Effect of radiation processing on the quality of chilled meat products

The Effect of Irradiation on Meat Products

The effects of irradiation on meat constituents including water, proteins, and lipids are multifaceted. Irradiation leads to the decomposition of water molecules, resulting in the formation of free radicals that can have both positive and negative effects on meat quality and storage. Although irradiation reduces the number of microorganisms and extends the shelf life of meat by damaging microbial DNA and cell membranes, it can also accelerate the oxidation of lipids and proteins, particularly sulfur-containing amino acids and unsaturated fatty acids. With regard to proteins, irradiation affects both myofibrillar and sarcoplasmic proteins. Myofibrillar proteins, such as actin and myosin, can undergo depolymerization and fragmentation, thereby altering protein solubility and structure. Sarcoplasmic proteins, including myoglobin, undergo structural changes that can alter meat color. Collagen, which is crucial for meat toughness, can undergo an increase in solubility owing to irradiation-induced degradation. The lipid content and composition are also influenced by irradiation, with unsaturated fatty acids being particularly vulnerable to oxidation. This process can lead to changes in the lipid quality and the production of off-odors. However, the effects of irradiation on lipid oxidation may vary depending on factors such as irradiation dose and packaging method. In summary, while irradiation can have beneficial effects, such as microbial reduction and shelf-life extension, it can also lead to changes in meat properties that need to be carefully managed to maintain quality and consumer acceptability.

Exploring the impact of irradiation on the sensory quality of pork based on a metabolomics approach

The effects of irradiation on pork quality characteristics were investigated by combining sensory experiments, pork color, TBARS, volatile components, and differential metabolites. Pork irradiated at a dose of 1 kGy received the highest sensory scores, whereas pork irradiated at doses of 3 and 5 kGy obtained lower sensory scores, particularly with regard to odor. Irradiation makes pork more ruddy and promotes fat oxidation, leading to increased a* and TBARS values. The main volatile substances in irradiated pork were hydrocarbons, aldehydes, and alcohols, and hexanal, heptanal, and valeric acid were considered as important substances responsible for the generation of radiation-induced off-flavors. 65 differential metabolites were identified. l-pyroglutamic acid, l-glutamate, l-proline, fumarate acids, betaine, and l-anserine were considered as the main substances contributing to the differences in pork quality. In addition, metabolic pathways such as arginine biosynthesis, alanine, aspartate and glutamate metabolism were found to be considerably affected by irradiation.

Meta-analysis of the effects of gamma irradiation on chicken meat and meat product quality

Background and Aim

Irradiation is one of the most effective microbial decontamination treatments for eliminating foodborne pathogens and enhancing chicken meat safety. The effect of gamma irradiation on the overall quality of chicken meat and its products must be observed to provide a comprehensive explanation to the public. This meta-analysis examined the effects of gamma irradiation on the oxidation parameters, microbial activity, physicochemical characteristics, sensory parameters, and nutrient quality of chicken meat and meat products.

Materials and Methods

We conducted a literature search using various search engines (Scopus®, PubMed®, and Google Scholar®) with "irradiation," "gamma," "chicken," and "meat" as keywords. Gamma irradiation treatment was set as a fixed effect, and the difference between experiments was set as a random effect. This study used a mixed-model methodology. After evaluation, we selected 43 articles (86 studies) for inclusion in the database.

Results

Gamma irradiation significantly increased (p < 0.01) thiobarbituric acid-reactive substance levels on days 0, 7, and 14 of storage. Gamma irradiation reduced total aerobic bacteria, coliforms, Salmonella, yeast, and mold activity (p < 0.01). According to our meta-analysis, 21.75 kGy was the best dose for reducing total aerobic bacteria. On day 0, gamma irradiation did not affect the color parameters (L*, a*, b*). However, a significant difference (p < 0.01) was noted for a* and b* parameters between the control and irradiation treatments at 7 and 14 days. Although irradiation treatment was less consistent in sensory parameters, overall acceptability decreased on days 0, 7, and 14 after storage (p < 0.05). Regarding nutrient composition, gamma irradiation reduced moisture content and free fatty acid (FFA) content (p < 0.05). Although irradiation significantly reduces the microbial population, it increases the oxidation of chicken meat and its products. Irradiation decreases FFA content and overall acceptability, but it does not affect flavor, tenderness, juiciness, or cooking loss.

Conclusion

Gamma irradiation positively reduces the microbial activity in chicken meat and its products but increases the oxidation parameters. Although gamma irradiation does not alter the flavor, tenderness, juiciness, or cooking loss, gamma irradiation can reduce the FFA content and overall acceptability.

Insight into the Relationship between the Causes of Off-Odour and Microorganism Communities in Xuanwei Ham

To expound on the correlation between the microorganism communities and the formation of off-odour in Xuanwei ham, the microorganism communities and volatile compounds were investigated in the biceps femoris (BF) and semimembranosus (SM) of Xuanwei ham with different quality grades (normal ham and spoiled ham). The single molecule real-time sequencing showed that differential bacteria and fungi were more varied in normal hams than in spoiled hams. Headspace solid-phase microextraction-gas chromatography (HS-SPME-GC-MS) results indicated that aldehydes and alcohols were significantly higher in spoiled hams than those in normal hams (p < 0.05). The off-odour of spoiled hams was dominated by ichthyic, malodourous, sweaty, putrid, sour, and unpleasant odours produced by compounds such as trimethylamine (SM: 13.05 μg/kg), hexanal (BF: 206.46 μg/kg), octanal (BF: 59.52 μg/kg), methanethiol (SM: 12.85 μg/kg), and valeric acid (BF: 15.08 μg/kg), which are positively correlated with Bacillus cereus, Bacillus subtilis, Bacillus licheniformis, Pseudomonas sp., Aspergillus ruber, and Moraxella osloensis. Furthermore, the physicochemical property and quality characteristics results showed that high moisture (BF: 56.32 g/100 g), pH (BF: 6.63), thiobarbituric acid reactive substances (TBARS) (SM: 1.98 MDA/kg), and low NaCl content (SM: 6.31%) were also responsible for the spoilage of hams with off-odour. This study provided a deep insight into the off-odour of Xuanwei ham from the perspective of microorganism communities and a theoretical basis for improving the flavour and overall quality of Xuanwei hams.

Application of gamma radiation in the beef texture development during accelerated aging

This study aimed to evaluate the effects of gamma radiation (3 kGy) on the quality of post-rigor beef (M. longissimus lumborum) aged for up to 21 days at different temperatures (1, 7, and 15°C). Irradiation reduced the mesophilic and lactic acid bacteria counts, which were higher in the non-irradiated samples aged at 7 and 15°C. The water retention capacity was lower in the irradiated beef, resulting in higher values of exudation and cooking losses. High aging temperatures increased the exudation loss and myofibrillar proteolysis (lower fragmentation index; FI) and reduced the total and insoluble collagen contents and the beef Warner-Bratzler square Shear Force (WBsSF). However, irradiated beef had higher FI and SF than non-irradiated ones, increasing the time required for the beef tenderizing. Gamma irradiation (3 kGy) can be used to ensure the microbiological safety during short storage at high temperatures (up to 15°C) in order to accelerate the process of beef tenderizing.

Effect of three kinds of natural preservative cocktails on vacuum-packed chilled pork

The aim of this study was to investigate the effects of three different natural preservatives on the microbial profile, the total volatile base nitrogen (TVB-N), and biogenic amine contents of vacuum-packed chilled pork during storage at 4°C. Solution A comprised of tea polyphenols, chitosan, spice extract, propolis, and nisin. Solution B comprised of clove extract, cassia bark extract, ginger juice, garlic juice, and lactobacillus fermentation solution. Solution C consisted of only lactobacillus fermentation solution. The results indicated that solution A was a good natural preservative with higher bacteria inhibitory effect and higher sensory score than B and C. Besides the effect on appealing color, solution B could inhibit microbial activity although its inhibition effect was not as good as solution A. Thus, solution A could be used as a good preservative in industry. Solution C could inhibit the initial growth of Pseudomonas and partially inhibited the growth of Enterobacteriaceae; however, the content of putrescine in the pork treated with solution C was as high as 30.14 ± 2.89 mg/kg after 21 days of storage at 4°C. Hence, solution C is not an ideal preservative for vacuum-packed chilled pork.

Development and evaluation of retort pouch processed chhenapoda (cheese based baked sweet)

A study has been undertaken to optimize ingredient proportions for preparation of chhenapoda and the effect of retort processing on its quality and storability. Chhenapoda was prepared from cottage cheese with standard practices followed by confectioners using different levels of semolina (0, 50, 100, 150, 200 g) and sugar (0, 100, 200, 300, 400 g) per kg cheese and ingredient proportion was optimized based on sensory scores. Prepared chhenapoda sample of 200 g were packed in pre-fabricated 3 side seal multilayer laminated retortable pouches, hermetically sealed and retort processed at different temperatures (100, 110 and 120 °C) and time intervals (15, 30 and 45 min). It was found from Response Surface Methodology (RSM) technique that addition of 18.5% sugar and 7.5% semolina with cottage cheese was optimum for chhenapoda preparation. Microbiological analysis showed that total plate count and yeast and mould count (YMC) decreased from 110 × 10⁷ to 4 × 10⁴ and YMC from 3 × 10³ to 0 respectively during retort processing (30 min thermal processing in laminated pouch at 120 °C). From the storage study, it can be concluded that retort processing of chhenapoda in laminated pouch at 120 °C for 30 min resulted in microbiological safe and sensory acceptable product which could be stored up to 30 days under refrigerated condition.

Effect of Irradiation on Quality of Vacuum-Packed Spicy Beef Chops

To develop an alternative pasteurization process for the spicy beef jerky (SBJ), it was treated with irradiation doses of 0, 0.5, 1.5, 3, 4, 6, and 8 kGy and the sensory attributes, texture properties, drip loss, and the protein biological efficiency were studied. The results showed that lightness, drip loss, and off-odor of SBJ increased, while the hardness, chewiness, gumminess, color preference, and taste of SBJ decreased with the increase in irradiation dose. This tendency was obvious as the irradiation dose increased to 6 kGy and 8 kGy. The possible reason for these quality changes might be due to the free radicals produced by irradiation. This speculation is supported by the decrease of the content of capsanthin and the increase of the content of TBARS of SBJ with the increase in irradiation dose. The plate counts of treated SBJ indicated that 4 kGy was suitable for pasteurization of SBJ.

Predicting bacterial growth in raw, salted, and cooked chicken breast fillets during storage

Growth curves were evaluated for aerobic mesophilic and psychrotrophic bacteria, Pseudomonas spp. and Staphylococcus spp., grown in raw, salted, and cooked chicken breast at 2, 4, 7, 10, 15, and 20 ℃, respectively, using the modified Gompertz and modified logistic models. Shelf life was determined based on microbiological counts and sensory analysis. Temperature increase reduced the shelf life, which varied from 10 to 26 days at 2 ℃, from nine to 21 days at 4 ℃, from six to 12 days at 7 ℃, from four to eight days at 10 ℃, from two to four days at 15 ℃, and from one to two days at 20 ℃. In most cases, cooked chicken breast showed the highest microbial count, followed by raw breast and lastly salted breast. The data obtained here were useful for the generation of mathematical models and parameters. The models presented high correlation and can be used for predictive purposes in the poultry meat supply chain.

Combined Effect of Kimchi Powder and Onion Peel Extract on Quality Characteristics of Emulsion Sausages Prepared with Irradiated Pork

This study was conducted to investigate the effects of kimchi powder and onion peel extract on the quality characteristics of emulsion sausage manufactured with irradiated pork. The emulsion sausages were formulated with 2% kimchi powder and/or 0.05% onion peel extract. The changes in pH value of all treatments were similar, depending on storage periods. The addition of kimchi powder increased the redness and yellowness of the emulsion sausage. The addition of onion peel extract decreased the thiobarbituric acid reactive substances value of the emulsion sausages prepared with irradiated pork. The volatile basic nitrogen value of the emulsion sausage prepared with kimchi powder was the highest, whereas that of the emulsion sausage prepared with onion peel extract was the lowest. The treatment without kimchi powder or onion peel extract and the treatments prepared with onion peel extract showed lower microbial populations than the other treatment. Sensory evaluations indicated that a higher acceptability was attained when kimchi powder was added to the emulsion sausages manufactured with irradiated pork. In conclusion, our results suggest that combined use of kimchi powder and onion peel extract could improve quality characteristics and shelf stability of the emulsion sausage formulated with irradiated pork during chilled storage.

Effects of gamma irradiation on microbial load and quality characteristics of veal

Background:

Veal is a rich nutrient medium that provides a suitable environment for proliferation of veal spoiling microorganisms and common food-borne pathogens. In this study, the effects of irradiation on the veal microbiological quality and half life of minced beef during chilled storage was investigated.

Materials and Methods:

Twenty samples of minced veal were irradiated with doses of 2, 5, 7, and 10 kGy (Cobalt-60, gamma cell 220) and evaluated for their microbiological quality up to 10 days.

Results:

The results showed that gamma irradiation reduced the number of microorganisms in all the irradiated minced veal samples, with 2, 5, 7, and 10 kGy (P < 0.01). Moreover, the half life of the samples were increased considerably (P < 0.01). In addition, the results indicated that there was a significant difference in the number of coliformes between untreated and irradiated samples (P < 0.05). While, Staphylococcus aureus could not be detected in the irradiated samples with doses of 7 and 10 kGy.

Conclusion:

These results indicated that irradiation could be employed as an effective mean to inactivate common food-borne pathogens namely S. aureus and increases the half life of veal.

Effects of irradiation dose and O(2) and CO(2) concentrations in packages on foodborne pathogenic bacteria and quality of ready-to-cook seasoned ground beef product (meatball) during refrigerated storage

Combined effects of gamma irradiation and concentrations of O(2) (0, 5, 21%) and CO(2) (0, 50%) on survival of Escherichia coli O157:H7, Salmonella enteritidis, Listeria monocytogenes, lipid oxidation, and color changes in ready-to-cook seasoned ground beef (meatball) during refrigerated storage were investigated. Ground beef seasoned with mixed spices was packaged in varying O(2) and CO(2) levels and irradiated at 2 and 4 kGy. Irradiation (4 kGy) caused about 6 Log inactivation of the inoculated pathogens. Inactivation of Salmonella was 0.9- and 0.4-Log lower in 0 and 5% O(2), respectively, compared to 21% O(2). Irradiation at 2 and 4 kGy increased thiobarbituric acid reactive substances in meatballs by 0.12 and 0.28 mg malondialdehyde kg(-1), respectively, compared to control. In reduced-O(2) packages, radiation-induced oxidation was lower, and the initial color of an irradiated sample was maintained. Packaging with 0% + 50% CO(2) or 5% O(2) + 50% CO(2) maintained the oxidative and the color quality of irradiated meatballs during 14-day refrigerated storage. MAP with 5%O(2) + 50% CO(2) combined with irradiation up to 4 kGy is suggested for refrigerated meatballs to reduce the foodborne pathogen risk and to maintain the quality.

The use of natural herbal extracts for improving the lipid stability and sensory characteristics of irradiated ground beef

Ground Longissimus dorsi of beef were treated with herbal extracts of marjoram, rosemary and sage at concentration of 0.04% (v/w), radiation (2 or 4.5 kGy) or their combination. Treated samples were stored at 5°C and analyzed periodically for thiobarbituric acid reactive substances (TBARS), sensory characteristics and psychrotrophic bacterial counts during storage for 41 and 48 days for samples treated at 2 and 4.5 kGy respectively. Results demonstrated a significant benefit of the addition of herbal extracts to the ground beef prior to irradiation. All three extracts significantly (P<0.05) lowered the TBARS values and off-odor scores and significantly (P<0.05) increased color and acceptability scores in all samples with marjoram being the most effective. The combination treatment with herbal extracts plus irradiation resulted in extension of the shelf life of samples treated with 2 kGy by one week and samples treated with 4.5 kGy by two weeks, over that treated with irradiation alone. In conclusion, the addition of herbal extracts can minimize lipid oxidation, improve color and decrease off-odor production in irradiated ground beef.

Efeito da irradiação em carne de coelho congelada

O crescimento nacional da produção de carne de coelhos necessita de maior conhecimento sobre características da carne, bem como o efeito de um processo que permita sua maior conservação. Os cortes congelados da carne de coelho: coxa, pernil e lombo, tratados com dois tipos de antibióticos, norfloxacina e ciprofloxacina, foram irradiados nas doses de 0, 3 e 6 kGy e determinados os teores de ferro heme e não heme dos cortes. As doses de irradiação empregadas foram influentes nos teores de ferro heme e não heme, sendo que a dose de 3 kGy foi a que apresentou os maiores valores, independente do tipo de antibiótico utilizado. Para o ferro heme o antibiótico norfloxacina apresentou os maiores valores e para o ferro não heme os maiores valores foram notados para o antibiótico ciprofloxacina.