Eduardo Mendes Ramos

Antimicrobial activity of Satureja montana L. essential oil against Clostridium perfringens type A inoculated in mortadella-type sausages formulated with different levels of sodium nitrite

This research evaluated the antimicrobial effect of the winter savory (Satureja montana L.) essential oil (EO) against Clostridium perfringens type A (ATCC 3624) inoculated in mortadella-type sausages formulated with different levels of sodium nitrite (NaNO₂: 0 ppm, 100 ppm and 200 ppm) in addition to EO at concentrations of 0.0%, 0.78%, 1.56% and 3.125% stored at 25°C for 30 days. The EO extracted by hydrodistillation and analyzed by gas chromatography-mass spectrometry (CG-MS) was tested in vitro using an agar well diffusion method for determination of minimum inhibitory concentration (MIC) on C. perfringens. According to compositional analysis of the winter savory EO, 26 chemical compounds were identified, and the major constituents were thymol (28.99%), p-cymene (12.00%), linalool (11.00%) and carvacrol (10.71%). The results obtained showed that EO applied at a concentration of 1.56%, which was defined as the MIC, exhibited antimicrobial activity against C. perfringens in the in vitro assays, and the transmission electron microscopy (TEM) revealed structural damage and cell lysis of C. perfringens caused by EO treatment. A synergistic effect between NaNO₂ and EO was observed. In mortadella-type sausages formulated with 100 ppm of NaNO₂ and EO at all concentrations tested, the population of target microorganisms was reduced (p≤0.05) compared to control samples during all storage period. This data suggests the potential combined use of savory EO and minimal amounts of the synthetic additive, NaNO₂ to control C. perfringens in mortadella, which goes according to current market trends, where consumers are requesting natural products.

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.

Fatty acid profile and qualitative characteristics of meat from zebu steers fed with different oilseeds

The objective of this study was to evaluate the effects of dietary addition of ground oilseed sources on the quality, fatty acid profile, and CLA content of meat from zebu steers. Thirty-one zebu steers with an initial average age of 23 mo and an initial BW of 365 kg were used in this study. The experimental period was 84 d, which was preceded by an adaption period of 28 d. The diet was provided ad libitum with a forage:concentrate ratio of 40:60. Corn silage was used as the forage source. Four different concentrates were formulated for each treatment: without additional lipids (control) or with ground soybeans (SB), ground cottonseed (CS), or ground linseed (LS). The SB, CS, and LS diets were formulated to have 6.5% ether extract on a total dietary DM basis. The experiment was set up as a completely randomized design. After slaughter, samples were taken from the longissimus thoracis muscle for the measurement of fatty acid concentration and the evaluation of meat quality. The luminosity index was greater in the control and LS diets (P < 0.01). The greatest percentages of myristic acid (C14:0), palmitic acid (C16:0), trans octadecenoic acid (C18:1 trans-10, trans-11, or trans-12), and SFA in the subcutaneous fat were observed in the CS treatment (P < 0.01). Moreover, the least percentages of oleic acid (C18:1 cis-9) and total unsaturated fatty acids in the subcutaneous fat were observed in the CS diet (P < 0.01). The meat linoleic acid and α-linolenic acid percentages were greatest in the SB and LS treatments, respectively (P < 0.001). The unsaturated fatty acid:SFA ratio was smallest for the CS diet (P < 0.01). A gradual increase in oxidation was observed as a function of storage time; however, the diets did not affect the rancidity of the meat (P > 0.05). The fatty acid profile of subcutaneous fat was impaired by the addition of CS. Supplying ground oilseeds did not increase the content of CLA in the meat.

Fatty acid profile, color and lipid oxidation of meat from young bulls fed ground soybean or rumen protected fat with or without monensin.

The objective of the present study was to evaluate the meat quality and fatty acid (FA) profile of the muscle and subcutaneous fat of young bulls fed ground soybean grain (SB) or rumen protected fat (RPF) with (230 mg head(-1) day(-1)) or without monensin. Forty animals with an initial weight of 359 kg were allotted in a 2×2 factorial arrangement of treatments. The use of monensin increased the arachidonic and α-linolenic acids in the longissimus dorsi (LD) muscle and subcutaneous fat, respectively (P<0.05). The meat from the animals receiving RPF had greater C18:1 content (P<0.01). The CLA and C18:2 contents were greater in the LD muscle of the animals fed SB (P<0.01). However, α-C18:3 was greater in the LD muscle of animals fed RPF (P<0.01). In the subcutaneous fat, SB reduced C12:0 and C14:0 contents (P<0.01) and increased C18:0 (P<0.05). The inclusion of RPF increased the C18:1 and CLA contents (P<0.01) in the subcutaneous fat. Soybean elevated PUFA contents and increased susceptibility of muscle and subcutaneous fat to lipid oxidation.

Genotype x environment interactions for fatty acid profiles in Bos indicus and Bos taurus finished on pasture or grain.

A study was conducted to characterize lipid profiles in the M. longissimus thoracis of commercial Brazilian beef and to assess how those profiles are influenced by finishing system, genetic group, and their interaction. Intramuscular fat (IMF) and fatty acid (FA) profiles were determined in 160 bulls of the Bos taurus (n = 75) and Bos indicus (n = 85) genetic groups, finished on pasture (n = 46) or with grain supplementation (n = 114) and slaughtered in a commercial abattoir. Finishing system had a major impact on the deposition of IMF, as well as on the concentration of SFA, PUFA, and their ratio, but genetic groups showed important differences in the ability to convert SFA into cis-9 MUFA and to convert 16:0 into 18:0. When compared with pasture-finished animals, those finished with grain had greater content of IMF and SFA (P < 0.01), similar amounts of MUFA (P > 0.05), and about one-half the amount of PUFA (P < 0.01). Except for MUFA, differences in FA profiles among finishing systems were mostly mediated through their effect on IMF, even though the relationship of IMF with groups of FA differed among finishing systems. Under grain finishing, B. taurus had less SFA and greater MUFA than B. indicus (P < 0.01), but no differences were observed in PUFA (P > 0.05). With pasture-finishing, no differences were observed among the 2 genetic groups in SFA and MUFA (P > 0.05), but PUFA were decreased in B. taurus (P < 0.01). When genetic groups were compared in grain-finishing, B. taurus had a decreased ability for elongation and B. indicus had a decreased aptitude for desaturation of FA. On the other hand, with pasture-finishing a greater deposition of intermediate FA from ruminal biohydrogenation was observed in B. indicus than in B. taurus. Overall, FA profiles were affected more by finishing system in B. indicus than in B. taurus.

Color evaluation of carbon monoxide treated porcine blood

The stability of liquid porcine blood, treated with carbon monoxide (CO) at different pH values (7.40, 6.70, and 6.00) up to its complete saturation, was studied. Lowering the pH from 7.40 to 6.70 resulted in a decrease in the amount of CO necessary to obtain 100% carboxyhemoglobin. Further pH lowering to 6.00 did not result in additional reduction in the amount of gas. During 4 days of refrigerated storage CO treated liquid blood maintained, at every pH, a more stable and attractive red color than fresh blood, which was a result of an increase (P<0.05) of a(*) (redness) and b(*) (yellowness) values and no variation (P>0.05) on L(*) (lightness) value. Hue (h(*)) and chroma (C(*)) decreased in the untreated blood but not in the CO-treated blood. The results indicate that blood saturation with CO yields a product having greater potential for use in meat products without compromising its visual appearance.

Qualitative characteristics of meat from young bulls fed different levels of crude glycerin

The objective was to evaluate the fatty acid profile and qualitative characteristics of meat from young bulls fed crude glycerin. Forty-four animals with an initial live weight of 368 ± 4 kg were used in a completely randomized design, with four treatments: no glycerin or addition of 6, 12 or 18% glycerin. The animals were slaughtered with 519.5 ± 14.9 kg of live weight. The meat characteristics assessed were chemical composition, shear force, fatty acid concentration, color and lipid oxidation. The addition of glycerin increased the content of ether extract (P<0.05) in the muscle. A linear increase was observed (P<0.05) in the oleic acid contents (C18:1 cis 9). The saturated fatty acid (SFA) contents linearly decreased in the muscle as a function of glycerin addition. The lightness (L*) and yellowness (b*) indices increased with the use of crude glycerin (P<0.05). The crude glycerin increased the intramuscular fat and oleic acid content in the longissimus dorsi muscle.

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.

Physicochemical properties of meat from Bos taurus and Bos indicus

The objective of this study was to characterize meat quality in Bos taurus and Bos indicus and to determine the influence of finishing system and genetic group on the physicochemical properties of the longissimus thoracis at 24 hours and 10 days post mortem (1oC). The sample included 160 bulls of the B. taurus (n=75) and B. indicus (n=85) groups, finished either on pasture (n=46) or with grain supplementation (n=114), slaughtered at a carcass weight of 270 to 300 kg. Pasture-finished animals had higher pH, lower red content and a fat content 2.5 times lower than those finished with supplementation. Meat from supplement-finished animals had lower shear force in comparison to that from animals finished on pasture, with means of 7.7 and 8.5 kg at 24 hours, and of 5.5 and 5.9 kg at 10 days, respectively. Samples of B. taurus and B. indicus were similar in moisture and protein, but B. taurus presented higher means for ash and lower means for fat. Aged samples of B. indicus finished on pasture showed lower values for lightness and yellowness. Overall, lightness and yellow content increased and red content decreased with 10-day ageing. Means for shear force were lower in B. taurus than in B. indicus, with differences of 1.4 kg in fresh meat and 0.6 kg in aged samples. The reduction in shear force with ageing was more pronounced in samples with higher initial shear force, in spite of the positive relationship between shear force before and after ageing.