This study aimed to evaluate the effects of slow (–18 °C) and fast freezing (liquid nitrogen) of pork meat, and the use of exudate released upon thawing, on the physicochemical, color, rheological, microbiological, histological, and sensory characteristics of cooked ham. The meat samples were frozen at –18 °C and thawed after 22 weeks for the production of cooked ham. No significant difference was observed regarding physicochemical, color and microbiological parameters or in sensory acceptance. The hardness and chewiness parameters showed significant differences when compared to the control sample (ham made from chilled meat). Light microscopy of cooked ham samples showed that changes in the tissues were caused by freezing and thawing the meat. The effect of exudate was significant on the sodium content and compression force parameters, but this difference was not perceived in the sensory analysis, confirming that frozen pork meat can be used to produce cooked ham without loss of quality.

A gordura intramuscular (GIM) influencia importantes características qualitativas da carne, tais como: sabor, suculência, palatabilidade, odor e maciez. Assim, objetivou-se aplicar diferentes técnicas de processamento de imagem para quantificar a GIM na carne bovina: paleta, amostragem, intervalo de coordenadas, limiar de preto e branco e função discriminante de cores. Foram utilizadas 35 amostras de bifes com uma ampla gama de GIM. Foram capturadas imagens coloridas das amostras de carne de diferentes músculos com uma variabilidade no conteúdo de GIM. A gordura intramuscular da secção transversal e fina de carne foi determinada por extração química dos lipídios e predita por análise de imagem. O método químico foi comparado com a análise de imagem. Os procedimentos de segmentação foram validados pelo ajustamento de uma equação de regressão linear na série de valores observados e preditos e os parâmetros da regressão avaliados pelo teste F. O poder preditivo destas aproximações também foi comparado por meio de análise residual e pela decomposição do quadrado médio dos desvios. Os resultados mostraram que a função discriminante foi o melhor método de segmentação da cor para mensurar a gordura intramuscular via imagem digital, mas necessita de ajustes no padrão de predição.

Intramuscular fat (IMF) influences important quality characteristics of meat, such as flavor, juiciness, palatability, odor and tenderness. Thus, the objective of this study was to apply the following image processing techniques to quantify the IMF in beef: palette; sampling, interval of coordinates; black and white threshold; and discriminant function of colors. Thirty-five samples of beef, with a wide range of IMF, were used. Color images were taken of the meat samples from different muscles, with variability in the IMF content. The IMF of a thin cross-section meat was determined by chemical lipid extraction and was predicted by image analysis. The chemical method was compared with the image analysis. The segmentation procedures were validated by the adjustment of a linear regression equation to the series of values that were observed and predicted, as well as the regression parameters evaluated by the F-test. The predictive power of these approaches was also compared by residual analysis and by the decomposition of the mean square deviations. The results showed that the discriminant function was the best color segmentation method to measure intramuscular fat via digital images, but required adjustments in the prediction pattern.

Cooked ham is considered a high-value product due to the quality of its raw material. Although its consumption is still low in Brazil, it is increasing due to the rising purchasing power of sectors of the population. This study aimed to assess the microbiological, physicochemical, rheological, and sensory quality of cooked hams (n=11) marketed in Brazil. All samples showed microbiological results within the standards established by Brazilian legislation. Eight of the eleven samples studied met all the legal requirements; two samples violated the standards due to the addition of starch; one sample had lower protein content than the minimum required, and another one had sodium content higher than that stated on the label. The use of Hierarchical Cluster Analysis allowed the agglomeration of the samples into three groups with distinct quality traits and with significant differences in moisture content, chromaticity, syneresis, and heating and freezing loss. Principal Component Analysis showed that the samples which correlated to higher sensory acceptance regarding flavor and overall acceptability were those with higher moisture, protein, fat, and luminosity values. This study confirmed the efficacy of multivariate statistical techniques in assessing the quality of commercial cooked hams and in indicating the physicochemical parameters associated with the perception of product quality.

Os principais problemas observados em presuntos são a má fatiabilidade e a perda excessiva de líquidos após o cozimento. Para reduzir esses problemas, a indústria utiliza ingredientes não cárneos, tais como a proteína de soja e a carragena, porém, segundo a legislação brasileira, não é permitida a adição de amido ou amido modificado. Neste trabalho, foram testados três ingredientes, em presunto cozido de peru: amido modificado (0 a 2,0%), goma guar (0 a 0,30%) e colágeno hidrolisado (0 a 2,0%), seguindo um delineamento fatorial completo 2³ com cinco repetições no ponto central. A goma guar apresentou baixa resistência ao reaquecimento, no entanto, nas perdas por resfriamento, os resultados foram adequados. O colágeno hidrolisado testado não proporcionou resultados satisfatórios, sendo que os produtos apresentaram baixa aceitação devido à formação de gel e a maiores perdas. Os produtos desenvolvidos não foram diferentes do produto comercial em relação à textura (P>0,05). A formulação F6 (2,0% amido modificado) foi a que obteve os melhores resultados e a maior aceitação por parte dos julgadores. Com base nos resultados obtidos, parece-nos adequado propor a permissão legal de amido em presunto ou a criação de uma nova classe de produto para a qual se permita a utilização deste ingrediente.

The main problems observed in cooked hams are bad sliceability and excessive fluid loss after cooking. To reduce these problems the industry uses non-meat ingredients such as soy protein and carrageenan, but under Brazilian law, it is not allowed to add starch or modified starch in hams. Three ingredients were tested in the present research: modified starch (0 to 2.0%), gum guar (0 to 0.30%) and hydrolyzed collagen (0 to 2.0%), following a 2³ full factorial design with five repetitions in the central point. The guar gum produced low resistance to reheating, however in losses by cooling, the results were adequate. The hydrolyzed collagen tested did not give satisfactory results, showing low acceptance due to formation of gel in the ham and high losses. The developed products were not different from the commercial product in relation to texture (P>0.05). The formulation F6 (2.0% of modified starch) was the one with the best results and greater acceptance as detected by the tasters. Based on the results obtained it seems appropriate to propose the legal permission of starch in ham or the creation of a new class of product in which starch addition would be allowed.