Optimization of lipid profile and hardness of low-fat mortadella following a sequential strategy of experimental design.

This study aims to optimize simultaneously the lipid profile and instrumental hardness of low-fat mortadella. For lipid mixture optimization, the overlapping of surface boundaries was used to select the quantities of canola, olive, and fish oils, in order to maximize PUFAs, specifically the long-chain n-3 fatty acids (eicosapentaenoic-EPA, docosahexaenoic acids-DHA) using the minimum content of fish oil. Increased quantities of canola oil were associated with higher PUFA/SFA ratios. The presence of fish oil, even in small amounts, was effective in improving the nutritional quality of the mixture, showing lower n-6/n-3 ratios and significant levels of EPA and DHA. Thus, the optimal lipid mixture comprised of 20, 30 and 50% fish, olive and canola oils, respectively, which present PUFA/SFA (2.28) and n-6/n-3 (2.30) ratios within the recommendations of a healthy diet. Once the lipid mixture was optimized, components of the pre-emulsion used as fat replacer in the mortadella, such as lipid mixture (LM), sodium alginate (SA), and milk protein concentrate (PC), were studied to optimize hardness and springiness to target ranges of 13-16 N and 0.86-0.87, respectively. Results showed that springiness was not significantly affected by these variables. However, as the concentration of the three components increased, hardness decreased. Through the desirability function, the optimal proportions were 30% LM, 0.5% SA, and 0.5% PC. This study showed that the pre-emulsion decreases hardness of mortadella. In addition, response surface methodology was efficient to model lipid mixture and hardness, resulting in a product with improved texture and lipid quality.

Effect of the smoking using Brazilian reforestation woods on volatile organic compounds, lipid oxidation, microbiological and hedonic quality of bacons during shelf life.

The aim of this study was to investigate the effect of using different reforestation woods (Acacia mearnsii and Eucalyptus citriodora) on the formation of volatile organic compounds and to evaluate the changes in the lipid fraction (peroxide value and thiobarbituric acid reactive substances), microbiological counts and overall liking in bacons stored for 60 days at 5 ± 1 °C. Smoking with Eucalyptus citriodora wood increased the total phenolic content and, consequently, reduced the concentration of hexanal, TBARS, and PV values. Although smoking with different reforestation woods did not impact negatively on the liking of products, no changes on antimicrobial activity was observed in the developed products. Thus, the use of Eucalyptus citriodora wood may be an alternative for smoking meat products as it reduced lipid oxidation and improved the volatile compounds profile, and provided higher antioxidant activity. The information generated herein can be used as a platform for companies to test the viability of producing meat products smoked with reforestation woods.

A peptidomic approach of meat protein degradation in a low-sodium fermented sausage model using autochthonous starter cultures.

Fermented sausage technology is currently compromised in decreasing the addition of NaCl. Use of starter cultures with peptidogenic potential could be a valuable strategy that can mask or hide off flavors produced by the use of NaCl substituents. In the present work, the peptidogenic potential of four lactic acid bacteria species was evaluated in a low-sodium beaker sausage (BS) model. Using a peptidomic approach, a total of 86 low molecular weight (LMW) peptides were accurately identified, mostly derived from myofibrillar proteins, especially actin, which generated 53 peptides. The BS inoculated with L. curvatus CRL705 generated 56 LMW peptides, followed by Enterococcus (E.) mundtii CRL35 with 43 peptides. In addition, BS inoculated with Lactobacillus (L.) plantarum and with L. sakei produced higher amino acid amounts over time as compared to the rest of BS models, highlighting the importance of both, time and sample effect on the overall free amino acid generation. The presence of each LAB strain in BS models generated a unique profile of small peptides and amino acids that could serve as a distinctive biochemical trait to differentiate specific fermented products. According to these results, E. mundtii and L. sakei, which are compatible between them, are proposed as the most efficiently adapted to low-sodium conditions. The use of selected strains during the processing of low-sodium fermented sausages could have a positive effect on the production of small peptides and free amino acids.

Effect of ultimate pH and ageing on thermal denaturation of bovine muscle proteins.

The thermal denaturation of proteins was evaluated in the natural state of bovine muscle using differential scanning calorimetry (DSC). The Longissimus lumborum muscle was selected according to ultimate pH (pHu) values classified into two groups: low pHu with values between 5.4 and 5.8, and intermediate pHu with values between 5.81 and 6.19. The muscles were cut and aged at 2°C up to 21d post mortem. The three maximum temperatures of denaturation (Tmax1, Tmax2, Tmax3) found in muscle were evaluated, showing higher thermal stability in the intermediate pHu group, which could be an indicator of protection of proteins against aggregation or enzymatic activity. The thermal behavior of muscle proteins could be defined by biochemical factors that are affected by pHu of the muscle, however, further studies are necessary to explain this process, which could have a great impact on the understanding of the final tenderness achieved in meat.