Search

Along with the increasing demands for meat due to the growth of population, environmental concerns are raised. Under these circumstances, more substitutes for meat are brought to the market, however, with unsatisfying flavor characteristics. Hence, this research aimed to develop a new version of vegan nuggets based on texturized soy protein (TSP), but with the incorporation of tempeh for flavor improvement. A consumer tests (n = 92) was conducted for evaluating three types of nuggets: chicken nuggets, pure TSP-based nuggets and TSP-based nuggets with added tempeh. Results showed that the chicken nuggets were the most preferred and with more pleasing flavor characteristics; no differences were detected between the two TSP-based nuggets. Subsequently, a 2nd consumer evaluation (n = 80), focused on taste differentiation between the two TSP-based nuggets was conducted. Results indicated that the incorporation of tempeh in the formulation had little effect on overall liking but altered intensities of sweet, bitter and cheesy taste. Besides, texture profile analysis (TPA) showed significant differences on instrumental texture parameters among the types of nuggets. On the other hand, results of life-cycle assessment pointed out a variation of impacts which depended on different functional units used: carbon footprint based on kg of product and on kg of protein showed opposite results; other factors, especially formulation and processing method had significant impacts, indicating the importance of product design when developing a more environmentally friendly meat-alternative. Future research should focus on further improvement of the recipe for plant-based nuggets, both from sensory and environmental aspects.

Proteins are important macronutrients for the human body to grow and function throughout life. Although proteins are found in most foods, their very dissimilar digestibility must be taking into consideration when addressing the nutritional composition of a diet. This review presents a comprehensive summary of the in vitro digestibility of proteins from plants, milk, muscle, and egg. It is evident from this work that protein digestibility greatly varies among foods, this variability being dependent not only upon the protein source, but also the food matrix and the molecular interactions between proteins and other food components (food formulation), as well as the conditions during food processing and storage. Different approaches have been applied to assess in vitro protein digestibility (IVPD), varying in both the enzyme assay and quantification method used. In general, animal proteins tend to show higher IVPD. Harsh technological treatments tend to reduce IVPD, except for plant proteins, in which thermal degradation of anti-nutritional compounds results in improved IVPD. However, in order to improve the current knowledge about protein digestibility there is a vital need for understanding dependency on a protein source, molecular interaction, processing and formulation and relationships between. Such knowledge can be used to develop new food products with enhanced protein bioaccessibility.

Bovine (meat and heart) and porcine (hemoglobin and plasma) raw materials were hydrolyzed by Protease A (both endo-and exopeptidase activity), with or without glucosamine added during the enzyme inactivation step. Hydrolysates were characterized via peptide analysis (yield, UVand fluorescence scanning spectroscopy, and peptide size distribution via size exclusion chromatography), sensory evaluation, and volatile compound analysis via gas chromatography mass-spectrometry (GC-MS) to determine if glucosamine-induced Maillard reaction improved taste and flavor. Porcine hemoglobin produced the most flavor-neutral hydrolysate, and could expectedly have the broadest application in food products. Both bovine meat and-heart hydrolysates were high in umami, and thereby good candidates for savory applications. Porcine plasma hydrolysate was high in liver flavor and would be suitable for addition to certain meat products where liver flavor is desirable. All hydrolysates had low perceived bitterness. Glucosamine-induced Maillard reaction had just a minor influence on the sensory profile via an increased perception of sweet taste (p = 0.038), umami taste (p = 0.042), and yolk flavor (p = 0.038) in the hydrolysates, irrespective of raw material. Glucosamine addition had a statistically significant effect on 13 of 69 volatiles detected in the hydrolysates, but the effect was minor and raw material-specific.

Meat is highly nutritious and contributes with several essential nutrients which are difficult to obtain in the right amounts from other food sources. Industrially processed meat contains preservatives including salts, possibly exerting negative effects on health. During maturation, some processed meat products develop a specific microbiota, forming probiotic metabolites with physiological and biological effects yet unidentified, while the concentration of nutrients also increases. Meat is a source of saturated fatty acids, and current WHO nutrition recommendations advise limiting saturated fat to less than ten percent of total energy consumption. Recent meta-analyses of both observational and randomized controlled trials do not support any effect of saturated fat on cardiovascular disease or diabetes. The current evidence regarding the effect of meat consumption on health is potentially confounded, and there is a need for sufficiently powered high-quality trials assessing the health effects of meat consumption. Future studies should include biomarkers of meat intake, identify metabolic pathways and include detailed study of fermented and other processed meats and their potential of increasing nutrient availability and metabolic effects of compounds.

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.

Sous-vide cooking of meats has been a game changer for most restaurants and foodies all around the world, allowing very tender textures of tough cuts and enabling a perfect control of doneness. However, sous-vide cooked meat lacks strong browning on the surface and roasted flavour notes. Chefs have traditionally use a two stage procedure to overcome this problem, with a more intense cooking method either before or after sous-vide. However, there is a lack of knowledge about the consequences on cooked meat quality parameters, such as cooking loss, water content, colour formation or flavour development. In this study we showed the consequences on these parameters of cooking lamb loins by coupling oven roasting and sous-vide cooking in two possible combinations: sous-vide followed by oven roasting (SV/O) or oven roasting before sous-vide (O/SV). The differences were not so marked, with the exception of a more intense surface browning and lower rate of oxidation to Maillard compounds in SV/O. The potential use of adding reducing sugars to sous-vide cooked meats to promote Maillard reactions is also discussed.

There is a growing market for the use of hydrolysates from animal side-streams for production of high-protein supplements. However, there can be issues with development of off-flavors, either due to the raw material in question or due to the hydrolysis process itself. This study examined the development of volatile compounds during hydrolysis of hemoglobin. Briefly, porcine hemoglobin was hydrolyzed by 0.5% papain for up to 5 h, and the development of volatile compounds was analyzed via gas chromatography-mass spectrometry. The results showed that there was significant development of a number of volatile compounds with time, e.g., certain Maillard reaction and lipid oxidation products, which are likely candidates for the aroma development during hydrolysis. Furthermore, it was shown that development of a number of the volatiles was due to the hydrolysis process, as these compounds were not found in a control without enzyme.

Along with the increasing demands for meat due to the growth of population, environmental concerns are raised. Under the circumstances, more substitutes for meat are brought to the market, however, with unsatisfying flavor characteristics. Hence, this research was aiming to develop a new version of vegan nuggets based on textured soy protein (TSP), but with an incorporation of tempeh to have flavor improvement. Two consumer tests (N=92 and N=80) were conducted on the campus in University of Copenhagen. Three types of nuggets: chicken nuggets, pure TSP-based nuggets and TSP-based nuggets with tempeh added, were provided to meat-eaters on the 1st consumer test. Results showed that the chicken nuggets were the most preferred and with superior flavor characteristics; however, no difference was presented between the two TSP-based nuggets. Subsequently, the 2nd consumer evaluation including both meat-eaters and non-meat eaters, focused on the taste differentiation between the two TSP-based nuggets. Results of the 2nd test indicated that the incorporation of tempeh altered intensities of sweet, bitter and cheesy taste, but still not on liking. On the other hand, results of life-cycle assessment (LCA) pointed out a variation of impacts which depended on different functional units used. Besides, texture profile analysis (TPA) showed significant differences on instrumental texture parameters among the types of nuggets. Future research could focus on further improving the recipe we developed for the TSP-based nuggets, and should take into account of the varieties of tempeh which may provide various effects on sensory improvement

Recently, the addition of cheese powder to meat products, was found to be an interesting tool to boost flavour traits, with a potential use in reduced salt fermented meat products. In the present investigation, the effect of the different cheese powders (EBS, EHC, ORG) and salt content (standard and 40% reduction) was investigated on the physicochemical (weight loss, pH, water activity, percentage of NaCl, moisture content, instrumental texture and instrumental colour) and sensory characteristics of dry fermented sausages. Furthermore, the identification of - glutamyl kokumi peptides were determined by means of UHPLC-MS/MS in the final products and cheese powders. A reduction of 40% of salt and an addition of 1% of cheese powder in dry fermented sausages have an effect on physicochemical parameters (water holding capacity, salt percentage, and instrumental chewiness, and adhesiveness) and sensory attributes (saltiness, sourness, flavour intensity, and complexity). However, the addition of cheese powder only improves the instrumental adhesiveness and the sensory attributes flavour intensity and sourness. Moreover, 5 and 6 γ-glutamyl dipeptides were identified in dry fermented sausages and cheese powders (EBS, EHC, ORG), respectively: γ-Glu-Val, γ-Glu-Leu or γ-Glu-Ile, γ-Glu-Lys, γ-Glu-Phe, γ-Glu-Met, and γ-Glu-Glu, the latter is only found in the cheese powders. Although, no effect on the peptide fraction and γ-glutamyl dipeptides was observed from the addition of cheese powders and salt reduction in dry fermented sausages, the presence of γ-glutamyl dipeptides might influence the kokumi sensation of these meat products. Furthermore, high concentrations of small peptides (<300Da) and identification of γ-glutamyl dipeptides in cheese powders confirm their potential as a flavour enhancer in food products.

Low temperature long time (LTLT) sous-vide cooking may modify meat proteins in a way that could promote satiety. We investigated the effects of (1) cooking method (LTLT 58 °C vs. oven 160 °C), (2) LTLT holding time (17 h vs. 72 min), and (3) pork structure, LTLT 58 °C for 17 h (minced vs. roast) on appetite regulation and in vitro protein digestibility. In a cross-over study, 37 healthy men consumed four meals containing pork: LTLT-cooked roast, 58 °C, 72 min; LTLT-cooked roast, 58 °C, 17 h; and, oven-cooked roast, 160 °C to a core temperature of 58 °C and LTLT-cooked minced patties, 58 °C, 17 h. Ad libitum energy intake (EI) after three hours was the primary endpoint. Moreover, subjective appetite sensations were assessed. Protein digestibility was determined in an in vitro simulated digestion model. Ad libitum EI did not differ between the meals. Furthermore, appetite ratings were not clearly affected. LTLT cooking for 72 min increased the proteolytic rate in the early gastric phase during digestion as compared to LTLT cooking for 17 h or oven cooking. In conclusion, LTLT cooking, LTLT holding time, and pork structure did not affect ad libitum EI. However, LTLT cooking at 58 °C for 72 min seemed to enhance in vitro protein digestibility.

BACKGROUND: In superchilling (SC), meat is kept at temperatures around 1 °C below its initial freezing point, leading to a significant increase in shelf life. This study aimed to address the oxidative changes taking place in pork loins during prolonged storage at SC temperature. Loins were stored either at chilling (CH) conditions (2-4 °C) for 4 weeks or at SC temperature (around -1 °C) for 12 weeks. RESULTS: Storage at SC temperature diminished the rate of lipid and protein oxidation and discoloration in pork loins, so that final levels of most oxidation products and instrumental color values after 12 weeks of SC storage were similar to those after 4 weeks at CH conditions. However, hexanal content peaked by the end of SC storage, pointing to a potential accumulation of compounds from lipid oxidation during SC storage. CONCLUSION: SC storage of pork slows down the rate of lipid and protein oxidation. However, accumulation of volatile compounds from lipid oxidation could be a limiting factor for shelf life.

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

Porcine gelatin was subjected to the action of different amounts of commercial transglutaminase (TGase) and subsequently used to produce foams or gels. Foam stability at 20 °C and 80 °C, and thermal stability and instrumental texture of the gels were studied. Gelatin and TGase contents significantly increased the foam stability at both temperatures, but the effect of TGase was much more marked. Also both factors enhanced the thermal stability of gelatin gels, so that gels containing 3% of gelatin and 0.7% TGase were still gelled after 1 h at 80 °C, while any of the gelatin-based gels without TGase turned rapidly into liquid in less than 10 min at 80 °C. Hardness and chewiness of the gels were strongly enhanced by gelatin content, but very especially by TGase concentration. Gels tended to be less springy with increasing amounts of TGase. Modification of gelatin-based foams and gels with the addition of TGase appears as an interesting approach for culinary recipes in which gelatin should be heated. However, a careful optimization should be done to avoid a too rubbery texture.

This study revealed the possibility of manufacturing prefried lamb nuggets from low-value cuts (flank) and evaluated the effect of formulation (50:50 vs. 20:80 of leg/flank cuts) and freezing (−20 ℃ for two months) on different quality parameters. Frying process produced a decrease of water content, an increase in lipid oxidation indicators, and an intense browning of nuggets surface. The use of flank up to a 75% of the total meat in the formula led to higher fat contents and higher polyunsaturated fatty acid proportions in fried nuggets. This made them more prone to get oxidized during the freezing storage and subsequent final frying. Nuggets with a higher proportion of flank also showed lower shear force values. However, nuggets with both formulations showed similar sensory acceptance. Freezing storage of lamb meat nuggets for two months increased the levels of lipid oxidation indicators, but again not to a level high enough to influence the sensory perception by consumers. So that, frozen nuggets from both formulations showed similar consumer acceptance to freshly produced ones with quite good scores (3.46–3.86 out of 5). Thus, low-value lamb cuts are suitable for being processed into highly acceptable prefried frozen lamb nuggets, which constitutes an opportunity for adding value to the whole lamb value chain.