Leila Picolli da Silva

Prebióticos na nutrição de não ruminantes

Due to the increasing constraint on the use of veterinary drugs as growth promoters in nonruminants nutrition there is a need to develop alternatives in supporting the microflora of the digestive tract in their approach to control pathogenic bacteria. The prebiotics are resistant compounds to digestion in the animal digestive tract, but selectively fermentable by intestinal microflora. These compounds can beneficially affect native microbiota, immune system and intestinal mucosal improving the digestion and absorption of nutrients. However, not always the use of the prebiotics causes alterations in the biological response. There may be several factors involved that partly explain the lack of response, such as: differences in the chemical composition of the ingredients of the diet, differences in the levels (percentage) of the prebiotics used in the diet, adaptation and the selectivity of the microflora and stress factors.

Estrutura dos grânulos de amido e sua relação com propriedades físico-químicas

Due to poor Brazilians work on the structure of starch granules, the purpose of this review was to demonstrate the advances in current understanding of architecture and chemical structure of this polymer. Many studies evaluating the relationship between the molecular structure of starch and its behavior in some physicochemical properties, suggest that several structural features, such as amylose content, amylopectin chain length distribution and the degree of crystallinity in the granule, are closely related to the events associated with gelatinization and retrogradation as starch granule swelling, amylose and/or amylopectin leaching, loss of radial structure (birefringence), supra-molecular (crystallinity) and molecular order, and recrystallization. The main focus of this review was to make a compiler of studies in order to gain better understanding of the granule structure and characteristics of starch components and physicochemical properties (gelatinization and retrogradation) that could play a significant role in improving the quality of different food products.

Alterations in fatty acid composition due to cold exposure at the vegetative stage in rice.

Rice is a tropical plant, so cold temperature may be detrimental to its development, depending on the genotype and environmental conditions. Degree of lipid unsaturation has been related to cold tolerance due to its effect on membrane stability. So, the aim of this study was to characterize the fatty acid composition and its alterations due to cold temperature in rice genotypes of diversified origin. Forty-four rice genotypes at the V4 stage were submitted to two temperature conditions: 10°C and 28°C for two days and after this they had their leaves collected for lipid extraction and quantification. Control plants were allowed to regrow until presenting four leaves fully expanded and then were subjected to 10°C for ten days for cold tolerance evaluation. Plant survival was measured seven days after recovery at 28°C and the genotypes were grouped in three cold tolerance classes: tolerant, intermediate and sensitive. These classes differed for total saturated and unsaturated fatty acids only under the cold temperature treatment. Further analysis of the more abundant fatty acids: linoleic, linolenic and palmitic, showed that the two last ones differed between tolerant and sensitive genotypes. Linolenic acid increased after cold exposure in cold tolerant genotypes while palmitic acid decreased, and an opposite behavior was found in the cold sensitive genotypes. These evidences indicate that these fatty acids are potential molecular markers useful for breeding programs as well as for future basic studies on cold tolerance in rice.

Dietary fibre: The scientific search for an ideal definition and methodology of analysis, and its physiological importance as a carrier of bioactive compounds

There is a growing need for a global consensus on the definition of dietary fibre and the use of appropriate methodologies for its determination in different food matrices. Oligosaccharides (prebiotic effect) and bioactive compounds (antioxidant effect) are important constituents of dietary fibre, which enhance its beneficial effects in the body, such as those related to maintaining intestinal health. These dietary components need to be quantified and addressed in conjunction with fibre in nutritional studies due to the close relationship between them and their common destiny in the human body. This review discusses updates to the concept of dietary fibre, with an emphasis on biological and methodological aspects, and highlights the physiological importance of fibre as a carrier of bioactive compounds.

Atividade antibacteriana, antioxidante e tanante de subprodutos da uva

The aim of this research was to determine in vitro the antibacterial, antioxidant and tanning activity from grape by-products (Vitis vinifera), for its use as alternative ingredients in the poultry industry and food conservation. Polar compound had been extracted of the defatted grape seed (SUD) in a solution with acetone, water and acetic acid, in the 90: 9.5: 0.5 ratio respectively, resulting in a yield of 10.3% of defatted grape seed extract (ESUD). ESUD has high antibacterial activity against strains of S. aureus and E. coli, but not against Salmonella sp. The antioxidant activities of the ESUD had comparable to the ascorbic acid. The capacity to bind proteins was considered low for the seed and high for the ESUD.

Cultivo de jundiás alimentados com dietas com casca de soja ou de algodão

The objective of this work was to evaluate the effect of crude fiber on growth, digestive parameters, and yield and carcass quality of jundia (Rhamdia quelen) juveniles in net cages. The experimental design was completely randomized in a 2x3 factorial scheme (two sources - soy and cotton hull - and three levels of crude fiber: 4, 7 and 10%), with three replicates. Four hundred and fifty fishes (129.11± 7.8 g) were randomly distributed in 18 net cages (1 m3), at densities of 25 fish per cage, in 0.1 ha earth fishpond. The following parameters were evaluated: weight, total length, weight gain, biomass, survival, carcass and fillet yield, chemical composition of fillet, digestive and hepato-somatic indexes, intestinal quotient. No difference was detected in the growth performance. Fish fed with soy hull diets presented more fat and mineral accumulation on fillets. The sources and fiber levels tested do not affect jundias performance.

Amido resistente: características físico-químicas, propriedades fisiológicas e metodologias de quantificação

Found in different foods, starch is the most important source of carbohydrates in the diet. Potentially digested by enzymes in the gastrointestinal tract, it is absorbed as glucose in the small intestine. Despite this fact, significant amount of starch may escape digestion, reaching the colon, where it is fermented by intestinal flora. This fraction, known as resistant starch, has been extensively studied for some years because of its potential beneficial effects on human health. Many methods are used to determine resistant starch. Nevertheless, none has received unanimous approval, since the existing ones have important differences in protocols and in obtained results. In this context, the present work aimed at providing subsidies to better understand the physico-chemical characteristics, metabolic and physiological properties as well as variations in the existing methodologies for resistant starch determination.

Cultivar, harvest year, and storage conditions affecting nutritional quality of common beans (Phaseolus vulgaris L.

Compararam-se as caracteristicas fisico-quimicas de dezesseis cultivares de feijao-comum cru ao longo de duas safras consecutivas, assim como se avaliou o efeito das condicoes de armazenagem nos teores de amido e fibra alimentar em graos cozidos. A analise de agrupamento possibilitou a identificacao de grupos de cultivares com caracteristicas nutricionais distintas. Estas cultivares foram categorizadas em quatro grupos de acordo com o conteudo de macronutrientes (proteina bruta-PROT, fibra alimentar total-TDF, fibra alimentar insoluvel-IDF, fibra alimentar soluvel-SDF, amido disponivel-DS e amido resistente-RS) ou de micronutrientes (Fe, Zn, Mn, Cu, Ca, Mg, e P). Guateian 6662 e Rio Tibagi mostraram-se as cultivares mais adequadas para prevenir deficiencias nutricionais, devido aos altos teores de PROT, DS, Fe e Zn. Os altos teores de fibra alimentar total e RS das cultivares Irai, Minuano e TPS Bonito, e especialmente os altos teores de fibra soluvel das cultivares Guateian 6662 e Rio Tibagi sugerem que estas poderiam auxiliar no controle dos lipidios e glicose sericos. Os graos cozidos apresentaram reducao no DS e aumento de RS apos armazenagem (4 °C ou -20 °C), mas estas alteracoes foram mais pronunciadas em feijoes que tinham baixos teores de RS antes do cozimento do que naqueles com altos teores. Os teores de TDF, IDF, e SDF nao alteraram apos a armazenagem.

Produção de salgadinho extrusado de quirera de arroz para uso na indústria de alimentos

Brazil is the main producer of rice outside the Asiatic continent. During the manufacturing, about 14% of broken rice are generated, which represents economic loss for the countrys rice industry. Nevertheless, this residual product has enormous potential for using in food industry. The aim of the study was to evaluate the applicability of broken rice in the extruded snack formulation. The snack was sensory evaluated by testing acceptability and purchase intent, and chemically, by centesimal composition. The snacks of broken rice cheese flavor showed good sensorial acceptability, in spite of the loss in appearance and color scores when compared to the corn ones prepared by the same company. The extruded snacks showed lower moisture content, equal levels of protein and higher levels of ash, fat and fiber when compared to native broken rice. The changes promoted in broken rice by extrusion made possible its commercial application.

Componentes da parede celular e digestibilidade in vitro de palha de arroz (Oryza sativa) com diferentes teores de silício

Silicon (Si) is absorbed by plants and accumulated in shoot, what can affect nutritional quality of forages. The objective of this work was to evaluate the cell wall composition, estimated by FDA, FDN and lignin, and in vitro digestibility of rice shoots cultivated in nutritious solution with and without Si. There were differences in organic matter and ash contents, and there were no differences in total wall, cellulose and lignin. There were more minerals associated with cell wall of rice straw with Si, which presented less hemi-cellulose deposition in this material. Silicon did not affect in vitro digestibility of rice straw.