Abstract The objective of this work was to investigate the application of microwave vacuum drying (MWVD) as a fast drying method to produce salted-and-dried beef cuts. Moreover, aiming to reduce the sodium content in the meat product, the partial replacement of NaCl by KCl during the salting stage was also investigated. To this end, beef cuts were salted by immersion in one of three saline solutions before drying: Solution A- 100% NaCl; Solution B- 75% NaCl and 25% KCl; and (iii) Solution C- 50% NaCl and 50% KCl. The proposed MWVD method was compared with convective drying (CD) and vacuum drying (VD) in terms of drying kinetics as well as physicochemical and mechanical properties of obtained samples. The average drying times for the samples to reach water activity of 0.7 was more than 40 h for CD, 36 h for VD, and 0.45 h for MWVD. The salting with different solutions had no influence in these times. Moreover, the MWVD samples presented higher values of porosity and rehydration capacity. Thus, the results presented in this study have technological importance for the design of new industrial technologies to produce salted-and-dried meat, as charque and jerked beef, with lower sodium content.

Abstract The objective of this research was to evaluate the ability and efficiency of different software tools for the deconvolution of DSC thermograms of protein denaturation in salted beef. The salted samples were obtained by immersing beef pieces in NaCl solutions with concentrations of 20, 50, 100 and 330 g NaCl L-1 of water for 48 hours at 10 °C. The raw beef were used as control samples. Three software tools were considered: (i) Pyris7, (ii) OriginPro v.8, and (iii) Solver tool from MS-Excel. These computer programs were used for estimating the thermal denaturation temperature of myosin, sarcoplasmic proteins, and actin, as well as the value of denaturation enthalpy of these proteins. Based on the results obtained, we concluded that the model developed and programmed in MS-Excel showed better agreement with the data found in literature than the results obtained with the Pyris and OriginPro tools.

Para a preparação de refeições rápidas é comum o uso de legumes cozidos. A integração dos processos de cozimento e resfriamento de cenouras em um mesmo tanque pelo uso do resfriamento a vácuo é descrito neste artigo. A combinação de diferentes métodos de cozimento e resfriamento a vácuo foi investigada. O processo integrado de cozimento-resfriamento a vácuo em um mesmo tanque permitiu obter cenouras cozidas-resfriadas com temperaturas finais de 10 ºC, o que é adequado à preparação de refeições rápidas com segurança. Quando o processo de cozimento-resfriamento foi realizado com amostras imersas em água de cozimento, a perda efetiva de massa foi de aproximadamente 3,6%. Quando o processo de cozimento-resfriamento foi realizado com amostras imersas em água fervente ou vapor, e o resfriamento a vácuo foi realizado após drenagem da água de cozimento, a perda de massa ficou entre 15 e 20%, ocasionando mudanças na textura dos produtos. Estes problemas podem ser compensados pela etapa de reidratação, utilizando pequena quantidade de água resfriada estéril. As propriedades de textura das amostras de cenoura reidratadas sob condição de vácuo e sob pressão atmosférica foram similares. Portanto, o processo integrado de cozimento-resfriamento a vácuo de cenouras em um mesmo tanque é uma alternativa viável para o processamento deste tipo de produto.

Cooked vegetables are commonly used in the preparation of ready-to-eat foods. The integration of cooking and cooling of carrots and vacuum cooling in a single vessel is described in this paper. The combination of different methods of cooking and vacuum cooling was investigated. Integrated processes of cooking and vacuum cooling in a same vessel enabled obtaining cooked and cooled carrots at the final temperature of 10 ºC, which is adequate for preparing ready-to-eat foods safely. When cooking and cooling steps were performed with the samples immersed in boiling water, the effective weight loss was approximately 3.6%. When the cooking step was performed with the samples in boiling water or steamed, and the vacuum cooling was applied after draining the boiling water, water loss ranged between 15 and 20%, which caused changes in the product texture. This problem can be solved with rehydration using a small amount of sterile cold water. The instrumental textural properties of carrots samples rehydrated at both vacuum and atmospheric conditions were very similar. Therefore, the integrated process of cooking and vacuum cooling of carrots in a single vessel is a feasible alternative for processing such kind of foods.

A impregnação a vácuo (IV) tem sido estudada como uma alternativa para reduzir o tempo dos processos de salga aplicados a diversos alimentos. Neste trabalho, foi investigada a influência da aplicação de vácuo no processo de salga de cortes de peito de frango. Os cortes foram submersos em soluções com diferentes concentrações de NaCl para a avaliação de dois processos distintos de impregnação de sal: a) processo inteiramente a pressão atmosférica (IPA); e b) com aplicação de vácuo seguido do restabelecimento da pressão atmosférica (IV). A transferência de massa entre a amostra e a solução salina foi avaliada através das determinações de ganho de água (GA), ganho de sal (GS) e ganho de massa total (GM) pelas amostras submetidas à IV e à IPA. A comparação entre os processos de IV e IPA, com 6 horas de imersão, indicou que a utilização de um período inicial de vácuo pode incrementar o GA, GS e GM em 78, 25 e 54%, respectivamente. Isso se deve à contribuição sinérgica do mecanismo hidrodinâmico (HDM) aos mecanismos osmóticos e difusivos existentes. Deste modo, a IV pode ser considerada como uma alternativa de processo para a salga de cortes de carne de frango. No entanto, deve-se estar atento para que os ganhos de água e sal sejam compatíveis com as exigências legais e tecnológicas.

Vacuum impregnation has been studied as an alternative for reducing time in the salting process applied to different kinds of food. In this study, the influence of vacuum application on the salting process of chicken breast cuts was evaluated. The chicken samples were submerged in solutions with different NaCl concentrations and two processes were evaluated: a) a process entirely under atmospheric pressure (API); and b) a process with vacuum application followed by atmospheric pressure restoration (VI). Mass transfers were characterized by water gain (WG), salt gain (SG), and total weight increment (WI). The comparison between the VI and API processes, with 6 hours of immersion time, indicated that the utilization of an initial vacuum period can increase the WG, SG and WI in 78, 25 and 54%, respectively. This is due to the synergistic contribution of the hydrodynamic mechanisms (HDM) to the existing osmotic and diffusive mechanisms. Thus, VI can be considered as an alternative for the salting process of chicken cuts. However, special care must be taken in order to assure that water and salt increments are compatible with legal and technological requirements.