Alcinéia de Lemos Souza Ramos

Effects of the addition of mechanically deboned poultry meat and collagen fibers on quality characteristics of frankfurter-type sausages

The effects of mechanically deboned poultry meat (MDPM) and levels of collagen fibers on comminuted, cooked sausage quality characteristics were investigated using the central composite rotatable design of response surface methodology (RSM). Use of collagen fiber as an additive affected the sausage characteristics, but the effect depended on the amount of the MDPM used. While MDPM additions resulted in higher cooking loss and darker and redder frankfurters, the addition of collagen fibers improved cooking yields and contributed to the lightness of the final product. Higher collagen fiber content was also accompanied by a significant increase in frankfurter hardness regardless of the MDPM content. Use of collagen fibers countered the negative effects of MDPM on sausage quality attributes, especially on cooking yields and final product color.

Composition and color stability of carbon monoxide treated dried porcine blood

Color stability of swine blood was studied over 12 weeks of storage in plastic bags, after pH (7.40, 6.70, or 6.00) adjustment, saturation with carbon monoxide (CO) and spray-drying. CO-treated dried blood presented a redder color and higher reflectance between 610 and 700 nm, compared to a brownish-red color and lower reflectance of untreated samples. As indicated by reflectance spectra, blood pH adjustment did not influence (P>0.05) the initial color of dried blood but influenced (P<0.05) its color stability (browning index). During storage, CO-treated blood showed a reduction in reflectance percentages as well as in CIE L(*) and a(*) values, which was more pronounced in polyethylene (OTR=4130 cm(3)/m(2)/day/atm) packaged samples. After 12 weeks of storage, CO-treated samples packaged in high OTR bags presented color indexes similar to those of the untreated dried samples. CO-treated samples packaged in nylon-polyethylene (OTR=30-60 cm(3)/m(2)/day/atm) bags showed a smaller rate of discoloration and color difference (DeltaE(*)) between the CO-treated and untreated samples. Even with some darkening, packaging CO-treated dry blood in low OTR bags still gives an acceptable reddish color after 12 weeks of storage while untreated dry blood has a brownish color just after drying.

Selection of a chitosan gelatin-based edible coating for color preservation of beef in retail display.

Chitosan gelatin-based coating films were applied to beef steaks, and their effects on color preservation and lipid oxidation during retail display were evaluated. Response surface methodology was used to model and describe the effects of different biopolymer concentrations (0 to 6% gelatin; 0.5 to 1.5% chitosan; and 0 to 12% glycerol based on dry gelatin+chitosan weight) in the coating film for optimizing the best combination for meat application. Film application reduced weight loss and lipid oxidation of the steaks after 5 days of storage, and films with higher gelatin concentrations were more effective. The percentage levels of different myoglobin-redox forms were not affected by coating, but myoglobin oxidation during retail display was reduced and the percentage of deoxymyoglobin increased with the gelatin content of the film. Steak color stability during retail display was promoted by film application; the steaks exhibited a darker, more intensely red color when coated in blends with higher gelatin and chitosan contents. Blends containing between 3% and 6% gelatin, between 0.5% and 1.0% chitosan and 6% glycerol exhibited the best results and provide a promising alternative to the preservation of beef in retail display.

Freezing, thawing and aging effects on beef tenderness from Bos indicus and Bos taurus cattle.

The objective of this study was to determine the effects of freezing prior to aging on the meat tenderness of young Nellore and Aberdeen Angus bulls. Samples of the longissimus thoracis muscle were submitted to two treatments: conventional aging and freezing (-20°C for 40 days) followed by thawing and aging periods. The meats were evaluated after 0, 7, 14 and 21 aging days (1°C). Freezing increased (P<0.05) purge, cooking loss and total exudate loss throughout aging. Nellore meats had greater total exudate loss and shorter sarcomere lengths (P<0.05). Freezing increased proteolysis during aging in the meats of both breeds, but reduced shear force was found (P<0.05) only in Aberdeen Angus meats and only at time zero. These results suggest that the meat tenderizing process by freezing prior to aging may contribute to meat tenderness in the first weeks of aging, but it is dependent on the animal breed.

Comparison of Warner-Bratzler shear force values between round and square cross-section cores from cooked beef and pork Longissimus muscle.

This study was conducted to investigate the effect of core sampling on Warner-Bratzler shear force evaluations of beef and pork loins (Longissimus thoracis et lumborum muscles) and to determine the relationship between them. Steaks of 2.54 cm from beef and pork loins were cooked and five round cross-section cores and five square cross-section cores of each steak were taken for shear force evaluation. Core sampling influenced both beef and pork shear force values with higher (P<0.05) average values and standard deviations for square cross-section cores. There was a strong and linear relationship (P<0.01) between round and square cross-section cores for beef (R(2)=0.78), pork (R(2)=0.70) and for beef+pork (R(2)=0.82) samples. These results indicate that it is feasible to use square cross-section cores in Warner-Bratzler shear force protocol as an alternative and potential method to standardize sampling for shear force measurements.

Application of a check-all-that-apply question for evaluating and characterizing meat products.

Four different mortadella samples were technologically characterized by physical/chemical and instrumental analyses and were sensorially characterized by acceptance testing and check-all-that-apply (CATA) questions. Samples were divided into three groups by using a principle component analysis (PCA) of the technological characteristics and by using an internal preference map (IPM) of the sensory attributes from the acceptance test. CATA divided these samples into four different external preference map (EPM) groups because each sample was associated with different sensory attributes. The PCA indicated that there was a relationship between the instrumental color and texture analyses and the CATA attributes, whereby identifying the terms that positively or negatively contributed to sample acceptance. The CATA questions effectively discriminated between the meat products regarding their sensory characteristics. In addition, these attributes were linked to chemical and instrumental quality parameters. Thus, the CATA questions are a potential tool for evaluating and developing novel products.

Technological and sensory quality of restructured low-fat cooked ham containing liquid whey

The use of liquid whey to replace water (at 0, 25, 50, 75 or 100%) in a restructured cooked ham formulation was studied and several technological and sensory quality properties were determined. The test results showed no statistically significant differences (P 0.05) less reddish (a* value reduction) and more grayish and yellowish (lesser C* and higher h values) with higher whey additions. A lower (P 0.05). These results suggest that up to 38% natural fresh liquid whey can be added to a restructured cooked ham formulation with similar results to products cured with a conventional formulation.

Comparison of Warner-Bratzler shear force values between round and square cross-section cores for assessment of beef Longissimus tenderness

The objective of this experiment was to determine whether there is a difference between Warner-Blatzler shear force values of round (WBSF) and square (WBsSF) cross-section cores for assessment of beef tenderness. To compare the effect of core sampling, Longissimus thoracis muscles were obtained from 43 beef carcasses at 1, 14, and 28days postmortem. For each sample, tenderness was assessed by a trained sensory panel and by WBSF and WBsSF techniques. There was a strong and linear relationship (R2=0.77) between WBSF and WBsSF, but the average shear force of square cores were (P<0.05) greater than those of round cores. The WBsSF had greater repeatability (R=0.85 vs 0.81) and explained slightly more of the variation in sensory panel perception of beef tenderness (76% vs 74%) than WBSF. The results indicate that WBsSF seems to be a more precise method of measuring shear force, being little more sensitive for detecting tenderness differences than WBSF.

Radiação gama e tempo de armazenamento sobre a oxidação lipídica, cor objetiva, pigmentos heme e nitrito residual de mortadelas elaboradas com diferentes níveis de nitrito

The present study was undertaken to evaluate the irradiation doses (0, 7,5 and 15kGy) and nitrite levels (0, 7,5 and 15kGy) effects on the TBARS index, objective color (CIELAB), residual nitrite content and total and nitrous heme pigments in bologna-type sausage during storage (4°C) for 69 days. Irradiation increased (P 0.05) by irradiation. Results indicated that high doses of gamma radiation can be applied in bologna-type sausages with 75ppm nitrite added without major changes in color and chemical characteristics.

Effect of freezing prior to aging on myoglobin redox forms and CIE color of beef from Nellore and Aberdeen Angus cattle

The objective of this study was to evaluate the effect of freezing prior to wet aging on the color of Nellore and Aberdeen Angus cattle meat. Samples of the Longissimus thoracis muscle were subjected to two treatments: conventional aging (0, 7, 14 and 21days); and freezing (-20°C for 40days) followed by thawing and aging. Freezing promoted (P<0.05) formation of metmyoglobin during aging, especially in Nellore beef. Frozen meats showed (P<0.05) lower lightness (L*) values and higher redness (a*), chroma (C*) and hue angle (h*) values at the first day of storage, deteriorating quickly with aging time. The color of the Nellore meat was less (P<0.05) stable to freezing, being lighter, yellower and less red than Angus meat. The results suggest that color stability in vacuum-packed beef is reduced by freezing prior to aging and that reduction depends on the animal breed.