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Different types of cheese powder were added to meat emulsion sausages in order to address its influence on chemical composition, volatile compounds profile and sensory properties, and its potential to reduce salt content through boosting saltiness. Addition of cheese powder to emulsion sausages modified their profile of volatile compounds. Blue cheese increased some ketones, alcohols, and esters, while brown cheese brought typical Maillard reaction compounds. Overall, addition of cheese powders to sausages enhanced the intensity of flavour traits. A mixture of hard and blue cheese powder showed the highest effect on boosting saltiness, while brown cheese powder showed the strongest umami and meat flavour boosting effect, and sausages with added blue cheese powder showed a more intense aftertaste. Hardness significantly increased due to the addition of blue cheese powder. Addition of cheese powder to emulsion sausages might be an interesting tool to boost flavour and reduce salt content in cooked sausages with no negative effect on saltiness or overall flavour. [ABSTRACT FROM AUTHOR]

This study aimed to address the proteolytic phenomena taking place in pork loins during prolonged storage at superchilling (SC) temperature. Loins were stored at either chilling (CH) conditions (2–4 °C) for 4 weeks or at SC temperature (around −1 °C) for 12 weeks. Storage at SC temperatures slowed down the rate of proteolysis in pork loins, so that final levels of most indicators for proteolysis, including after 12 weeks of SC storage were similar to those after 4 weeks at CH conditions. Consequently, the texture of SC pork under extended storage was not so different to that of CH pork. However, total amino acid content peaked by the end of SC storage, pointing out to a potential ongoing exopeptidase activity. Overall, proteolysis seemed to be slowed down in pork at SC conditions, with similar levels for most indicators after 12 weeks of SC storage or 4 weeks at CH conditions. [ABSTRACT FROM AUTHOR]

Structural modifications of pork proteins under an assortment of industrial heat treatments were studied. With raw as control, assorted heat treatments involved were 58, 80, 98 and 160 °C for 72 min, 118 °C for 8 min and 58 °C for 17 h, resembling most common processing procedures. Protein denaturation, surface protein hydrophobicity state and protein aggregation behaviour were investigated. Modifications and molecular chemistry in protein structures were tracked by Fourier Transform Infrared Spectroscopy in order to extract relative proportions of β-sheet, α-helix and residual conformations. In comparison to uncooked samples, cooked ones showed more than two-fold increase in hydrophobicity and larger particles. Thermograms from differential scanning calorimetry showed endothermic transitions (positive enthalpy) indicating a different pattern of protein denaturation as a result of varied cooking temperatures and cooking times. Deconvolution and curve fitting procedures (R 2 = 0.99) provided information on rise of the β-sheet to α-helix ratio that further confirmed aggregation with thermal rise and longer cooking time. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes the influence of different factors on sous-vide cooked pork. Pork cheeks were cooked at different combinations of temperature (60°C or 80°C), time (5 or 12h) and vacuum (vacuum or air packaged). Weight losses were lower and moisture content higher in samples cooked for a shorter time (P=0.054) and at a lower temperature (P<0.001). Samples cooked at 60°C showed more lightness (L*) and redness (a*) (P<0.001). Lipid oxidation showed an interaction between cooking time and temperature (P=0.007), with higher TBARs values for samples cooked for 12h at 60°C and lower for those cooked for 12h at 80°C. Samples cooked at 80°C for 12h showed lower (P<0.05) values for most textural parameters than all the other types of samples. Vacuum packaging showed no influence on any of the studied variables. For the treatments evaluated, cooking temperature×time combination seems to be more important than vacuum packaging in the textural and colour parameters of pork cheeks. [Copyright &y& Elsevier]

• A one-stage fatty acid transmethylation method has been optimized for meat products. • A fast GC run for fatty acid analysis has been established. • Quality control parameters have shown an accurate performance of this methodology. • High recovery percentages of fatty acids have been found with the improved method. • A straightforwardly and quickly fatty acid analysis for meat products has been proven. The quantification of fatty acids (FA) in meat products is frequently carried out by two-stage methylation procedures followed by long gas chromatography (GC) runs. This work aimed to simplify this methodology by means of a one-stage transmethylation method and a fast GC run, evaluating the influence of sample preparation, reagents and type of heating on the amount of FA in different meat products and optimizing a fast GC-FID (flame ionization detector) run. This allowed to establish the optimum combination of parameters (methanol + chlorotrimethylsilane, lyophilized samples and oven heating) to achieve the quantification of the highest possible amount of FA and to reduce the time of GC run from 60 to 10 min. The quality evaluation of this method obtained satisfactory results. Thus, the quantification of FA in meat products was achieved in a straightforwardly and quickly way by using a one-stage transmethylation procedure followed by a fast GC-FID run. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the impact of endo- and exo-peptidase treatment on certain structural characteristics of peptides and volatile compounds of porcine hemoglobin and whole blood hydrolysates. Porcine hemoglobin and whole blood were hydrolyzed by endo- and exo-peptidases. The presence of exopeptidases reduced the bitterness and altered the volatile profiles of protein hydrolysates. Exopeptidase treatment can release terminal amino acids from peptides, which in turn may contribute to formation of volatile compounds by Maillard reactions. In contrast, endopeptidases conferred a slightly bitter taste and different volatile profiles. For hemoglobin hydrolysates, principal component analysis revealed that proteases were categorized into three groups based on endo- or exo-peptidase activity. Whole blood is a more complex raw material, yet the proteases were still categorized in a similar fashion. This work contributes to understanding structural characteristics responsible for taste and volatile profiles of protein hydrolysates. Unlabelled Image • Porcine hemoglobin and whole blood were hydrolyzed using endo- and exo-peptidases. • Two hemoglobin subunits exhibited different enzymatic resistance. • Exopeptidases reduced bitterness and altered volatile profiles of protein hydrolysates. • There was a correlation between taste attributes and peptide MW ranges. • PCA analysis revealed that proteases were grouped based on endo- or exo-peptidase activity. [ABSTRACT FROM AUTHOR]

The aim of the study was to characterize Maillard reactions in meat under different cooking treatments. Considered temperature-time combinations included raw samples (control), 58, 80, 98 and 160 °C for 72 min, 118 °C for 8 min and 58 °C for 17 h. Furosine, a marker for heat treatment, was detected in all groups with roasting having a 4-fold increase over the control. Sous-vide treatment at 80 °C, boiling and autoclaving also contribute to a significant increase in furosine. N ɛ -carboxymethyllysine, an indicator for advanced glycation end products, showed negligible amount in control, but increased with cooking temperature, with oven samples showing the highest values. A similar increasing trend was observed in lanthionine, covalently bonded protein crosslinks, which arises due to severe thermal regimes. Simultaneously, glycation and deamidation formation were tracked in meat proteins through peptidomics to highlight residue level changes that might affect nutrient value in processed muscle based foods. [ABSTRACT FROM AUTHOR]

The impact of thermal processing on meat proteins oxidation was investigated. Cooking treatments included 58 °C for either 72 min or 17 h (mimicking low temperature-long time sous vide cooking), 80, 98 and 160 °C for 72 min (mimicking common cooked meat products, stewing and roasting, respectively) and 118 °C for 8 min (autoclaving). Tryptophan degradation, fluorescent oxidation products, free thiol content and α-aminoadipic and γ-glutamic semialdehydes were tracked. For all of them, there was a consistent trend to increased levels of oxidative damage with higher cooking temperatures and longer cooking times, although the extent varied from one indicator to another. Through proteomics, peptide oxidative modifications like carbonylation, malonaldehyde adducts and hydroxykynurenin (tryptophan oxidation products) were also detected at residue level. Our findings indicate that protein oxidation is dependent upon the heat treatment, which point out to a different effect on the nutritional quality of proteins in meat products. [ABSTRACT FROM AUTHOR]

This study aimed to identify in which extent cooling rate in pork subjected to superchilling influences the final weight loss after storage. Different cooling systems (brines at −15 °C and -9 °C, forced air at −18 °C and still air −24 °C) led to a range of cooling rates in pork model systems. The ice crust on the surface of pork grew faster in those systems with a higher energy flux. Higher cooling rates led to lower weight loss after superchilling storage, highlighting the importance of using fast cooling systems for superchilled pork. [ABSTRACT FROM AUTHOR]

Spray-dried microcapsules from double (DM) and multilayered (MM) fish oil emulsions were produced to evaluate the effect of type of emulsion on the fatty acid composition during the microencapsulation process and after one month of storage at refrigeration (4 °C) and room (20 °C) temperature. Encapsulation efficiency, loading and loading efficiency were significantly higher in MM than in DM. C20:5 n-3 (EPA) and C22:6 n-3 (DHA) showed higher proportions in MM than in DM. Some differences in microstructural features were detected, with DM showing cracks and pores. The influence of the storage was significant, decreasing the content of polyunsaturated fatty acids in both MM and DM, above all at 20 °C. This decrease was more notable in DM. Multilayered emulsions are more suitable to encapsulate fish oil in terms of quantity of encapsulated oil, microstructure of the microcapsules and protection of fatty acids, especially EPA and DHA, during storage. [ABSTRACT FROM AUTHOR]

The effect of thermal processing on the in vitro digestibility of pork proteins was studied. Raw samples were considered the control group, while the thermal treatments included 58, 80, 98 and 160 °C for 72 min, 118 °C for 8 min and 58 °C for 17 h, resembling a range of different cooking procedures. Samples were subsequently subjected to pepsin digestion at pH 3.00 in the gastric phase followed by trypsin and α-chymotrypsin at pH 8.00 in the intestinal phase. Pork cooked at 58 °C for 72 min had a significantly higher pepsin digestibility rate than meat cooked at 80 °C or 160 °C. The trend was similar in the intestinal phase, with samples cooked at 58 °C for 72 min having enhanced digestion rate over other treatments after 120 min of digestion. A PLS model pointed out to an inverse relationship between in vitro proteolysis rate and variables like Maillard reaction compounds or protein structural changes. • In vitro protein digestibility in pork under different heat treatments was studied. • Protein digestion rate decreased with higher cooking temperature and time. • Structural and chemical modifications of pork proteins were related to change in digestion rate. • Maillard reactions, protein aggregation and % beta sheet negatively affected protein digestion. [ABSTRACT FROM AUTHOR]