Improving the poor texture and technological properties of chicken wooden breast by enzymatic hydrolysis and low-frequency ultrasound.

Wooden breast (WB) is a recurrent myopathy in fast-growing birds, which alters the appearance, functionality, and the texture of the breast muscle. The objectives of this study were (i) to evaluate the effect of a combined use of papain enzyme and ultrasound on the texture of WB chicken using response surface methodology and (ii) to assess the effect of marinating on the quality of WB chicken meat. Full factorial experimental design method was used to obtain the ideal conditions to soften the WB meat. The independent variables were the concentration of papain (0.1%-0.3%) and the time in ultrasonic bath (10-30 min); shear force (SF) was the dependent variable. The optimum results were obtained at a concentration of 0.2% papain and 20 min on ultrasound. Papain enzyme had a great influence on the texture of WB meat, reducing its hardness. However, the effect of the ultrasound time on the SF response was not observed. The marinated WB meat showed similar SF values and texture profile than those from normal (N) meat, with reduction in the parameters of protein and lipid oxidation. The use of papain without ultrasound bath proved to be an efficient means for improving the tenderness of WB breasts. PRACTICAL APPLICATION: This study shows the efficiency of the application of two technological procedures (enzymatic treatment and ultrasound) to improve the texture profile and technological properties of chicken breasts affected by the wooden breast myopathy. The economic loss caused by the world-wide occurrence of wooden breast is enormous, and the application of papain has been found to counteract the impaired properties of this abnormal chicken breasts. Since papain is already widely used in the food industry to tenderize meat, its application in improving the quality of WB meat is straightforward.

Effect of adding byproducts of chicken slaughter on the quality of sausage over storage.

The use of byproducts generated by the food industry is a strategy that can have advantages in economic, technological, nutritional, and environmental terms. The aim of this study was to evaluate the influence of the addition of byproducts of chicken slaughter (skin and abdominal fat) on the quality of fresh sausage stored under freezing. Partial chemical characterization of the byproducts was performed. Three batches of chicken sausage were prepared with skin, abdominal fat, and with skin and abdominal fat added; thereafter were stored for 135 d in freezer. Partial chemical composition, physical characteristics, microbiological quality, and product acceptance were determined. Skin and abdominal fat are rich sources of fat. However, the addition of skin provided to sausage higher protein content, hardness, water retention capacity, and less cooking loss compared to added abdominal fat treatments. In contrast, the addition of abdominal fat provided higher lipid content to the sausages and displaying higher acceptability. The addition of byproducts in fresh sausage manufacture would be a great strategy to increase the chicken sausage value, with physicochemical quality improvement, and without sensory acceptability issues.

Impact of use of byproducts (chicken skin and abdominal fat) on the oxidation of chicken sausage stored under freezing.

Fresh chicken sausage is a meat product with high consumption in the world. The addition of a lipid source (other than abdominal fat), such as chicken skin, is considered an alternative to harnessing slaughter byproducts in the preparation of processed meat products. The aim of this study was to evaluate the impact of use of skin and/or abdominal fat on chicken sausages and their effect on oxidative stability of chicken sausages during freezing storage. Three formulations with chicken meat added of abdominal fat (SF), or chicken skin (SS), or chicken fat and skin (SFS) were elaborated. Chemical composition, fatty acid profile, instrumental color and texture, oxidative stability of lipids and proteins, and sensory acceptability of chicken sausages were determined. SS formulation showed lower lipid and protein oxidation and softness during storage. Consumers showed greater preference and high purchase intent for SFS formulation, which showed average values of chemical composition and oxidation of chicken sausages stored under freezing. Therefore, the combined addition of lipid sources, skin, and abdominal fat is recommended for use in chicken sausages, considering that the addition of fat improves the sensory characteristics of chicken sausages and skin minimizes the oxidative effects of storage. PRACTICAL APPLICATION: The combined addition of skin fat and abdominal fat is recommended for use in chicken sausages as it does not interfere with consumer acceptability and further ensures nutritional quality during freezing storage. In addition, it is an alternative to using a byproduct of chicken slaughter, bringing economic advantages to the industry and less environmental damage to the world.

Rhizoglomus dalpeae, R. maiae, and R. silesianum, new species.

We examined three arbuscular mycorrhizal fungi (AMF; phylum Glomeromycota) producing glomoid spores. The mode of formation and morphology of these spores suggested that they represent undescribed species in the genus Rhizoglomus of the family Glomeraceae. Subsequent morphological studies of the spores and molecular phylogenetic analyses of sequences of the nuc rDNA small subunit (18S), internal transcribed spacer (ITS1-5.8S-ITS2 = ITS), and large subunit (28S) region (= 18S-ITS-28S) confirmed the suggestion and indicated that the fungi strongly differ from all previously described Rhizoglomus species with known DNA barcodes. Consequently, the fungi were described here as new species: R. dalpeae, R. maiae, and R. silesianum. Two of these species lived hypogeously in the field in habitats subjected to strong environmental stresses. Rhizoglomus dalpeae originated from an inselberg located within Guineo-Sudanian transition savanna zone in Benin, West Africa, where the temperature of the inselberg rock during a 5-mo drought ranges from 40 to 60 C. Rhizoglomus silesianum originated from a coal mine spoil heap in Poland, whose substrate is extremely poor in nutrients, has unfavorable texture, and may heat up to 50 C. By contrast, R. maiae was found in more favorable habitat conditions. It produced an epigeous cluster of spores among shrubs growing in a tropical humid reserve in Brazil. Moreover, the compatibility of phylogenies of species of the family Glomeraceae reconstructed from analyses of sequences of 18S-ITS-28S and the largest subunit of RNA polymerase II (RPB1) gene was discussed.