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1.
Anim Sci J ; 94(1): e13870, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37743546

RESUMEN

Venison, a type of game meat, has several health benefits because it contains not only high protein and low fat but also bioactive peptides with several physiological properties, including antioxidative and angiotensin-converting enzyme inhibitory properties. The aim of the present study was to investigate the antioxidant activity of venison treated by in vitro cooking and gastrointestinal digestion. We subjected venison along with pork and beef to in vitro cooking and digestion and assessed their antioxidant activity via 2,2-diphenyl-1-picrylhydrazyl radical scavenging (DPPH-RS) and hydrophilic oxygen radical absorbance capacity (H-ORAC) assays. The peptide contents of all types of cooked and digested meat samples were higher than those of the untreated and cooked samples. The DPPH-RS activities and H-ORAC of digested venison, pork, and beef were increased compared with those of untreated samples. DPPH-RS activity was significantly higher in the digested venison samples than in the digested pork and beef samples. In this study, several fractions of digested venison from the chromatography exhibited DPPH-RS activity. Peptide analysis, using liquid-chromatography with tandem mass spectrometry, unveiled two peptides DIDDLELTLAK and TQTVCNFTDGALVQHQEWDGK with high DPPH-RS activities. Thus, venison is a rich source of antioxidant peptides and potentially demonstrate an antioxidation ability by digestive enzymes in vivo.


Asunto(s)
Antioxidantes , Carne , Bovinos , Animales , Antioxidantes/metabolismo , Carne/análisis , Péptidos/metabolismo , Culinaria/métodos , Digestión
2.
Food Chem ; 401: 134191, 2023 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-36113220

RESUMEN

Few studies were dedicated to characterizing the dromedary milk (DM) as consumed by Bedouins, mixed with a small amount of dromedary urine (DU). Therefore, this work aimed to reveal some physical and biochemical characteristics of the DM alone, and incorporated with DU at two different concentrations. pH, colour, Brix, fats, and minerals were evaluated with proteins and sugar content using FTIR; in addition to protein oxidation. The results showed that DM counts as a rich source of the nutritional element yet its proprieties were affected by the addition of DU. An important increase in colour, sugar, fat, and protein concentration with a remarkable augmentation in the pH, mineral content, and protein oxidation where the more urine is added the more milk proteins are oxidated as demonstrated by the characteristics showed in the two mixtures which will negatively affect DM therapeutical proprieties, especially the one related to proteins.


Asunto(s)
Árabes , Camelus , Animales , Humanos , Proteínas de la Leche , Minerales , Azúcares
3.
Foods ; 13(1)2023 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-38201040

RESUMEN

Curing produces a characteristic pink color during meat processing through the production of nitrosyl myoglobin (NOMb), which requires nitric oxide (NO). Nitrites and nitrates in coloring agents are crucial NO sources; however, a reducing agent is necessary to facilitate their chemical conversion to NO. This study aimed to investigate the effect of the reducing properties of whey protein hydrolysate (WPH) on the reddening of cured meat products. Cured and cooked sausage models were treated with WPH, which enhanced the reddening of the meat color and increased the a* value in the models compared with that of the controls. Additionally, ethanol-extracted WPH induced Fe3⁺ reduction, lowered oxidation-reduction potential, and decreased nitrite (NO2-) levels. Moreover, ethanol-extracted WPH promoted the formation of NOMb in myoglobin solution. This effect was also observed when ethanol-extracted WPH treated with maleimide was used, implying that certain peptides rather than the thiol group of WPH are involved in promoting NOMb formation. Furthermore, the peptides that decreased NO2- levels were isolated from ethanol-extracted WPH, identified, and synthesized. These synthesized peptides, particularly the FFVAPFPEVFGK peptide, showed NO2--reducing activity. Hence, WPH may promote the coloration of cured meat products through the reducing potential of the peptides contained within.

4.
Foods ; 11(14)2022 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-35885366

RESUMEN

The aim of this study was to investigate the inherent bacteria that contribute to expressing the angiotensin I-converting enzyme (ACE) inhibitory activity and the antioxidant activity of dry-cured meat products without a bacterial starter. Among the ten dry-cured meat product samples, Coppa and Milano salami exhibited high ACE inhibitory activity, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability, and oxygen radical absorbance capacity (ORAC). No consistent trend was observed in the pH values or the total peptide and imidazole dipeptide concentration of the products that exhibited high ACE inhibitory and antioxidant activities in the tested samples. To investigate the bacteria contributing to the ACE inhibitory and antioxidant activities of the product, 16S rRNA sequencing analysis, isolation, and identification of bacteria were performed using not only Coppa and Milano salami but also the Jamon Serrano and Parma prosciutto products that had low functional activities. Results suggest the Lactobacillales order, particularly the species Latilactobacillus sakei and Pediococcus pentosaceus, were the main inherent bacteria in Coppa and Milano salami, respectively, compared with the Jamon Serrano and Parma prosciutto products. Therefore, the inherent lactic acid bacteria in dry-cured meat products without bacterial starter is important for ACE inhibitory and antioxidant activities of the products.

5.
Prep Biochem Biotechnol ; 52(10): 1097-1108, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35171080

RESUMEN

In this study, bovine sodium caseinate (NaCas) was hydrolyzed with four proteases, alcalase, savinase, subtilisin A, and flavourzyme. In addition to the structural changes occurred through the enzymatic hydrolysis, the solubility, oil binding capacity, zeta potential, emulsification properties, and in vitro antioxidant capacity, anti-carcinogenic and antidiabetic properties of hydrolysates were determined. FTIR combined with hierarchical cluster analysis (HCA) made in Amide I region enable to classification of the samples based on the changes of the secondary structure depending on the enzyme type and degree of fragmentation. Technological properties of NaCas were enhanced through the enzymatic hydrolysis, and those were more prominent in serine-type enzymes, regardless of the enzyme type, all hydrolysates showed high antioxidant capacities. All hydrolysates, specifically those produced by savinase and alcalase, reduced the viability of the carcinogenic Caco-2 cells in a dose-dependent manner and showed a very low level of cytotoxicity against healthy HEK-293 cells. The hydrolysis treatment made a significant contribution to the antidiabetic activity of NaCas. Particularly alcalase and savinase hydrolysates suppressed the activity of α- amylase and α- glucosidase. Therefore, the generated milk protein hydrolysates could be used in functional food developments for specific dietary purposes.


Asunto(s)
Caseínas , Péptido Hidrolasas , Bovinos , Animales , Humanos , Péptido Hidrolasas/metabolismo , Caseínas/química , Antioxidantes/farmacología , Antioxidantes/química , Células CACO-2 , Células HEK293 , Hidrolisados de Proteína/química , Subtilisinas/química , Hidrólisis , alfa-Amilasas , Hipoglucemiantes
6.
Foods ; 9(9)2020 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-32854180

RESUMEN

Game meat has been underutilized, while it offers the potential to diversify not only the human diet but also increase food production and the nutritional value of meat products. This study aimed to determine the angiotensin I-converting enzyme (ACE) inhibitory activities of the digested game meats (venison and boar meat) compared with those of livestock meats (beef and pork). Through the sodium dodecyl sulfate polyacrylamide gel electrophoresis and size chromatography results, we found that the digested products from each meat had different molecular weights. The ACE inhibitory ratio in all tested samples had gradually increased following by the enzyme treatments. ACE inhibitory ratios and the half maximal inhibitory concentration values indicated that digested venison was the most potent inhibitor of ACE activity, followed by the digested boar meat. The level of anserine in digested venison was higher than that in the other meats, but the carnosine level was lower. Through fractionations and liquid chromatography-tandem mass spectrometry analysis, five ACE inhibitory peptides were identified from the digested venison. Of these peptides, Isoleucine-Lysine- Glutamic Acid-Valine-Threonine-Glutamic Acid-Arginine (IKEVTER) demonstrated the highest ACE inhibitory activity. Therefore, the game meat is food that is believed potentially to offer high bioactivities, particularly antihypertensive forces.

7.
J Food Sci Technol ; 56(1): 200-207, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30728561

RESUMEN

Phenolics and essential oil of peppermint were obtained by pressurized hot water extraction (PHWE). The best extraction conditions were found to be 130 °C for temperature, 10 min for extraction time, and 3 cycles for extraction number. There were no statistically significant differences between 130 and 160 °C in terms of essential oil content. Total phenolic contents (TPC) of the extracts were higher at 160 °C than that of 130 °C. However, further HPLC analysis of the extracts revealed that hydrolysis and/or decomposition of phenolics were observed in the extracts obtained at 160 °C. The main phenolic of peppermint was determined as eriocitrin by HPLC-DAD, while menthol was the dominant component in essential oil fraction of peppermint by GC-FID. The present study demonstrated that PHWE was a suitable technique for simultaneous extraction of phenolics and essential oil from peppermint. The technique might be used as an analytical extraction tool for determination of phenolics and essential oil. Moreover, the extracts of PHWE could directly be evaluated for the enrichment of liquid food formulations or be transformed into solid form by suitable techniques such as spray drying for easy storage and subsequent enrichment of food products.

8.
Food Res Int ; 104: 48-58, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29433783

RESUMEN

Living with pain is one of the distressing effects of food insecurity and malnutrition among millions of internally displaced persons (IDPs) worldwide. Vulnerability to emotional pain, metabolic imbalance, chronic illnesses and non-communicable diseases by IDPs are associated with stressed livelihood and restricted access to balanced diets in their camps. Tackling the complexity of issues related to internal displacement is challenging as 45% are globally trapped in protracted conditions. In this review, a diet-based intervention is proposed considering the potential benefits of nutrient synergy and analgesic constituents in organ meat. Providing an affordable, value added and well packaged nutrient dense diet is suggested to meet daily protein and micronutrient requirements from organ meat. Also, unlocking health-promoting bioactive substances and analgesics in restructured organ meat product is proposed as personalized dietary remedy to exert opioid bioactivity in food matrix. Exploiting the nutrient synergy of this animal by-product will not only improve the nutritional status or wellbeing but also raise the composite score of dietary diversity or food security index among IDPs by 2030.


Asunto(s)
Analgésicos/administración & dosificación , Abastecimiento de Alimentos , Alimentos Fortificados/provisión & distribución , Desnutrición/prevención & control , Carne/provisión & distribución , Valor Nutritivo , Dolor/prevención & control , Refugiados/psicología , Adaptación Psicológica , Animales , Dieta Saludable , Emociones , Salud Global , Humanos , Hambre , Desnutrición/epidemiología , Desnutrición/fisiopatología , Desnutrición/psicología , Estado Nutricional , Dolor/epidemiología , Dolor/fisiopatología , Dolor/psicología , Ingesta Diaria Recomendada
9.
Artículo en Inglés | MEDLINE | ID: mdl-30598684

RESUMEN

Bacteria are one of the major causes of severe infections and diseases of plants and animals. Salmonella are crucially important due to infection in poultry leading to huge economical loses. Due to high cost and microbial resistance to the currently available chemical antibiotics, demand of screening natural products with antibiotics effects is increased. Plants are rich sources of natural bioactive compounds with antibiotic effects. Saponins are natural compounds of plant sources having a diverse range of applications. In present study we investigated the in vitro and in vivo antibacterial activities of green tea seed extracted saponins. Green tea seeds crude extract was prepared in 70% ethanol by continuous reflux in heating mantel for 5 hours. Crude saponins were extracted from the crude ethanolic extract of green tea seed by column chromatography using macroporous resin (D101). Saponin mixture in fraction 1 (Fr1) was obtained from crude saponins extract via column chromatography. Fr2 and Fr3 were isolated from saponins mixture by preparative HPLC. Antibacterial activities of the isolated saponins fractions were investigated against Escherichia coli (ATCC 25922), Streptococcus aureus (ATCC 12600), and six serovars of Salmonella. In vitro antibacterial activities were determined by disc-diffusion method and growth inhibition in liquid culture using 96-well plate. Results showed that the green tea isolated saponins fractions possess antibacterial effects in the following order Fr1>Fr2>Fr3. Antibacterial mechanism of saponins was elucidated by cell wall and membrane damaging potential of saponins determined by measuring AKP and soluble proteins levels. Fr1 was further used for in vivo antibacterial activities. Five-week grown chickens were selected for in vivo work, divided into three groups as control, infected, and treatment groups. Infected and treatment groups chickens were infected with bacteria and only treatment group chickens were treated with saponins. The qRT- PCR analysis of the blood and feces samples of the different groups' animals shows the presence of bacteria only in infected group while reduced expression levels of the bacterial pathogens were found in the samples of treatment group. Our results demonstrated that the green tea seed saponins used in this study possess strong antibacterial activities.

10.
Meat Sci ; 127: 35-44, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28113096

RESUMEN

The effects of utilizing fermented soybeans paste (miso) as an alternative flavor-coating material for eliminating unpleasant odor of sulphuric and sotolone compounds from cemen in commercial pastirma were investigated. Results showed that miso-pastirma (MP) and commercial pastirma (CP) had higher L* values in comparison with the fresh meat. While no pathogen was detected in all the meat samples, statistically significant stearic acid was increased (P<0.05) and also oleic and arachidic acids were observed in MP. SDS-PAGE patterns indicated that miso had higher impacts on muscle proteins than cemen suggesting that miso can generate proteins and peptides with better technological or nutritional properties. None of the sulphur containing compounds responsible for unpleasant odor was detected in MP. Limonene, 5 esters, beta-pinene and saponins in MP contributed to citrus fruit aroma with smoother, roasty flavor and delicious taste. These findings suggest that miso contain good flavoring molecules for enhancing fruity smell and quality of pastirma. Thus, laminating cured meat with miso can be used as an alternative to cemen for producing healthier pastirma with extended shelf life and better flavor.


Asunto(s)
Aromatizantes , Manipulación de Alimentos/métodos , Glycine max/química , Carne/análisis , Semillas/química , Alimentos de Soja , Gusto , Animales , Monoterpenos Bicíclicos , Compuestos Bicíclicos con Puentes/análisis , Bovinos , Color , Ciclohexenos/análisis , Ésteres/análisis , Ácidos Grasos/análisis , Fermentación , Conservación de Alimentos/métodos , Furanos/análisis , Humanos , Limoneno , Productos de la Carne/análisis , Monoterpenos/análisis , Proteínas Musculares/análisis , Odorantes/análisis , Saponinas/análisis , Alimentos de Soja/análisis , Compuestos de Azufre/análisis , Terpenos/análisis , Turquía
11.
Anim Sci J ; 88(3): 507-516, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27480048

RESUMEN

In the lactic acid bacteria (LAB) strains screened from our LAB collection, Lactobacillus (L.) sakei strain no. 23 and L. curvatus strain no. 28 degraded meat protein and tolerated salt and nitrite in vitro. Fermented sausages inoculated strains no. 23 and no. 28 showed not only favorable increases in viable LAB counts and reduced pH, but also the degradation of meat protein. The sausages fermented with these strains showed significantly higher antioxidant activity than those without LAB or fermented by each LAB type strain. Angiotensin-I-converting-enzyme (ACE) inhibitory activity was also significantly higher in the sausages fermented with strain no. 23 than in those fermented with the type strain. Higher ACE inhibitory activity was also observed in the sausages fermented with strain no. 28, but did not differ significantly from those with the type strain. An analysis of the proteolysis and degradation products formed by each LAB in sausages suggested that those bioactivities yielded fermentation products such as peptides. Therefore, LAB starters that can adequately ferment meat, such as strains no. 23 and no. 28, should contribute to the production of bioactive compounds in meat products.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/análisis , Antioxidantes/análisis , Fermentación , Lactobacillus/fisiología , Productos de la Carne/análisis , Productos de la Carne/microbiología , Carne/análisis , Carne/microbiología , Proteolisis
12.
Anim Sci J ; 82(4): 571-9, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21794017

RESUMEN

The aims of this study were to investigate the diversity of lactic acid bacteria (LAB) isolated from traditional Mongolian dairy products, and to estimate the probiotic potential of the isolated strains. We collected 66 samples of the traditional Mongolian dairy products tarag (n = 45), airag (n = 7), aaruul (n = 8), byasulag (n = 1) and eezgii (n = 5), from which 543 LAB strains were isolated and identified based on 16S ribosomal DNA sequence. The predominant species of those products were Lactobacillus (L.) delbrueckii ssp. bulgaricus, L. helveticus, L. fermentum, L. delbrueckii ssp. lactis and Lactococcus lactis ssp. lactis. However, we could not detect any LAB strains from eezgii. All LAB isolates were screened for tolerance to low pH and to bile acid, gas production from glucose, and adherence to Caco-2 cells. In vitro, we found 10 strains possess probiotic properties, and almost identified them as L. plantarum or L. paracasei subspecies, based on 16S ribosomal DNA and carbohydrate fermentation pattern. These strains were differentiated from each other individually by randomly amplified polymorphic DNA analysis. Additionally, it was notable that 6/10 strains were isolated from camel milk tarag from the Dornogovi province.


Asunto(s)
Productos Lácteos/microbiología , Lactobacillus/aislamiento & purificación , Lactobacillus/fisiología , Probióticos , Mongolia
13.
Anim Sci J ; 81(3): 362-8, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20597894

RESUMEN

The water-holding capacity (WHC), and toughness (shear force) of chicken gizzard were evaluated during postmortem storage for 4.5, 7, 12, 24, 48, 72 and 96 h at 4 degrees C. Degradation of the cytoskeletal proteins desmin, talin and vinculin were monitored by sodium dodecyl sulfate--polyacrylamide gel electrophoresis and Western blotting during the same designated storage period. The WHC of the gizzards decreased significantly from 12 h to 72 h of storage, but by 96 h the WHC was restored to the level measured after storage for 12 h. The shear force value of the gizzards increased rapidly until 12 h and then decreased until 24 h, with a further slight decrease by 48 h. Degradation products of desmin, talin and vinculin appeared at 96 h, 12 h and 48 h postmortem, respectively. The intensity of immunolabeling for desmin, talin and vinculin after storage for 96 h decreased to 51%, 25% and 52% of the initial value. The appearance of desmin degradation products was accompanied by an increase in WHC. This suggests that the postmortem degradation of desmin is involved in the increase of WHC in chicken gizzard during storage at 4 degrees C, and talin and vinculin may be involved.


Asunto(s)
Pollos , Molleja de las Aves/fisiología , Animales , Desmina/análisis , Conservación de Alimentos , Molleja de las Aves/química , Cambios Post Mortem , Talina/análisis , Temperatura , Vinculina/análisis , Agua/análisis
14.
Meat Sci ; 86(1): 110-8, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20554123

RESUMEN

We tested the hypothesis that meat is a source of peptides that are effective at preventing and reducing chronic lifestyle-related diseases (CLSRDs) such as hypertension. This analysis reflects the importance of empowering hypertensive people in quality versus quantity of life issues, and in offering nutritional treatment options rather than medical alternatives. For both hypertensive and normotensive individuals, chemically based medications may have harmful side effects. Functional food rich in antioxidant vitamins, and proteins or biologically active peptides, can lower blood pressure in persons with essential hypertension, possibly by preventing an underlying cause of the condition. Deficiency in consumption of crucial nutrients such as proteins from meat origins, along with abnormalities in carbohydrate and fat metabolism, may underlie the etiology of the clinical course of hypertension. Food derived from meat rich in nutrients may provide physiologically functional peptides, as well as improve digestion, and the metabolism of carbohydrate and fats, thus lowering blood pressure, and normalizing associated biochemical and histopathological changes. Meat was found to have value, because proteolysis of meat muscle generated a substantial number of multi-amino acid peptides that have nutrafunctional roles, and some of which have strong angiotension-converting enzyme inhibitory activity. This also demonstrates that meat proteins might lead to better nutraceutical therapy that minimizes health problems, and might aid in finding the most effective approaches for meeting the needs of all hypertension patients.


Asunto(s)
Antihipertensivos/administración & dosificación , Antihipertensivos/metabolismo , Proteínas en la Dieta/administración & dosificación , Proteínas en la Dieta/metabolismo , Hipertensión/prevención & control , Hidrolisados de Proteína/administración & dosificación , Hidrolisados de Proteína/metabolismo , Inhibidores de la Enzima Convertidora de Angiotensina/administración & dosificación , Inhibidores de la Enzima Convertidora de Angiotensina/química , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Animales , Presión Sanguínea/efectos de los fármacos , Enfermedades Cardiovasculares/dietoterapia , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/fisiopatología , Enfermedades Cardiovasculares/prevención & control , Diabetes Mellitus/dietoterapia , Dieta , Suplementos Dietéticos/análisis , Alimentos Funcionales/análisis , Humanos , Hipertensión/dietoterapia , Hipertensión/epidemiología , Hipertensión/fisiopatología , Hipoglucemiantes/administración & dosificación , Hipoglucemiantes/metabolismo , Carne , Péptidos/administración & dosificación , Péptidos/química , Péptidos/farmacología , Peptidil-Dipeptidasa A/metabolismo
15.
Biosci Biotechnol Biochem ; 73(3): 607-12, 2009 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-19270387

RESUMEN

The mechanism for the hypocholesterolemic action of a cattle heart protein hydrolysate (HPH) is clarified. The micellar solubility of cholesterol in vitro was significantly lower in the presence of HPH than in the presence of casein. The suppression of cholesterol uptake by Caco-2 cells was significantly higher in the cholesterol micelles containing HPH than in the cholesterol micelles containing casein. The serum cholesterol concentrations and atherogenic index were significantly lower in the rats fed with HPH than in those fed with casein. The cholesterol absorption measured by [(3)H]-cholesterol was significantly lower by HPH feeding than by casein feeding in rats in vivo accompanying the changes in fecal steroid excretion. Thus, the hypocholesterolemic action of HPH involved the inhibition of jejunal cholesterol absorption. The cattle heart protein hydrolysate ultra-filtrate (HPHU, MW < ca. 1,000 Da peptide fraction) derived from HPH imparted stronger hypocholesterolemic activity than HPH in rats.


Asunto(s)
Colesterol/metabolismo , Hipercolesterolemia/metabolismo , Proteínas Musculares/farmacología , Miocardio , Hidrolisados de Proteína/farmacología , Absorción/efectos de los fármacos , Animales , Células CACO-2 , Caseínas/farmacología , Bovinos , Proteínas en la Dieta/farmacología , Proteínas en la Dieta/uso terapéutico , Humanos , Hipercolesterolemia/inducido químicamente , Hipercolesterolemia/tratamiento farmacológico , Masculino , Micelas , Proteínas Musculares/química , Proteínas Musculares/uso terapéutico , Fragmentos de Péptidos/farmacología , Hidrolisados de Proteína/química , Hidrolisados de Proteína/uso terapéutico , Ratas , Solubilidad , Ultrafiltración
16.
Meat Sci ; 83(4): 759-67, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20416625

RESUMEN

This study examined the effects of microbial transglutaminase (MTG; 3.1mg/ml) on chicken skeletal, smooth, and cardiac muscles; the meat containing the different muscle types was shaped into sausages and treated at 40°C and/or 78°C for 30min. Although the three muscle types were obtained from the same bird, the effects of MTG addition were not uniform. All the muscle types showed a significant increase in the breaking strength (P<0.01), but skeletal muscle exhibited the maximum increase. All samples showed a decrease in the fluorescence intensity and a significant reduction in the concentration of proteins that were extracted in a high ionic strength solution (P<0.05). Scanning electron microscopy images and histological studies revealed that different muscle types had different physical structures and frameworks after MTG treatment, which is a reflection of the differences in the reaction specificity of MTG with different muscle proteins. Histological studies revealed that the reactions of MTG with meat proteins are both exogenous and endogenous. Cooking loss data suggested that MTG did not have any negative effect on water retention during cooking. MTG appears to be a functional and contributive substance since the results suggest that MTG can function on all muscle types that are mechanically processed for different industrial applications. MTG aggregates muscle proteins in different ways that improve their organoleptic properties such as texture, appearance, and water retention.

17.
Meat Sci ; 82(2): 260-5, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20416742

RESUMEN

This study aimed to evaluate the effects of osmotic dehydration sheet (ODS) packaging on the quality parameters of beef biceps femoris muscle samples stored at 4°C for 0, 1, 3 and 7 days. Quality indices such as Hunter color values (L(∗), a(∗) and b(∗), the percentage of metmyoglobin (Met-Mb%), K value (freshness index), and the contents of adenosine triphosphate (ATP)-related compounds (ARCs), thiobarbituric acid reactive substances (TBA-RS) and volatile basic nitrogen (VBN) were measured. ODS gave lower a(∗) and b(∗) values and lower Met-Mb% compared with control samples wrapped in polyvinylidene chloride film (PVDCF) (P<0.01), but had no effect on L(∗) (P<0.01). As a result, with higher levels of osmotic dehydration produced by the ODS, the percentage of weight loss and the total contents of ARCs and inosine monophosphate of the samples also increased (P<0.05). The K values of ODS samples were also significantly lower than PVDCF-wrapped samples (P<0.05). Low performance ODS wrapping reduced the TBA-RS values below those found with PVDCF and high performance ODS processing (P<0.01). Moreover, the use of ODS had no effect on VBN values. Thus, although the bright red of beef samples changed to a dark purple color and the weights of samples decreased, the ODS approach has potential as a tool for decreasing the deterioration of other quality indices such as Met-Mb%, TBA-RS, ARCs, K values and the VBN content of cold-stored beef.

18.
Meat Sci ; 82(2): 170-8, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20416767

RESUMEN

The objective of this research was to investigate the difference between chicken and beef in the interaction of actomyosin (myosin B) with microbial transglutaminase (MTG). The gel strength of myosin B was improved in both species and was significantly greater in beef than in chicken (P<0.01). The degree of protein viscosity and the ε(γ-glutamyl)lysine (G-L) content were significantly higher in beef than in chicken (P<0.01). Myosin heavy chain (MHC) bands visualized by SDS-PAGE revealed that the same proteins in various meat species vary in their size and structure. Scanning electron microscope images (SEMI) revealed that myosin B in both species was polymerized, and formed multi-projection structures of G-L; surprisingly, more of these structures were found in beef than in chicken. It is possible that the proteins in chicken are folded into a strand shape that tightly encases a considerable number of glutamine and lysine residues, whereas MTG substrate cannot couple glutamine and lysine. This suggests that the reactivity of MTG is dependent on the residual amino acids present on the surface of myosin B in meat. Some protein components (peptides with long reiterated methylene groups attached) joined by disulfide bonds (cysteine) in chicken samples were inhibitory and reduced MTG activity. SEMI also suggested that all MTG-dependent mega-structures of protein molecules generated in chicken and beef may vary greatly in size, configuration and complexity after treatment with MTG. We concluded that the optimal cross-links in myosin B induced by MTG are heterogeneous in chicken and beef.

19.
J Agric Food Chem ; 56(2): 355-60, 2008 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-18163567

RESUMEN

In the search for novel peptides that inhibit the angiotensin I-converting enzyme (ACE), porcine skeletal troponin was hydrolyzed with pepsin, and the products were subjected to various types of chromatography to isolate active peptides. Glu-Lys-Glu-Arg-Glu-Arg-Gln (EKERERQ) and Lys-Arg-Gln-Lys-Tyr-Asp-Ile (KRQKYDI) were identified as active peptides, and their 50% inhibitory concentrations were found to be 552.5 and 26.2 microM, respectively. These are novel ACE inhibitory peptides, and the activity of KRQKYDI was the strongest among previously reported troponin-originated peptides. KRQKYDI was slowly hydrolyzed by treatment with ACE, and kinetic studies indicated that this peptide was a competitive inhibitor of the enzyme. When KRQKYDI was administered orally to spontaneously hypertensive rats (SHR) at a dose of 10 mg/kg, a temporary antihypertensive activity was observed at 3 and 6 h after administration.


Asunto(s)
Músculo Esquelético/química , Fragmentos de Péptidos/farmacología , Porcinos , Troponina/química , Secuencia de Aminoácidos , Inhibidores de la Enzima Convertidora de Angiotensina/administración & dosificación , Inhibidores de la Enzima Convertidora de Angiotensina/química , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Animales , Hipertensión/tratamiento farmacológico , Pepsina A/metabolismo , Fragmentos de Péptidos/administración & dosificación , Fragmentos de Péptidos/química , Ratas , Ratas Endogámicas SHR , Troponina/metabolismo
20.
Meat Sci ; 76(3): 455-62, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22060987

RESUMEN

This research investigated the improvement in the texture of chicken and beef sausages induced by using microbial transglutaminase (MTG). The ε-(γ-glutamyl)lysine (G-L) content and the extractability of myofibrillar proteins from these sausages were also investigated. Treatment with MTG significantly affected the breaking strength score in both meat types, especially for beef cooked at 80°C (p<0.001). The protein concentration of both meat types treated with MTG and extracted in water-soluble protein solution (WSP) was slightly decreased; compared with a significant decrease (p<0.003) in samples extracted in Guba-Straub-ATP solution (GS-ATP). The variation in protein extractability of both meat types could lead to some considerations of the mechanisms and the high affinity reaction between MTG and myosin heavy chain (MHC). SDS-PAGE analysis revealed significant changes in the density of the bands after adding MTG, especially for the beef samples. The G-L content in the presence of MTG was double that in control samples of both meat types. The amount of crosslinking in chicken and beef meat was different and found to be reasonable. Collectively, this suggests that the binding ability of myofibrillar proteins with MTG is strong and dominated by MHC. There was a unique reaction among MHC proteins with MTG molecules considered as a very advantageous reaction. This leads us to suggest that the functional properties of MTG make it a beneficial protein-binding agent, positively helping the functionality of proteins to improve the texture and gelation of meat products that are treated mechanically, such as sausages. Some variation in gel improvement level between chicken and beef sausages was observed; this resulted from the variation in meat proteins in response to MTG, as well as to the original glutamyl and lysine contents.

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