Maria Emília de Sousa Gomes Pimenta

Silagem de resíduos da filetagem de tilápia do nilo (Oreochromis niloticus), com ácido fórmico - análise Bromatológica, físico-química e microbiológica

O experimento avaliou o valor nutritivo da silagem acida da filetagem da tilapia do Nilo (Oreochromis niloticus Linneaus, 1758), visando sua utilizacao em substituicao a farinha de peixe na alimentacao de organismo aquatico. A silagem consistiu de residuos da filetagem de tilapia (carcaca) e 3% de acido formico, armazenada em temperatura ambiente (maxima media de 21,5oC) e temperatura minima media de 15oC, por trinta dias, em baldes de polietileno com um orificio, por onde os gases saiam. O pH foi monitorado no 1o, 15o e 30o dia. Foram realizadas analises microbiologicas para contagem total de microrganismos e coliformes a 35oC e 45oC. O pH apresentou media de 3,95 ao final dos 30 dias. Nas analises microbiologicas observou-se a ausencia de coliformes a 45oC e, que a quantidade de microrganismos diminuiu gradativamente. Do ponto de vista microbiologico, a silagem acida de residuo da filetagem de tilapia mostrou-se como alimento alternativo viavel para a alimentacao animal.

Ractopamine levels on performance, carcass characteristics and quality of pig meat

This study evaluated the effect of ractopamine (RAC) on the performance of finishing pigs and the meat quality of these animals. Seventy crossbred pigs (35 barrows and 35 females) selected for high gain of lean meat, with initial weight of 77.1±0.32 kg were distributed in randomized blocks with five treatments (0, 5, 10, 15, and 20 ppm RAC in the diet) and seven replications during 28 days. The experimental unit was represented by a male and a female pig. Regarding the performance variables, there was a linear increase in final weight with increasing levels of RAC, as well as in average daily weight gain. An improvement in feed conversion was observed for animals fed RAC, and the optimal level - estimated by the LRP model - was ~ 5 ppm. For feed intake, no significant effect on intake of digestible lysine and energy intake was observed. Carcass yield responses increased linearly with the RAC dose. Ash content, color component b* and loss drip linearly decreased with increasing doses of RAC. There was also a significant difference in the percentage of ether extract and crude protein in the loin, and treatment with 20 ppm RAC showed a lower amount of protein and larger amounts of lipids. Moisture content, color component L*, weight loss by cooking and defrosting, shear force and pH were not affected by the treatment. Concerning the lipid oxidation, there was no effect of RAC on the concentration of TBARS (thiobarbituric acid reactive substances) under cooling and under freezing. Thus, all ractopamine levels improve performance compared with control and do not negatively affect the quality of fresh, chilled or frozen pig meat.

Alternative fat substitutes for beef burger: technological and sensory characteristics.

This study aimed to develop a type of hamburger meat product and evaluate the physical features and sensory formulations of oatmeal flour, flour of green banana pulp, flour of green banana peel, flour of apple peel and pulp of Green Banana as fat substitutes. Regarding color, the formulations containing fat substitutes based on green banana presented lower values for b* and L*. Hamburgers with added oatmeal and apple peel flour obtained high values of a* and low values of L*, producing the reddest burgers. Substitutes based on green banana differed from others, resulting in a higher yield of burgers and water-holding capacity during cooking, besides having lower toughness and less shrinkage. The sensory acceptance test for untrained consumers suggests that the flour of peel and pulp of green banana, and oatmeal flour are excellent choices for fat-substitution in beef burger. Although fat contributes to a series of physical and sensory attributes such as softness, juiciness and yield, it is possible to reduce the lipid content in beef burgers without depreciating the quality of food through the use of the following fat substitutes: oat flour, apple peel flour, green banana pulp flour, green banana peel flour and green banana pulp.

Evaluation of Nile tilapia strains cultivated in cages under different feeding programmes

The objective of this study was to evaluate the performance of three Nile tilapia Oreochromis niloticus strains cultivated in cages and subjected to different feeding programmes. Initially, 31,200 Nile tilapia juveniles with an average weight of 61.15 g were distributed in 48 cages. Two genetically improved strains were used together with one from the Fish Culture Section of Universidade Federal de Lavras (UFLA). The fish were subjected to four feeding programmes, consisting of different levels of crude protein (CP) in diets provided at different stages of cultivation. There was no interaction effect of the strain and feeding programme for most variables. The UFLA strain presented the highest weight gain, but with greatest lack of uniformity at the end of cultivation. The feeding programme with diets containing 36%, 32% and 28% CP, consecutively, promoted the highest weight gain and highest final biomass. The UFLA strain has great growth potential, justifying the development of a breeding programme for this strain. Crude protein levels below 36% for tilapias between 60 and 170 g and below 32% for tilapias between 170 and 700 g worsen fish performance.

Níveis de farinha de peixe em rações para juvenis de tilápia

This study was conducted to evaluate, in the ration, the use of fish meal supplement with amino acids on performance, carcass characteristics, and on hematological analysis in Nile tilapia juvenils. It was used 140 juveniles with an average weight of 14.0 ± 0.14 g, randomly distributed in a complete random design with five levels of fish meal (0; 1.5; 3.0; 4.5; and 6.0%) in the ration, each one with four replicates. The rations were isoenergetic (3,000 kcal of digestible energy) and isocalcium and fish were fed three times a day until apparent satiety for 60 days. It was evaluated the weight gain, feed intake, apparent feed conversion, protein efficiency rate, hepatosomatic index, carcass weight, carcass yield, nitrogen retention, and hematocrit and hemoglobin rates. The levels of fish meal did not change the weight gain, food conversion, ration intake, hepatosomatic level, carcass yield, carcass weight and hemoglobin rate, but they had a quadratic effect on nitrogen retention, humidity, and fat content on the carcass, and on the hematocrit rate. The higher the levels of fish meal, the lowest the protein efficiency rate and the higher the protein and ash levels in the carcass. The 3% level of fish meal does not affect performance neither carcass characteristics of Nile tilapia juveniles.

Influence of the Addition of Minced Fish on the Preparation of Fish Sausage: Effects on Sensory Properties

In this study, we evaluated the effect of minced fish (MF) inclusion on the acceptance of tilapia sausages. One hundred consumers participated in the sensory acceptance test in relation to the attributes appearance, color, aroma, flavor, texture, overall impression, and purchase intent. The tests were conducted using the same composition of ingredients, varying only the raw material (MF and fillet), resulting in 5 different formulations. To represent the results of the sensory attributes, we generated internal preference maps through principal component analysis and parallel factor analysis, as well as frequency histograms. The data showed greater acceptability for the sample produced with 50% MF, although all had shown satisfactory results. We conclude that inclusion of MF can be suitable in the preparation of fish sausage due to high consumer acceptance.

Fish filleting residues for enrichment of wheat bread: chemical and sensory characteristics.

The fish processing industry generates a large amount of materials discarded as residue. It is known that fish and its residue are a source of essential nutrients. Conversely, bread is a food accessible to different social classes but is deficient in protein, minerals, and fatty acids. Thus, this study aimed to develop bread products based on the addition of flour from Red-tailed Brycon (Brycon cephalus) processing residue and then evaluate the chemical and sensory qualities of the products. In relation to a standard bread formulation without fish flour, the addition of fish flour to bread formulations resulted in products with not only higher contents of protein, essential fatty acids, and minerals, especially calcium and phosphorus, but also lower contents of carbohydrates. The breads with fish flour received sensory acceptance better than or as good as that of a bread formulation without fish flour. Hence, the addition of fish processing residue to breads is a way to provide essential nutrients to the population through a well-accepted, accessible, and low-cost product.

Effect of ractopamine on the chemical and physical characteristics of pacu(Piaractus mesopotamicus) steaks

The objective was to evaluate the use of ractopamine (RAC) in the diet for pacu (Piaractus mesopotaminus) in the finishing phase on some quality parameters of the fillets. Thirty-five animals weighing 0.868±0.168kg were distributed in a completely randomised design with five treatments (0.0 - control; 11.25, 22.50, 33.75 and 45 ppm of RAC) and seven replicates with two fillets obtained from the same animal. The diets were isocaloric and isoprotein and experimental time was 90 days. RAC did not affect (P>0.05) the initial pH or ph after 24 hours of the fillets. Compared to the control, RAC increased (P<0.05) the moisture content of the fillets in natura and lipid oxidation of samples stored for 12 days in the refrigerator or freezer for 60 days. The RAC in 11.25 ppm reduced (P<0.05) the lipid content, while 45 ppm reduced (P<0.05) the crude protein in the fillets. Considering only RAC, there was a linear increase (P<0.05) in the lipid content (P<0.05) and a linear reduction in crude protein and weight loss after cooking the fillets. There was a quadratic effect (P<0.05) on the ash content, weight loss and lipid oxidation in fillets stored in the refrigerator or freezer. A RAC dose of 33.75 ppm resulted in a lower lipid oxidation index. In conclusion, ractopamine at 11.25 ppm is effective for reducing the fat content in fillets of pacu, although it increases the formation of peroxides in samples kept in the freezer for longer than 60 days. At 33.75 ppm, ractopamine is effective in reducing the effect of oxidation during storage in the refrigerator or freezer.

Desempenho produtivo de Brycon orthotaenia em tanques-rede sob diferentes densidades de estocagem

The objective of this study was to determine the stocking density of matrinxa (Brycon orthotaenia) in cages, considering the productive performance. Juvenile Brycon orthotaenia (n = 5280) were distributed in 16 cages of 4m³ at densities of 45, 70, 95 and 120 fish m -3. The fish were fed with commercial feed with 40% crude protein during all experimental period. Data were subjected to analysis of variance and linear regression to estimate the best fit using 5% probability. The production parameters such as survival, initial weight, final weight, feed conversion and specific growth rate were not influenced by stocking density, as well as the parameters of water quality. However, final biomass, biomass gain and feed intake showed a positive linear relationship with stocking density. Evaluating these results, it was concluded that the stocking density of matrinxa (Brycon orthotaenia) up to 120 fish m -3 represent the best productive performance.

Desempenho produtivo e digestibilidade pela tilápia do NILO (Oreochromis niloticus Linnaeus, 1758) alimentada com dietas suplementadas com níveis crescentes de silagem ácida de pescado

The experiments were carried out in order to evaluate the apparent digestibility coefficients of the nutrients and gross energy of acid silage of filetage residues of the Nile tilapia. The treatments were based on the increasing levels (0, 10, 20, 30, 40%) of the acid silage by substitution of fish meal in the diets. In the digestibility assay a total of 200 sexually inverted juveniles were used. The average weight was 2.0 g and were kept in 40 liter aquariums. Feces collect was made during seven subsequent days and the apparent digestibility coefficients and apparent digestible energy were determined by indirect method, using 1.0% of Cr203 as an indicator. In the performance assay 2000 sexually inverted juveniles were used, with average weight of 0.45g, kept in 1m2 hapas, in a fish crawl. The analyzed variables were: final weight (FWG), total feed intake (TFI), apparent feed conversion (AFC) and length increase (LI). The randomized outline was used with five treatments and four repetitions. The values for apparent digestibility were: apparent digestibility coefficient of dry matter, 95.49%; apparent digestibility coefficient of gross protein, 96.66%; apparent digestibility coefficient of ether extract, 97.18%; apparent digestibility coeficient of gross energy, 95.44%. There was no significant difference (P>0.05) for total feed intake (TFI). One observed a quadratic effect (P<0.01) in the final weight (FWG), apparent feed conversion (AFC) and length increase. One concluded that the acid silage of filetage residues should be efficiently used by the Nile tilapia.