Color stability of Bos indicus bull steaks in modified atmosphere packaging (MAP)

Evaluations of meat quality, including color, influence purchasing decisions and can be affected by type of fresh meat the packaging system. In this study, fresh steaks from Bos indicus bull were packaged in the vacuum (vacuum), 75% O2/25% CO2 (HiOx-MAP) and 40% CO2/0.4% CO/59.6% N2 (CO-MAP). Emphasis is placed on the color and lipid oxidation of bull beef steaks. Results reveal that the steaks stored in CO-MAP and HiOx-MAP exhibited similar or brighter red color than fresh steaks (exposed only to oxygen) or vacuum. The red color of the LD bull beef steaks packaged in CO-MAP was more intense than the color of meat stored in HiOx-MAP after the 14th day of storage. Vacuum packing dramatically impaired the color of the LD bull steaks, which were severely discolored (brown) after all storage times. Bos indicus steaks of all treatments showed extremely low TBARS values in all storage times. The results suggested that HiOx-MAP or CO-MAP may be utilized to stabilize or improve the red color of fresh steaks from bull of so appreciated by the consumer.Evaluations of meat quality, including color, influence purchasing decisions and can be affected by type of fresh meat the packaging system. In this study, fresh steaks from Bos indicus bull were packaged in the vacuum (vacuum), 75% O2/25% CO2 (HiOx-MAP) and 40% CO2/0.4% CO/59.6% N2 (CO-MAP). Emphasis is placed on the color and lipid oxidation of bull beef steaks. Results reveal that the steaks stored in CO-MAP and HiOx-MAPexhibited similar or brighter red color than fresh steaks (exposed only to oxygen) or vacuum. The red color of the LD bull beef steaks packaged in CO-MAP was more intense than the color of meat stored in HiOx-MAP after the 14th day of storage. Vacuum packing dramatically impaired the color of the LD bull steaks, which were severely discolored (brown) after all storage times. Bos indicus steaks of all treatments showed extremely low TBARS values in all storage times. The results suggested that HiOx-MAP or CO-MAP may be utilized to stabilize or improve the red color of fresh steaks from bull of so appreciated by the consumer

Quality of Longissimus thoracis e lumborum muscles of bulls and cows: influence of storage in modified atmosphere and vacuum

Como líder mundial nas exportações de carne bovina, o Brasil vem se adequando às exigências dos mercados internacionais, investindo na aplicação de novos padrões de produção e comercialização. Entre as tecnologias desenvolvidas e aplicadas pela indústria de carnes, principalmente na Europa e nos Estados Unidos, a embalagem em atmosfera modificada visa a manutenção da qualidade durante a comercialização da carne in natura, centralizando as operações, rotulagem e distribuição do produto, além de estender a vida útil. Baseado no exposto, o presente trabalho teve como objetivo avaliar o efeito dos sistemas de embalagens a vácuo e em atmosfera modificada sobre parâmetros de qualidade de carne de bovinos machos inteiros e fêmeas de descarte. Músculos Longissimus thoracis e Longissimus lumborum de ambos os sexos foram porcionados em bifes, embalados a vácuo e em três tipos de atmosferas modificadas (75%O2/25%CO2; 60%CO2/0,2%CO/39,8%N2 e 40%CO2/0,4%CO/59,6%N2) e estocados sob refrigeração a 2 °C por um período de 28 dias. Foram avaliadas características de cor, pH, oxidação lipídica e protéica, índice de fragmentação miofibrilar, colágeno total; força de cisalhamento e perda de peso por cocção. Atmosferas contendo CO melhoraram a estabilidade da cor da carne in natura ao longo do período experimental, resultando em bifes de cor vermelha desejável. Bifes embalados em atmosfera com O2 e vácuo apresentaram menor estabilidade da cor. Não houve interferência dos tipos de embalagem no pH da carne, no entanto, foram observados maiores valores nos bifes de macho inteiro comparado aos de fêmea de descarte. A estabilidade oxidativa, lipídica e protéica, da carne foi drasticamente afetada pela presença de O2 na embalagem, observando-se um processo oxidativo acelerado comparado às embalagens anóxicas. Os bifes apresentaram amaciamento gradual como corroborado pelas análises de força de cisalhamento e índice de fragmentação miofibrilar nos diferentes sistemas de embalagens, porém, atmosferas contendo CO favoreceram um processo acelerado do amaciamento da carne quando comparadas ao vácuo e atmosfera com alto O2. O teor de colágeno total e as perdas de peso por cocção dos bifes não foram afetados pelos diferentes sistemas de embalagem e o período prolongado de estocagem. Houve correlações significativas (p<0,05; 0,01; 0,0001) entre determinados parâmetros de qualidade da carne para ambos os músculos e sexos.As a world leader in beef exports, Brazil has been adapting to the demands of international markets, investing in the application of new patterns of production and marketing. Among the developed and applied technologies by the meat industry, mainly in Europe and the United States, modified atmosphere packaging is designed to ensure quality during the marketing of fresh beef, centralizing operations, labeling and distribution of the product and extends life. Based on the foregoing, the present study was to evaluate the effect of vacuum packaging systems and modified atmosphere on quality parameters of meat from bulls and cows. Longissimus thoracis and Longissimus lumborum of both sexes were portioned into steaks, vacuum-packed in three types of modified atmospheres (75%O2/25%CO2, 60%CO2/0.2%CO/39.8%N2 and 40%CO2/0.4%CO/59.6%N2) and stored under refrigeration at 2ºC for a 28 days period. Were evaluated characteristics like color, pH, lipid and protein oxidation, myofibrillar fragmentation index, total collagen, shear force and cooking loss. Atmospheres containing CO have improved color stability of fresh beef during the trial period, resulting in a beef with the desirable red. Steaks packaged in atmosphere with O2 and vacuum had a lower color stability. There was no interference of the packaging types in the pH of meat, however, higher values were observed in all male beef compared to the females of discard. The oxidative stability, lipidic and proteic of meat, has been drastically affected by the presence of O2 in the pack, observing an accelerated oxidation process compared to anoxic packaging. The steaks showed gradual tenderization as corroborated by shear force and myofibrillar fragmentation index analysis, in different packaging systems, however, atmosphere containing CO favored an accelerated process of tenderization of the flesh when compared to vacuum and high-oxygen atmospheric. The total collagen content and the cooking losses by the steaks were not affected by different packaging systems and the long time of stocking. There were significant correlations (p < 0.05, 0.01, 0.0001) between certain parameters of meat quality for both muscles and sexes

Proteomic study of maize (Zea mays L.) varieties obtained by classical breeding and genetic recombination.

O melhoramento genético clássico de sementes milho (Zea mays L.) permitiu desenvolver inúmeras variedades, incluindo o milho com qualidade proteica melhorada (Quality Protein Maize, QPM), que visava aumentar os teores proteicos e as propriedades nutricionais. Por outro lado, novas variedades comerciais foram obtidas por vegetais geneticamente modificados (GM), com foco em parâmetros agronômicos. Em ambos os casos, a segurança dessas variedades para uso como alimento é uma das principais preocupações dos desenvolvedores e dos órgãos de regulamentação. A Equivalência Substancial é a base do sistema de avaliação da segurança de culturas geneticamente modificadas, no entanto alterações na expressão de proteínas não são devidamente analisadas e esclarecidas. As abordagens proteômicas complementam as técnicas de avaliação de biossegurança para alimentos GM, bem como permitem investigar possíveis efeitos indesejáveis derivados do melhoramento clássico. Os objetivos do presente estudo foram caracterizar e comparar os perfis proteicos de variedades de milhos convencionais melhorados (QPM) e geneticamente modificados (GMs), contra suas respectivas linhas convencionais utilizando técnicas proteômicas como eletroforese bidimensional (2-DE) e bottom up shotgun (gel-free). Num primeiro estudo, foram utilizadas três amostras de milho, sendo duas variedades convencionais com QPM (QP1 e QP2) e uma variedade convencional normal (CN). No segundo estudo, foram analisadas duas cultivares de milho GM (GM1 e GM2) e seus respectivos convencionais genitores (CG1 e CG2). As composições químicas de todas as amostras também foram avaliadas quanto a Equivalência Substancial. O extrato bruto proteico foi submetido à análise de eletroforese unidimensional (1-DE), bidimensional (2-DE) e bottom up shotgun (gel-free). As imagens dos mapas proteicos foram analisadas pelo software Image Master 2D Platinum 7.0 (GE). Os spots diferencialmente expressos e selecionados foram sequenciados por MS. Pela composição química das principais frações das amostras de milho foi possível identificar a equivalência substancial entre as amostras convencionais e GMs, bem como QPMs e sua convencional dentro das faixas de variabilidade esperadas da espécie. Nos géis 1-DE foram observadas bandas proteicas com perfis similares entre os grupos de amostras avaliadas para ambos estudos. Nas imagens dos géis 2-DE não houveram alterações extremas entre as amostras de milhos GMs e seus respectivos convencionais genitores (CGs), mas apenas diferenças na intensidade dos spots proteicos. As variedades QPMs e CN apresentaram diferenças devido à distribuição dos spots. Os mapas proteicos das amostras CG1 x GM1 e CG2 x GM2 apresentaram maior semelhança com porcentagens de matchings superiores a 70 %, enquanto as porcentagens de matchings entre variedades diferentes (QPMs e CN) foram menores. No total foram identificadas 219 proteínas das amostras CGs x GMs e QPMs x CN, classificadas quanto aos seus processos biológicos e função molecular. Em conclusão, foram encontradas diferenças entre os cultivares GMs e CGs, indicando uma variação normal entre variedades de milho, que não comprometem a segurança alimentar das amostras estudadas. Quanto às amostras com QPM e CN as diferenças encontradas são devido à sua distância nas linhagens ou germoplasma.The classic genetic breeding of corn seeds (Zea mays) has enabled the development of many varieties, including corn with improved protein quality (Quality Protein Maize, QPM), which aimed to increase protein levels and nutritional properties. On the other hand, new commercial varieties have been obtained out of genetically modified (GM) vegetables, with a focus in agronomic parameters. In both cases, the safety of these varieties for food use is one of the main concerns for the developers and for the regulatory agencies. Substantial Equivalence is the basis of the safety evaluation system for genetically modified crops, however, alterations in the protein expressions are not been properly analyzed and clarified. The protein approaches complement the techniques of biosafety evaluation for GM foods, as well as allow for possible undesirable effects derived from classic improvement to be investigated. The goals of the current studies were to characterize and compare the protein profiles of the different varieties of conventionally improved (QPM) and genetically modified (GM) corn, against their respective conventional lines using proteomic techniques, such as, two-dimensional electrophoresis (2-DE), bottom up shotgun (gel-free) and masses spectrometry (MS). In a first instance of the study, three samples of corn were used, two of conventional varieties with QPM (QP1 and QP2) and one conventional normal variety (CN). In a second instance of the study, two cultures of GM corn (GM1 and GM2) were analyzed and their respective conventional genitors (CG1 and CG2). The chemical compositions of all the samples were also evaluated for their Substantial Equivalence. The protein raw extract was submitted to analysis of one-dimensional (1-DE), two-dimensional (2-DE) electrophoresis, and bottom up shotgun (gel-free). The protein image maps were analyzed by the Image Master 2D Platinum 7.0 (GE) software. The spots which were expressed and selected differentially were sequenced by MS. By the chemical composition of the main fractions of the samples of corn, it was possible to identify the substantial equivalence between the conventional samples and GMs, likewise with OPMs and their conventional in the ranges of variability which were expected for the species. On the 1-DE gel, it was observed protein bands with similar profiles amongst the groups of evaluated samples for both studies. In the images of the 2-DE gel, there were no alterations between the GM corn and their respective conventional genitors (CGs), but only differences in intensity of the protein spots. The OPM and CN varieties presented differences due to the distribution of the spots. The protein maps of samples CG1 vs. GM1 and CG2 vs. GM2 presented greater similarities with the percentages of matchings superior to 70%, while the percentage of matchings among different varieties (QPMs and CN) were smaller. In total, there were 219 proteins identified in the samples CGs vs. GMs and QPMs vs. CN, classified by the biologic processes and molecular function. In conclusion, there were found differences between the cultures of GMs and CGs, indicating a normal variation among the corn varieties, which do not affect the food security of the studied samples. As per the samples with QPM and CN, the differences found were due to the line distances or germplasm

Color stability of Bos indicus bull steaks in modified atmosphere packaging (MAP)

Evaluations of meat quality, including color, influence purchasing decisions and can be affected by type of fresh meat the packaging system. In this study, fresh steaks from Bos indicus bull were packaged in the vacuum (vacuum), 75% O2/25% CO2 (HiOx-MAP) and 40% CO2/0.4% CO/59.6% N2 (CO-MAP). Emphasis is placed on the color and lipid oxidation of bull beef steaks. Results reveal that the steaks stored in CO-MAP and HiOx-MAPexhibited similar or brighter red color than fresh steaks (exposed only to oxygen) or vacuum. The red color of the LD bull beef steaks packaged in CO-MAP was more intense than the color of meat stored in HiOx-MAP after the 14th day of storage. Vacuum packing dramatically impaired the color of the LD bull steaks, which were severely discolored (brown) after all storage times. Bos indicus steaks of all treatments showed extremely low TBARS values in all storage times. The results suggested that HiOx-MAP or CO-MAP may be utilized to stabilize or improve the red color of fresh steaks from bull of so appreciated by the consumer

Color stability of Bos indicus bull steaks in modified atmosphere packaging (MAP)

Evaluations of meat quality, including color, influence purchasing decisions and can be affected by type of fresh meat the packaging system. In this study, fresh steaks from Bos indicus bull were packaged in the vacuum (vacuum), 75% O-2/25% CO2 (HiOx-MAP) and 40% CO2/0.4% CO/59.6% N-2 (CO-MAP). Emphasis is placed on the color and lipid oxidation of bull beef steaks. Results reveal that the steaks stored in CO-MAP and HiOx-MAP exhibited similar or brighter red color than fresh steaks (exposed only to oxygen) or vacuum. The red color of the LD bull beef steaks packaged in CO-MAP was more intense than the color of meat stored in HiOx-MAP after the 14th day of storage. Vacuum packing dramatically impaired the color of the LD bull steaks, which were severely discolored (brown) after all storage times. Bos indicus steaks of all treatments showed extremely low TBARS values in all storage times. The results suggested that HiOx-MAP or CO-MAP may be utilized to stabilize or improve the red color of fresh steaks from bull of so appreciated by the consumer.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Sao Paulo ESALQ, Dept Agroind Food & Nutr, CP 09, BR-13418900 Piracicaba, SP, BrazilUniv Fed Sao Paulo, Dept Exact Sci & Earth Pharmaceut Sci, 275 Prof Arthur Riedel, BR-09972270 Diadema, SP, BrazilUniversidade Federal de São Paulo (UNIFESP) Dept. of Exact Sciences and Earth/Pharmaceutical Science, 275 Prof. Arthur Riedel 09972-270 Diadema, SP Brazil.FAPESP: 2010/08182-2CNPq: 483251/2009-7Web of Scienc

Color stability of Bos indicus bull steaks in modified atmosphere packaging (MAP)

Evaluations of meat quality, including color, influence purchasing decisions and can be affected by type of fresh meat the packaging system.In thisstudy,fresh steaks from Bos indicusbull were packaged in the vacuum (vacuum), 75% O2/25% CO2(HiOx-MAP) and 40% CO2/0.4% CO/59.6% N2(CO-MAP). Emphasis is placed on the color and lipid oxidation of bull beef steaks. Results reveal that the steaks stored in CO-MAP and HiOx-MAPexhibited similar or brighter red color than fresh steaks (exposed only to oxygen) or vacuum. The red color of the LD bull beef steaks packaged in CO-MAP was more intense than the color of meat stored in HiOx-MAP after the 14thday of storage. Vacuum packing dramatically impaired the color of the LD bull steaks, which were severely discolored (brown) after all storage times. Bos indicussteaks of all treatments showed extremely low TBARS values in all storage times. The results suggested that HiOx-MAP or CO-MAP may be utilized to stabilize or improve the red color of fresh steaks from bull of so appreciated by the consumer

Stability of Carotenoids, Total Phenolics and In Vitro Antioxidant Capacity in the Thermal Processing of Orange-Fleshed Sweet Potato (Ipomoea batatas Lam.) Cultivars Grown in Brazil

Intervention strategies regarding the biofortification of orange-fleshed sweet potato, which is a rich source of carotenoids for combating vitamin A deficiency, are being developed in Brazil. This study was conducted to evaluate the concentrations of individual carotenoids, total phenolic compounds and antioxidant capacity in the roots of four biofortified sweet potato cultivars that were raw or processed by four common heat treatments. HPLC, Folin-Ciocalteu, DPPH and ABTS assays were used. All cultivars showed high levels of carotenoids in raw roots, predominantly all-trans-beta-carotene (79.1-128.5 mg.100 g(-1) DW), suggesting a high estimated vitamin A activity. The CNPH 1194 cultivar reported carotenoids values highest than those of other cultivars (p &lt; 0.05). The total phenolic compounds varied among cultivars and heat treatments (0.96-2.05 mg.g(-1) DW). In most cases, the heat treatments resulted in a significant decrease in the carotenoids and phenolic compounds contents as well as antioxidant capacity. Processing of flour presented the greatest losses of major carotenoids and phenolics. The phenolic compounds showed more stability than carotenoids after processing. There were significant correlations between the carotenoids and phenolic compounds and the antioxidant capacity.Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Fundacao de Estudos Agrarios Luiz de Queiroz (FEALQ

Penetration of hydrolysed soy protein-added brine and its effect on yield and pH of beef steaks from the biceps femoris muscle

This study was aimed to evaluate the penetration behaviour of different brines with tumbled beef steaks from the biceps femoris muscle, specifically their interactions with pH and effects on yield. Six muscles from different animals, divided into origin (OP) and insertion (IP) portions, were cut into 60 steaks of 2.5 cm thickness and tumbled for 30 or 60 min. The steaks were tumbled with two brines, with (WTB/HSP) or without (WTB) hydrolysed soy protein (HSP), and steaks that were not tumbled with brine or water were used as controls. Brine penetration was verified by measuring the amount of dye-containing brine (absorbance at 627 nm) recovered from homogenates of four thin (2 mm) slices from the surface of the beef steaks after tumbling. The WTB/HSP steaks exhibited greater (P < 0.05) brine penetration when tumbled for 60 min than for 30 min. The OP steaks showed greater yield and lower pH (P < 0.05) than IP steaks. HSP-added brine increased the water absorption and retention in the first slices of the steaks, and its efficiency was increased with a longer tumbling time. The portion of the biceps femoris muscle used influenced brine absorption and retention, impacting meat yield. (C) 2010 Elsevier Ltd. All rights reserved.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo - FAPESP[2007/57337-6