Rosana Aparecida Manólio Soares

Effect of natural antioxidant combinations on lipid oxidation in cooked chicken meat during refrigerated storage

The effect of combinations of sage, oregano and honey on lipid oxidation in cooked chicken meat during refrigeration at 4°C for 96h was determined. Chicken samples (thigh and breast) were then separated into five groups: control; butylated hydroxytoluene; oregano+sage; oregano+sage+5%honey and oregano+sage+10%honey. Quantitative measurements of thiobarbituric acid reactive substances, conjugated dienes, hexanal, fatty acids, cholesterol and cholesterol oxides were used as indicators of lipid oxidation. Acceptability and preference were also evaluated. The effectiveness of the natural antioxidants for reducing the velocity of lipid oxidation in cooked chicken thigh and breast was demonstrated after 48 and 96h of refrigeration at 4°C. The treatments that presented the lowest hexanal values after 96h of refrigeration were oregano+sage+5%honey and oregano+sage+10%honey. Only traces of free cholesterol oxides were found (25-OH, 7-k, 7α-OH and 7β-OH). The natural antioxidants protected cooked chicken meat from oxidation processes and resulted in great acceptability.

Composição química do feijão caupi (Vigna unguiculata L. Walp), cultivar BRS-Milênio

Cowpea is one of the major food cultures of the northeastern region of Brazil. To improve its resistance against plagues and to increase its productivity, a new cultivar (BRS-Milenio) was obtained by genetic improvement. This study aimed at determining the proximate composition, amino acid and fatty acid profiles, mineral constituents and trypsin inhibitory activity of this cultivar. The seed presents (g.100 g-1): 24.5 protein, 51.4 carbohydrates, 16.6 insoluble fiber and 2.7 soluble fiber, 2.6 ash; major mineral constituents (mg.100 g-1) were: iron - 6.8, zinc - 4.1, manganese - 1.5, phosphorus - 510.0 and potassium - 1430.0. Lipid content was 2.2%, and its fatty acids profile: 29.4% saturated and 70.7% unsaturated. The caloric value was estimated as 323.4 kcal.100 g-1 of seeds. A low trypsin inhibitory activity was found (8.0 TIU.mg-1 of sample). The amino acid profile is in accordance with the reference amino acid standard, except for the sulfur amino acid deficiency, suggesting the need to encourage the combination of this bean with other food sources. Results suggest that cowpea presents high contents of energy, protein, dietary fiber, minerals and a low trypsin inhibitory activity. Although it contains low amounts of lipids, its composition presents a high unsaturated fatty acid profile.

Major Peptides from Amaranth (Amaranthus cruentus) Protein Inhibit HMG-CoA Reductase Activity

The objective of this study was to identify the major peptides generated by the in vitro hydrolysis of Amaranthus cruentus protein and to verify the effect of these peptides on the activity of 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMG-CoA reductase), a key enzyme in cholesterol biosynthesis. A protein isolate was prepared, and an enzymatic hydrolysis that simulated the in vivo digestion of the protein was performed. After hydrolysis, the peptide mixture was filtered through a 3 kDa membrane. The peptide profile of this mixture was determined by reversed phase high performance chromatography (RP-HPLC), and the peptide identification was performed by LC-ESI MS/MS. Three major peptides under 3 kDa were detected, corresponding to more than 90% of the peptides of similar size produced by enzymatic hydrolysis. The sequences identified were GGV, IVG or LVG and VGVI or VGVL. These peptides had not yet been described for amaranth protein nor are they present in known sequences of amaranth grain protein, except LVG, which can be found in amaranth α‑amylase. Their ability to inhibit the activity of HMG-CoA reductase was determined, and we found that the sequences GGV, IVG, and VGVL, significantly inhibited this enzyme, suggesting a possible hypocholesterolemic effect.

Influence of home cooking conditions on Maillard reaction products in beef.

The influence of home cooking methods on the generation of Maillard reaction products (MRP) in beef was investigated. Grilling and frying hamburgers to an internal temperature below 90 °C mainly generated furosine. When the temperature reached 90 °C and 100 °C, furosine content decreased by 36% and fluorescent compounds increased by up to 98%. Baking meat at 300 °C, the most severe heat treatment studied, resulted in the formation of carboxymethyllysine. Boiling in water caused very low MRP formation. Acrylamide concentrations in grilled, fried or baked meat were extremely low. Home cooking conditions leading to low MRP generation and pleasant colours were obtained and could be used to guide diabetic and chronic renal patients on how to reduce their carboxymethyllysine intake.

Influence of seasonality on the chemical composition of oysters (Crassostrea rhizophorae).

This paper aimed to evaluate the influence of seasonality on the chemical composition of oysters (Crassostrea rhizophorae). Samples were collected during summer and winter from the estuary and lagoon complex of the municipality of Barra de São Miguel, Alagoas, Brazil. Statistical differences (p<0.05) between summer and winter were observed in relation to chemical composition. The oysters cultivated in the winter presented some nutritional advantages because of the higher levels of proteins and functional nutrients, such as the eicosapentaenoic-docosahexaenoic acid combination and percentages of polyunsaturated fatty acids (n-3 and n-6), and the lower levels of saturated fatty acids. Therefore, the animals in winter presented a higher content of cholesterol oxides. The levels of cholesterol oxides found in these products during winter may encourage researchers to investigate the composition of oysters cultivated in different climates all over the world.

Effect of storage and processing of Brazilian flaxseed on lipid and lignan contents

Flaxseed has been widely studied around the world; its incorporation into products habitually consumed by human populations has been stimulated due to its unique nutritional value. The objective of this study was to evaluate the chemical composition of Brazilian flaxseed, to analyze the stability of lipids present in whole flaxseed flour (WFF) or partially defatted flaxseed flour (DFF) stored under several temperatures, and to investigate the effect of bread making on a product containing flaxseed. Whole flaxseed flour presented (g.100 g-1) 25.7 of insoluble fiber, 10.7 of soluble fiber, 38.9 of lipids, and 2.65 of lignan. Defatted flaxseed flour presented 65% less lipids, 36% more fiber and 56% more lignan than whole flaxseed flour. The fatty acid profile was maintained in the defatted flaxseed flour, and it presented a stable composition during storage under ambient temperature, refrigeration, and freezing. The fatty acid profile was similar in the bread containing defatted flaxseed flour after dough development, baking, and storage at room temperature or refrigerated. After baking, 89% of the lignan content was kept in bread. Results show that Brazilian flaxseed has an interesting chemical composition, and that defatted flaxseed, by-product of lipid extraction, presents a good stability to grind and storage under several temperatures. Thus, defatted flaxseed flour can be incorporated in bread, increasing its nutritional and functional value.

Efeito do beneficiamento sobre o valor nutricional do peixe mandim (Arius spixii)

In an attempt to analyze how processing enhances the nutritional value of the mandim fish (Arius spixii) marketed in Maceio-AL, Brazil, the following nutritional components were determined in fresh and processed (salted-dried) fish: centesimal composition, calorie count, chloride, fatty acid and cholesterol profile. The presence of cholesterol oxides was also investigated. Respective results for fresh and processed mandim fish were: moisture (70.13% and 40.31%), proteins (51.73% and 38.07%, dried), carbohyrdrates (4.67% and 2.24%, dried), calories (486 kcal/100g and 367 kcal/100g, dried), fatty acids (polyunsaturared 14,54% and 15,49%, omega-3 8,51% and 6,51%), cholesterol (82.66 mg/100g and 61.30 mg/100g) and oxides (7-ketocholesterol 8.31 µg/g and 17.90 µg/g). These figures clearly showed that processing led to significant change in the nutritional value of the mandim fish.

Fish oil and vitamin E change lipid profiles and anti-LDL-antibodies in two different ethnic groups of women transitioning through menopause

BACKGROUND studies have investigated the relationship between the transition through menopause and cardiovascular diseases. White population, generally, have lower levels of traditional coronary heart risk factors, particularly dyslipidemia, hypertension, obesity, and diabetes, and lower rates of coronary heart disease mortality, than black population. Furthermore many studies have shown the cardioprotective and anti-inflammatory effects of omega-3 polyunsaturated fatty acids (eicosapentaenoic acid and docosahexaenoic acid) of marine origin. The aim of this study was to investigate the effect of omega-3 supplementation, combined or not with vitamin E, on oxidative biomarkers and lipid profiles in nonwhite and white women with dyslipidemia transitioning through menopause. METHODS a randomized, double-blind, placebo-controlled trial was conducted. Seventy-four eligible women were assigned to receive: fish oil, fish oil plus vitamin E and placebo for three months. At baseline, 45 and 90 days blood sample for biochemical variables and biomarkers of oxidative stress were taken. Socioeconomic and lifestyle variables were collected with standardized questionnaires. RESULTS after 90 days the fish oil plus vitamin E treated group had a significant decrease in total cholesterol and LDL-C. Furthermore, there was a decrease in anti- LDL- autoantibodies after 45 days. Plasma TBARS concentrations were increased after 90 days in the group receiving only fish oil when compared to the placebo and fish oil-vitamin E groups. All of the effects observed were independent of ethnic group. CONCLUSION supplementation with fish oil and vitamin E reduced total cholesterol and LDL-C, but had opposite effects on oxidative stress compared to supplementation with fish oil alone.

Storage stability of snacks with reduced saturated and trans fatty acids contents

Partially hydrogenated vegetable oil has been used in snack flavoring for its ability to entrap hydrophobic aroma compounds. However, increasing concerns about the health risks of saturated and trans fatty acids (TFA) consumption led to the development of alternative agents for this use. We studied the use of rapeseed oil (O) as a replacement for partially hydrogenated vegetable oil (F) in snack flavoring. Products with several different rapeseed oil contents were designed, packed, and then stored for twenty weeks at room temperature. Fatty acids compositions, TBA reactive substances (TBARS), shear strength and sensory acceptability were assessed throughout storage time. Total replacement reduced saturated fat by 72.5% in relation to market available snacks. TFA were initially absent in these products, but their production occurred spontaneously on the 8th week with gradual increase during storage up to levels still lower than those observed in commercially available snacks. Low TBARS levels and stability of shear strength during the twenty-week of storage were also observed. Snacks flavored with F or O were equally well accepted during the storage period. It is feasible to develop a storage stable snack with reduced saturated and trans fatty acid contents while maintaining the high sensory acceptability typical of this food product.

COMPOSIÇÃO CENTESIMAL E TEOR DE MINERAIS DE DIETAS ENTERAIS ARTESANAIS

O objetivo do presente trabalho foi determinar a composicao centesimal de dietas enterais artesanais a base de hidrolisado proteico de carne. Metodos. A obtencao do hidrolisado proteico de carne foi a descrita por PINTO e SILVA et al, 1999 . Foram analisadas tres formulas com hidrolisado de carne (bovina, frango ou peru) acrescidas de arroz, cenoura, beterraba, amido de milho, glicose de milho e oleo de soja. A composicao centesimal foi determinada pela metodologia preconizada pelo INSTITUTO ADOLFO LUTZ, 1985. A analise de colesterol foi obtida por HPLC. Os acidos graxos foram separados por cromatografia gasosa de alta resolucao. Os valores de fibra alimentar total pela metodologia apresentada por PROSKY et al, 1988. Os minerais foram determinados por espectrofotometria de Absorcao Atomica em aparelho Perkin Elmer modelo 5.100. Resultados. As formulas foram classificadas como hipocaloricas. O teor proteico das formulas variou entre 2.09 e 2.52g/100g, lipideos entre 1.04 e 1.32g/100g, carboidratos 9.32 e 9.67g/100g, com 8g/L de fibras. O colesterol variou entre 14.32mg/100g (frango) e 37.59mg/100g (bovino). As tres formulas desenvolvidas apresentam maior concentracao de acidos graxos monoinsaturados, com prevalencia do oleico. Em relacao aos minerais, os valores de cobre variaram entre 0.07 mg/100g e 0.06 mg/100g, zinco 0.28 mg/100g e 0.62 mg/100g, ferro 0.47 mg/100g e 0.63 mg/100g, magnesio 8.08 mg/100g e 8.58 mg/100g e calcio 1.34 mg/100g e 1.40 mg/100g. As formulas apresentaram teor proteico adequado com predominância de acidos graxos monoinsaturados, sendo indicadas a pacientes que requerem suplementacao nutricional.