Chemical and optical characterization of white efflorescences on dry fermented sausages under modified atmosphere packaging

Meat color and iridescence: Origin, analysis, and approaches to modulation

Meat color is an important aspect for the meat industry since it strongly determines the consumers' perception of product quality and thereby significantly influences the purchase decision. Emergence of new vegan meat analogs has renewed interest in the fundamental aspects of meat color in order to replicate it. The appearance of meat is based on a complex interplay between the pigment-based meat color from myoglobin and its chemical forms and light scattering from the muscle's microstructure. While myoglobin biochemistry and pigment-based meat color have been extensively studied, research on the physicochemical contribution of light scattering to meat color and the special case of structural colors causing meat iridescence has received only little attention. Former review articles focused mostly on the biochemical or physical mechanisms rather than the interplay between them, in particular the role that structural colors play. While from an economic point of view, meat iridescence might be considered negligible, an enhanced understanding of the underlying mechanisms and the interactions of light with meat microstructures can improve our overall understanding of meat color. Therefore, this review discusses both biochemical and physicochemical aspects of meat color including the origin of structural colors, highlights new color measurement methodologies suitable to investigate color phenomena such as meat iridescence, and finally presents approaches to modulate meat color in terms of base composition, additives, and processing.

Influence of wet extrudates from pumpkin seed proteins on drying, texture, and appearance of dry-cured hybrid sausages

Hybrid meat products represent a promising, more sustainable alternative to all-meat formulations. However, differences among plant- and animal-based proteins may alter traditional handling and final product properties. In this study, pork meat was partially replaced with texturized pumpkin seed proteins at 12.5, 25, 37.5, and 50% to obtain dry-cured hybrid meat sausages and their ripening (acidification, drying) during 21 days and final product properties (texture, sensory) were characterized and compared to a control (all-meat formulation). The drying behavior and distribution of moisture and free water of hybrids with extrudate contents of 12.5 and 25% were comparable to the sample made with meat and no significant (p > 0.05) differences in proximate composition were found. In contrast, higher meat replacement levels resulted in distinct changes of compositional and textural attributes i.e. chewiness was decreasing by up to 70%. Results suggested 25% of extrudates as an important threshold in manufacture of hybrid dry-cured sausages due to alterations in their ability to bind or release water. Results may be used to understand the influence of alternative texturized proteins in hybrid formulations and help product developers to understand related process and product relevant changes.

Influence of phosphate chelators on white efflorescence formation in dry fermented sausages with co-extruded alginate casings

The aim of the study was to investigate the effect of different condensed phosphates on the white efflorescence formation on dry fermented sausages with calcium alginate casings. The efflorescence formation is induced by the complexation of the divalent cations magnesium and calcium with lactate on the surface of the product. Phosphates are known to complex divalent cations like magnesium and calcium, which are responsible for the efflorescence formation with lactate. To treat the surface of the raw fermented sausages a mixture of di- and polyphosphates and a polyphosphate were used. The sausages were dipped in 5% solutions of the phosphates. The mixture of di- and polyphosphate showed the best results in reducing the white efflorescence formation, the amount of efflorescences on the surface was 18.12% after 8 weeks of storage. The diffusion of magnesium was significantly reduced by ~40% after 8 weeks of storage compared to the control for both phosphates. However, the crystals formed during storage had a different structure and size compared to the control. Isothermal titration calorimetry measurements showed that the divalent calcium ions and the polyphosphates from aggregates caused the crystal formation on the surface, whereas this effect was not seen in combination with magnesium. The surface treatment with the phosphates did not inhibit the white efflorescence formation. However, the extent was reduced but different kind of crystals were formed on the surface during the storage.

Effects of combined measures to minimize white efflorescence formation on dry fermented sausages co-extruded with alginate casings

On dry fermented sausages, especially co-extruded with calcium alginate casings, the formation of white crystals on the surface of the product is a common problem. In this study a hurdle system of combinations of different metal complexing chelators (citric acid and polyphosphate) was investigated. The control and the sample produced with 1.1% citric acid in the alginate gel showed strong white efflorescence formation during the storage (∼60% of the surface was covered), whereas the samples with added 0.3% polyphosphate showed no efflorescence formation. The efflorescence-causing substances such as lactate, magnesium, and calcium increased significantly in the samples, which showed the strongest white efflorescence formation. In the control, lactate increased by 45.0%, calcium by 23.9%, and magnesium by 150.8%, whereas in the samples without white efflorescence, the magnesium and lactate content increased only slightly, and the calcium content even decreased during the storage of 8 weeks. The best results were observed on the addition of 0.3% polyphosphates and the citric acid surface treatment directly after the co-extrusion. Moreover, the strong complex formation could be due to the complexation of magnesium and calcium by lactate, whereby they are removed from the diffusion equilibrium leading to an increased diffusion of the efflorescence-causing substances. PRACTICAL APPLICATION: White efflorescence formation on dry fermented sausages is a major problem on dry fermented sausages, which causes food waste and financial loss for the producer. This study investigated different combinations of promising methods and it was possible to inhibit the white efflorescence formation during the storage. The methods are easy to implement during the manufacturing of the products and are therefore quite interesting for the industrial applications.

Optimum hexametaphosphate concentration to inhibit efflorescence formation in dry fermented sausages

The occurrence of efflorescences on the surface of dry fermented sausages represents a current issue for the meat processing industry. Preventing the efflorescence formation by the addition of sodium hexametaphosphate (SHMP) was shown to be promising in a previous study. The optimum SHMP addition was studied by adding SHMP (0.0, 1.0, 3.0, and 5.0g/kg) directly to the sausage batter. Visual and chemical analyses were conducted during 8weeks of storage under modified atmosphere. Visual analyses revealed significant lower amounts of efflorescences on the sausage surface after 8weeks when 1.0 (27.1%), 3.0 (9.0%), and 5.0g/kg SHMP (3.4%) were added, compared to the control with 38.0% efflorescences. SHMP significantly affected the occurrence (8weeks) of magnesium on the surface: +85.5%, +23.7%, +3.5%, and -28.2% for 0.0, 1.0, 3.0, and 5.0g/kg, respectively. The addition of 4.785g/kg was calculated to fully inhibit the formation of efflorescences by complexing magnesium ions.

Inhibitory effect of phosphates on magnesium lactate efflorescence formation in dry-fermented sausages

This study aimed to prevent the phenomena of efflorescence formation on the surface of dry fermented sausages due to the complexation of efflorescence forming cations with phosphates. Efflorescence formation is a critical issue constituting a major quality defect, especially of dry fermented sausages. Different phosphates (di- and hexametaphosphate) were added (3.0g/kg) to the sausage batter. As a hypothesis, these additives should complex with one of the main efflorescence-causing substances such as magnesium. The formation of efflorescences was determined for dry fermented sausages without phosphate addition, with diphosphate, or hexametaphosphate addition during 8weeks of storage under modified atmosphere. The visual analyses of the sausage surface revealed high amounts of efflorescences for the control (42.2%) and for the sausages with added diphosphate (40.9%), whereas the sausages containing hexametaphosphate had significantly reduced amounts of efflorescence formation, showing only 11.9% efflorescences after 8weeks of storage. This inhibition was a result of strong complexation of hexametaphosphate with magnesium ions, thus preventing the diffusion of magnesium towards the sausage surface. This can be explained by the magnesium content on the sausage surface that increased by 163.9, 127.8, and 52.8% for the sausages without phosphate, diphosphate, and hexametaphosphate addition, respectively. The mass transport of lactate and creatine was not affected by phosphate addition. Isothermal titration calorimetry confirmed that, theoretically, 4.5g/kg of diphosphate or 2.8g/kg hexametaphosphate are required to complex 0.2g/kg magnesium ions naturally occurring in dry fermented sausages and, thus, the chosen overall phosphate concentration of 3.0g/kg was enough when adding hexametaphosphate, but not for diphosphate, to inhibit the efflorescence formation.