Catfish Fillets Research Articles

Pangasius Catfish Feeding with Flammulina velutipes Extract Decreases the Disease Ratio, Prevents Lipid Oxidation, Structure Damage and Color Changes during Cool Preservation

ABSTRACT The effect of dietary supplementation of Flammulina velutipes concentrated extract (CE) on catfish fillet quality under cool preservation was evaluated. The catfish were fed by feed supplementing with 0% to 15% CE during the growth phase. After 30 days, the fish were filleted and stored at 4 ± 0.2°C for 7 days. The results showed that with 10% CE, the fish produced the best growth performance from 605 to 1106 g, corresponding to the lowest disease rate of 1.5%. Ergothioneine in muscle reached the highest value at 20.63 ± 1.35 mg/Kg. During the preservation, ergothioneine, 2,2-Diphenyl-2-picrylhydrazyl (DPPH) and lipid decreased slightly while free fatty acid (FFA) increased gradually until day 7. Peroxide and thiobarbituric acid reactive substances increased slowly after 7 days to 0.90 and 0.55 mg/Kg MDA, respectively. The b* value and total color variation (∆E) showed the slowest increase of −0.21 ± 0.67 and 46.85 ± 0.97, respectively, while the a* value decreased gradually during storage. pH decreased slightly on day 1, then increased to 6.4 ± 0.2 on day 7. The fillet was firmer on day 1, then decreased gradually in all treatments. Therefore, an increasing ergothioneine in catfish muscle leads to higher growth performance with a low disease rate and helps to prevent lipid oxidation, improving color and structural stability.

Characteristics of Oil Mixed Red Palm Oil with Catfish Oil (Pangasius hypothalmus)

Riau Province is the region that has the largest plantation area in Indonesia with 2.4 million hectares of land in 2017 and production contributes 6 million tons per year and contributes 28.2 percent of Indonesia’s total CPO exports. On the other hand, the Kampar and Pelalawan districts are centers for the production of special freshwater fish for catfish (Pangasius hypoptalmus), where from year to year they have increased rapidly. This study aimed to charaterized oil mixed of red palm oil and catfish oil byproduct of catfish fillet. This research was conducted using a one-factor factorial experimental method, namely the difference in the ratio of the mixture between red palm oil and catfish oil. Red palm oil and catfish are stirred in a ratio of 70: 30 (B1), 60: 40 (B2), and 50:50 (B3). A serial of organoleptic and chemical test (saponification rate, iodine number, number acid, and fatty acid profile) were carried out. The results showed saponification rate was - 295.36, iodine concentration was 80.33 and acid number was 0.05. Furthermore, the fat content of each ratio B1 (14.28%, B2 (16.21% and B3 (17.11%), while the types of fatty acids obtained are saturated fatty acids (SAFA), unsaturated fatty acids single (MUFA) and polyunsaturated fatty acids (PUFA). The quality of the mixture of red oil and catfish oil produced in this study meets the FDA (Food and Drug Administration) standards, in which the best one was B3 (50: 50). It can be interpreted that the mixture can be used as a source of fatty acids needed by the body which contains omega-9 fatty acids, omega-6 and omega-3.

Effect of freshwater fish oil feed supplementation on the reproductive condition and production parameters of hybrid catfish (Pangasius larnaudii x Pangasianodon hypophthalmus, Sauvage, 1878) broodstock

Increased sales of freshwater catfish fillet in global markets is causing high demand for quality fingerlings to be used in aquaculture production. Due to limited freshwater catfish broodstock availability, the gap between fingerling supply and demand drives the continuous need for improvement of production chain, including increased fertility and fecundity of broodstock. Recent technological advances support the possibility to increase hybrid catfish (Pangasius larnaudii x Pangasianodon hypophthalmus) broodstock reproductive parameters by adding small amounts of freshwater fish oil (FFO) to their diet. Catfish broodstock were fed with three different levels of FFO feed supplementation (0%, 1%, and 2% FFO) during the spawning (April-August) and post-spawning (September-December) season. Significant differences in weight gain and average daily growth were observed in fish fed with 1% FFO supplemented diet. Biomarkers of reproductive status in females (17 β-estradiol /E2; 1577 ± 5.26 pg/mL−1) and males (testosterone /T; 3.28 ± 0.41 ng/mL−1) fed with FFO supplements were significantly higher than the control (113.12 ± 43.33 pg/mL−1 and 2.56 ± 0.95 ng/mL−1), respectively). The oocytes and spermatocytes from fish fed with 1% and 2% FFO were in higher histological stages of maturity compared to control. Freshwater fish oil supplementation in fish feed during spawning season supported increased growth and enhanced reproduction indicators of hybrid catfish broodstock in aquaculture.

Ergothioneine accumulated in the catfish muscle by supplementation of Flammulina velutipes extract prevents lipid oxidation, improves color stability, and limits soft structure of the fillet during frozen storage

This study aimed to evaluate whether ergothioneine (ESH) accumulated in catfish muscle affected to fillet quality during frozen storage. The fish after fed by feed supplemented 0 to 15% concentrated extract (CE) from Flammulina velutipes for 30 days were filleted and stored at −18 ± 0.2°C for 90 days. The results show that with 10% CE, the highest accumulation of ESH in fish muscle was 21.02 mg/Kg. During preservation, ESH decreased gradually with DPPH. Peroxide and FFA were the lowest value at 1.09 meq/Kg and 0.35% on day 90, respectively. L* achieved lower while a* and b* values were quite stable during the first 60 days. The a* dropped slightly, but the b* and ∆E increased slowest from days 60 to 90. The muscle hardness was more stable during storage. Therefore, high accumulation of ESH in catfish muscle could prevent lipid oxidation, improving color stability, and limit soft structure during frozen storage. Novelty impact statement The Pangasius processing industry in the Mekong Delta depends on the catfish harvest time point and export demand, so it usually needs 1 to 3 months preservation in the freezer in which the quality of the fillet may be changed. The results from this study indicated that the highest ESH accumulation corresponding to 10% CE of F. velutipes supplemented with feed for 30 days feeding showed the most effectiveness during 90 days preservation in terms of limiting lipid oxidation, preventing discoloration, and making the fish structure less soft after thawing from frozen storage. Therefore, the supplementation of F. velutipes during feeding shows a great solution for improving catfish fillet quality during frozen storage.

Effects of high‐molecular‐weight chitosan coating prepared in different solvents on quality of catfish fillets during 6‐month frozen storage

Effects of high-molecular-weight (800 kDa) chitosan coating on quality of catfish fillets were examined during 6-month frozen (-20 °C) storage. Coating solutions, included distilled water (Control), 800AC1% (1% w/v chitosan in 1% v/v acetic acid), AS3% (3% w/v aspartic acid), and 800AS3% (3% w/v chitosan in 3% w/v aspartic acid). Changes in physicochemical, microbial, and consumer perception of chitosan-coated catfish fillets during frozen storage were examined. The 800AS3% coating was found to be effective in inhibiting microbial growth, controlling lipid oxidation, reducing drip loss and cooking loss, and retaining color and texture of catfish fillet during frozen storage. After 6-month frozen storage, the aroma of thawed fillets coated with 800AS3% was accepted by 77.92% of consumers with 66% positive purchase intent. This study demonstrated that a nonpungent aspartic acid, instead of commonly used pungent acetic acid, can be used in preparation of preservative high-molecular-weight chitosan coating. PRACTICAL APPLICATION: The findings of this study indicated that high-molecular-weight chitosan coating showed preservative effects on quality of frozen raw catfish fillets. In our previous study, chitosan (800 kDa) at 1% and 3% concentrations showed antibacterial activity in vitro. The nonpungent aspartic acid can be used as a solvent to dissolve high-molecular-weight chitosan instead of the commonly used pungent acetic acid. The most effective coating treatment was 3% w/v chitosan in 3% w/v aspartic acid. This finding would be applicable to other seafood and fish products.

Effect of high molecular weight chitosan coating on quality and shelf life of refrigerated channel catfish fillets

This study investigated effects of the high molecular-weight (800 kDa) chitosan coating on quality and shelf life of channel catfish (Ictalurus punctatus) fillets stored at 4 °C. Distilled water (control), CHAC1% (1% w/v chitosan in 1% v/v acetic acid), AS3% (3% w/v aspartic acid), and CHAS3% (3% w/v chitosan in 3% w/v aspartic acid) were used as coating solutions. Microbial (total aerobic mesophilic bacteria-TAMB; total aerobic psychrophilic bacteria-TAPB), physicochemical, and consumer perception parameters of chitosan-coated catfish fillets were analyzed at 0, 3, 6, 8, and 10 days. Chitosan coating treatments, especially CHAS3%, effectively inhibited microbial growth, delayed lipid oxidation, reduced cooking loss, and retained water holding capacity, color, and texture. Overall acceptance and purchase intent of CHAS3% fillets drastically decreased from 6.16 to 84% on the 8th day to 4.31 and 44.67% on the 10th day of storage. Shelf life of catfish fillets was extended by CHAS3% from 6 days to 8 (based on consumer acceptance) and/or 10 (based on TAMB and TAPB) days compared to the control. This study demonstrated that CHAS3% coating showed promise as a natural preservative to extend shelf life by delaying chemical and microbial deterioration of refrigerated catfish fillets, and potentially for other fish fillets.

Atrazine in fish feed and african catfish (Clarias gariepinus) from aquaculture farms in Southwestern Nigeria

Extensive use of atrazine as herbicide in crop farming in Nigeria may lead to its accumulation in fish feed ingredients or aquatic ecosystem from aerosol or by runoff resulting in its residue in aquatic animals. Atrazine residues were determined in fish feed and catfish (Clarias gariepinus) fillets from commercial aquaculture farms in Southwestern Nigeria by matrix solvent particle dispersion and quantification using an ELISA kit. The mean atrazine concentrations in feed and fish were about 1.3–1.5 μg/kg and 1.4–1.8 μg/kg respectively. Atrazine was mostly detected in catfish from Ogun State (91.3%) and feed from Lagos State (80.0%) with mean concentrations of 1.4 ± 0.4 μg/kg and 1.5 ± 0.5 μg/kg, respectively. Mean atrazine concentration in catfish samples from Lagos State was significantly higher (P < 0.05) than the mean concentration in catfish samples from Ogun State. This study showed that the Estimated Average Daily Intake (EADI) of atrazine in fish samples from the selected states were below the Acceptable Daily Intake (ADI) value of 6 μg/kg for herbicide residues and thus within safe limit but their presence in fish is a cause for concern.

Rapid and nondestructive determination of qualities in vacuum‐packaged catfish (Clarias leather) fillets during slurry ice storage

This study investigated the effect of different site and vacuum package on catfish quality during slurry ice storage and feasibility of rapid detection of fillet quality using near infrared spectroscopy (NIRs). The results showed the nutrients content of fillet had significant difference (p < .05) between front and rear mid-line site in catfish (using the ventral back end as the mid-line). After 30 days slurry ice storage, drop loss and ΔΕ significantly increased to 6.04% and 5.92, respectively. Total volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA), pH, and total viable count (TVC) of fillet were over acceptable limit for fish at day 30. The accuracy (R2) for TVB-N, TBA, drip loss, L*, ΔE, and whiteness detection by partial least squares regression (PLSR) models was 0.86–0.90 and residual predictive deviation (RPD) was 2.66–3.19, indicating that NIRs technology combined with PLSR calibration analysis had great capability for qualitative and quantitative of catfish freshness. Practical applications The development of rapid freshness detection method is important to meet the requirements of quality evaluation and grading of fish products. In this study, using chemometrics method to fit infrared spectra data with freshness of catfish, the optimal infrared quantitative prediction model of catfish fillets could be established to evaluated freshness of catfish, which will provide a simple, rapid, viable, and not destructive method for freshness determination in the process of production and circulation.

Nutrient Composition of Steam Cooked Pangasius Meat and Their Analysis of Proximate, Fatty Acid and Mineral Composition

The aim of this research has to be removal of saturated and mono-unsaturated fatty acid it was done by steaming method. After deafatted meat were analyse the nutritional compositions. Catfish essential fatty acid is low because of a small amount of n-3 family PUFA and high amount of MUFA and SFA. The SFA and trans C18: 1 MUFA can increase risk of chronic cardiovascular diseases that affects the heart, blood vessels, and brain. Effective processing of heat treatment method can get reduced of the fat content in Pangasius catfish fillet in this meat was contain essential proteins and provide a good protein food for consumers. The present project is therefore proposed to develop a suitable preprocessing method for removal of fat from catfish fillets. normal steam pressure cooking method as used heat treatment such as steam cooked method were used to reduce in the SFA and MUFA content of fish fillets. The present research is proposed to study the proximate composition, fatty acid composition and minerals composition of steam defatted fillets. This chemical composition such as mainly had studied about mineral such as sodium, iron, phosphorus, calcium, magnesium and zinc. Fatty acid composition has been studied about saturated and mono-unsaturated fatty acid it is rendered to produced free fatty acid oxidized odour it can be produced off-flavour of the products it were removed by different heat treatment were conducted by microwave energy treatment and grilled and steam heat treatment it was reduced to saturated and monounsaturated fatty acid and is this was increased about poly-unsaturated fatty acid and provide to nutritional stuff for human begins.

STUDYING THE EFFECT OF STATIC MAGNETIC FIELDS TO FREEZING TIME FOR VIETNAMESE CATFISH (PANGASIUS) FILLETS

The main objective of paper is to study the effect of static magnetic fields to the freezing time for the Vietnameses catfish (Pangasius) fillets. In this study, the catfish fillets were considered with an average size of 210x80x15mm (length x width x thickness). They were frozen from 12°C to -18°C (center temperature) in a medium temperature of -40°C, -35°C and -30°C with air velocity of 5m/s in two different methods: the conventional air blast freezing (ABF) and the innovation air blast freezing assisted static magnetic fields (SMF) with 431, 453, 499 and 528 Gauss to study the influence of static magnetic fields to freezing time. At the same air freezing temperature, the freezing time with SMF decrease from 34% to 56% compared to the ABF when the magnetic density increases from 431 Gauss to 528 Gauss. This shows the innovation freezing assisted static magnetic fields may influence positively the decreasing of freezing time to save energy as well as the improving of quality for the Vietnamese catfish fillets.

A novel paper-based and pH-sensitive intelligent detector in meat and seafood packaging

The annual amount of food waste or loss is about one-third of the total edible food globally produced for human consumption. Continuous and real-time monitoring by spoilage detectors can significantly reduce food waste. A novel paper-based pH-sensitive meat spoilage detector was developed. A mixture of soybean hulls (SBHs) (hydrothermally-treated in an acidic environment), bentonite, and bromocresol purple (BCP) was coated on paper to produce the detector. The resultant meat spoilage detector was evaluated as a real-time freshness and spoilage indicator of catfish fillets (Ictalurus punctatus). Freshness and spoilage of fish meat with varying weights and headspace were determined by tailoring the detector's pH. Elemental, structural, and functional analysis verified the formation of a packed SBH-bentonite matrix with enhanced gas adsorption capacity and effective BCP-immobilization. Binder nanofibrillation increased the overall visual color vibrancy and decreased the binder demand in the coating formulation. Headspace volume in the studied range (40 and 160 cm3) did not affect the activation time of the detectors. However, increasing fish weight decreased the detectors' optimum activation time and pH. The findings of this study show that the developed detectors can be tailored for a wide range of sample and packaging sizes by simply adjusting the pH of the detector.

Prevalence of antibiotic resistance Escherichia coli isolated from Pangasius catfish (Pangasius hypophthalmus) fillet during freezing process at two factories in Mekong Delta Vietnam

Total of 261 samples of fish and environmental samples (i.e. wash water, swabs of hand/ gloves of workers, fish contact surfaces i.e. knives, cutting boards and working tables) were collected from two Pangasius processing factories (PPF1 and PPF2). A total of seventy-one (71) isolates of Escherichia coli were selected to study the prevalence of antibiotics resistance using disk agar diffusion method. Overall, it was determined that 61% (22/36) of PPF1 isolates were resistant except to colistin while 68.57% (24/35) of PPF2 isolates were resistant except kanamycin. High resistance was against ampicillin in both PPF1 and PPF2 isolates (47.22% and 42.86%), followed by cefotaxime (33.33% and 40%) respectively. Varying resistance response to all other tested antibiotics such as streptomycin, meropenem, tetracycline, sulfamethoxazole/trimethoprim and nalidixic acid was also observed among the E. coli isolates from both factories. About 50% of the multidrug resistant (3-9 antibiotics) among PPF1 were observed whereas there were 45.83% multi-drug resistant (3-7 antibiotics) among PPF2 isolates. The result from this study reflected that there was a prevalence of multi-drug resistance of E. coli isolated during the processing of Pangasius at the studied factories. Therefore, there is a need for an effective risk management assessment models and management plans from stakeholders involved in the Pangasius value chain (i.e. farmers, processors and government) to ensure the food safety of production chain

Effect of Traditional and Liquid Smoke on the Quality of Sea Catfish Sausages (Sciades herzbergii, Bloch, 1794)

ABSTRACT Smoking is a technique used to improve the sensory attributes and increase the shelf life of fish. The objective of the present study was to evaluate the nutritional, physicochemical, microbiological, and sensory characteristics of sausages made with sea catfish (Sciades herzbergii) fillets subjected to the traditional and liquid smoking processes. The traditionally smoked sausages showed lower (p < .05) moisture content and higher protein, fat, and mineral levels, higher weight loss during processing, higher pH, higher a* (red intensity), and lower L* (luminosity) values. The percentage of shrinkage, water holding capacity, water activity, hardness, cohesiveness, and elasticity were not influenced (p > .05) by the smoking methods tested. The microbial counts of both treatments were in compliance with the current Brazilian legislation. The sensory acceptance of the liquid smoked sausages was higher (p < .05) when compared to the traditionally smoked sausages for the attributes of color, aroma, texture, flavor, and overall acceptance, with scores ranging from 6 (liked slightly) to 7 (liked moderately). Between the two smoking methods tested, liquid smoking presented better sensory acceptance, easier execution, greater process control, and less environmental impact; thus, it is a viable alternative to the traditional smoking of sea catfish (Sciades herzbergii) sausages.

Effects of HVEF treatment on microbial communities and physicochemical properties of catfish fillets during chilled storage

The effects of high-voltage electrostatic field (HVEF) on the microbial communities and quality characteristics of catfish fillets were investigated. Samples with 30 kV/15 min HVEF treatment and without treatment (control) were stored at 4 °C for 0, 1, 3, 5 and 7 d. The total volatile basic nitrogen (TVB-N) and total viable count (TVC) of HVEF-treated sample (20.5 mg/100 g and 5.64 log CFU/g, respectively) were significantly lower than those of the control (32.4 mg/100 g and 7.42 log CFU/g, respectively) at 7 d. Therefore, the shelf life of HVEF-treated fillets was 2 days longer than the control (5 d). Besides, HVEF treated samples showed less tissue damages, lower thiobarbituric acid-reactive substances (TBARS) and higher water holding capacity throughout the chilling storage. Additionally, the high-throughput sequencing results indicated that HVEF treatment reduced the relevant abundance of Flavobacterium and Geobacillus at 0 d, and mainly inhibited the growth of Acinetobacter and Streptococcus after 7 d storage, which meant the growth of spoilage bacteria were inhibited, corresponding with the results of TVB-N and TVC. The results indicated HVEF treatment could be implemented as a new fish processing technology to delay product quality deterioration and extend the shelf life of catfish fillets.

Pengaruh Kondisi Post Mortem Ikan Patin (Pangasius Djambal) dengan Kematian Menggelepar yang Disimpan pada Suhu Berbeda Terhadap Mutu Filletnya

This study aimed to determine the quality of differences in catfish fillets made in the pre rigor, rigor mortis, and post rigorstage. This research is divided into 2 stages, the preliminary research stage and further research. Data processing is carried out quantitatively by analyzing parametric statistical data with Anova and non parametric tests with the Kruskal Wallis test. The parameters of this study include stiffness index, pH value, TVB and organoleptic test. Preliminary research results on catfish at the meeting room temperature pre rigor, rigor mortis, and post rigor are interrelated at 0, 1.5, 9 hours with rigor index values of 0%, 27%, 5% and time of pre rigor and rigor mortis at cold temperatures at 0 and 6 hours with rigor index values of 0% and 70%.. In the main study it was shown that all TVB comparisons are significantly different and at pH values all are significantly different except for cold temperature pre rigor and post rigor comparisons. The results of organoleptic fillets showed significantly different results in the comparison of rigor mortis and post rigor phases in the part of testing the appearance of meat integrity and color appearance of filllet meat at cold temperatures.

Microstructure and physicochemical properties: Effect of pre-chilling and storage time on the quality of Channel catfish during frozen storage

The objective this research was to investigate pre-chilling time (1, 4, 8 and 24 h) on the histomorphology and physicochemical properties of catfish fillets during frozen storage (1, 4, 12 and 24 weeks). With the extended pre-chilling (4 °C) and frozen storage (−18 °C) time, cells of catfish fillet were gradually dissociated in three aspects: size change, dispersion and breakage by ice crystals. Catfish fillets pre-chilled for 24 h or stored for more than 12 weeks showed apparent higher cell structure damage than other treated groups. The Magnetic resonance imaging (MRI) results showed that the activity of hydrogen protons was progressively enhanced with the storage time up to the 4 weeks and then decreased. With the increasing frozen storage period, pH of catfish samples were transferred from weakly alkali to weakly acid, shear force and whiteness of frozen channel catfish fillets was progressively decreased (P < 0.05), while the total volatile base-nitrogen (TVB-N), K value, expressible moisture and thiobarbituric acid-reactivate substance (TBARS) contents were increased (P < 0.05). Therefore, the maximum pre-chilling time and shelf-life of frozen catfish fillets should be recommended as 8 h and 12 weeks, respectively. This research provided theoretical support for aquatic processing industrially.

Enhanced microbial safety of channel catfish (Ictalurus punctatus) fillet using recently invented medium molecular weight water-soluble chitosan coating.

Chitosan with higher molecular weight exhibited higher antimicrobial efficacy against foodborne pathogens. However, the poor water solubility of higher or medium molecular weight chitosan limits its applications. To overcome the challenge, our research team searched for simple preparation procedure for fast-dissolving medium molecular weight chitosan in water. Throughout the process, we were able to obtain a higher concentration of medium molecular weight water-soluble (MMWWS) chitosan (400kDa). The MMWWS chitosan showed physicochemical properties that are suitable for edible coating. Antibacterial activities of 400-kDa chitosan coating prepared in acetic acid (1% v/v) or aspartic acid (1% or 3% w/v) were examined. The surface of catfish cubes was inoculated with six foodborne pathogens and then coated with chitosan solutions. The survival of each pathogen was evaluated during shelf life storage. Compared with the control, 3% w/v chitosan coating in aspartic acid solution exhibited the most effective antibacterial activities among other coating treatments, completely inhibiting Vibrio parahaemolyticus on the surface of catfish. The study suggested that chitosan dissolved in aspartic acid has the potential for use as an alternative antimicrobial coating for catfish fillet.

Effect of partial replacement of polyphosphate with alkaline electrolyzed water (AEW) on the quality of catfish fillets

Effect of partial replacement of polyphosphate (50%) with alkaline electrolyzed water (AEW) on the water retention capacity, color, textural properties and lipid oxidation of catfish fillets was investigated. Catfish fillet samples were divided into five soaking group: Group 1 (AEW: pH = 11.6), Group 2 (EOA: AEW with 1.25 g/L sodium tri-polyphosphate, 0.3 g/L sodium metapolyphosphate, 0.4 g/L sodium polyphosphate, pH = 11.4), Group 3 (NEO: water with 2.5 g/L sodium tri-polyphosphate, 0.6 g/L sodium metapolyphosphate, 0.8 g/L sodium polyphosphate, pH = 9.0), Group 4 (WAT: tap water) and Group 5 (NOT: no soaking treatment). The results showed that AEW and EOA can improve catfish fillets weight gain and enhance water retention capacity similar to the phosphate enhancement treatment (NEO), but had no effect on product L* value and hardness and elasticity. For the total color difference (ΔE) and oxidation resistance, EOA treatment was better than AEW and NEO. Therefore, AEW alone or AEW with phosphate used in the traditional phosphate enhancement solutions can be used to enhance the quality of catfish fillets.

Effect of pre-chilling time on the physicochemical properties of channel catfish during frozen storage

Abstract The objective of this study was to investigate pre-chilling time (1, 8 and 24 h) on the changes of channel catfish's physicochemical properties during frozen storage (1, 4, 8, 12 and 24 weeks). During the pre-chilling process, onset and full rigor mortis of the catfish were reached at 1 h and 8 h post mortem. Light microscopy observation showed that gaps among the muscle cells of the catfish increased gradually with the pre-chilling time. Shear force of the catfish fillet with 1 h of pre-chilling (P1 fillet) continuously declined (P

Effect of pecan variety and the method of extraction on the antimicrobial activity of pecan shell extracts against different foodborne pathogens and their efficacy on food matrices

The shells of pecans are a rich source of bioactive compounds with potential inhibitory activity against various pathogenic microorganisms. This study investigated the antimicrobial activity of pecan shell extracts as effected by the type of cultivar and the method of extraction against various foodborne bacterial pathogens. Defatted shell powders of 19 different pecan cultivars were subjected to aqueous and ethanolic extraction (1:20 w/v) procedures, respectively. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of lyophilized pecan shell extracts dissolved in deionized water containing 5% DMSO (v/v) were determined against multiple strains of Listeria monocytogenes, Salmonella enterica, and Escherichia coli O157:H7. The antimicrobial activity of pecan shell extracts was found to be pathogen specific and strain dependent. Overall, L. monocytogenes was found to be least resistant to treatment with pecan shell extracts with an MIC and/or MBC values ranging from 1.25 to 5 mg/mL followed by Salmonella enterica (2.5 to ≥5 mg/mL) and E. coli O157:H7 (≥5 mg/mL). Type of cultivar and the method of extraction found to have a variable effect on the antimicrobial activity. Furthermore, the challenge studies on fresh-cut cantaloupes and thawed catfish fillets treated with 5 mg/mL pecan shell extracts and stored at 4 °C for up to 5 days showed a <0.5 to 4 log less growth in L. monocytogenes when compared to the controls with no treatment. No significant change in the color quality of treated food samples was observed with pecan shell extract treatment. The results of this study showed promise to use pecan shell extracts as a natural antimicrobial agent to inhibit the growth of tested foodborne bacterial pathogens.