Minced Pork Research Articles

Predictive modelling of TBARS changes in the intramuscular lipid fraction of raw ground pork enriched with plant extracts

The aim of the study was to develop and compare the predictive models of lipid oxidation in minced raw pork meat enriched with selected plant extracts (allspice, basil, bay leaf, black seed, cardamom, caraway, cloves, garlic, nutmeg, onion, oregano, rosemary and thyme) by investigation TBARS values changes during storage at different temperatures. Meat samples with extract addition were stored under various temperatures (4, 8, 12, 16, and 20°C). TBARS values changes in samples stored at 12°C were used as external validation dataset. Lipid oxidation was evaluated by the TBARS content. Lipid oxidation increased with storage time and temperature. The dependence of lipid oxidation on temperature was adequately modelled by the Arrhenius and log-logistic equation with high R2 coefficients (0.98–0.99). Kinetic models and artificial neural networks (ANNs) were used to build the predictive models. The obtained result demonstrates that both kinetic Arrhenius (R2 = 0.83) and log-logistic (R2 = 0.84) models as well as ANN (R2 = 0.99) model can predict TBARS changes in raw ground pork meat during storage.

Effects of antibiotics ceftriaxone and levofloxacin on the growth of Calliphora vomitoria L. (Diptera: Calliphoridae) and effects on the determination of the post-mortem interval

The determination of the post-mortem interval (PMI) is one of the main tasks of forensic entomology, where growth and stages of development of arthropods are used for PMI determination. It is well acknowledged that maggot development is significantly influenced by temperature. Attention has also been paid to the microbial populations of the cadaver, because toxic substances contained in the substrate can influence the microorganisms and affect arthropods growth and development. However, little is known about the influence of antibiotics taken during lifetime of a person on insect development after that persons death. The aim of this study was to test the hypothesis that the antibiotics ceftriaxone and levofloxacin cause inhibition of growth and delay of pupation of the blow fly Calliphora vomitoria, which would then lead to an incorrect determination of the post-mortem interval in forensic cases. It was found that maggot development was delayed by levofloxacin mixed in minced pork, where a mixture of both antibiotics increased this effect. The maggot growth in the samples with ceftriaxone was not delayed. Pupation was delayed in treatments with a mixture of both antibiotics. The mortality was reduced by separate or combined application of ceftriaxone and levofloxacin, which we attribute to a bactericidal effect of the antibiotics on maggot pathogens. Depending on the concentration of the antibiotics, an underestimation of the post-mortem interval between 24 and 48 h could be suspected. We conclude that antibiotics need to be considered if instar stages are to be used to determine the PMI and that some antibiotics may improve the breeding conditions of maggots.

Quinoa protein-gum Arabic complex coacervates as a novel carrier for eugenol: Preparation, characterization and application for minced pork preservation

Minced pork is prone to quality deterioration during storage. To maintain the quality of minced pork for longer time, eugenol encapsulated multi-core microcapsules were developed using quinoa protein (QP) and gum Arabic (GA) as wall materials via complex coacervation. The optimum conditions for the formation of QP-GA coacervates were determined as pH 4 and a QP-GA mixing ratio of 4:1. The optimally produced eugenol microcapsules were found to possess multi-core structure with an average particle size of 29.53 μm. Fourier transform infrared (FTIR) analysis further proved existence of electrostatic interaction between QP and GA, and formation of hydrogen bonds between eugenol (core material) and coacervates (shell material). After freeze drying, the eugenol microcapsules were studied on encapsulation yield (EY), encapsulation efficiency (EE), payload (PL), thermal stability, and release behavior. The results revealed the high EY (94.27%), EE (88.60%), and PL (60.33%) of eugenol microcapsules, while eugenol showed good thermal stability and release property after microencapsulation using QP and GA. Moreover, the eugenol microcapsules were found to be more effective in inhibiting the increases in pH, total volatile basic nitrogen (TVB-N), and total bacterial counts (TBC) than free eugenol and prolonged the shelf life of minced pork to 9 days at 4 °C, which suggested its good application prospect in meat preservation.

The microbiological quality of minced pork treated with garlic in combination with vacuum packaging

The present study aimed to evaluate the microbial quality of minced pork treated with fresh garlic, dried garlic, and garlic oil in combination with vacuum packing. The growth of Total Viable Counts (TVC), Coliform Bacteria (CB), and Pseudomonas spp. were evaluated. The microbiological analyses were performed by the plate dilution method. The average value of TVC was 8.45 log CFU.g-1 in aerobically packed samples, 5.59 log CFU.g-1 in samples treated with garlic oil, 5.36 log CFU.g-1 in vacuum packed samples, and samples treated with dried garlic, and 4.98 log CFU.g-1 in samples treated with fresh garlic on 8th day of storage. The number of TVC was significantly lower in samples treated with fresh garlic compared to samples treated with dried garlic and garlic oil on the 8th day of storage (p <0.05). The average value of CB was 4.13 log CFU.g-1 in aerobically packed samples, 1.82 log CFU.g-1 in samples treated with garlic oil, the value of CB in vacuum packed samples, in samples treated with fresh garlic and also with dried garlic was lower than 1.00 log CFU.g-1 on 8th day of storage. The number of CB was significantly higher in aerobically packed samples and samples treated with garlic oil compared to vacuum-packed samples, samples treated with fresh garlic and dried garlic on the 8th day of storage (p <0.05). The average number of Pseudomonas spp. was 2.45 in aerobically packed samples, count of Pseudomonas spp. was lower than 1.00 log CFU.g-1 in vacuum packed samples and in the sample with garlic on the 8th day of storage. The number of Pseudomonas spp. was significantly higher in aerobically packed samples in comparison with vacuum-packed samples, samples with fresh garlic, dried garlic, and garlic oil (p <0.05).

Colorimetric ammonia (NH3) sensor based on an alginate-methylcellulose blend hydrogel and the potential opportunity for the development of a minced pork spoilage indicator

Hydrogels based on alginate and methylcellulose were developed as a colorimetric indicator for monitoring minced pork spoilage. The hydrogel was fabricated by an external gelation method using Ca2+ as the crosslinking agent. The pH-sensitive dye bromothymol blue was incorporated into the hydrogel to act as an indicator. The hydrogel’s swelling index increased with an increasing ratio of methylcellulose, suggesting that the water uptake capacity is tunable by the polymer composition. The hydrogel’s compression strength is directly proportional to the alginate content. The hydrogel indicator demonstrated a color change from orange to yellow (day 6) upon detecting total volatile basic nitrogen (TVB-N) built up in the package during minced pork storage at 4 °C, and the results showed a positive correlation between the color change, TVB-N and pH change of minced pork. This result demonstrated the potential application of the hydrogel as a spoilage indicator in intelligent packaging.

Microwave heating of dried minced pork slices with different fat content: An assessment of dielectric response and quality properties

Dried minced pork slices (DMPS) have been widely accepted owing to their unique flavor and taste, but traditional roasting (TR) process for making DMPS are time-consuming and complicated. This study presents a microwave heating (MH) method for rapid preparation of DMPS with different fat pork levels. The results indicated that DMPS size significantly affected the MH patterns. As the fat pork content increased, the complex permittivity showed a downward tendency, and the 30% fat pork content improved both the heating rate and uniformity. Fat components significantly altered the texture and color characteristics, but DMPS made by MH possessed a higher hardness and toughness values than TR. Low-field nuclear magnetic resonance analysis demonstrated that the proportion of T21 gradually decreased in MH group, while no distinct changes were observed in the TR group with the increase of fat pork content. In addition, the results of comprehensive sensory evaluation in the MH and TR groups revealed that such a convenient MH technology is alternative for the fabrication of DMPS with acceptable product quality.

NIR handheld miniature spectrometer to increase the efficiency of Iberian pig selection schemes based on chemical traits

• Setting-up NIR methodology for the non-destructive analysis of pork loin cuts. • A miniature NIR device evaluated for the on-site analysis of meat quality traits in Iberian pig selection programmes. • Comparison of NIR linear and non-linear regression developed with a large library of intact and minced meat pork samples.

Properties of Banana (Cavendish spp.) Starch Film Incorporated with Banana Peel Extract and Its Application.

The objective of this study was to develop an active banana starch film (BSF) incorporated with banana peel extract. We compared the film’s properties with commercial wrap film (polyvinyl chloride; PVC). Moreover, a comparison of the quality of minced pork wrapped during refrigerated storage (7 days at ±4 °C) was also performed. The BSF with different concentrations of banana peel extract (0, 1, 3, and 5 (%, w/v)) showed low mechanical properties (tensile strength (TS): 4.43–31.20 MPa and elongation at break (EAB): 9.66–15.63%) and water vapor permeability (3.74–11.0 × 10−10 g mm/sm2 Pa). The BSF showed low film solubility (26–41%), but excellent barrier properties to UV light. The BSF had a thickness range of 0.030–0.047 mm, and color attributes were: L* = 49.6–51.1, a* = 0.21–0.43, b* = 1.26–1.49. The BSF incorporated with banana peel extracts 5 (%, w/v) showed the highest radical scavenging activity (97.9%) and inhibitory activity of E. coli O157: H7. The BSF showed some properties comparable to the commercial PVC wrap film. Changes in qualities of minced pork were determined for 7 days during storage at ±4 °C. It was found that thiobarbituric acid reactive substances (TBARS) of the sample wrapped with the BSF decreased compared to that wrapped with the PVC. The successful inhibition of lipid oxidation in the minced pork was possible with the BSF. The BSF incorporated with banana peel extract could maintain the quality of minced pork in terms of oxidation retardation.

Rapid detection of minced pork and chicken adulteration in fresh, stored and cooked ground meat

A common fraudulent practice throughout the supply chain is the partial substitution of meat products with other meat species than the ones claimed. Thus, detection of meat adulteration using rapid, non-invasive methods during production, processing, distribution, consumption, and disposal of food products is of vital importance for the protection of consumers. In that framework the objective of this work was the detection of minced pork with chicken (and vice versa) adulteration in (a) raw fresh, (b) raw stored and (c) cooked minced meat using multispectral imaging (MSI) in tandem with support vector machines classification (SVM). Multispectral images were acquired at 0 h (freshly ground meat samples, n = 360), after 24 h and 48 h (stored meat samples, n = 180). Subsequently, at 48 h of storage, samples were cooked, and new images were acquired (n = 180). SVM classification models were developed and externally validated with sets from (a), (b) and (c). Their performance for the external validation in terms of accuracy were: for (a) freshly ground meat, 96.67% (n = 360), (b) stored minced meat, 0 h = 93.33%, 24 h = 97.78% and 48 h = 95.56%, (n = 180) and (c) cooked minced meat, 95.56% (n = 180). MSI data coupled with SVM algorithm exhibit promising potential for the rapid detection of adulterated meat samples in all three cases.

Elastic Light Scatter Pattern Analysis for the Expedited Detection of Yersinia Species in Pork Mince: Proof of Concept.

Isolation of the pathogens Yersinia enterocolitica and Yersinia pseudotuberculosis from foods typically rely on slow (10–21 day) “cold enrichment” protocols before confirmed results are obtained. We describe an approach that yields results in 39 h that combines an alternative enrichment method with culture on a non-selective medium, and subsequent identification of suspect colonies using elastic light scatter (ELS) analysis. A prototype database of ELS profiles from five Yersinia species and six other bacterial genera found in pork mince was established, and used to compare similar profiles of colonies obtained from enrichment cultures from pork mince samples seeded with representative strains of Y. enterocolitica and Y. pseudotuberculosis. The presumptive identification by ELS using computerised or visual analyses of 83/90 colonies in these experiments as the target species was confirmed by partial 16S rDNA sequencing. In addition to seeded cultures, our method recovered two naturally occurring Yersinia strains. Our results indicate that modified enrichment combined with ELS is a promising new approach for expedited detection of foodborne pathogenic yersiniae.

Improved prediction of minced pork meat chemical properties with near-infrared spectroscopy by a fusion of scatter-correction techniques

The modelling near-infrared (NIR) spectroscopy data requires removal of scattering effects from the data before applying advanced chemometrics methods. Often different scatter-correction techniques are explored, and the scatter-correction technique with the best performance is selected. However, the information highlighted by different scatter-correction techniques may be complementary and their fusion may result in better models for predicting characteristics, such as meat quality. To test this, sequential and parallel preprocessing fusion approaches will be used in this work to fuse information from different scatter-correction techniques to try to improve the predictive performance of NIR models. Three different chemical properties, i.e., moisture, fat and protein content, were predicted. For comparison, partial least-squares regression (PLSR) was performed on standard normal variate (SNV) corrected data, as this is a widely used scatter-correction technique. Compared to this commonly used procedure, the scattering fusion approaches reduced the error and bias by up to 52% and 84%, respectively. The results suggest that fusion of scatter-correction techniques is essential to achieve optimal NIR prediction models for predicting meat characteristics such as moisture, fat and protein content.

Application of sage herbal dust essential oils and supercritical fluid extract for the growth control of Escherichia coli in minced pork during storage

Sage has various biological activity and long tradition of the using in phytopharmaceutical preparations and, recently, in food industry. In this work, the essential oil obtained by hydrodistillation and essential oil and extract obtained by supercritical fluid extraction from sage herbal dust, waste product of filter tea factory, were screened for antimicrobial activity against Escherichia coli in the medium which simulates the conditions in meat and in real system of minced pork. The supercritical fluid extract had much lower effect to the reduction of a number of E. coli in meat simulation medium. The total inhibition of E. coli growth was achieved after 12 h and 24 h with the addition of 0.6 μl/ml of essential oil obtained by hydrodistilation and supercritical fluid extraction, respectively. The addition of essential oils and supercritical fluid extract of sage herbal dust could be used for the effective control of E. coli growth in minced meat.

Fennel essential oil loaded porous starch-based microencapsulation as an efficient delivery system for the quality improvement of ground pork

Porous starch (PS) was used as the core material carrier to adsorb fennel essential oil (FEO). Using sodium alginate (SA)-chitosan (CS) as the wall material and glutaraldehyde as the curing cross-linking agent, CS/SA/PS-FEO microcapsules were successfully prepared by polyelectrolyte complex coagulation method. The formation process, structural properties and release behavior of CS/SA/PS-FEO microcapsules were analyzed. The results showed that the essential oil was encapsulated in the form of micro-capsules according to infrared spectroscopy and X-ray diffraction analysis. In open and closed systems, the 16-day cumulative release rate of FEO obtained was 70.62% and 43.87%, respectively indicating that the prepared CS/SA/PS-FEO microcapsules had a good sustained-release ability. The fennel essential oil micro-capsules exhibited good antibacterial and antioxidant activities, delayed the oxidation of fat and protein, reduced the total viable counts, total volatile-base nitrogen and methemoglobin. The textural property and status of water (analyzed by NMR) suggested that the quality of the meat can be maintained for an extended period by incorporating the CS/SA/PS-FEO microcapsules in the minced pork meat.

Natural Vitamin D in Food: To What Degree Does 25-Hydroxyvitamin D Contribute to the Vitamin D Activity in Food?

ABSTRACTVitamin D3, vitamin D2, 25‐hydroxyvitamin D3 [25(OH)D3], and 25‐hydroxyvitamin D2 [25(OH)D2]constitute the vitamin D activity in food. In general, vitamin D activity in food depends on the food's fat content, the feed the animals have been fed, and the animal's exposure to ultraviolet B (UVB) light. There are many gaps in our knowledge of 25‐hydroxyvitamin D in food, including the amount present in different types of food, and the amount we process in our daily dietary intake. We aimed to assess the vitamin D vitamers in food (eggs, milk, dairy products, chicken, veal, beef, and pork) on the Danish market using accredited analytical methods. We then combined these data with existing Danish data, as well as with the information from the Danish Dietary Survey to estimate the dietary intake of vitamin D3 and of 25(OH)D3 by Danes. We report the level of vitamin D in 10% minced pork from free‐range pigs slaughtered in summer as 1.39 μg vitamin D3/100 g and 0.40 μg 25(OH)D3/100 g, which are significantly higher amounts (p < 0.001) than in early spring. The levels of vitamin D2 and 25(OH)D2 are usually <0.05 μg/100 g, though in beef they are up to 0.14 μg/100 g. 25(OH)D3 accounts for up to 100% in veal and 8% in fat from free‐range pigs. In the Danish diet, the share of 25(OH)D3 is 24% for children (4–17 years) and 18% for adults (18‐75 years). Changes in animal‐feeding strategy in the agriculture sector could change the share of 25(OH)D3 to 11% and 12% if extra vitamin D3 is added to the feed, and the animals are exposed to sunlight or UVB lightlight. Replacing vitamin D3 by 25(OH)D3 in the feed may result in a share of 25(OH)D3 of 52% and 40%, respectively, in children and adults. These estimates are based on the assumption that vitamin D3 and 25(OH)D3 contribute equally to the vitamin D activity. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Design of Conformal Spiral Dual-Band Antenna for Wireless Capsule System

This paper presents a conformal spiral antenna that is miniaturized and with dual-resonant for the wireless implantable capsule system. The spiral antenna conforms to a swallowable capsule with a radius of 3 mm and a length of 26 mm without occupying the internal space of the capsule. The compact antenna adopts two spiral arms to extend the effective current path for miniaturization. Biocompatible flexible polyimide was used as the dielectric substrate and capsule shell, achieving conformal properties of the antenna as well as compatibility with human tissue. The antenna has been simulated in different environmental models. The bandwidth of the antenna can reach 39.16 % (1.82 GHz-2.76 GHz) and 12.06 % (5.36 GHz-6.06 GHz) at 2.4 GHz and 5.8 GHz. The maximum gains of −35.2 dBi and −28.1 dBi can be achieved at 2.4 GHz and 5.8 GHz, respectively. In addition, the transmission characteristics of the antenna were experimentally verified in the minced pork and pig intestine. By analyzing the communication link, the communication distance between transceivers at 2.4 GHz and 5.8 GHz can meet 14 m and 5 m. These results show that the proposed antenna is suitable for wireless implantable capsule systems.

Comparison of two antioxidant packaging based on rosemary oleoresin and green tea extract coated on polyethylene terephthalate for extending the shelf life of minced pork meat

Two antioxidant active packaging systems containing rosemary oleoresin and green tea extract for meat preservation were compared. Minced pork was packaged in active films and its quality was evaluated by sensory analysis, color, thiobarbituric acid reactive substances (TBARS) and total volatile basic nitrogen content (TVB-N). The active films coated with green tea extract showed high antioxidant capacity. The TBARS value of meat packaged with films containing 6 % green tea at day 14 was 0.62 mg of malonaldehyde/kg of meat. This value was equal to day 0 value of TBARS and 37 % lower than the TBARS value of pork in blank group at day 14. The TVB-N values obtained for 6 % green tea and 8 % rosemary at day 14 were 40 and 39 mg N/100 g meat, approximately 25 % lower than the blank. These results indicate the potential application of active films with green tea extract in meat preservation.

Screening of volatile decay markers of minced pork by headspace-solid phase microextraction–gas chromatography–mass spectrometry and chemometrics

Headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME–GC–MS) was used to analyze the volatile compounds of minced pork meat during storage. The origin of aromatic hydrocarbons in pork was verified by migration test. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were applied to characterize the profile of volatile compounds in pork meat and identify the potential volatile markers associated with the spoilage of pork. A total of 41 compounds were identified. Migration test showed that the aromatic hydrocarbons in raw pork are from packaging. Three compounds: ethanol, 2,3-butanediol and 2-ethyl-1-hexanol were selected based on the loading plot and their variables importance in the projection (VIP) values, since they contribute mainly to the discrimination of pork with different storage times. These compounds can be used as additional indicators for quality control of pork.

Occurrence, Antimicrobial Resistance and Molecular Diversity of Enterococcus faecium in Processed Pork Meat Products in Korea.

Because Enterococcus faecium is an important nosocomial pathogen and sentinel organism for tracking antimicrobial resistance, information on the contamination and antimicrobial resistance patterns of E. faecium in food are essential to public health and food safety. We analyzed the occurrence of E. faecium in retail pork meat products (n = 124), and antimicrobial resistance of 30 E. faecium isolates were examined against 14 antimicrobials using the broth dilution test and disc diffusion test. Rep-PCR-based molecular diversity was also analyzed using Deviersilab. The highest contamination of enterococci was observed for minced pork meat but most of the E. faecium was isolated from meatball-type frozen pork meat products (FP). Incidences of antimicrobial-resistant E. faecium against erythromycin, clindamycin and nitrofurantoin were 80%, 50% and 20%, respectively. No vancomycin-resistant enterococci were analyzed. Rep-PCR showed distinctive clusters with a similarity ≥ 98%, consisting of 18 E. faecium isolates from FP manufactured in seven companies. The analyzed data on the contamination and antimicrobial resistance patterns combined with molecular typing can be useful to derive risk management of antimicrobial-resistant enterococci in food.

Mimicking myofibrillar protein denaturation in frozen-thawed meat: Effect of pH at high ionic strength

This study aims at providing new insight on protein denaturation in freezing-thawing. Freezing-thawing minced pork reduced water-holding of myofibrils and increased surface hydrophobicity. One additional freezing-thawing cycle at slow freezing rate caused appearance of a 160 kDa myosin-4 fragment in SDS-PAGE, further decreased water-holding of myofibrils and increased surface hydrophobicity. Fresh minced pork was exposed to either high salt (2 M KCl) only or high salt with lower pH to mimic conditions in freezing. Exposure to high salt only increased water-holding of myofibrils and hence did not reproduce myofibrillar protein changes in freezing. Exposure to combinations of lower pHs and high salt decreased water-holding and increased surface hydrophobicity, suggesting myofibrillar protein denaturation occurred by a comparable mechanism as in freezing-thawing. We propose that exposure to decreased pH combined with high solute concentrations in the unfrozen water of frozen meat is the primary cause of myofibrillar protein denaturation in frozen-thawed meat.

Effects of coenzyme Q 10 and sodium succinate on color stability of minced pork during refrigerated storage

The objective of the study was to investigate the effects of coenzyme Q10 (CoQ10) and sodium succinate (SS) on the redness and thiobarbituric acid reactive substances (TBARS) of minced pork under 4 ± 1°C for 9 days. Different dosages of CoQ10 and SS were added to the minced pork, respectively. The results showed that CoQ10 or SS addition could retard the decrease of a* value effectively. The TBARS value decreased significantly with CoQ10 (0.002%–0.008%) or SS addition. The optimal levels of CoQ10 and SS addition were 0.006% and 0.04%, respectively. Compared to adding individually, the combination addition of 0.006% CoQ10 and 0.04% SS could make the a* value of minced pork more stable during storage, while the TBARS value and metmyoglobin content decreased significantly (p < .05). CoQ10 and SS can be used to improve the color stability of minced pork during storage by inhibiting lipid oxidation and metmyoglobin formation. Practical applications The discoloration of minced pork during storage affects edible quality and commercial value seriously. The process of color change can be effectively delayed by adding various antioxidants. Due to potential health risks of synthetic antioxidants, the demand for natural antioxidants has been increased. Coenzyme Q10 is one of the most consumed nutritional supplements, and succinate can improve meat color stability as a Krebs cycle substrate. The combination addition of coenzyme Q10 and sodium succinate can retard redness decrease, as well as inhibit lipid oxidation of minced pork during refrigerated storage. The practical implication of this study is that coenzyme Q10 and sodium succinate can be used as promising food additives to improve color stability and extend shelf life of meat or meat products.