An overlooked compound contributing to boar taint and consumer rejection of meat products: 2-Aminoacetophenone.

Mainly skatole and androstenone have so far been considered causative for boar taint. Using a mixed methods approach it is shown herein that 2-aminoacetophenone (AAP) affects human perception of pork, too. We explored the importance of AAP in four trials: (1) chemical analyses of 221 fat samples from boar carcasses revealed that AAP occurs, on average, in similar quantities as skatole while the levels of androstenone being four-fold.

Identification of Cross-Species Marker Peptides for the Detection of Mammalian and Poultry Meat in Vegan and Vegetarian Foods.

Authentication of vegan and vegetarian foods is important since these increasingly popular food items could be adulterated with cheap meat to increase profit margins. In this study, nine marker peptides for the detection of meat (several species) were identified applying liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). These marker peptides enable the crucial differentiation of beef versus milk and chicken meat versus egg, demonstrated by the investigation of 19 commercial vegetarian meat substitutes containing milk and egg.

Comparison of Targeted (HPLC) and Nontargeted (GC-MS and NMR) Approaches for the Detection of Undeclared Addition of Protein Hydrolysates in Turkey Breast Muscle.

The adulteration of fresh turkey meat by the undeclared addition of protein hydrolysates is of interest for fraudsters due to the increase of the economic gain by substituting meat with low cost ingredients. The aim of this study was to compare the suitability of three different analytical techniques such as GC-MS and H-NMR with HPLC-UV/VIS as a targeted method, for the detection of with protein hydrolysates adulterated turkey meat. For this, turkey breast muscles were treated with different plant- (e.

Biodiversity of refrigerated raw milk microbiota and their enzymatic spoilage potential.

The refrigerated storage of raw milk selects for psychrotolerant microorganisms, many of which produce peptidases and lipases. Some of these enzymes are heat resistant and are not sufficiently inactivated by pasteurisation or even ultra-high temperature (UHT) treatment. In the current study, 20 different raw cow's milk samples from single farms and dairy bulk tanks were analysed close to delivery to the dairies or close to processing in the dairy for their cultivable microbiota as well as the lipolytic and proteolytic potential of the isolated microorganisms.

Investigation of the Germination of Barley and Wheat Grains with a Design of Experiments for the Production of Hydrolases.

The production of hydrolases from cereals has been examined in order to investigate food-derived enzymes as an alternative source to microbial enzymes for the use in food processes. For that, the influence of temperature on the pretreatment, imbibition and germination of barley and wheat grains was determined by measuring the β-glucosidase, β-galactosidase and lipase activities using a design of experiments. The evaluation of the statistical model showed an increase of the β-glucosidase activity with low imbibition and low germination temperature for barley grains and low imbibition and high germination temperature for wheat grains.

Automated multi-step purification protocol for Angiotensin-I-Converting-Enzyme (ACE).

Highly purified proteins are essential for the investigation of the functional and biochemical properties of proteins. The purification of a protein requires several steps, which are often time-consuming. In our study, the Angiotensin-I-Converting-Enzyme (ACE; EC 3.

Isothermal titration calorimetry as a tool to determine the thermodynamics of demicellization processes.

Demicellization of a 90 mM sodium dodecyl sulfate (SDS) solution in water at 10, 22, and 30 °C was studied by isothermal titration calorimetry (ITC). ΔH of the demicellization process was strongly temperature dependent, having an exothermic progression (-20.4 ± 0.

Expression, one-step purification, and immobilization of HaloTag(TM) fusion proteins on chloroalkane-functionalized magnetic beads.

The presented work introduces a novel method to immobilize enzymes either purified or directly out of a crude extract onto magnetic particles in the micrometer range. This method is based on the creation of a fusion protein consisting of the enzyme of choice and a mutant dehalogenase. The dehalogenase gene is commercially available from the company Promega under the name HaloTag(TM).

Circular dichroism analysis of penicillin G acylase covalently immobilized on silica nanoparticles.

Circular dichroism (CD) was used to characterize the secondary structure of penicillin G acylase upon covalent immobilization on silica nanoparticles. Covalent immobilization was achieved by functionalizing the silica nanoparticles with glutardialdehyde and coupling to the free NH(2) groups of the enzyme (lysine and arginine side chains). The loading of the covalently bound enzyme was increased up to saturation, which was reached at 54.