Muscle Press Juice Research Articles

Glazing herring (Clupea harengus) fillets with herring muscle press juice: effect on lipid oxidation development during frozen storage

SummaryIn this study, fish muscle press juice, PJ, was evaluated as an antioxidative liquid for glazing of fish fillets prior to frozen storage. PJ has in previous studies efficiently protected fish mince lipids against haemoglobin‐mediated oxidation. Frozen herring fillet were glazed with water, PJ or 50 mm phosphate buffer of the same pH as herring PJ (6.5). Over 52 weeks, peroxide value (PV), TBA‐reactive substances (TBARS), rancid odour and colour were monitored. From 26 to 52 weeks, water‐glazed fillets were significantly (P < 0.05) more oxidised compared to fillets glazed with PJ or buffer, most clearly shown by PV and TBARS data. The protective effects of both PJ and buffer compared to water could indicate a role, for example, of the physiological ionic strength. The finding that PV became elevated in PJ which was frozen stored alone in a thin layer indicates that PJ stripped from, for example, trace lipids and haemoglobin would provide better protection.

Antioxidative Properties of Press Juice From Herring (Clupea harengus) Against Hemoglobin (Hb) Mediated Oxidation of Washed Cod Mince

The antioxidative effect of herring (Clupea harengus) light muscle press juice (PJ) against hemoglobin-(Hb-) mediated oxidation of washed cod mince during ice storage was tested. The PJ was fractionated into low-molecular-weight (LMW; <1 [corrected] kDa) and high-molecular-weight (HMW; >1, >3.5, and > 50 kDa) fractions; it was preheated (10 min, 100 degrees C) and tested with or without removing heat coagulated proteins. Its antioxidative effect was compared with that given by endogenous levels of two tentative antioxidant candidates: ascorbic acid and uric acid. Oxidation was followed by determining rancid odor, peroxide value, and redness. Whole herring PJ and the LMW-PJ fraction significantly (p < 0.001) extended the oxidation lag phase of controls, from 2 up to 8 and 7 days, respectively. The HWM-PJ fractions were significantly (p < 0.05) less efficient than the whole and LMW-PJ samples, giving only 3.5-4.5 days of lag phase. Heat-treated PJ, with and without the heat-coagulated proteins, gave 7 and 5 days of oxidation lag phase, respectively. Heating different batches of the LMW-PJ fraction grouped the results into two categories: one where heating almost fully destroyed the antioxidative activity (fractions prepared from spring-caught herring) and another where heating had no or a minor effect (fractions prepared from fall-caught herring). The spring LMW-PJ had low ascorbic acid levels (18-42.6 microM), and 50-100% were destroyed by the heating. In fall LMW-PJ, the levels were 76.2-137.6 microM, and only 43-51% were destroyed. Ascorbic acid fortification of heated spring LMW-PJ to reach the levels found in the corresponding unheated spring LMW-PJ sample and the heated fall LMW-PJ gave back most of the antioxidative activity, which proved an important role of ascorbic acid for the antioxidative activity of LMW-herring PJ. This conclusion is drawn despite the fact that pure solutions with endogenous levels of ascorbic acid (giving 8.4-19.6 microM in final model) only very slightly delayed Hb-mediated oxidation of the washed cod mince.

Inhibitory Effect of Known Antioxidants and of Press Juice from Herring (Clupea harengus) Light Muscle on the Generation of Free Radicals in Human Monocytes

Reactive oxygen species (ROS) can cause oxidative stress, which has been linked to various diseases. It has been suggested that antioxidant-rich foods can reduce such oxidative stress. However, the lack of suitable model systems to screen for in vivo effects of food-derived antioxidants has prevented a clear consensus in this area. In this study, the aim was to use a single-cell model system (human monocyte) to evaluate whether certain pure antioxidants and complex muscle extracts (herring light muscle press juice, PJ) could prevent ROS formation under in vivo like conditions. ROS were excreted from the monocytes upon stimulation with phorbol myristate acetate and were then detected as isoluminol-enhanced chemiluminescence (CL). Adding 2000 units of catalase and 50 units of superoxide dismutase to the monocytes model lowered the CL response by 35 and 86%, respectively. Ascorbate (14.1 mM) lowered the response by 99%, alpha-tocoperhol (188 microM) by 37%, and Trolox (50 microM) by almost 100%. Crude herring PJ gave a dose-dependent reduction in the CL response. At 10, 100, and 1000 times dilution, the PJ reduced the CL signal by 93, 60.5, and 10.6%. PJ fractionated into low molecular weight (LMW) (<1000 Da) and high molecular weight (>3500 Da) fractions decreased the CL response by 52.9 and 71.4%, respectively, at a 100-fold dilution. Evaluation of the PJ samples in the oxygen radical absorbance capacity test indicated that proteins may be the primary radical scavenging compounds of PJ, whereas the ROS-preventing effect obtained from the LMW fraction may also be attributed to other mechanisms. Thus, this study proved that the monocyte assay can be a useful tool for studying whether food-derived antioxidants can limit ROS production under physiologically relevant conditions. It also showed that herring contains numerous aqueous compounds demonstrating antioxidative effects in the monocyte model system.

Loss of Redness (a*) as a Tool To Follow Hemoglobin-Mediated Lipid Oxidation in Washed Cod Mince

Instrumental measurement of redness loss (decrease in a* value) was evaluated as a tool to follow hemoglobin (Hb)-mediated lipid oxidation in fish muscle. Two washed cod mince model systems were used (prepared at pH 6.5 and 5.5), both fortified with 15 micromol/kg of trout Hb and adjusted to pH 6.5 and 81% moisture. The rate of oxidation was varied through pH alterations (pH 6.1 and 6.9) and addition of an antioxidative cod muscle press juice. During ice storage, TBARS, painty odor, and a* values were followed. In all "oxidizing" samples, a* values correlated well with TBARS and painty odor development; r = -0.95 and -0.77, respectively. In press juice containing samples, the correlation was lower (0.55 for a vs TBARS) because there was a slight a* value decrease even in the absence of measurable lipid oxidation. a* values distinguished between "oxidizing" and stable samples within 1 day, before any lipid oxidation products could be chemically detected. It was confirmed in an aqueous phosphate buffer model system that the redness loss corresponded to a buildup of brownish met-Hb at the expense of oxy- and deoxy-Hb. The a* value data were best used as a lipid oxidation index by calculating the rate of decrease (k value) in the "initial phase" of the redness loss (before accumulation of lipid oxidation products) or in the "differentiation phase" (during the exponential raise in TBARS/painty odor). Calibration to lipid oxidation products must, however, be made for each specific sample type. Washing method, pH, Hb-type, etc., all affected both k values and absolute a* readings. Small yellowness (b*) increases also occurred along with a value losses, possibly the result of polymerized Schiff bases.

Aqueous extracts from some muscles inhibit hemoglobin-mediated oxidation of cod muscle membrane lipids.

It was evaluated whether trout hemoglobin (Hb)-mediated oxidation of minced washed cod muscle lipids could be prevented by an aqueous isolate from cod and some other muscle sources. Lipid hydroperoxides and painty odor developed approximately 4 days faster in washed than unwashed cod mince. When adding back an aqueous fraction (press juice) isolated from unwashed mince to washed mince at 2-6-fold dilutions, development of hydroperoxides and painty odor was either delayed or completely prevented. The inhibitory substances were heat stable, and their effect was slightly reduced at reduced pH. The <1 kDa fractions of whole and heated press juices were as inhibitory as the unfractionated press juices. Inhibition by the unheated, heated, and ultrafiltered (30 kDa) press juices was lost after dialysis. These findings implied the presence of one or more highly effective aqueous low molecular weight antioxidants in cod muscle press juice. The same antioxidative properties were found in heated haddock, dab, and winter flounder muscle press juices but not in heated herring and chicken muscle press juices. Unheated chicken press juice was however highly inhibitory.

Differentiation between fresh beef and thawed frozen beef

In order to prevent meat retailers offering thawed, imported frozen beef as fresh domestic beef, the method of Gottesmann and Hamm for differentiating between fresh and frozen/thawed meat is recommended. The principle of this method is based on the fact that freezing and thawing of meat results in a release of the enzyme β-hydroxyacyl CoA-dehydrogenase (HADH) from the mitochondrion into the sarcoplasm; an elevated HADH activity in the muscle press-juice indicates freezing and thawing of tissue. The HADH colour test of Gottesmann and Hamm was modified by replacing the electron-transmitter meldolablue by resazurin which results in a much higher colour stability after reaction with fresh meat extracts.

Observations on muscle press juice from bovine, ovine and porcine muscles

Differences in the amounts and protein concentrations of muscle press juices from fresh and frozen psoas and l. dorsi muscles of bovine, ovine and porcine origin suggest the value of species and anatomical selection for functional applications in meat products.

Lipoamide dehydrogenase, citrate synthase and beta-hydroxyacyl-CoA-dehydrogenase in skeletal muscle. 12. The influence of electric stimulation of beef carcasses on activity and subcellular distribution

The effect of electrical stimulation (ES) of beef carcasses at 450 V on the total extractable activity and subcellular distribution of the mitochondrial enzymes lipoamide dehydrogenase, citrate synthase and beta-hydroxyacyl-CoA-dehydrogenase in skeletal muscle (activities in the supernatant of a phosphate buffer extract and in muscle press juice) was studied. There was no influence of ES on the total activity and the subcellular distribution of these enzymes in the muscle tissue stored at +2 degrees C for 7 days nor did ES influence the extent of the release of the three enzymes from the mitochondria into the sarcoplasm by freezing (-20 degrees C) and thawing. From these results it can be concluded that ES does not result in an appreciable disintegration of the inner membrane of muscle mitochondria.

Lipoamide dehydrogenase, citrate synthase and beta-hydroxyacyl-CoA-dehydrogenase in skeletal muscle. I. Determination of activity in tissue extracts

It is to be expected that changes in the subcellular distribution of the mitochondrial enzymes lipoamide dehydrogenase (LIPDH), citrate synthase (CS) and beta-hydroxyacyl-CoA-dehydrogenase (HADH) in the muscle tissue give information on the type and the extent of damage of mitochondria during storage and treatment of meats; such changes may be also used as basis of methods for the differentiation between fresh and frozen/thawed meat. Standard methods for the determination of the activities of LIPDH, CS, and HADH in tissue extract and muscle press juice are described. The influence of enzyme concentration, pH and temperature on the enzyme activities in muscle extract was investigated. Furthermore the error in the enzyme analyses by the standard methods was determined.

On the enzymatic breakdown of tripolyphosphate and diphosphate in comminuted meat. VII. Influence of sodium chloride on the tripolyphosphatase and diphosphatase activity in bovine muscle (author's transl)

Sodium chloride activates the tripolyphosphatase of the muscle tissue. Optimum activity occurs at 4--5 percent NaC1. The increase in activity seems to be due to the effect of C1-ions. NaC1 inhibits the tripolyphosphatase activity of muscle press juice. NaC1 decreases the total diphosphatase activity of muscle tissue as well as the diphosphatase activity of muscle press juice. Addition of NaC1 to pre-rigor muscle increases the ultimate pH value (post-rigor-muscle) and, consequently, causes a lower tripolyphosphatase activity and a higher diphosphatase activity than is observed, when NaC1 is added to the post-rigor muscle.

Influence of temperature and rate of freezing of bovine muscle on the subcellular distribution of some mitochondrial enzyme (author's transl)

Samples of bovine muscle were frozen at -5 degrees, -10 degrees, -20 degrees, -40 degrees, -60 degreese, -80 degreese, and -196 degrees C at slow (about 1 degrees/10 min) and high freezing rate (maximum 1 degrres/0.05 min) and subsequently thawed at room temerature. The changes in the extractable activity ("total activity") of the enzymes aconitase (AC), fumarase (FU) succine dehydrogenase (SDH), glutamic oxaloacetic transaminase (GOT), the mitochondrial isozyme of the COT (GOTM) and glutamate pyruvate transaminase (GPT) by freezing and thawing were studied. Neither the temperature nor the rate of freezing influenced the total activity of these enzymes. The subcellular distribution of these enzymes was investigated by determination of the enzyme activities in the muscle press juice. Freezing at -5 degrees C hat only little influence, but between -10 degrees and -40 degrees or -60 degrees C the release of AC, FU, GOTM and GPT from the mitochondria into the sarcoplasma increased with falling temperature, apparently by increasing damage of the mitochondria. The extent of this effect was not significantly influenced by the rat of freezing. Between -60 degrees and -196 degrees C no further rise of this effect was observed. A release of SDH did not occur at all conditions of freezing. It is suggested that the damage of muscle mitochondria by freezing and thawing is mainly due to a dehydration process.

On the existence of a complex of glycolytic enzymes

It has been suggested in the literature that the glycolytic enzymes are organized into a multi-enzymic complex. We have evaluated this hypothesis for the phosphotriose-glycerate phosphate group of glycolytic enzymes of muscle using sucrose density gradient centrifugation, gel filtration, and ultrafiltration. Attempts were made to avoid dilution and changes in pH. The ratio of activities of the phosphotriose-glycerate phosphate group of enzymes was similar to that found in several other tissues that has led to their designation as a constant proportion group of enzymes. However, no evidence was obtained that they exist as a multi-enzymic complex in chicken breast muscle. As the pH of the press juice is raised to 7.0 and the temperature to 25°C, association occurs between some components in the muscle press juice as evidenced by a blocking of the pores of an ultrafiltration membrane. This association, however, does not involve the enzymes of the phosphotriose-glycerate phosphate group.

Transaminases of Skeletal Muscle. 1. The Activity of Transaminases in Post‐Mortem Bovine and Porcine Muscles

SUMMARY: The activity of glutamic‐oxaloacetic transaminase (GOT) and glutamicpyruvic transaminase (GPT) of bovine and porcine muscle tissue and muscle press juice was determined. The total GPT activity of muscle tissue is about one tenth of the GOT activity. There are no remarkable differences in the activities of GOT and GPT between these slaughter animals and other species (rat, rabbit and man). The GOT activity of the longissimus dorsi muscle of pigs is significantly higher than that of the same bovine muscle. The mitochondrial (GOTM) and sarcoplasmic isozymes (GOTB) of GOT in skeletal muscles of cattle and pigs were determined after electrophoretic separation. The ratio GOTM:GOTS in skeletal muscle was found to be about 1:1. There is only a small decrease in GOT activty during storage of muscle tissue at 0 or +4°C for several weeks postmortem. The small activity of GOTM in the muscle press juice does not substantially change during storage of muscle tissue under these conditions, indicating that there is no drastic change of the mitochondrial structure during aging of meat. Bacterial spoilage of meat, however, results in the release of GOTM from the mitochondria.

Transaminases of Skeletal Muscle. 3. Influence of Freezing and Thawing on the Subcellular Distribution of Glutamic‐Oxaloacetic Transaminase in Bovine and Porcine Muscle

SUMMARY: Freezing and thawing of bovine and porcine muscle cause a remarkable release of the mitochondrial isozyme of the glutamic‐oxaloacetic transaminase (GOTM) from the mitochondrial structures resulting in an increase of GOTM activity in the muscle press juice. The lower the freezing temperature the stronger is this effect. Repeated freezing and thawing increases the release of GOTM. It is considered that the level of GOTM activity in the muscle press juice indicates the extent of mitochondrial damage. On the basis of these results a simple and rapid routine method was developed which allows a reliable differentiation between nonfrozen and frozen and thawed meat.

Bacteriology of spoilage of fish muscle. IV. Role of protein.

Clarified muscle press juice from English sole (Parophrys vetulus) was fractionated by gel filtration into a protein and a protein-free fraction. Upon inoculation with spoilage bacteria, the protein fraction failed to show any signs of spoilage, but the protein-free fraction spoiled according to the usual organoleptic and chemical criteria. Despite its spoilage-resistant qualities, the protein fraction accelerated spoilage of the protein-free fraction when the two were combined. Protein breadkown due to bacterial action was greatest in the unfractionated juice and was least in the protein fraction. No significant proteolysis occurred until after spoilage became evident.

BACTERIOLOGY OF SPOILAGE OF FISH MUSCLE. 3. CHARACTERIZATION OF SPOILERS.

A total of 807 bacterial isolates from fresh and spoiling fillets of English sole (Parophrys vetulus) stored at 5 C were classified as to genus and tested for various biochemical activities, including the ability to spoil sterile muscle press juice at 5 C. Production of off-odor, volatile reducing substances, and trimethylamine was used to estimate spoilage. It was found that (i) spoilers could be distinguished from nonspoilers on the basis of the juice spoilage test, (ii) differentiation between spoilers and nonspoilers could not be achieved by means of the usual biochemical tests, (iii) no micrococci, flavobacteria, and "coryneforms" were spoilers, (iv) certain specific subgroups of the genus Pseudomonas consisted exclusively of spoilers whereas others were inactive, (v) the genus Achromobacter likewise consisted of spoilers and nonspoilers, and (vi) "coliforms" could produce spoilage. It was concluded that a method is now available to determine directly and unequivocally the role played in spoilage by various bacterial groups and that it is no longer necessary to rely on indirect evidence.

BACTERIOLOGY OF SPOILAGE OF FISH MUSCLE. I. STERILE PRESS JUICE AS A SUITABLE EXPERIMENTAL MEDIUM.

A sterile raw fish muscle press juice, diluted 1:4 with saline, has been prepared. This dilution greatly facilitated Seitz filtration and affected the spoilage properties of the medium only negligibly. At 5.5 C, the spoilage pattern of naturally contaminated diluted juice was almost identical to that of naturally contaminated fillets. This was shown by comparing the quantitative and qualitative aspects of the bacterial flora on the two substrates and by measuring the production of volatile reducing substances (VRS) and of trimethylamine (TMA). With the sterile raw muscle press juice, some preliminary data showed that individual members of the genera Achromobacter and Pseudomonas differ markedly in their spoilage capabilities: some grew but did not produce spoilage detectable either organoleptically or chemically; others gave rise to strong off odors and to high levels of VRS and TMA.

Studies of Fish Spoilage: VIII. Volatile Acid of Cod Muscle Press Juice

Acetic acid has been identified as the only volatile acid produced in spoiling cod muscle press juice. Lactic acid present and that formed from some unknown precursor is oxidized to acetic acid and carbon dioxide. The significance of these results is discussed.

Studies of Fish Spoilage: IX. Changes in Buffering Capacity of Cod Muscle Press Juice

Cod muscle press juice during storage shows a decrease and later an increase in buffering capacity, both due to bacterial action. Reduction of trimethylamine oxide causes the decrease, and oxidation of lactic acid to acetic acid slightly lessens the effect. The increase is possibly entirely due to hydrolysis of protein by bacteria. Since the decrease occurs during the onset of spoilage, the buffering capacity gives useful data as to the state of preservation.

Studies of Fish Spoilage: VII. Dimethylamine Production in the Spoilage of Cod Muscle Press Juice

Although as yet the precursor is unknown, the mechanism of dimethylamine production in spoiling cod muscle press juice appears to be similar to that of trimethylamine production.