Kurt Herrmann

Impact of carboxymethyl cellulose (CMC) and microcrystalline cellulose (MCC) on functional characteristics of emulsified sausages.

Inclusion of fibers, such as carboxymethyl cellulose (CMC) and microcrystalline cellulose (MCC), at the expense of fat or protein in meat batters could be used to produce healthier sausages while lowering production costs. To study the impact of CMC/MCC on structural/functional characteristics of emulsified sausages, standard-fat Lyoner-style sausages were formulated with CMC/MCC at concentrations of 0.3-2.0%. Methods of analysis included rheology, water binding capacity (WBC), texture measurements, and Confocal Laser Scanning Microscopy (CLSM). WBC, texture measurements, and rheology all indicated that addition of CMC (>0.7%) led to destabilization of the batter, which upon heating could no longer be converted into a coherent protein network, a fact that was also revealed in CLSM images. In contrast, MCC was highly compatible with the matrix and improved firmness (1405-1651N/100g) with increasing concentration compared to control (1381N/100g) while keeping WBC (4.6-5.9%) with <2% MCC at the level of the control (4.8%). Results were discussed in terms of molecular interactions of meat proteins with celluloses.

Oil-in-water emulsions as a delivery system for n-3 fatty acids in meat products.

The oxidative and physical stabilities of oil-in-water emulsions containing n-3 fatty acids (25 wt.% oil, 2.5 wt.% whey protein, pH 3.0 or pH 6.0), and their subsequent incorporation into meat products were investigated. The physical stability of fish oil emulsions was excellent and neither coalescence nor aggregation occurred during storage. Oxidative stability was better at pH 6.0 compared to pH 3.0 likely due to antioxidative continuous phase proteins. Incorporation of fish oil emulsions into pork sausages led to an increase in oxidation compared to sausages without the added fish oil emulsion. Confocal microscopy of pork sausages with fish oil emulsions revealed that droplets had coalesced in the meat matrix over time which may have contributed to the decreased oxidative stability. Results demonstrate that although interfacial engineering of n-3 fatty acids containing oil-in-water emulsions provides physical and oxidative stability of the base-emulsion, their incorporation into complex meat matrices is a non-trivial undertaking and products may incur changes in quality over time.

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

BACKGROUND Dry fermented sausages that are packed under modified atmosphere are often affected by the formation of white crystals on the surface. These so called efflorescences are rejected by consumers and lead to high financial losses for the meat processing industry. In this study, the distribution of efflorescence-causing components was investigated over the sausage profile during 8 weeks of storage under modified atmosphere at 4 °C. In addition, two visual methods (image and sensory analyses) were compared regarding the ability to quantify the efflorescence content. RESULTS The initial formation of efflorescences was observed after 2 weeks (7%). After 4 weeks of storage, 23.4% of the sausage surface was covered with efflorescences, and the amount of efflorescences did not change significantly by the end of storage. Furthermore, chemical analyses revealed that magnesium (increased by 98.1%), lactate (increased by 54.2%) and creatine (increased by 51.8%) are enriched on the sausage surface during storage. CONCLUSION Sensory and image analyses lead to comparable results (r = 0.992) and therefore both are suitable to quantify the amount of efflorescences. The moisture gradient in the interior of the sausages which is built upon drying is supposed to be the driving force for the movement of efflorescence-causing compounds.

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.

Extension of the Vane Pump-Grinder Technology to Manufacture Finely Dispersed Meat Batters

A vane pump-grinder system was extended to enable the manufacture of finely dispersed emulsion-type sausages by constructing and attaching a high-shear homogenizer at the outlet. We hypothesized that the dispersing capabilities of the extended system may be improved to the point of facilitating meat-fat emulsification due to an overall increased volumetric energy input EV . Coarsely ground raw material mixtures were processed to yield meat batters at varying volume flow rates (10 to 60 L/min) and rotational rotor speeds of the homogenizer nrotor (1000 to 3400 rpm). The normalized torques acting on pump, grinder, and homogenizer motors were recorded and unit power consumptions were calculated. The structure of the manufactured meat batters and sausages were analyzed via image analysis. Key physicochemical properties of unheated and heated batters, that is, texture, water-binding, color, and solubilized protein were determined. The mean diameter d10 of the visible lean meat particles varied between 352 and 406 μm whereas the mean volume-surface diameter d32 varied between 603 and 796 μm. The lightness L* ranged from 66.2 to 70.7 and correlated with the volumetric energy input and product structure. By contrast, varying process parameters did not impact color values a* (approximately 11) and b* (approximately 8). Interestingly, water-binding and protein solubilization were not affected. An exponential process-structure relationship was identified allowing manufacturers to predict product properties as a function of applied process parameters. Raw material mixtures can be continuously comminuted, emulsified, and subsequently filled into casings using an extended vane pump-grinder.

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.