Sensory, physicochemical and microbiological properties of dry-cured formed ham: comparison of four different binding systems

Technological and sensory characteristics in development of innovative symbiotic boneless dry-cured lamb meat snack

Novel shelf-stable and high-protein meat products that are affordable, convenient, and healthy are hot topic in current food innovation trends. To offer technological databases for developing new functional lamb meat products, this study aimed to evaluate the technological and sensory aspects of dry-cured lamb meat snacks incorporated with the probiotic culture Lactobacillus paracasei and the prebiotic lactulose. Four formulations were analyzed: control (without prebiotic or probiotic); PREB (with 2% lactulose); PROB (with 107 CFU/g of L. paracasei); and SYMB (with 2% lactulose and 107 CFU/g of L. paracasei). Fitted curves revealed that weight-loss behavior during snack ripening was not affected (P > 0.05) by treatments. Snack moisture, water activity, pH, titratable acidity, lipid oxidation, and residual nitrite were affected (P < 0.05) only by ripening time. The target probiotic strain stood out against competitive flora and was detected at 107 CFU/g in the snack-supplemented formulations (PROB and SYMB). In snacks supplemented with prebiotics (PREB and SYMB), the lactulose content was maintained at 2.17%. Significant differences were not observed in the chemical composition, texture profiles, and CIE color indices between the proposed functional snacks and the control. In addition to texture, flavor, and overall impression evaluation, only color attributes were positively impacted (P < 0.05) in the acceptance and multiple comparison tests against the control. The proposed formulation and bench process parameters produced potential nutritionally and sensory-appreciated, microbiologically stable, and safe (multi-hurdle perspective) functional high-protein restructured lamb snacks.

Inter-laboratory Validation of an HPLC–MS/MS Method for the Detection of Microbial Transglutaminase in Meat and Meat Products

Microbial transglutaminase (TG) is an enzyme isolated on an industrial scale from Streptomyces mobaraensis. Technical TG, a formulated powder, is primarily used to restructure meat in the meat-processing industry, typically at a 1% concentration and is often referred to as “meat glue.” In the European Union, meat restructured with TG requires the indication “formed meat” on the label according to Regulation (EU) No 1169/2011. In order to detect food fraud like the undeclared TG usage in meat and meat products, a qualitative mass spectrometric method using specific tryptic marker peptides has been published in 2017. Here the successful inter-laboratory validation and first-time standardization of a proteomics method for food control is described, which was subsequently included into the Official Collection of Analysis Methods according to the German Food and Feed Code (§ 64 LFGB). Thirteen laboratories from governmental, academic, and private institutions participated in the study, whereas four laboratories did not meet the minimal quality criteria and therefore their results had to be excluded. Three different test materials containing between 0.2 and 2% technical TG as well as blank samples were produced and tested. The laboratories used triple-quadrupole mass spectrometers from several vendors as well as quadrupole time-of-flight instruments. The detection of TG was considered to be positive, if three mass transitions for the marker peptides VTPPAEPLDR (TG-1) and SPFYSALR (TG-2), each, showed a signal-to-noise ratio of at least 3. The level of detection LOD95% for the median laboratory with intermediate performance was 0.31%, the false-positive rate was 0% and the false-negative rate was 2.1%.

Effect of Salt Reduction on the Quality of Boneless Dry-Cured Ham from Iberian and White Commercially Crossed Pigs

Iberian dry-cured ham has great value in a traditional Spanish diet, although experts have recommended its consumption should be reduced because of its high salt content and link to cardiovascular diseases. Eighteen boneless Iberian hams (RIB), eighteen boneless white commercially crossed pig hams (RWC), and eighteen traditionally salted and processed Iberian hams (TIB) were manufactured to check whether the breed (RIB vs. RWC) or the processing (RIB vs. TIB) affects their physical–chemical and sensory characteristics. Moisture, protein, total nitrogen, nonprotein nitrogen, proteolysis index, NaCl, and ash contents were higher in RWC, contrary to the fat values, which were more than double in RIB. All macrominerals, except Ca, were affected by the processing stage and breed, whereas only the micromineral Zn was higher in RWC. The breed did not affect the free amino acid content; however, the total content was slightly higher in RWC. Regarding the manufacturing process, the deboning of RIB allowed the reduction of salt by over 30%. However, the microbiological stability was not affected, resulting in a safe product. Although deboning and salt reduction significantly affect the hardness, adhesiveness, deformation, and elasticity of dry-cured hams, consumers value all sensory parameters with higher scores in RIB.

Production of dry-cured formed ham with different concentrations of microbial transglutaminase: Mass spectrometric analysis and sensory evaluation

Dry-cured formed hams were produced with different concentrations of microbial transglutaminase (TG; 0.05, 0.1, 0.2, 0.5, and 0.8% Activa PB) and glucono-delta-lactone as control. A sensory evaluation was performed during a 43-day storage to determine cohesion, cavities, and local separation of dry-cured formed ham. Rising TG concentrations resulted in a slight increase in the evaluation of all sensory parameters, whereas amounts of TG higher than 0.5% led to an only very minor improvement. Dry-cured formed ham samples were analyzed by a sensitive HPLC-MS/MS method for the detection of TG using five tryptic marker peptides. Even very small amounts of Activa PB (0.05%) were detectable unambiguously. A decrease of TG detectability during the storage time of dry-cured formed ham was not observed. Using four marker peptides, no false-positive or -negative results were obtained. The amounts of two marker peptides were calculated using isotope-labeled peptides. They showed high correlations to the amount of Activa PB (R²>0.995).

A sensitive high performance liquid chromatography-tandem mass spectrometry method for the detection of microbial transglutaminase in different types of restructured meat

A sensitive HPLC-MS/MS-method for the detection of microbial transglutaminase (TG) from Streptomyces mobaraensis in different types of restructured meat (pork, beef, chicken, and turkey) was developed using six tryptic marker peptides (8-11 amino acids). Meat binding experiments were performed with two technical TG mixtures with and without caseinate. After optimization of the conditions of extraction and tryptic digestion, restructured meat and blank values (total samples: 62) were analyzed in a raw and heated state. By investigation of samples pre-treated with oil marinade, emulsion marinade, seasoning salt as well as breadcrumbs, only very little effects of the type of pre-treatment on the detectability of TG were found. Using four marker peptides, no false-positive or false-negative results were obtained. The limit of detection (LOD) was about a factor of 10 below the recommended amount of transglutaminase for raw as well as heated restructured meat.