The objective of this study was to evaluate the effects of non-meat ingredients, blade tenderization and vacuum-tumbling on the textural, visual and sensory characteristics of steaks from Biceps femoris, Supraspinatus, Triceps brachii long head, and Longissimus dorsi muscles packaged in high oxygen, modified atomosphere (MAP) system. United Department of Agriculture (USDA) Select muscles (n=72) from each cut were obtained from a commercial processor over three processing days. Muscles were aged for five days at 4ºC. Denuded muscles within a processing day were randomly assigned to one of 24 treatments. This study was a 2 x 4 x 3 factorial arrangement where treatments were control, injection (injected or non-injected), blade tenderization (0, 1, or 2 passes) and vacuum-tumbling (0, 5, 10 or 20 minutes). Injected muscles contained up to 10% of a brine containing 1.55% potassium lactate, 0.1% sodium diacetate, 0.3% sodium tripolyphosphate blend and 0.4% salt in the final product. Muscles were vacuumtumbled and blade tenderized sequentially after injection. Steaks from the muscles were stored in a high oxygen (80% O2, 20% CO2) MAP system for 0, 3, 7, 10 and 14 days at 2ºC. Steaks were evaluated for package purge (%), Warner-Bratzler shear force (kg), cook loss (%), cook time (min), pH, CIE L* a* b* color space values and trained color panel scores on each storage day. A trained descriptive attribute sensory panel evaluated steaks on day 1 only. Warner-Bratzler shear force (P<0.01) and trained sensory panel results (P<0.05) showed that the addition of non-meat ingredients improved tenderness in all four muscles. Sensory detectable connective tissue was lower (P<0.01) in injected steaks for all muscles except in Biceps femoris steaks. Injected steaks had higher pH (P<0.01) measurements than non-injected treatments in all muscles except the Triceps brachii long head. Neither blade tenderization nor vacuum-tumbling had consistent effects in all four muscles. Vacuum-tumbled Biceps femoris steaks had lower bitter flavor aromatics (P<0.05). In conclusion, enhancing beef with non-meat ingredients had the greatest impact on the quality attributes of high connective tissue cuts and Longissimus dorsi steaks.

Catfish fillets that were enhanced with salt and various phosphate treatments through vacuum tumbling or multi-needle injection were evaluated for yield, protein exudate (only tumbling), surface color, pH, cooking loss, tenderness, purge loss and shelf-life. An agglomerated sodium phosphate blend (AGSP) was the optimum treatment for both vacuum tumbling and multi-needle injection and was further utilized in conjunction with potassium lactate (PL) and/or potassium acetate (PA) through vacuum tumbling to determine their effect on the quality, shelf-life and sensory characteristics of enhanced catfish fillets. In addition, the combination of AGSP and PA+PL that maximized shelf-life was further utilized in conjunction with liquid or wood smoking to evaluate the quality and inhibition of L. monocytogenes growth in ready-to-eat (RTE) smoked catfish fillets. All phosphate treatments increased (P<0.05) tenderness, but AGSP that contained mono-, tri-, and polyphosphates increased (P<0.05) pH and yield and decreased (P<0.05) yellowness in both tumbling and injection systems when compared to the control treatment. In addition, AGSP decreased (P<0.05) protein exudate when fillets were tumbled and increased (P<0.05) solution pick-up when injected. Psychrotrophic plate counts (PPC) for all phosphate treatments were similar to the control at each storage time and reached 7 log CFU/g by day 7 of storage; however, when AGSP was used in conjunction with PA+PL, PPC and sensory spoilage scores of raw catfish fillets were lower (P<0.05) than the control at each storage time. Marinating with a combination of 0.25% PA and 0.58% PL increased shelf-life (P<0.05) to between 10 and 14 days when compared to the control which had a shelf-life between 7 and 10 days. In addition, consumers preferred (P<0.05) fried catfish fillets that were treated with AGSP with and without PA+PL when compared to non-marinated controls with respect to appearance, flavor and overall acceptability. In conclusion, AGSP optimized yield and improved the quality of refrigerated catfish fillets, and extended shelf-life three days over other treatments when combined with PA+PL. This combined treatment also enhanced sensory properties of fried catfish fillets and had a synergistic effect with wood smoke constituents that inhibited the growth of L. monocytogenes on RTE smoked catfish fillets.

O efeito da injeção do lactato de potássio associado ao uso de atmosfera modificada com alto oxigênio sobre músculos Longissimus lumborum de bovinos machos inteiros foi avaliado. Foram utilizados animais anelorados (com características fenotípicas de Nelore) com diferentes faixas de pH final (pHf - 48h post mortem). Foram coletados 18 músculos e divididos em 3 grupos, sendo eles: baixo (controle; 5,4 < pHf < 5,8), intermediário (5,81 < pHf < 6,3) e alto (pHf > 6,3). Na primeira etapa, foi injetada em cada músculo uma solução de lactato de potássio a 2,5%, em seguida foram cortados em bifes, embalados em atmosfera modificada contendo 80% de oxigênio e 20% de gás carbônico e estocados no escuro a 2 ± 1ºC durante 5 dias. Posteriormente, estes seguiram para um expositor refrigerado com iluminação e temperatura controlada (2 ± 1ºC), onde permaneceram por 9 dias, completando 14 dias de vida útil. Análises de composição gasosa, pH, composição centesimal, sensorial de odor, avaliação microbiológica, oxidação lipídica e cor instrumental foram realizadas nos dias: 0, 5, 8, 11 e 14. Os resultados estatísticos obtidos foram analisados pelo método de medidas repetidas no tempo e também utilizando análise não-paramétrica. A oxidação lipídica foi menor (P < 0,05) e apresentou maior estabilidade em músculos com pHf alto. Não houveram diferenças (P > 0,05) na análise sensorial de odor entre os grupos. A contagem microbiana permaneceu dentro dos limites aceitáveis para consumo humano. Os grupos de pHf intermediário e alto apresentaram uma maior (P < 0,05) estabilidade da cor (maiores valores de a*, croma e oximioglobina). Nas condições do presente estudo, a injeção do lactato de potássio associada à atmosfera com alto oxigênio atuou beneficamente na estabilidade da cor e vida útil de músculos de pHf intermediário e alto. Pode-se concluir que a injeção desta solução é uma alternativa viável para tornar a aparência de bifes provenientes de músculos L. lumborum mais atrativa para o consumidor por meio da estabilização da cor, sem prejudicar a vida útil mesmo nas condições de embalagem utilizadas. / The effect of potassium lactate enhancement in a high oxygen modified packaging on bulls\' Longissimus lumborum was studied. Zebu animals (with phenotypic characteristics of Nellore) animals with different range of ultimate pH (pHu - 48h post mortem) were used. Eighteen muscles were collected and segregated into three groups, wich were: low (control; 5.4 < pHu < 5.8), intermediate (5.81 < pHu < 6.3) and high (pHu > 6.3). In the first stage, a 2.5% potassium lactate solution was injected into each muscle, then they were cut into steaks, packaged in a modified atmosphere containing 80% oxygen and 20% carbon dioxide and stored in the dark at 2 ± 1ºC for 5 days. Later, they were displayed with light and controlled temperature (2 ± 1ºC), where remained for 9 days, completing 14 days of shelf life. Gas composition, pH, proximate analysis, odor sensory, microbiological evaluation, lipid oxidation and instrumental color analysis were performed on days: 0, 5, 8, 11 and 14. The statistical results were analyzed by the method of repeated measurements over time and also using non-parametric analysis. The lipid oxidation decreased (P < 0.05) and showed greater stability on high pHu treatment. There were no differences (P > 0.05) between the treatments on odor sensory analysis. Microbial counts remained within acceptable limits for human consumption. The intermediate and high pHu groups had a higher (P < 0.05) color stability (higher values of a*, chroma and oxymyoglobin). Under the conditions of this study, the potassium lactate enhancement associated with high oxygen atmosphere (Hi-Ox MAP) can be an alternative to increase color stability and shelf life of intermediate and high pHu muscles. It can be concluded that the injection of this solution is a viable alternative to make L. lumborum steaks appearance more attractive to the consumer through the color stabilization, without sacrificing shelf life even under packaging conditions used.

A new product, pork sticks, was developed. Optimum shelf life and safety were major concerns associated with this product. Potassium lactate (3%) or citric acid (0.5%, 0.56%, 0.60% or 0.66%) was added to pork sticks to determine their effects on microbial growth, sensory evaluation, and shelf life when stored frozen (-20°C), refrigerated (2°C), or at room temperature (22°C). Two raw materials, pork blade meat (shoulder meat; 91% lean, 9% fat) and regular 80:20 pork trim (80% lean, 20% fat) were used. The consumer panel preferred lean pork sticks made from blade meat over high-fat pork sticks made from regular 80:20 pork trim, regardless of the addition of potassium lactate (3%) or citric acid (0.5%). Pork sticks vacuum-packaged and held at 2°C or -20°C did not develop bacterial spoilage during six months storage. However, bacterial spoilage and oxidative rancidity occurred in the unpackaged control samples held at 22°C for one month. Incorporation of potassium lactate (3%) or citric acid (0.5%) decreased the color uniformity and red color intensity and increased the brown color intensity of the pork sticks made from blade meat. Vacuum-packaged pork sticks with added citric acid (0.56%, 0.60% and 0.66%) stored at 22°C did not develop bacterial spoilage, but discoloration occurred after one month storage.

In recent years, several studies have linked sodium intake to hypertension, and the consequent mortality risk due to vascular diseases. Several UE member states and the WHO recommend reducing the salt intake level to a maximum of 5 g per day. Salt is a useful ingredient for meat product processing. A reduction of added salt provokes a decrease in the quality of meat products. As a technological strategy, the reduction of the amount of added salt and the addition of potassium lactate, until a 30% molar substitution (taking into account the salt standard amount (30 g/kg)), have been proposed. This substitution could modify the product evolution during its processing. The knowledge of these effects could make the optimization of the process easier. In dry-cured meat products with a reduced salt content, it could be concluded that the proposed strategy reduces the processing period, as well as the anomalous texture risk; it increases the product safety and it does not modify the visual attributes. / Al llarg dels darrers anys, diversos estudis han evidenciat una correlació entre el consum de sal/sodi i la hipertensió arterial, i conseqüent risc de mortalitat degut a malalties vasculars. Diversos països membres de la UE i l’OMS recomanen reduir el consum de sal a 5 grams diaris. La sal és un ingredient essencial en el processat de productes carnis. Una reducció de la quantitat afegida provoca una disminució de la qualitat. Com a estratègia per a no minvar-la, es planteja la reducció de la sal afegida i l’addició de lactat potàssic, fins a un 30% de substitució molar de la quantitat de sal estàndard (30 g/kg); quelcom que pot modificar els paràmetres de procés. El coneixement dels efectes facilitaria l’optimització del processat. En productes carnis crus-curats amb contingut reduït de sal, es conclou que l’estratègia plantejada redueix tant el temps requerit pel processat com el risc d’aparició de textures anòmales; incrementa la seguretat del producte acabat i no modifica els atributs visuals.

O efeito da injeção do lactato de potássio associado ao uso de atmosfera modificada com alto oxigênio sobre músculos Longissimus lumborum de bovinos machos inteiros foi avaliado. Foram utilizados animais anelorados (com características fenotípicas de Nelore) com diferentes faixas de pH final (pHf - 48h post mortem). Foram coletados 18 músculos e divididos em 3 grupos, sendo eles: baixo (controle; 5,4 < pHf < 5,8), intermediário (5,81 < pHf < 6,3) e alto (pHf > 6,3). Na primeira etapa, foi injetada em cada músculo uma solução de lactato de potássio a 2,5%, em seguida foram cortados em bifes, embalados em atmosfera modificada contendo 80% de oxigênio e 20% de gás carbônico e estocados no escuro a 2 ± 1ºC durante 5 dias. Posteriormente, estes seguiram para um expositor refrigerado com iluminação e temperatura controlada (2 ± 1ºC), onde permaneceram por 9 dias, completando 14 dias de vida útil. Análises de composição gasosa, pH, composição centesimal, sensorial de odor, avaliação microbiológica, oxidação lipídica e cor instrumental foram realizadas nos dias: 0, 5, 8, 11 e 14. Os resultados estatísticos obtidos foram analisados pelo método de medidas repetidas no tempo e também utilizando análise não-paramétrica. A oxidação lipídica foi menor (P < 0,05) e apresentou maior estabilidade em músculos com pHf alto. Não houveram diferenças (P > 0,05) na análise sensorial de odor entre os grupos. A contagem microbiana permaneceu dentro dos limites aceitáveis para consumo humano. Os grupos de pHf intermediário e alto apresentaram uma maior (P < 0,05) estabilidade da cor (maiores valores de a*, croma e oximioglobina). Nas condições do presente estudo, a injeção do lactato de potássio associada à atmosfera com alto oxigênio atuou beneficamente na estabilidade da cor e vida útil de músculos de pHf intermediário e alto. Pode-se concluir que a injeção desta solução é uma alternativa viável para tornar a aparência de bifes provenientes de músculos L. lumborum mais atrativa para o consumidor por meio da estabilização da cor, sem prejudicar a vida útil mesmo nas condições de embalagem utilizadas. / The effect of potassium lactate enhancement in a high oxygen modified packaging on bulls\' Longissimus lumborum was studied. Zebu animals (with phenotypic characteristics of Nellore) animals with different range of ultimate pH (pHu - 48h post mortem) were used. Eighteen muscles were collected and segregated into three groups, wich were: low (control; 5.4 < pHu < 5.8), intermediate (5.81 < pHu < 6.3) and high (pHu > 6.3). In the first stage, a 2.5% potassium lactate solution was injected into each muscle, then they were cut into steaks, packaged in a modified atmosphere containing 80% oxygen and 20% carbon dioxide and stored in the dark at 2 ± 1ºC for 5 days. Later, they were displayed with light and controlled temperature (2 ± 1ºC), where remained for 9 days, completing 14 days of shelf life. Gas composition, pH, proximate analysis, odor sensory, microbiological evaluation, lipid oxidation and instrumental color analysis were performed on days: 0, 5, 8, 11 and 14. The statistical results were analyzed by the method of repeated measurements over time and also using non-parametric analysis. The lipid oxidation decreased (P < 0.05) and showed greater stability on high pHu treatment. There were no differences (P > 0.05) between the treatments on odor sensory analysis. Microbial counts remained within acceptable limits for human consumption. The intermediate and high pHu groups had a higher (P < 0.05) color stability (higher values of a*, chroma and oxymyoglobin). Under the conditions of this study, the potassium lactate enhancement associated with high oxygen atmosphere (Hi-Ox MAP) can be an alternative to increase color stability and shelf life of intermediate and high pHu muscles. It can be concluded that the injection of this solution is a viable alternative to make L. lumborum steaks appearance more attractive to the consumer through the color stabilization, without sacrificing shelf life even under packaging conditions used.