Meat Extract Research Articles

Cooked or discarded? Experimental distinction of rabbit burnt bones and its application to the archaeological record

Leporid bones from Middle Palaeolithic assemblages may result from the contributions of various predators, including humans, or natural processes. Although the acquisition, processing, and consumption of small mammals by Neanderthal groups has been widely demonstrated, there are still some unresolved issues. Cut marks are typically the most reliable indicators of human processing of carcasses. However, animals the size of rabbits often pose a challenge in this regard, as the use of stone tools is not always necessary for their consumption, particularly for meat or marrow extraction. Consequently, the quantity of these types of marks, such as cuts or hammer-stone percussion damage, indicating human processing, may be limited. Burning is another type of bone damage that could be indicative of human action, although both intentional and accidental processes could lead to the thermal alteration of remains without necessarily linking them to consumption. Therefore, efforts to distinguish the processes resulting in bone burning are of vital importance in determining the origin of these animals in archaeological assemblages. In this work, the results of several experimental series designed to characterise the roasting and subsequent cleaning of waste on rabbit bones are presented. These results confirm most of the characteristics described in previous experimental works on burnt bones, highlighting the differential damage between bones with and without meat. The current study aims to contribute new data for characterising burned rabbit bones resulting from human actions, which can then be applied to Middle Palaeolithic assemblages with this type of thermal alteration bone modifications.

Design, development and performance evaluation of a motorized periwinkle meat extraction machine

Efficient cracking and separation of periwinkle shells are essential unit operations in periwinkle meat processing. Mechanization remains the panacea to achieving timely processing of periwinkle meat. This study was carried out to design, develop and evaluate the performance of a viable machine for the extraction of meat from periwinkle. The performance of the machine was dependent on certain processing parameters, such as cracking speed (CS), Agitating speed (AS), feed rate (FR) and heat conditioning time (HCT), while periwinkle cracking efficiency (CE), separating efficiency (SE), Throughput capacity (TP) and periwinkle meat loss (PML) were the responses. The maximum periwinkle meat CE of 84.05 % was obtained at CS of 130 rpm, FR of 0.2 kgs-1 and HCT of 6 min. The result for SE indicated that most efficient periwinkle meat separation of 78.79% can be achieved when HCT, CS, AS and FR set at 6 min,130 rpm,1.11m/s and 0.40 kg/s respectively. Highest TP value of 26.79 kg/h was obtained when the machine was operated at CS of 130 rpm, AS of 1.23 m/s under the HCT of 6 min at FR of 0.40 kg/s. Also, the lowest PML value of 10.71 % was obtained when the machine was operated at CS of 120 rpm, AS of 1.04 m/s under the HCT of 4 min at feed rate of 0.30 kg/s. These machine parameters have significant effects on the periwinkle meat processing. The study has provided a viable option to replace the time-consuming crude manual method of periwinkle meat postharvest processing.

Rapid Quantitative Detection for Nitrofurantoin Based on Nitrogen-Doped Highly Photoluminescent Carbon Dots.

Nitrogen-doped carbon dots (NCD) with high fluorescence retention and good stability were successfully fabricated using citric acid and urea via a facile and eco-friendly one-step microwave method, which exhibited superior specificity for detection of nitrofurantoin (NFT). Upon the addition of NFT, the fluorescence intensity of NCD at 450 nm was significantly decreased. Besides, a satisfactory linear relationship between the fluorescence quenching efficiency and concentrations of NFT was obtained. Especially, NCD was qualitatively and quantitatively applied for detection NFT in milk and meat extract samples with a high recovery rate. Consequently, it was suggested that the detection method had potential application in the specific detection of NFT, offering a novel approach for veterinary drug residue detection.

Antioxidant and Antimicrobial Potential of Peptide from Rabbit Meat Hydrolysate Prepared by Trypsin and Zingibain.

<b>Background and Objective:</b> Rabbit meat is a livestock product potentially viable as a protein source to obtain peptides. Antioxidant and antimicrobial peptides are ingredients extracted from various foods through enzymatic hydrolysis, chemical hydrolysis and fermentation to produce health-promoting foods. This research aims to investigate the potential of rabbit meat as a source of antioxidant and antimicrobial peptides through hydrolysis using trypsin and zingibain enzymes. <b>Materials and Methods:</b> This research conducted an explorative-descriptive approach, focusing on antioxidant and antimicrobial activity. Rabbit meat was extracted using trypsin, zingibain and a combination of trypsin and crude extract zingibain. The hydrolyzed rabbit meat extract was tested at intervals of 0, 2, 6, 16, 24, 40 and 48 hrs to determine the degree of hydrolysis and the profile of hydrolyzed proteins with electrophoresis SDS PAGE. The antioxidant activity was tested using the DPPH method and the antimicrobial activity using agar well diffusion method. <b>Results:</b> The degree of hydrolysis increased with the hydrolysis time. The highest protein content of rabbit meat extract hydrolyzed with trypsin was 287.65 mg/mL, observed during 12 hrs hydrolysis. The optimum conditions for the hydrolysis of rabbit meat protein were obtained at 24 hrs, with an IC<sub>50</sub> value of 52.45% hydrolyzed by trypsin. As per antimicrobial activities, <i>Escherichia coli</i> and <i>Salmonella</i> sp. were more effective in inhibiting rabbit meat hydrolysates compared to <i>Pseudomonas aeruginosa</i> and <i>Staphylococcus aureus</i>. The inhibition of all pathogen increased until 12 hrs hydrolysis but decreased in 24 hrs hydrolysis. <b>Conclusion:</b> The combination zingibain enzyme and trypsin is feasible for hydrolyzing rabbit meat and the optimum hydrolysis time was 24 hrs with IC<sub>50</sub> 52.45 ppm, although accompanied by reduction in antibacterial activities.

Comparison of meat yield and physicochemical characteristics of indigenous chicken and duck

Three indigenous male chicken and 3 indigenous male duck were slaughtered to compare the meat yield and quality characteristics. After slaughter meat yield characteristics of breast, thigh, drumstick, wing, liver, heart, head, gizzard, neck etc. were compared against their live weight. After comparing the yield characteristics the breast, thigh and drumstick of all birds were stored at 4˚C to evaluated different quality characteristics at 24-hour postmortem. The following parameters were compared; proximate composition, pH, cooking loss, drip loss, water holding capacity and instrumental color (CIE L* a* b*). Findings revealed that dressing, thigh, drumstick, breast, gizzard, heart and shank weight percentage were significantly higher in indigenous chicken (p<0.05), while blood weight, feather weight and head weight were significantly higher in indigenous duck (p<0.05). Significantly higher crude protein was observed in indigenous chicken breast and thigh meat (p <0.05), while ash and ether extract were significantly higher in indigenous duck breast and thigh meat. Significantly higher pH was observed in chicken breast and thigh meat compare to duck breast and thigh (p<0.05). Cooking loss was higher in duck breast but lower in thigh meat compare to chicken breast and thigh meat. Significantly higher (p <0.05) water holding capacity was found in duck breast compare to chicken breast meat (p <0.05). At 2 hour of post mortem, lightness (L*) of breast and thigh meat did not show significant differences (p , but highly significant difference was found in drumstick meat of chicken and duck (p Redness (a*) was significantly higher in duck breast and drumstick meat and yellowness was higher in duck breast at 2 hour of post mortem compare to chicken. At 24 hour of post mortem no significant differences were found between chicken and duck breast, thigh and drumstick meat. The present study reveals that the dressing, breast, thigh and drumstick weight percentage, crude protein and pH were significantly higher in the indigenous chicken compare to duck, while ether extract, ash and redness (a*) values were significantly higher in duck compare to chicken.

Study on the corrosion inhibitory performance of Pomacea canaliculata extract as a corrosion inhibitor for carbon steel in acidic environments

Pomacea canaliculata meat extract (PCE) was explored as a multifunctional green corrosion inhibitor on carbon steel (CS) in 1 M HCl and 0.5 M H2SO4. The results showed that PCE has a high corrosion inhibition effect in both acids. Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible universal (UV–Vis) and high–performance liquid chromatography (HPLC) were used to analyze the chemical composition and functional groups of PCE, which were mainly composed of leucine, glutamic acid, and arginine. The corrosion protection performance of PCE as a multifunctional corrosion inhibitor was studied by electrochemical methods, and the results showed that the corrosion inhibition efficiency of PCE on CS in 1 M HCl and 0.5 M H2SO4 were 97.94 % and 94.38 %, respectively. Scanning electron microscopy (SEM) and atomic force microscope (AFM) were used to observe the corrosion morphology of the metal. X–ray photoelectron spectroscopy (XPS) was used to determine the composition of CS surfaces. Quantum chemistry calculations (QC) and molecular dynamics simulations (MS) were used to predict the adsorption/inhibition properties of some major compounds and chemical transformations formed by the extract. This work helps to explain and understand the mechanism of green corrosion inhibitors in both acids. The study shows that using inexpensive and easily available natural substances as green corrosion inhibitors provides a new approach for achieving both resource utilization and environmental protection.

Using black soldier fly larvae as feed for Thai frog (Rana rugosa Temminck and Schlegel, 1838) – Preliminary study of the effect on production parameters

This study aimed to evaluate the effect of the inclusion of either fresh or dried black soldier fly larvae (BSFL) in diets on the production parameters and chemical composition of Thai frogs (Rana rugosa) cultured in net cages. Frog fingerlings have an initial weight of 20.4 g and were distributed randomly into fifteen net cages (2 x 3 x 1.5 m) at a density of 240 frog.net cage-1. Including five dietary treatments named: T1 (100% commercial feed used as a control), T2 (100% dried BSFL), T3 (50% dried BSFL + 50% commercial feed), T4 (50% fresh BSFL + 50% commercial feed), and T5 (100% fresh BSFL) with three replicates for each treatment. The results showed that the survival rate of frogs ranged from 64.3% to 87.0%, improved feed conversion ratio (1.43 to 1.90%), increased live weight (194.7 – 244.6 g), daily weight gain (2.9 – 3.7 g.day-1), and frog’s yield (6.30 – 7.96 kg.m-2). The contents of crude protein (18.21 – 23.19%), ether extract (0.28 – 0.53%), and total ash (0.99 – 1.05%) of frog meat in this study were affected by the inclusion of either fresh or dried BSFL in the diets of frogs. In recommendation, the diet comprised from 50% fresh BSFL + 50% commercial feed could be applied successfully in Thai frog cage production.

Immunostimulatory potential of extruded plant-based meat: effect of extrusion moisture level on macrophage activation.

In this study, the effect of different moisture levels in extruded plant-based meat on macrophage immunostimulation, and the potential of this meat as a protein source and a solution to environmental and economic challenges associated with conventional meat was investigated. To determine the effects of the extruded plant-based meat, cell viability assay, enzyme-linked immunosorbent assay, flow cytometry, and western blotting were performed. Low-moisture (LMME) and high-moisture meat extracts (HMME) showed higher potential to activate macrophages and regulate cytokine production than raw material extract. Treatment with LMME and HMME resulted in increased expression of CD80, CD86, and MHC class I/II proteins, indicating their potential to activate macrophages. Western blotting suggested that the immune activation observed in a previous study of macrophages was because of the phosphorylation of MAPKs and NF-κB. These findings suggest that extruded plant-based meat can potentially be used as an immunostimulatory food ingredient.

A closed-loop circularity in wood sugar as a renewable carbon source for fungal pigment production and application of pigments in wood colouration

The main objective is to demonstrate closed-loop circularity in the production of fungal pigment from renewable wood sugar hydrolysate (WSH) and impregnation of colour pigment into wood. Talaromyces sp 43 M, isolated from a New Zealand vineyard, was identified as Talaromyces ruber (TR) using multi-gene phylogenetic analysis. A mild pretreatment followed by ball milling was used to prepare Pinus radiata pulp which was enzymatically hydrolysed to generate WSH. Malt 30 g/L or WSH 40 g/L were optimum carbon sources when supplemented with peptone 10 g/L and meat extract 1 g/L as optimum nitrogen sources giving maximum production of extracellular pigment. TR completely metabolizes multiple carbon sources as well as fermentation inhibitors to elicit pigment production. The CIELAB colour characteristics of the pigment vary as a response to carbon sources (malt vs WSH) and fermentation time. The fluorescent pigment produced in malt and WSH medium were efficiently impregnated into wooden blocks.

Rabbit Meat Extract Induces Browning in 3T3-L1 Adipocytes via the AMP-Activated Protein Kinase Pathway.

The browning of white adipocytes may be an innovative approach to address obesity. This study investigated the effects of rabbit meat extract on 3T3-L1 adipocytes, with a specific emphasis on inducing browning. The browning effects of rabbit meat extract were evaluated by analyzing genes specifically expressed in 3T3-L1 adipocytes using quantitative PCR and immunoblotting. Rabbit meat extract increased the expression of brown adipocyte-specific markers, UCP1 and PGC1α, and mitochondrial biogenesis factors, TFAM and NRF1, without affecting cell viability in fully differentiated 3T3-L1 adipocytes. Moreover, adipocyte differentiation and the triglyceride content were decreased; hormone-sensitive lipase activity was promoted. Rabbit meat extract activated the AMPK pathway in the differentiated 3T3-L1 cells. However, in adipocytes treated with rabbit meat extract, the expression of genes related to browning was reduced by the AMP-activated protein kinase (AMPK) inhibitor, dorsomorphin dihydrochloride. To the best of our knowledge, this is the first study to demonstrate that rabbit meat extract induces the browning of white adipocytes via the activation of the AMPK pathway, thereby demonstrating its therapeutic potential in preventing obesity.

Antimicrobial and antioxidant potential of the silver nanoparticles synthesized using aqueous extracts of coconut meat (Cocos nucifera L)

Human pathogenic fungi and bacteria pose a huge threat to human life, accounting for high rates of mortality every year. Unfortunately, the past few years have seen an upsurge in multidrug resistance pathogens. Consequently, finding an effective alternative antimicrobial agent is of utmost importance. Hence, this study aimed to phytofabricate silver nanoparticles (AgNPs) using aqueous extracts of the solid endosperm of Cocos nucifera L, also known as coconut meat (Cm). Green synthesis is a facile, cost-effective and eco-friendly methods which has several benefits over other physical and chemical methods. The synthesized nanoparticles were characterized by UV–Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and dynamic light scattering (DLS). The Cm-AgNPs showed a UV–Vis peak at 435 nm and were crystalline and quasi-spherical, with an average size of 15 nm. The FTIR spectrum displayed functional groups of phenols, alkaloids, sugars, amines, and carbonyl compounds, which are vital in the reduction and capping of NPs. The antibacterial and anticandidal efficacy of the Cm-AgNPs was assessed by the agar-well diffusion method and expressed as a zone of inhibition (ZOI). Amongst all the test isolates, Staphylococcus epidermidis, Candida auris, and methicillin-resistant Staphylococcus epidermidis were more susceptible to the NPs with a ZOI of 26.33 ± 0.57 mm, 19.33 ± 0.57 mm, and 18 ± 0.76 mm. The MIC and MFC values for Candida spp. were higher than the bacterial test isolates. Scanning electron microscopic studies of all the test isolates at their MIC concentrations showed drastically altered cell morphology, indicating that the NPs could successfully cross the cell barrier and damage the cell integrity, causing cell death. This study reports the efficacy of Cm-AgNPs against several Candida and bacterial strains, which had not been reported in earlier studies. Furthermore, the synthesized AgNPs exhibited significant antioxidant activity. Thus, the findings of this study strongly imply that the Cm-AgNPs can serve as promising candidates for therapeutic applications, especially against multidrug-resistant isolates of Candida and bacteria. However, further investigation is needed to understand the mode of action and biosafety.

Nutrition Value of Baked Meat Products Fortified with Lyophilized Dragon Fruit (Hylocereus undatus).

This study evaluates the nutritional value of a baked pork meat product containing lyophilized dragon fruit pulp. The selected nutritional properties of a baked pork meat product fortified with lyophilized Hylocereus undatus pulp in doses of 0.5%, 1.5%, 2.5%, and 4% were evaluated. For this assessment, changes in the basic chemical composition of the products, the content of calcium, magnesium, potassium, iron, and phosphorus, and the profile of fatty acids were considered. Additionally, characteristics typical for meat products, such as pH, water activity, oxidation-reduction potential or thiobarbituric acid reactive substances, and antioxidant properties of the product during 21 days of refrigerated storage, were assessed. The findings indicate that the use of higher doses of lyophilizate, i.e., in the amounts of 2.5% and 4%, significantly (p < 0.05) increases the nutritional value of meat products, leading to an increase in the concentration of essential minerals important for the proper functioning of the human body (calcium, magnesium, potassium, and iron). These changes occurred without affecting the basic chemical composition (except for an increase in the content of fat and carbohydrates in the sample with the addition of 4% lyophilizate). The introduction of the fortification treatment improved the fatty acid profile, resulting in an increase in the content of C14:0, C16:0, C20:0, and C20:5n3. In addition, in the variant with a 4% dosage, there was an increased content of C8:0, C10:0, C16:1n7, C18:0, C18:1n9C + C18:1n9t, and C18:2n6C + C18:2n6t, C18:3n3 (alpha), C20:1n15, and C20:1n9. In this particular variant, an increase in saturated-, monounsaturated-, and polyunsaturated fatty acids was also observed, which was associated with an increased level of TBARS in meat products. However, the increase in the dose of lyophilizate caused an increase in the antiradical effect of meat extracts. Based on the results obtained, it seems reasonable to use a plant additive in the form of lyophilized dragon fruit pulp in the amount of 4.0% in the production of pork meat products.

Block copolymer-derived recessed nanodisk-array electrodes for electrochemical detection of β-lactam antibiotics

Antimicrobial resistance (AMR) is one of the major socio-economic factors contributing to public health. β-lactams are most commonly prescribed drugs for variety of bacterial infections. Frequent use of antibiotics leads to AMR in humans and animals. The present work is focused on developing an electro-immunosensor to control and regulate the excessive use of antibiotics in animal-based food products. An amphiphilic block co-polymer poly(ethylene oxide-block-methyl methacrylate)(PEO-b-PMMA) was used to fabricate recessed nano-disk array electrode (RNE) and immobilized with Pen-Ab and Cef-Ab antibodies. The Limit of detection (LOD) of RNE working electrode was found to be 14.8 pM for penicillin and 13.8 pM for cefalexin with good selectivity in presence of non-specific antibiotics. Fabricated RNE electrode could detect trace amounts of spiked antigen in real samples of milk, egg and meat extract. Further, mesoporous thin film and microarrays can eventually be used to develop point-of-care diagnosis of antibiotics in animal-based food products.

Inosine 5′- monophosphate derived umami taste intensity of beef determination by electrochemistry and chromatography

The umami sensation contributes to beef taste and acceptability. Inosine 5′- monophosphate (IMP), the most abundant 5′-ribonucleotide in meat, is known to impart an umami taste without the undesired side effects commonly associated with glutamate. Nevertheless, the investigation of IMP's role in beef flavor has thus far been overlooked. Traditional methods for detecting IMP have relied on liquid chromatography coupled with ultraviolet spectroscopy or mass spectrometry techniques. However, these methods are not practical for production settings due to the complexity and resource demands of sophisticated laboratory techniques. Alternative methods like cyclic voltammetry might offer more practical solutions for rapidly detecting IMP. The objectives of this study were to evaluate the efficiency of using electrochemistry and chromatography on differentiating beef strips spiked with different IMP contents. The IMP threshold was 0.30 mM determined by a trained panel using the Best Estimates Threshold method. Beef strip steaks of USDA Prime, Choice, and Select were spiked at 0.30 and 0.60 mM of IMP, based on green weight and an estimated moisture content of 65%. In this study, differences in the IMP content of steaks were not detected by liquid chromatography-mass spectrometry. However, the cyclic voltammetry approach differentiated IMP concentrations at 0.50 mM or above in aqueous solutions and subsequentially meat extracts from the buffered blank solutions. In conclusion, cyclic voltammetry holds potential as a rapid and effective approach for detecting IMP in beef and other meat products, offering promising applications for future research.

Antioxidant potential of L-asparaginase and L-glutaminase excreted by Monascus sp.

The L-asparaginases and L-glutaminases can be excreted by various organisms such as bacteria and fungi, but also by animal and plant tissues. Studies indicate that these enzymes can be used in the food industry to improve the flavor of foods and in pharmaceuticals as an ally in the treatment of some types of cancer. This article aimed to select a fungal strain that produces these amidohydrolases, investigate the potential production of said enzyme by submerged fermentation and whether the partially purified enzyme has biological activities. Initially, 19 fungal strains were selected by Submerged Fermentation in modified Czapek's Dox medium. The best extracellular enzyme producer, Monascus sp., was tested in Solid State Fermentation and Supplemented Submerged Fermentation, and enzymes extracted both extracellularly and intracellularly. The best yield of Monascus sp. was in Submerged Fermentation supplemented with glutamine (1% v/v), glucose (1% v/v) and meat extract (1% v/v), at pH 7.0 at 30 °C for 72h. Partial purification of the crude extract by ion exchange chromatography (DEAE SP) resulted in 19 fractions that were evaluated for their ability to hydrolyze glutamine and asparagine as substrate. The determination of the antioxidant activity was carried out, which presented an IC50 of 11.83 mg/mL by the DPPH method and 2.87 mg/mL by the ABTS method. In that study it was observed that Monascus sp. was able to excrete these amidohydrolases with affinities to hydrolyze glutamine and asparagine. Despite presenting good antioxidant activity, more studies must be carried out to determine its biotechnological potential.

Obtaining Efficient Mutant from the Wild Type Bacillus subtilis E6-5 by Physical and Chemical Mutagenesis for High Efficiency Protease Production, Optimizing the Mutant's Culture Medium

In this study, to enhance protease production, the wild type of Bacillus subtilis E6-5 was mutagenized by random mutagenesis using ultraviolet radiation and ethidium bromide. After combined treatment, several mutants were obtained. Among these mutants, the mutant strain with the largest proteolytic zone diameter (25 mm) was selected and named Bacillus subtilis ATA38. The enzyme production capacity of the obtained mutant was tested and the mutant strain (404 IU/mL at 24 hours) produced 6.7 times more enzyme than the parental strain (60 IU/mL at 32 hours). The effects of some important parameters in the growth medium on enzyme production were examined. The best carbon, organic nitrogen and metal ion were obtained with wheat starch (525 IU/mL), meat extract (850 IU/mL) and KCl+CaCl2 (548 IU/mL), respectively. pH 6.0, 37°C, 200 rpm, inoculum age 18 hours and inoculation amount 1% were obtained as the best physical factors.To further increase the yield, the best nutritional and physical parameters were combined to create a new modified medium. It was determined that the enzyme yield with mutant strain increased 2.7 times in the modified medium (1096 IU/mL) compared to the control (404 U/mL). The mutant strain (1096 IU/mL) showed an 18.2-fold increase in production compared to the wild type (60 IU/mL) in the modified medium. Protease enzyme obtained from ATA38 mutant strain may have great potential in industry for different purposes.

Metabolomic characterization of Liancheng white and Cherry Valley duck breast meat and their relation to meat quality

Liancheng white duck is a typical local duck breed in Fujian Province famous for its meat traits. To better understand how meat quality varies with breed, the chemical composition of breast meats of Liancheng white ducks (LD) and Cherry Valley ducks (CD) were examined using ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS).The correlation between meat quality and the differential metabolites was further analyzed. The results showed that the effects of breed on duck breast meat were significant for pH, color, cooking loss, and shear force. Liancheng white duck breast meat exhibited a higher shear force and pH, and lower cooking loss and lightness (L*24), redness (a*24), and yellowness (b*24) than CD. Metabolomic analysis revealed significant differences between the meat extracts from the 2 duck breeds. A total of 49 and 57 significantly different metabolites were identified in positive and negative ion modes, respectively. These differentially accumulated metabolites (DAMs) could be divided into 28 classes, of which the 4 main categories were carbohydrates, amino acids, fatty acids, and eicosanoids. Liancheng white duck might have better nutritional and medicinal value considering the higher content of (4Z,7Z,10Z,13Z,16Z,19Z)-4,7,10,13,16,19-docosahexaenoic acid (DHA), docosapentaenoic acid (DPA), eicosapentaenoic acid (EPA), and prostaglandinF3α (PGF3α), having anti-inflammatory orantioxidant effects. Carbohydrate concentration negatively correlated with pH24. The 4 metabolites positively correlated with the shear force. These results provide an overall perspective for bridging the gap between variation of duck meat quality and metabolites with respect to breed.

Mechanically separated meat prepared with edible tilapia filleting waste from a public fish market

This study aimed to produce mechanically separated meat (MSM) from tilapia obtained at the Teresina fish market in the state of Piauí, Brazil. Waste production and disposal and yields were estimated, and physico-chemical and microbiological MSM qualities were determined. A questionnaire was applied to the fish market sellers, followed by tilapia carcass sampling for MSM production and assessments concerning yields, microbiological (Escherichia coli and Staphylococcus coagulase positive counts and the detection of Salmonella spp.) and physicochemical (water activity, pH, reaction to hydrogen sulfide and ammonia) quality and proximate composition (moisture, ash, proteins, lipids, carbohydrates and total energy value). The questionnaire results indicated that tilapia is highly in demand and thats processing leads to significant waste. The yield analysis indicated that tilapia MSM presents adequate residual meat extraction rates from tilapia carcasses. All microbiological analyses were in compliance with Brazilian standards. Physicochemical results were as follows: protein (14.9 to 16.1%), lipids (16.6 to 22.1%), ash (1.3 to 2.8%), moisture (60.6 to 64 .1%), carbohydrates (0.6 to 1.5%) and calories (216.5 to 263.1 kcal 100-1). It is, therefore, clear that MSM constitutes a safe and nutritious foodstudd and comprises a viable alternative for the development of co-products.

Antimicrobial effect of catfish (Pangasius sp.) meat extract

Catfish (Pangasius sp) is a freshwater fish that contains fatty acids and amino acids. This study explores the antimicrobial ef-fect of catfish meat extract in vitro laboratory experiment with post-test only control group design. The extraction process of fish meat was carried out by maceration method using 96% ethanol solvent. The minimum inhibitory concentration test was carried out using the liquid dilution method and the inhibition zone test was carried out using the disc fusion method. The ex-tract concentrations used were 12.5%, 25%, 50%, 75%, and 100%. The results showed a cloudy appearance and no inhibi-tion zone in all tubes containing catfish meat extract tested on Staphylococcus aureus and Candida albicans bacteria. While in the Phorphyromonas gingivalis test, a clear appearance in the tube was found at a concentration of 50%, and an inhibition zone at a concentration of 25%. It is concluded that catfish meat extract has an anti-bacterial effect against P.gingivalis, but has no effect on S.aureus and C.albicans.

Deciphering the growth responses and genotypic diversity of bioluminescent Photobacterium phosphoreum on chicken meat during aerobic refrigerated storage

The advent of high-throughput sequencing technologies in recent years has revealed the unexpected presence of genus Photobacterium within the chicken meat spoilage ecosystem. This study was undertaken to decipher the occurrence, the growth patterns and the genotypic biodiversity of Photobacterium phosphoreum on chicken breast fillets stored aerobically at 4 °C through conventional microbiological methods and molecular techniques. Samples were periodically cultured on marine broth agar (MA; supplemented with meat extract and vancomycin) for the enumeration of presumptive bioluminescent Photobacterium spp. In total, 90 bioluminescent bacteria were recovered from the initial (time of first appearance), middle and end stages of storage. Concomitantly, 95 total psychrotrophic/psychrophilic bacteria were isolated from the same medium to assess the presence and diversity of non-luminous photobacteria. Genetic diversity between bioluminescent isolates was assessed with two PCR-based DNA fingerprinting methods, i.e. RAPD and rep-PCR. Moreover, the characterization of selected bacterial isolates at the genus and/or species level was performed by sequencing of the 16S rRNA and/or gyrB gene. Bioluminescent bacteria were scarcely encountered in fresh samples at population levels of ca. 2.0 log CFU/g, whilst total psychrotrophic/psychrophilic bacteria were found at levels of ca. 4.4 log CFU/g. As time proceeded and close to shelf-life end, bioluminescent bacteria were encountered at higher populations, and were found at levels of 5.3 and 7.0 log CFU/g in samples from the second and third batch, respectively. In the first batch their presence was occasional and at levels up to 3.9 log CFU/g. Accordingly, total psychrotrophic/psychrophilic bacteria exceeded 8.4 log CFU/g at the end of storage, suggesting the possible underestimation of bioluminescent populations following the specific cultivation conditions. Sequence analysis assigned bioluminescent isolates to Photobacterium phosphoreum, while genetic fingerprinting revealed high intra-species variability. Respectively, total psychrotrophs/psychrophiles were assigned to genera Pseudomonas, Shewanella, Psychrobacter, Acinetobacter, Vibrio and Photobacterium. Non-luminous photobacteria were not identified within the psychrotrophs/psychrophiles. Results of the present study reveal the intra- and inter-batch variability on the occurrence and growth responses of P. phosphoreum and highlight its potential role in the chicken meat spoilage consortium.