Dietary fish oil replacement with lard and soybean oil affects triacylglycerol and phospholipid muscle and liver docosahexaenoic acid content but not in the brain and eyes of surubim juveniles Pseudoplatystoma sp.

Triplicate groups of juvenile suribim were fed for 183 days one of four different isonitrogenous (47.6% crude protein) and isolipidic (18.7% lipid) diets formulated using three different lipid sources: 100% fish oil (FO, diet 1); 100% pig lard (L, diet 2); 100% soybean oil (SO, diet 3), and FO/L/SO (1:1:1, w/w/w; diet 4). The tissue levels of fatty acids 18:2n-6 and 18:3n-3 decreased relative to corresponding dietary fatty acid values. The 20:5n-3 and 22:6n-3 composition of muscle and liver neutral lipids were linearly correlated with corresponding dietary fatty acid composition. In contrast, the 22:6n-3 composition of the brain and eye were similar among treatments. The 22:6n-3 level was enriched in all tissues, particularly in the neural tissues. Similar results were observed for tissue polar lipids: fatty acids content reflected dietary composition, with the exception of the 22:6n-3 level, which showed enrichment and no differences between groups. Given these results, the importance of the biochemical functions (transport and/or metabolism) of 22:6n-3 in the development of the neural system of surubim warrants further investigation.

Separation and quantification of beer carbohydrates by high-performance liquid chromatography with evaporative light scattering detection.

An HPLC method with an evaporative light scattering detector was optimized and validated for quantification of carbohydrates in beer. The chromatographic separation was achieved using a Spherisorb NH2, 5 microm chromatographic column and gradient elution with acetonitrile/water. The determinations were performed in the linear range of 0.05-5.0 g/L for fructose, 0.05-5.0 g/L for glucose, 0.05-15.0 g/L for maltose, 0.05-10.0 g/L for maltotriose, and 0.05-5.0 g/L for maltotetraose. The detection limits were 0.005 g/L for fructose, 0.008 g/L for glucose, and 0.01 g/L for maltose, maltotriose, and maltotetraose. The reliability of the method in terms of precision and accuracy was evaluated in three beer matrices, low alcohol beer, 6% alcohol beer, and beer made with part of adjuncts (4.5% alcohol). Relative standard deviations (RSDs) ranged between 1.59 and 5.95% (n = 10), and recoveries ranged between 94 and 98.4%.

Flavor composition of cashew (Anacardium occidentale) and marmeleiro (Croton species) honeys.

The aim of this work was to characterize the volatile fractions of two Brazilian honeys known as caju and marmeleiro. The volatile components were isolated by a column extraction technique using acetone as the extraction solvent. Totals of 59 and 36 volatile compounds were definitely or tentatively identified in the caju and marmeleiro honeys, respectively, using reference substances, mass spectral libraries, and the odor qualities of the compounds eluted from the GC column. Aroma extraction dilution analysis allowed the tentative identification of furfuryl mercaptan, benzyl alcohol, delta-octalactone, gamma-decalactone, eugenol, benzoic acid, isovaleric acid, phenylethyl alcohol, and 2-methoxyphenol as impact volatile compounds in the caju honey. In the marmeleiro honey, only isovaleric acid, gamma-decalactone, benzoic acid, and vanillin were considered to be potent odorants. This study showed that the medium- to high-boiling volatile compounds are important contributors to the characteristic aroma of these honeys.

Development and sensory evaluation of soy milk based yoghurt.

Yoghurts were prepared by fermentation of soy milk using a mixed starter culture containing Lactobacillus bulgaricus and Streptococcus thermophilus. Soy milk at 9 degrees Brix was homogenised under pressure (17 MPa) and fermented with and without addition of sucrose (2.0 and 2.5 g per 100 g) for 4, 5, 6 and 7 hours. The yoghurts were evaluated in terms of sensory quality, pH, titrable acidity, phytic acid and oligosaccharides: A yoghurt with the best sensory quality was obtained using the homogenised soy milk with 2% sucrose addition and fermented for 6 h. Lactobacillus bulgaricus and Streptococcus thermophilus did not produce phytases and alpha-galactosidases at the experimental conditions, consequently, phytic acid and galactosides were not affected by the process.

Discrimination of Brazilian arabica green coffee samples by chlorogenic acid composition.

Coffee is basically consumed for the pleasure given by its taste and aroma, that is, the quality and acceptance of the coffee beverage are directly related to its sensorial characteristics. Thus, nowadays coffee quality is basically evaluated by sensorial analysis. However, together with this kind of analysis, it should be important to have available more objective chemical methods to assess coffee quality. One possible approach could be based on the analysis of chlorogenic acids (CGA), since they are considered precursors of coffee flavour and pigments during roasting. In the present work, high performance liquid chromatography (HPLC) analysis of chlorogenic acids was applied to six different Brazilian arabica green coffee samples which were previously characterised by sensorial analysis. The results showed the potential to correlate the chemical data, evaluated by the Principal Components Analysis (PCA) statistical method, with sensorial analysis in order to discriminate the quality of the samples. It was observed that the 3,4-dicaffeoylquinic (3,4-diCQA) and 3,5-dicaffeoylquinic (3,5-diCQA) isomers are very important for grouping the coffees into good and bad samples.

Synthesis and transport of different sphingomyelin species in rat Sertoli cells.

Cellular phospholipids of Sertoli cells from immature rats were labeled with [14C]-choline. Two sphingomyelin bands (SM1 and SM2) were identified by TLC. The incorporation of [14C]-choline over a 45 h period of incubation demonstrated that there are differences in labeling kinetics between SM1 and SM2. The subcellular location of SM1 and SM2 was investigated by accessibility to bacterial sphingomyelinase. The results showed the existence of two SM pools in Sertoli cells, but an equal cellular distribution of SM1 and SM2. SM2 is characterized by a relatively high content of unsaturated fatty acids. The inhibition of vesicular flow by monensin determines a decrease of about 60-70% in incorporation into SM1 and SM2, suggesting the existence of at least two sites of sphingomyelin synthesis. Pulse-chase and time-course experiments indicated a phosphatidylcholine --> SM precursor product relationship and differences in kinetic properties between SM1 and SM2. Resynthesis experiments showed that monensin had only a partial inhibitory effect on SM1 resynthesis, and a second sphingomyelinase treatment demonstrated that the resynthesized fraction reached the outer leaflet of the plasma membrane. The 60-70% inhibition of SM synthesis by monensin showed that the trans-Golgi cisternae and the trans-Golgi network are the most likely sites of bulk SM synthesis, and that about 15% of SM was synthesized in the cis/medial Golgi apparatus. Additionally the results indicated that plasma membrane SM synthase activity could be the site of about 15% of SM synthesis in Sertoli cells.

Discrimination of Brazilian arabica green cofee samples by chlorogenic acid composition

O café é consumido basicamente pelo prazer que seu sabor e aroma proporcionam, isto é, a qualidade e aceitacao da bebida do café estao diretamente relacionadas com suas características sensoriais. Por conseguinte, atualmente a avaliacao da qualidade dessa bebida é realizada através de análise sensorial. Entretanto, é óbvia a importância do desenvolvimiento de novas metodologias capazes de diferenciar, de forma prática e objetiva, os diferentes tipos de café. Nesse sentido, tem sido crescente os esforcos a fim de correlacionar a qualidade do café com o conteúdo dos chamados ácidos clorogenicos (ACG) do café, uma vez que esse grupo de compostos apresenta importância reconhecida com relacao á farmacao de pigmentos, sabor e aroma nesse produto. No presente trabalho foram obtidos, por cromatografía líquida de alta eficiencia (CLAE), os perfis dos diferentes isômeros dos ácidos clorogênicos de seis asmostras de cafés verdes brasileiros da espécie Coffea arabica, previamente classificadas sensorialmente. Os resultados obtidos indicaram que existe um bom potencial para correlacionar os dados químicos, tratados pelo método estatístico de Análise dos Componentes Principais (ACP), com as análises sensoriais como forma de diferenciar a qualidade desses tipos de amostra. Foi observado que os isomeros 3,4-dicafeoilquínico (3,4-diCQA) e 3,5-dicafeoilquínico (3,5-diCQA) sao muito importantes para o agrupamento das amostras boas e ruins mencionadas acima

Development and sensory evaluation of soy milk based yoghurt

Foram elaborados iogurtes através da fermentaçao de leite de soja, usando uma cultura mista de lactobacillus bulgaricus e Streptococcus thermophilus. O leite de soja com 9ºBrix foi homogeinizado sob pressao (17 MPa) e fermentado com e sem adiçao de sacarose (2,0 e 2,5g por 100g)por 4,5,6 e 7 horas. Os iogurtes obtidos foram analisados em relaçao as características sensoriais, pH, acidez titulável, fitatos e oligossacarídeos. Foi obtido um iogurte com óptimas qualidades sensoriais, a partir do leite de soja homogeinizado, com adicao de 2 por ciento de sacarose e fermentado por 6h. Os microrganismos utilizados nao produziram fitases e alfa-galactosidases e, consequentemente, os teores de alfa-galactosídeos e de filatos nao foram alterados pelo processamento

Effect of heat treatment on nutritional quality of germinated legume seeds.

The effect of heat treatment of germinated soybean, lupin, and black bean on chemical composition and protein utilization in rats was evaluated. Heat treatment caused complete inactivation of trypsin inhibitors whereas it did not affect phytic acid levels. Proximate components, minerals, and amino acids did not change, but low molecular weight sugars were affected by heat treatment differently for each germinated legume. The sugar digestibility ratio (total digestible sugars/total nondigestible sugars) in germinated black beans doubled after heat treatment. True protein digestibility (TD) increased with heat treatment only in germinated soybean. Net protein utilization was markedly improved (20%) with heat treatment in germinated soybean and lupin. Utilizable protein of heat-treated germinated legumes was 289, 236, and 132 g/kg of legume dry weight for soybean, lupin, and black bean, respectively. Supplementation with methionine did not alter TD but improved all other indices of protein utilization in the germinated legumes, particularly in black bean. All three germinated legumes become equivalent in protein quality when heating and supplementation with methionine are combined with germination. The use of germinated heat-treated soybean, lupin, and black bean on their own and/or as food ingredients is nutritionally advantageous due to the low content of nondigestible oligosaccharides and the high protein utilization.

[Effect of malting and thermoplastic extrusion on the technologic quality of soybean-derived products]. / Efeito da maltagem e da extrusão termoplástica sobre a qualidade tecnológica da cultivar de soja br 16.

Seeds of soybean cultivar BR 16 were submitted to malting for 24 and 48 hours and to extrusion originating flakes used as ingredient to make biscuits which were chemically and sensorially evaluated. Macronutrient composition did not show any relevant modification presenting only a small decrease in carbohydrates and increase in the relative lipid composition. Some anti-nutritional factors were affected by the processes. Trypsin inhibitors decreased about 50% after 24 h of malting and disappeared after extrusion. Phytic acid was resistant to the processes while alfa-galactosides presented about 80% of loss as a result of the combination of malting and extrusion.

Quality control of beer hopped with reduced isomerised products.

The traditional method for measuring bitterness in beer by UV absorbance (ASBC 9.6) remains a viable quality control method for normally hopped beer. However, after reduction of isoalpha acids specific absorptivity of active components change and HPLC analysis shows to be a reliable method for quality control of these materials. This work is intended to adapt mathematically the ASBC (American Society of Brewing Chemist) spectrophotometrical method and to evaluate an HPLC method to control the composition of different commercial reduced isomerised products added to unhopped wort and partially kettle hopped beer. The results we obtained showed that the HPLC method is reliable for quality control of reduced isomerised products and that the traditional spectrophotometrical method is viable for quality control of beer, also using reduced isomerised products as far as an adequate factor is used.

Trehalose accumulation in mutants of Saccharomyces cerevisiae deleted in the UDPG-dependent trehalose synthase-phosphatase complex.

In Saccharomyces cerevisiae, trehalose-6-phosphate synthase converts uridine-5'-diphosphoglucose and glucose 6-phosphate to trehalose 6-phosphate which is dephosphorylated by trehalose 6-phosphatase to trehalose. These two steps take place within a complex consisting of three proteins: trehalose-6-phosphate synthase encoded by the GGS1/TPS1 (= FDP1, = BYP1, = CIF1) gene, trehalose 6-phosphatase encoded by the TPS2 gene and by a third protein encoded by both the TSL1 and TPS3 genes. Using three different methods for trehalose determination, we observed trehalose accumulation in ggs1/tps1delta, tps2delta and tsl1delta mutants, and in the double mutants ggs1/tps1delta/tps2delta and also in ggs1/tps1delta deleted mutants suppressed for growth on glucose. All these mutants harbor MAL genes. Trehalose synthesis in these mutants is probably performed by the adenosine-5'-diphosphoglucose-dependent trehalose synthase, (ADPG-dependent trehalose synthase) which was detected in all strains tested. It is noteworthy that trehalose accumulation in these mutants was detected only in cells grown on weakly repressive carbon sources such as maltose and galactose or during the transition phase from fermentable to non-fermentable growth on glucose. alpha-Glucosidase activity was always present in high amounts. We also describe an adenosine-diphosphoglucosepyrophosphorylase (ADPG-pyrophosphorylase) activity in Saccharomyces cerevisiae which increased concomitantly with the accumulation of trehalose during the transition phase from fermentable to non-fermentable growth in MAL-constitutive (MAL2-8c) strains. The same was observed when MAL-induced (MAL1) strains were compared during growth on glucose and maltose. These results led us to conclude that maltose-induced trehalose accumulation is independent of the UDPG-dependent trehalose-6-phosphate synthase/phosphatase complex; that the ADPG-dependent trehalose synthase is responsible for maltose-induced trehalose accumulation probably by forming a complex with a specific trehalose-6-phosphatase activity and that ADPG synthesis is activated during trehalose accumulation under these conditions.

Nitrogen starvation in a Saccharomyces cerevisiae strain deleted in the trehalose-6-phosphate synthase complex.

Little is known about the mechanisms by which nutrient limitation leads to G1 arrest in Saccharomyces cerevisiae. We have shown that mutant cells deleted in the trehalose-6-phosphate synthase gene able to grow on glucose, when starved for nitrogen, did not arrest in the G1 phase of the cell cycle. We attribute this effect to an increase in the activity of cAMP-dependent protein kinase. When grown on maltose without nitrogen they arrested properly in G1. Tests with a mutant cell deleted in the specific trehalose phosphatase proved that the presence of the trehalose precursor, trehalose-6-phosphate, was sufficient to trigger the negative sign during nitrogen starvation, leading the cells to arrest in the G1 phase of the cell cycle.

Effect of subadequate maternal vitamin-A status on placental transfer of retinol and beta-carotene to the human fetus.

The placental transfer of retinol and beta-carotene was assessed based on maternal serum, cord serum and placental levels at term parturition in women with adequate (n = 15; serum retinol > 20 micrograms/dl) and subadequate (n = 16; serum retinol < or = 20 micrograms/dl) vitamin-A status. There was no difference in retinol and beta-carotene levels in placenta and cord serum between these groups. However, differences in the relation of maternal, placental and cord blood components were observed between women with adequate and subadequate vitamin-A status. In women with subadequate status, circulating fetal retinol levels correlated with placental retinol levels, and maternal serum beta-carotene correlated with placental retinol. Within this group, maternal serum beta-carotene and cord serum retinol correlated significantly in women with serum retinol levels lower than 15 micrograms/dl. These results suggest that beta-carotene may be a precursor of retinol in placenta and that this conversion may depend on the nutritional status of the mother, being particularly effective in a more depleted state.

Application of high performance liquid chromatography to the analysis of some non-volatile coffee components.

High performance liquid chromatography (HPLC) was applied to the analysis of caffeine, trigonelline, nicotinic acid and sucrose in Arabica and Robusta coffee. Green and roasted coffee samples were used in this study and the degradation of sucrose and trigonelline, with the formation of nicotinic acid, was followed during roasting. Caffeine did not undergo significant degradation with only 5.4% being lost under severe roasting. Sucrose was degraded rapidly during processing with light roasting producing a 97% loss and dark roasting degrading it completely. Loss of trigonelline was strongly dependent on the degree of roasting, being higher in the Robusta coffee. Trigonelline degradation was associated with nicotinic acid formation both in the Arabica and Robusta coffees as a consequence of the roasting process. Trigonelline and sucrose were determined simultaneously by partition chromatography and detection with the mass detector. Determination of caffeine was carried out using reversed phase chromatography and nicotinic acid by ion-pair reversed phase chromatography. Detection in both cases was achieved using an ultraviolet detector at 272 nm or 254 nm, respectively. HPLC showed adequate precision and accuracy for routine analyses. In addition, the methods used were more rapid and simple than traditional procedures. HPLC appears to be a suitable technique for quality control in the coffee industry, and for fundamental investigation on the mechanisms involved in the roasting process.

[Effect of roasting on the chromatographic profile obtained by gel filtration of Arabian coffee extract]. / Efeito da torrefacão no perfil cromatográfico obtido por filtração em gel de extratos de café Arábica.

Gel filtration chromatography under a high pressure system was used to investigate green and roasted coffee aqueous extracts. Chromatographic columns used were of the type TSK-PW 4000, in series. Chromatography of the extracts was monitored either using a refractive index (RI) detector in series with an ultraviolet (UV) detector at 420 nm or with two UV detectors at 280 and 325 nm, respectively. The utilization of RI detection showed significant differences in the molecular weight profile between green and roasted coffees. UV detection at 280 and 325 nm revealed similar chromatographic patterns, suggesting that phenolic compounds were probably bound to proteins. Pigment formation after roasting was monitored by detection at 420 nm, showing that colored material was distributed throughout the molecular weight range studied. The method provided a more rapid analysis compared to traditional gel filtration chromatography and proved to be useful for monitoring changes in molecular weight profile which occur during coffee roasting.