Effect of Transglutaminase Treatment on the Structure and Sensory Properties of Rice- or Soy-Based Hybrid Sausages.

Partial substitution of meat with non-protein sources in hybrid meat products generally leads to a decrease in texture attributes and, consequently, in sensory acceptance. In this study, we investigated the effects of transglutaminase (TG) at two concentrations (0.25% and 0.5%) on the physicochemical, textural, and sensory properties of hybrid sausages formulated with concentrated soy or rice proteins. TG caused a reduction in the heat treatment yield of hybrid sausages, particularly those made with rice protein. pH and color parameters were marginally affected by TG addition. Texture parameters increased substantially with TG, although escalating the TG level from 0.25% to 0.5% did not result in a proportional improvement in texture parameters; in fact, for rice-based hybrid sausages, no difference was achieved for all attributes, while only cohesiveness and chewiness were improved for soy-based ones. TG enhanced the sensory attributes of soy-based hybrid sausages to a level comparable to control meat emulsion, as evidenced by ordinate preference score and projective mapping. Our findings suggest that TG is a viable strategy for enhancing texture and sensory parameters in hybrid sausages, particularly for plant proteins that exhibit greater compatibility with the meat matrix.

Improving the textural and nutritional properties in restructured meat loaf by adding fibers and papain designed for elderly.

This study aimed to evaluate the effects of dietary fibers (apple, oat, pea, and inulin) in meat loaves treated with papain enzyme. In the first step, dietary fibers were added to the products at the level of 6%. All dietary fibers decreased the cooking loss and improved the water retention capacity throughout the shelf life of the meat loaves. Besides, the dietary fibers increased the compression force of meat loaves treated with papain, mainly oat fiber. The dietary fibers decreased the pH, especially the treatment with apple fiber. In the same way, the color was changed mainly by the apple fiber addition, resulting in a darker color in both raw and cooked samples. TBARS index increased in meat loaves added with both pea and apple fibers, mostly for the last one. In the next step, the combination of inulin, oat, and pea fibers was evaluated in the meat loaves treated with papain, combining fibers up to 6% total content likewise decreased cooking and cooling loss and increased the texture of the papain-treated meat loaf. The addition of fibers improved the acceptability of the texture-related samples, except for the three-fiber mixture (inulin, oat, and pea), which was related to a dry, hard-to-swallow texture. The mix of pea and oat fibers conferred the best descriptive attributes, possibly related to improved texture and water retention in the meat loaf, and comparing the use of isolated oat and pea, the perception of negative sensory attributes was not mentioned, such as soy and other off-flavors. Considering these results, this study showed that dietary fibers combined with papain improved the yielding and functional properties with potential technological use and consistent nutritional claims for elderly.

Evaluating different levels of papain as texture modifying agent in bovine meat loaf containing transglutaminase.

In this study, bovine meat loaves were produced with different levels of papain (0.00125%, 0.0025%, 0.00375%, and 0.005%) combined with transglutaminase (1%). The effect of this reformulation on pH, instrumental color, water activity, proximate composition, texture, yield, and scanning electron microscopy (SEM) of meat loaves was investigated. In addition, the enzymatic activity of papain was also analyzed. The papain addition increased the pH and the yield of the samples. The hardness was progressively reduced with the increase of papain level. Such changes could be seen through the images recorded by SEM, where an extremely fragmented structure was observed in treatments with higher papain concentration. Papain showed an optimum temperature of 80 °C. This study allowed to observe an intense proteolytic effect in all treatments, despite the papain concentration. Therefore, lower levels should be applied so that the product does not alter its sensory characteristics, such as soft and crumbly texture.

Interaction between papain and transglutaminase enzymes on the textural softening of burgers.

The present study investigated the effect of the enzymes papain (0.2%) and microbial transglutaminase (MTG) (1%) on the texture properties of beef and chicken burgers to develop a meat product with significant increase in softness due to the physiological limitations of the elderly. The products were characterized for pH, objective color, water activity, texture profile analysis (TPA), shear force, compression test, electrophoretic profile, cooking loss, and diameter reduction. A pronounced increase in softness was observed for both raw materials containing papain. An increase in shear force was observed for the beef burger containing only MTG, while the chicken burger showed a reduction of this parameter. The compression tests showed papain alone or combined with MTG decreased the hardness of the burgers. The results showed that the combination of the enzymes papain and MTG can be an effective strategy to develop beef and chicken burgers much softer, contributing to the future studies focused on the physiological needs of the elderly.

Radish powder and oregano essential oil as nitrite substitutes in fermented cooked sausages.

Radish powder (0.5 and 1.0%) and oregano essential oil (OEO) (100 mg/kg) were applied in fermented cooked sausages without the addition of nitrite. The products were evaluated along processing and storage at 4 °C and 20 °C during 30 and 60 days. Carvacrol (77.19%), p-cymene (8.78%), γ-terpinene (4.78%) and thymol (3.53%) were the main compounds identified in OEO, which are responsible for its antioxidant capacity. The use of radish powder resulted in an adequate development of colour (12.5-13.5 for a*), nitrite formation (1.9-2.4 mg/kg), pH (5.0-5.2), aw (0.91-0.92), weight loss (35.8-37.7%) and texture (70-75 N) properties for this type of fermented meat products, and it was also efficient in the decrease of mesophilic bacteria counts (2.3-2.4 log CFU/g in samples with 0.5% radish powder). Sensory analysis showed the consumer's preference regarding aroma for treatments added of OEO and no differences were found in overall acceptance among all treatments, indicating that despite the absence of synthetic nitrite in formulations, the combination of radish powder and OEO was approved by the consumers. However, lipid oxidation was not controlled during storage, since higher TBARS values were found in nitrite-free treated sausages, especially in those stored at 20 °C (2.80 mg MDA/kg in samples with 1% radish powder). Therefore, the use of radish powder and OEO showed promising results to development of fermented cooked sausages from a natural source of nitrite, mainly regarding their physicochemical stability and sensory acceptance.