ABSTRACT
Objetivou-se avaliar a correção da medida ultrassonográfica da área do músculo Longissimus dorsi, em coelhos da raça Nova Zelândia, pela análise de covariância usando modelos mistos. Foram realizadas análises em delineamento em blocos completos ao acaso, com cinco tratamentos (operadores) e seis blocos (animais), considerando na análise: a inexistência de covariáveis; a covariável comprimento de olho de lombo; a covariável profundidade de olho de lombo; e as duas covariáveis juntas. Como os animais são uma amostra aleatória, o efeito de bloco foi considerado como aleatório. Consideraram-se as covariáveis como medidas com efeito fixo sem erro, independentemente do tratamento e do comportamento linear. As estatísticas de critério de decisão CV%, R ² e R ¯ ² evidenciaram relação direta entre si e podem ser consideradas para avaliar a precisão experimental em ensaios com avaliação de carcaças. Os valores das estatísticas AIC, BIC e AICC apresentam coerência com a interpretação dos critérios de decisão e indicam que o modelo com duas covariáveis proporciona resultados acurados. A inclusão das covariáveis complementa o controle de local com melhoria na precisão do experimento. A utilização das medidas ultrassonográficas de profundidade e comprimento corrige a média da área do músculo Longissimus dorsi avaliado por diferentes operadores.(AU)
The objective of this study was to evaluate the correction ultrasonographic measurement of area the Longissimus dorsi muscle in New Zealand rabbits by covariance analysis using mixed linear models. The analyzes were performed in randomized block design with 5 treatments (operators) and 6 blocks (animals), considering in the analysis: absence of covariates; rib eye length as covariate; rib eye depth as covariate; the two covariates together. As the animals are a random sample, the block effect was considered to be random. The covariates were considered as measures of fixed effect without error, independent of treatment and linear comportment. The decision criterion statistics CV%, R², and R ¯ ²showed a direct relationship between them and can be taken into consideration to evaluate the experimental accuracy in tests with carcass evaluation. The AIC, BIC, and AICC statistics are consistent with the interpretation of the decision criteria and indicate that the two covariates in model provides accurate results. The inclusion of covariates complements the local control to improve the accuracy of the experiment. The use of ultrasound measurements of depth and length corrects the mean area of the Longissimus dorsi muscle evaluated by different operators.(AU)
Subject(s)
Animals , Male , Rabbits , Rabbits/anatomy & histology , Muscles/diagnostic imaging , Meat Industry , Ultrasonography/veterinaryABSTRACT
A new analytical method to determine trace volatile aldehydes isolated from the headspace of fish meat at room temperature by high-performance liquid chromatography (HPLC) in the form of 2,4-dinitrophenylhydrazone (DNPHo) derivatives has been developed. Aliquots (50 g) of the fish purée were introduced into a 500-mL glass recipient and were purged with N2 for 40 min through two SEP-PAK C18 cartridges (connected in series) coated with an acid solution of 2,4-dinitrophenylhydrazine. The cartridges were then eluted with acetonitrile (2 mL) and the 2,4-DNPHo formed was quantitated by HPLC-UV analysis using a Zorbax C18 column. The isolated compounds from the dynamic headspace sampling of four kinds of fish species were saturated aldehydes, formaldehyde, acetaldehyde, propanal, butanal, pentanal, and hexanal. Under optimized conditions the detection limits of the HPLC method were in the range of 0.75 nmol/g (formaldehyde) to 2.19 nmol/g (hexanal). The calibration curves were linear in the concentration range from 1.3 nmol/mL to 12.5 nmol/mL. Propanal and acetaldehyde were the major carbonyl compounds identified (ranging from 3.9 nmol/g and 10 nmol/g). This study has revealed the widespread occurrence of formaldehyde, acetaldehyde, propanal, butanal, pentanal, and hexanal in fish meat.
