consumers nutritional health, stainless steel and steatite can be used with relatively low risk, provided acid foods are not routinely prepared in those materials.

Identificación de proteínas extrínsecas en jamones cocidos por SDS-PAGE: Nivel de detección en sistemas modelo

El Código Alimentario Argentino establece que el jamón cocido, la paleta cocida y el lomo de cerdo cocido no pueden contener proteínas agregadas ni otros extensores, permitiendo el agregado de proteínas de soja según el límite para chacinados (2% de aislado de soja) únicamente para fiambre de cerdo cocido. Con el fin de establecer el nivel de detección de materias primas proteicas en mezcla con carne porcina en jamones cocidos se realizó la extracción de proteínas de diversos sistemas modelo y la posterior separación por electroforesis en gel de poliacrilamida, según el sistema de Laemmli (SDS-PAGE). Se estudiaron sistemas modelo de jamones cocidos con aislado de soja, caseinato, leche en polvo descremada, plasma bovino, plasma porcino y suero lácteo. El nivel de cuantificación del método fue de 0,5% de aislado de soja, de caseinato y de plasma bovino y de 1,0% de plasma porcino, de leche en polvo descremada y de suero lácteo en jamones cocidos. De acuerdo con estos resultados esta metodología resulta útil para controlar el agregado de ciertas materias primas proteicas por lo que resulta válida para verificar el cumplimiento de la legislación vigente para salazones cocidas y puede ser utilizada como metodología de control.

The Argentine Food Code (Código Alimentario Argentino) does not allow the use of any extrinsic protein in boneless ham, picnic pork shoulder and cured loin. It only allows the use of soy proteins (maximum 2% of soy isolates) in porcine products labelled "fiambre de cerdo cocido" . Protein extraction and separation in polyacrylamide slab gel electrophoresis with Laemmli system (SDS-PAGE) were used to establish the detection level of protein raw materials in mixtures with porcine meat in boneless cooked ham. Model systems of boneless cooked ham with soy protein isolates, caseinate, skim powdered milk, bovine plasma, porcine plasma and whey proteins were studied. The quantification level of this method was 0.5% for soy protein isolates, caseinate and bovine plasma and 1.0% for porcine plasma, milk powder and whey proteins in boneless cooked ham. The electrophoretic method proved to be useful to identify some proteinic raw materials in porcine meat products and verify compliance with Argentine legislation. It may be used as a control methodology.

Farinha extrusada de arroz como substituto de glúten na produção de pão de arroz

A procura pela produção de pão sem glúten (PSG) é muito importante nutricional, técnica e economicamente para pacientes celíacos e para países em desenvolvimento, que importam trigo. Os maiores problemas tecnológicos na produção de PSG é obter um substituto de glúten, que tenha baixo custo e que seja capaz de reter gás durante a fermentação e assamento do pão. O uso de amido gelatinizado parece ser promissor para substituir o glúten. Neste trabalho foi feito pão sem glúten, usando farinha de arroz crua (100%) e adição de 10% de farinha pré-gelatinizada de arroz, como substituto de glúten. Farinhas pré-gelatinizadas de arroz (FPG) produzidas num extrusor mono-rosca Brabender, variando-se a temperatura de extrusão (108 - 192ºC) e a umidade da matéria-prima (19,2 a 24,8%) foram usadas ao nível de 10% (em base de 100% de farinha de arroz) na produção do pão sem glúten. Os resultados mostraram que a farinha extrusada de arroz a alta temperatura (180ºC) e baixa umidade (20%) produziu pães com as melhores características tecnológicas, com cor de crosta e miolo semelhantes ao pão de trigo, mas volume e textura ainda não foram iguais.

Research regarding the production of gluten-free bread (GFB) is very important nutritionally, technically and economically speaking, both to celiac patients and to developing countries who import wheat. The main technological problem in the production of GFB is obtaining a gluten substitute that is both inexpensive and capable of retaining gas during bread fermentation and baking. The use of gelatinized starch as an alternative for gluten seems promising. In this project, rice bread was made using pre-gelatinized extruded rice flour as a gluten substitute. Pre-gelatinized rice flours (PRF) were manufactured in a single screw Brabender extruder, varying extrusion temperature (108-192ºC) and the moisture of the raw material (19.2 - 24.8 %), and were used in a proportion of 10g for every 100g of raw rice flour, in the production of gluten-free bread. Results showed that rice flour extruded at a high temperature (180º) and low moisture content (20%), rendered bread with the best technological characteristics, presenting crust and crumb color similar to those of conventional wheat bread, although with volume and texture not as satisfactory in the same comparison.

Composição de alimentos: um pouco de história

Dados sobre nutrientes e outros componentes presentes nos alimentos, in natura e processados, são necessários em inúmeros campos de atividades, tais como nutrição, saúde, agricultura, comércio, marketing. Pode-se considerar que, a partir do século XVII, é que se fundamentou o que viria a ser o estudo sistemático em relação à composição de alimentos. O século XIX apresentou inúmeros avanços, com o esclarecimento sobre a produção de energia a partir dos alimentos, a identificação de vários nutrientes e seu papel fisiológico. Começaram a surgir, também, as primeiras tabelas com dados de composição, finalizando o século com a publicação do The Chemical Composition of American Food Material do United States Departamento de Agricultura (USDA) de Atwater e Wood, em 1896. No século XX houve um refinamento em relação aos métodos de análise utilizados e a elaboração de tabelas de composição de alimentos por muitos países. Em 1984 foi criada a rede INFOODS (International Network of Food Data Systems), ligada à Universidade das Nações Unidas (UNU) e Food and Agriculture Administration (FAO), que propôs diretrizes e criou ferramentas que implicaram em grande avanço nas tabelas de composição. Atualmente a consciência relativa à biodiversidade de alimentos existentes vem ampliando o enfoque das tabelas e bancos de dados de composição química de alimentos. No Brasil a Tabela Brasileira de Composição de Alimentos (TBCA-USP), da Rede Brasileira de Dados de Composição de Alimentos (BRASILFOODS), desde sua criação em 1998, vem adotando esses padrões internacionais e encontra-se disponível da Internet (http://www.fcf.usp.br/ tabela), atualmente na versão 4.1.

Data on nutrients and other food components are necessary in several sectors, such as nutrition, health, agriculture, trading and marketing. From the 17th century on, the systematic study of food composition started to be established. During the 19th century, there were many advances, such as the clarification of food energy production, the identification of nutrients and their physiologic role. Also, the first food composition tables began to emerge, finishing the century with the publication of Atwater and Wood´s "The Chemical Composition of American Food Material" of the United States Department of Agriculture (USDA), in 1896. In the 20th century, the methods of analysis and the elaboration of food composition tables were improved in many countries. In 1984, INFOODS (International Network of Food Data Systems) was created. This network, linked to United Nations University (UNU) and Food and Agriculture Administration (FAO), proposed rules and created tools that brought great advances in food composition tables. Nowadays, the conscious related to food biodiversity has been amplifying the focus of food composition tables and databases. In Brazil, the Brazilian Food Composition Table (TBCA-USP), of the Brazilian Network for Food Composition Data (BRASILFOODS), since its creation in 1998, has been adopting these international patterns and is available on the Internet (http://www.fcf.usp.br/tabela), currently on the version 4.1.