Catarina Abdalla Gomide

Predicting pork quality using Vis/NIR spectroscopy

Visible and near-infrared reflectance spectroscopy (Vis/NIRS) was used to predict the ultimate pH (pHu), color, intramuscular fat (IMF) and shear force (WBSF) of pork samples and to build classifiers capable of categorizing the samples by tenderness (tender or tough) and juiciness (juicy and dry). Spectra were collected from 400 to 1495nm, and 200 data points were generated for every sample (n=134). Sixty-seven percent of the sample set was used for calibration, and 33% was used for validation. Partial least squares (PLS) calibration models were developed for each characteristic measured. A coefficient of determination (R(2)) and residual prediction deviation (RPD) were used to evaluate the accuracy of the calibration models. The pHu and color prediction models developed in this study fit this classification, indicating that these predictive models can be used to predict quality traits of intact pork samples. The Vis/NIRS offered great potential for correctly classifying pork Longissimus into two tenderness and two juiciness classes.

Crescimento heterogêneo de girinos de rã-touro alimentados com diferentes rações

This work tested the performance and growth variability (heterogeneous growth) of Rana catesbeiana tadpoles fed with isocaloric food constituted of four levels of crude protein: three experimental levels (33.6%, 26.6% and 22.5%), and one commercial feed (46.5%). The tadpoles were kept, during three months, in containers with capacity for 1,000 L supplied with running water at density of one tadpole L-1. The tadpoles were fed twice a day with ad libitum portions, and submitted to the body weight records every fifteen days. The group fed with commercial food (46.5% crude protein) showed better biomassa performance, however the heterogeneous growth was elevated, with body members deformations in some individuals (27% of tadpoles of the total tadpole-initiated metamorphosis, and 5% at the end). Tadpoles fed with 33.6% and 26.6% of crude protein had similar growth, less heterogeneous growth and did not show body deformations, indicating that these protein concentration might be more adequate than the commercial one. Food with 22.5% of crude protein showed to be inadequate for the nutritional needing of the tadpoles, so it was excluded from the experiment, in order to preserve the animals from injury and death.

Influência da diferença cátion-aniônica da dieta sobre o balanço de cálcio, fósforo e magnésio em ovinos

The dietary cation-anion balance (DCAB) effect on the macromineral (calcium, phosphorus and magnesium) balance, urinary and faecal pH, serum concentration of calcium, phosphorus and magnesium was studied in 16 Santa Ines adult sheep, during 26 days, being a seven-day-period of adaptation. The experiment consisted in a completely randomized block design with four treatments. Calcium chloride and sodium bicarbonate were added to DCAB manipulations to achieve the values: -12; + 30; +76 and +133mEq/kg DM. There was no effect of DCAB (P>0.10) on fecal and urinary pH, and on phosphorus and magnesium balance. The increase in the DCAB corresponded to a decrease in calcium absorption and calcium retention, and an increase in calcium fecal excretion values. The manipulation of the DCAB affected the macromineral metabolism, mainly the calcium metabolism.

Dehydration of "dedo de moça" pepper: kinetics and phytochemical concentration

A pimenta vermelha e rica em vitamina C e outros fitoquimicos e pode ser consumida como produto desidratado. A avaliacao das melhores condicoes de secagem pode garantir melhor qualidade do produto. Assim, o objetivo deste trabalho foi estudar o efeito da temperatura do ar de secagem (55, 65, 75 oC) sobre a cinetica de secagem, conteudos de vitamina C e fenolicos totais e cor do produto desidratado, comparando-os a pimenta in natura. A desidratacao foi feita por conveccao forcada em estufa. A cinetica de secagem foi determinada por pesagens periodicas ate peso constante. A umidade da pimenta in natura foi de aproximadamente 86%. As curvas de secagem foram ajustadas por tres modelos diferentes, avaliados na literatura. O modelo de Page apresentou o melhor ajuste para este processo. A analise de variância mostrou que a temperatura de secagem influenciou significativamente (p < 0,05) os parâmetros de qualidade (conteudo de vitamina C, conteudo de fenolicos totais, cor) da pimenta desidratada quando comparados aos da pimenta in natura. Apos a secagem, a retencao de vitamina C aumentou com a reducao da temperatura de secagem. De maneira geral, a qualidade do produto foi favorecida na secagem com menor temperatura, devido a reducao nas perdas de compostos bioativos.

Use of benzoic acid for piglets

Um experimento foi conduzido com o objetivo de avaliar os efeitos da inclusao de acido benzoico (Vevovitall®) na dieta sobre o desempenho e a morfologia intestinal do duodeno de leitoes de 28 a 70 dias de idade. Foram utilizados 160 leitoes Dalland × Penarlan desmamados aos 21 dias de idade, separados por sexo. O experimento foi dividido em fases pre-inicial 1 (28 a 35 dias de idade), pre-inicial 2 (36 a 46 dias de idade) e fase inicial (47 a 70 dias idade). Utilizou-se o delineamento experimental tipo blocos ao acaso com 5 tratamentos, cada um com 8 repeticoes de 4 animais, totalizando 40 unidades experimentais. Foram utilizados quatro niveis de acido benzoico (0; 0,25; 0,50 e 0,75%) e um tratamento testemunha com acido fumarico. Abateram-se, aos 70 dias de idade, dois animais por repeticao para coleta de amostras do duodeno e estudo da morfologia intestinal e um animal por repeticao para estudo de lesoes gastricas. Foram avaliadas as caracteristicas de desempenho (ganho de peso, consumo de racao e conversao alimentar) para cada fase e para o periodo total. Como caracteristicas morfologicas, foram avaliadas a altura das vilosidades, a profundidade de criptas e a relacao altura de vilosidades/profundidade de criptas. Avaliou-se ainda a incidencia de diarreia. No periodo de 28 a 70 dias, o uso de acido benzoico influencia o desempenho de suinos, que neste estudo foi melhor os niveis de 0,50 e 0,75%, e reduz a incidencia de diarreia. Animais alimentados com dietas contendo acido benzoico apresentam maior altura de vilosidade e profundidade de criptas.

Substitution of crude cell wall for neutral detergent fibre in the equations of the Cornell Net Carbohydrate and Protein System that predict carbohydrate fractions: application to sunflower (Helianthus annuus L.)

Prediction of carbohydrate fractions using equations from the Cornell Net Carbohydrate and Protein System (CNCPS) is a valuable tool to assess the nutritional value of forages. In this paper, these carbohydrate fractions were predicted using data from three sunflower (Helianthus annuus L.) cultivars, fresh or as silage. The CNCPS equations for fractions B2 and C include measurement of ash and protein-free neutral detergent fibre (NDF) as one of their components. However, NDF lacks pectin and other non-starch polysaccharides that are found in the cell wall (CW) matrix, so this work compared the use of a crude CW preparation instead of NDF in the CNCPS equations. There were no differences in the estimates of fractions B1 and C when CW replaced NDF; however, there were differences in fractions A and B2. Some of the CNCPS equations could be simplified when using CW instead of NDF. Notably, lignin could be expressed as a proportion of DM, rather than on the basis of ash and protein-free NDF, when predicting CNCPS fraction C. The CNCPS fraction B1 (starch + pectin) values were lower than pectin determined through wet chemistry. This finding, along with the results obtained by the substitution of CW for NDF in the CNCPS equations, suggests that pectin was not part of fraction B1 but present in fraction A. We suggest that pectin and other non-starch polysaccharides that are dissolved by the neutral detergent solution be allocated to a specific fraction (B2) and that another fraction (B3) be adopted for the digestible cell wall carbohydrates.

Rendimento e comportamento espectrofotométrico da lignina extraída de preparações de parede celular, fibra em detergente neutro ou fibra em detergente ácido

The lignin extracted from the forages by the acetyl bromide reagent (acetyl bromide lignin - AcBrL) to be used as a reference standard for the quantitative spectrophotometric determination of lignin could not originate from intact plant because of interference of other substances, which absorb ultraviolet light at the same wavelength of lignin. It is then recommended that lignin extraction be performed in one of the following materials: cell wall itself (CW), neutral detergent fiber (NDF), or acid detergent fiber (ADF). The lignin extraction yields as well as the spectrographic pattern of those were evaluated in these three compounds that came from diverse forage plants. On the average, extraction yields of AcBrL were fairly uniform among them; however as the concentration of ADF was the lowest among all preparations (mainly due to hemicellulose solubilization) and as far this preparation did not exhibit higher lignin extraction capacity, the AcBrL concentration from ADF on a whole plant basis was the lowest observed. The ultraviolet light absorption from the diverse lignin was unequal, as revealed by the graphic spectrograms, which would suggest that the cell wall preparation used for lignin isolation must be the same for the final determination of lignin concentration.

Fracionamento dos carboidratos pelas equações do Cornell Net Carbohydrate and Protein System de três cultivares de girassol na presença ou não de irrigação

This work aimed to estimate the carbohydrate fractions in three sunflower (Helianthus annuus L.) cultivars in the presence or absence of irrigation, using the Cornell Net Carbohydrate and Protein System (CNCPS) equations. The utilization of a fibrous preparation called cell wall (CW) in the CNCPS equations instead of neutral detergent fiber (NDF) showed no differences in the B1 and C fractions; however, there were differences in the A and B2 fractions. Because estimates of B1 fraction were lower than wet chemistry determinations of starch and pectin, it was assumed that pectin and other oligosaccharides, that are dissolved by the neutral detergent (soluble fiber), were part of fraction A, but not part of fraction B1. In spite the soluble fiber carbohydrates have high degradation rates, characterization of soluble fiber within fraction A seems inadequate. It seems coherent that soluble fiber (which includes pectin) be allocated exclusively to a fraction which could be fraction B2. In addition, a new fraction (B3) should be created for the digestible cell wall carbohydrates. Thus, the fraction B1 would be constituted only by starch. It was verified that the equation for the fraction C, which estimates the indigestible cell wall carbohydrates, could be simplified, expressing lignin on a dry matter basis, instead of ash + protein-free NDF as it is used currently. This finding has a practical implication, because it has been recommended that the indigestible cell wall be related to NDF, and not to DM, on the basis that the inhibitory effects of lignin occur on the plant cell wall fibrous carbohydrates and not on the cell content.