Changes in Microbial Parameters and Gas Composition During Modified Atmosphere Storage of Fresh Pork Loin Cuts

1991 ◽  
Vol 54 (10) ◽  
pp. 778-783 ◽  
Author(s):  
LYNN M. MCMULLEN ◽  
MICHAEL E. STILES
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Storage Life ◽  
Microbial Load ◽  
Modified Atmosphere ◽  
Packaging Film ◽  
Brochothrix Thermosphacta ◽  
Pork Loin ◽  
Atmosphere Storage ◽  
Storage Temperatures

The storage life of modified atmosphere packaged pork loin cuts in 40% CO2 and 60% N2 was determined at −1, 4.4, and 10°C in three packaging films with oxygen transmission rates (OTR) of 0.0, 12.6, and 26.5 ml/m2/24 h at 23°C, 0% relative humidity and 1 atm pressure. The pork loin cuts were “commercially” or “aseptically” prepared. Gas atmosphere of the packages, microbial load, and pH were monitored throughout storage. The principal factor influencing change in the headspace gases under the conditions of these studies was gas transmission through the packaging film. A 100-fold difference in initial microbial load between commercially and aseptically prepared meat cuts resulted in a 2-week difference in storage life at both −1 and 4.4°C. Spoilage at each of the three storage temperatures could be attributed to the growth of different groups of bacteria and was influenced by package type. At −1°C, Brochothrix thermosphacta was the predominating microflora of samples stored in plastic film with an OTR of 26.5; lactic acid bacteria predominated on samples stored in foil packs with 0.0 and 12.6 OTR. At 4.4°C, lactic acid bacteria predominated, and at 10°C, Enterobacteriaceae predominated, regardless of packaging film. Under commercial packaging conditions in foil laminate packages with 0.0 or 12.6 OTR, storage life of pork cuts was 5 or 8 weeks at 4.4 or −1°C, respectively. This result was not definitive because of a difference among replicates. Samples in replicate 2 had a reduced storage life at each of the three storage temperatures.

Effect of Single or Sequential Hot Water and Lactic Acid Decontamination Treatments on the Survival and Growth of Listeria monocytogenes and Spoilage Microflora during Aerobic Storage of Fresh Beef at 4, 10, and 25°C

2004 ◽  
Vol 67 (12) ◽  
pp. 2703-2711 ◽  
Author(s):  
KONSTANTINOS P. KOUTSOUMANIS ◽  
LAURA V. ASHTON ◽  
IFIGENIA GEORNARAS ◽  
KEITH E. BELK ◽  
JOHN A. SCANGA ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Hot Water ◽  
Microbial Profile ◽  
Spoilage Bacteria ◽  
Brochothrix Thermosphacta ◽  
Survival And Growth ◽  
Spoilage Microflora ◽  
Storage Temperatures

The survival and growth of Listeria monocytogenes and spoilage microflora during storage of fresh beef subjected to different decontamination treatments was studied. Fresh beef inoculated with a five-strain mixture of L. monocytogenes (5.18 log CFU/cm2) was left untreated (control) or was immersed (30 s) in hot water (HW; 75°C), 2% lactic acid (LA; 55°C), hot water followed by lactic acid (HW-LA), or lactic acid followed by hot water (LA-HW) and then stored aerobically at 4, 10, and 25°C for 25, 17, and 5 days, respectively. Initial populations of L. monocytogenes were reduced by 0.82 (HW), 1.43 (LA), 2.73 (HW-LA), and 2.68 (LA-HW) log CFU/cm2. During storage, the pathogen grew at higher rates in HW than in control samples at all storage temperatures. Acid decontamination treatments (LA, HW-LA, and LA-HW) resulted in a weaker inhibition of L. monocytogenes (P < 0.05) at 25°C than at 4 and 10°C. In general, the order of effectiveness of treatments was HW-LA > LA > LA-HW > HW > control at all storage temperatures tested. In untreated samples, the spoilage microflora was dominated by pseudomonads, while lactic acid bacteria, Enterobacteriaceae, and yeasts remained at lower concentrations during storage. Brochothrix thermosphacta was detected periodically in only a limited number of samples. Although decontamination with HW did not affect the above spoilage microbial profile, acid treatments shifted the predominant microflora in the direction of yeasts and gram-positive bacteria (lactic acid bacteria). Overall, the results of the present study indicate that decontamination with LA and combinations of LA and HW could limit growth of L. monocytogenes and inhibit pseudomonads, which are the main spoilage bacteria of fresh beef stored under aerobic conditions. However, to optimize the efficacy of such treatments, they must be applied in the appropriate sequence and followed by effective temperature control.

scholarly journals Formation of Biogenic Amines in Chicken Meat Stored under Modified Atmosphere

2010 ◽  
Vol 79 (9) ◽  
pp. S107-S116 ◽  
Author(s):  
Leo Gallas ◽  
Eva Standarová ◽  
Iva Steinhauserová ◽  
Ladislav Steinhauser ◽  
Lenka Vorlová
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Biogenic Amines ◽  
Storage Period ◽  
Coliform Bacteria ◽  
Modified Atmosphere ◽  
Psychrotrophic Bacteria ◽  
Modified Atmospheres ◽  
Brochothrix Thermosphacta ◽  
Microbiological Indicators

The aim of the study was to investigate the effects of two modified atmospheres with a different combination of gases on selected groups of microorganisms and on concentrations of biogenic amines (BAs) in samples of poultry breast muscle. The samples were packaged under modified atmosphere A (75% O2 a 25% CO2) or B (75% N2 and 25% CO2) and stored at temperatures from +2 to +4 °C for 14 days. During the storage period, O2 concentrations in modified atmosphere A (MA A) decreased from the initial 74.8 ± 0.3% to 55.9 ± 6.6% at the end of the storage period. In all samples, counts of psychrotrophic bacteria counts, Brochothrix thermosphacta, lactic acid bacteria and coliform microorganism were determined. The tests were made on the packaging day, and then after three, nine and fourteen days of storage. At the end of the storage period, higher numbers of psychrotrophic bacteria (6.5 ± 0.7 log10 cfu g-1), Brochothrix thermosphacta (4.8 ± 0.3 log10 cfu g-1) and lactic acid bacteria (1.7 ± 0.4 log10 cfu g-1) were found on samples packaged under MA A. Samples packaged under modified atmosphere B on the other hand contained higher numbers of coliform bacteria (4.1 ± 0.6 log10 cfu g-1) at the end of the storage period. In addition to microbiological indicators, concentrations of biogenic amines (putrescine, cadaverine, histamine, tyramine, spermine, spermidine and β-phenylethylamine) were also determined. In fresh samples and after three days of storage, only spermine and spermidine were found. After 9 and 14 days, also other BAs were detected. The biogenic amine totals at the end of the storage period was 60.0 ± 13.2 mg kg-1 in samples packaged under MA A and 129.0 ± 41.3 mg kg-1 in samples packaged under MA B. The most abundantly represented biogenic amines in samples packaged under MA A were putrescine and spermine (49.7 and 24.8%, respectively, at the end of the storage period), and putrescine and cadaverine in samples packaged under MA B (47.0 and 32.9 %, respectively, at the end of the storage period).

scholarly journals Role of Broiler Carcasses and Processing Plant Air in Contamination of Modified-Atmosphere-Packaged Broiler Products with Psychrotrophic Lactic Acid Bacteria

2006 ◽  
Vol 73 (4) ◽  
pp. 1136-1145 ◽  
Author(s):  
Elina Vihavainen ◽  
Hanna-Saara Lundstr�m ◽  
Tuija Susiluoto ◽  
Joanna Koort ◽  
Lars Paulin ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
23S Rrna ◽  
Processing Plant ◽  
Modified Atmosphere ◽  
Production Plant ◽  
Meat Spoilage

ABSTRACT Some psychrotrophic lactic acid bacteria (LAB) are specific meat spoilage organisms in modified-atmosphere-packaged (MAP), cold-stored meat products. To determine if incoming broilers or the production plant environment is a source of spoilage LAB, a total of 86, 122, and 447 LAB isolates from broiler carcasses, production plant air, and MAP broiler products, respectively, were characterized using a library of HindIII restriction fragment length polymorphism (RFLP) patterns of the 16 and 23S rRNA genes as operational taxonomic units in numerical analyses. Six hundred thirteen LAB isolates from the total of 655 clustered in 29 groups considered to be species specific. Sixty-four percent of product isolates clustered either with Carnobacterium divergens or with Carnobacterium maltaromaticum type strains. The third major product-associated cluster (17% of isolates) was formed by unknown LAB. Representative strains from these three clusters were analyzed for the phylogeny of their 16S rRNA genes. This analysis verified that the two largest RFLP clusters consisted of carnobacteria and showed that the unknown LAB group consisted of Lactococcus spp. No product-associated LAB were detected in broiler carcasses sampled at the beginning of slaughter, whereas carnobacteria and lactococci, along with some other specific meat spoilage LAB, were recovered from processing plant air at many sites. This study reveals that incoming broiler chickens are not major sources of psychrotrophic spoilage LAB, whereas the detection of these organisms from the air of the processing environment highlights the role of processing facilities as sources of LAB contamination.

Effect of dietary supplementation with powder derived from Moringa oleifera and Azadirachta indica leaves on growth and microbial load of edible crickets

2021 ◽  
pp. 1-14
Author(s):  
J. Ng’ang’a ◽  
S. Imathiu ◽  
F. Fombong ◽  
J. Vanden Broeck ◽  
J. Kinyuru
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Azadirachta Indica ◽  
Moringa Oleifera ◽  
Antibacterial Properties ◽  
Acheta Domesticus ◽  
The Body ◽  
Microbial Load ◽  
Field Cricket ◽  
Bacterial Endospores

Cricket farming has shown its potential to address food and nutrition insecurity in parts of the world. However, one of the remaining challenges limiting mass production of edible insects is the affordability of feeds. One possible way to address this issue would be to explore the use of traditional plants such as Moringa oleifera leaf (MOL) and Azadirachta indica leaf (AIL) that are locally available, are protein-rich and possesses some antibacterial properties in insect feed formulation. In this regard, a study was conducted to evaluate the effect of supplementation of MOL (5 or 10%) and AIL (5 or 10%) powder in the commercially used starter chicken feed on growth and microbial load of house cricket (Acheta domesticus) and field cricket (Gryllus bimaculatus). After feeding for four weeks, the supplemented feeds with 10% MOL or 10% AIL in A. domesticus and G. bimaculatus significantly decreased (P<0.05) the body weights. Also, supplementation with MOL (5 or 10%) and AIL (5 or 10%) increased the mortality in both cricket species. Although high counts of total aerobic, Enterobacteriaceae, lactic acid bacteria, bacterial endospores, yeasts and moulds were observed, significantly lower counts (P<0.05) of lactic acid bacteria and bacterial endospores were observed in treatments containing MOL (5 or 10%) and 10% AIL in both cricket species. After processing (toasting and boiling), significant reductions (P<0.001) of all vegetative microbial cells were observed but bacterial endospores were not completely eliminated. Thus, during production and processing of insects and insect-derived products, bacterial endospores would require special attention. Salmonella and Escherichia coli were not detected in processed crickets’ samples. In conclusion, supplementation with 5% MOL or 5% AIL can produce crickets with similar body weight as control feed. Mortality increased significantly when feeds were supplemented with either MOL or AIL powder. Supplementation with MOL and AIL powders significantly reduced the cell numbers for some bacterial groups in both cricket species.

scholarly journals Microbiological Condition of Retail Beef Steaks: A Canadian Survey

2018 ◽  
Vol 7 (4) ◽  
pp. 1 ◽  
Author(s):  
Xianqin Yang ◽  
Julia Devos ◽  
Hui Wang ◽  
Mark Klassen
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Microbial Quality ◽  
Indicator Organisms ◽  
Mean Values ◽  
E Coli ◽  
Upper Limit ◽  
Brochothrix Thermosphacta ◽  
Beef Steaks

The second national baseline microbiological survey of beef steaks offered for retail in Canada was conducted in 2015. A total of 621 steaks of four types (cross rib, CR; inside round, IR; striploin, SL; top sirloin, TS) collected from 135 retail stores in five cities across Canada were tested. Swab samples each from swabbing the entire upper surface of each steak were processed for enumeration of seven groups of indicator organisms: total aerobes (AER), psychrotrophs (PSY), lactic acid bacteria (LAB), pseudomonads (PSE), Brochothrix thermosphacta (BRO), coliforms (COL) and Escherichia coli (ECO). The overall mean values (log CFU/100 cm2) were 5.17±1.29, 4.92±1.36, 4.79±1.42, 3.26±1.49, 2.34±1.88, and 0.80±1.05 for AER, PSY, LAB, PSE, BRO, and COL, respectively. ECO were not recovered from 87.3% of the steaks and when there was recovery, the numbers were mostly ≤ 1 log CFU/100 cm2. Strong correlation was found between the log numbers of AER and PSY, of AER and LAB, and of PSY and LAB, while the correlation between the log numbers of COL and ECO was weak. The numbers of COL and ECO from different groups of steak types or from different cities were not substantially different. Of the four types of steaks, IR had the lowest median values for AER, PSY, LAB, PSE and BRO, followed by CR. The microbiological condition of retail beef steaks in this survey was on par with that in the previous one, with very low numbers of generic E. coli being recovered from very few steaks and the indicators for microbial quality being at numbers much lower than the upper limit for shelf life of beef.

Survival of Campylobacter jejuni in Modified Atmosphere Packaged Turkey Roll

1991 ◽  
Vol 54 (3) ◽  
pp. 194-199 ◽  
Author(s):  
RANDALL K. PHEBUS ◽  
FRANCES A. DRAUGHON ◽  
JOHN R. MOUNT
Keyword(s):  
Lactic Acid ◽  
Campylobacter Jejuni ◽  
Co2 Concentration ◽  
Initial Population ◽  
Modified Atmosphere ◽  
Bacterial Populations ◽  
Direct Plating ◽  
Low Co2 ◽  
Co2 Levels ◽  
Storage Temperatures

Survival of Campylobacter jejuni, inoculated into turkey roll slices and stored under seven different atmospheric mixtures, was determined. Turkey roll samples were stored at 4°C for 18 d and at 21°C for 48 h. The effects of various atmospheric mixtures on aerobic, psychrotrophic, and lactic acid bacterial populations were also determined throughout storage. Campylobacter jejuni was inactivated under all atmospheric gas mixtures tested throughout storage. Increasing CO2 concentration inside the package from 0% to 100% CO2 resulted in a lower rate of inactivation of C. jejuni at both storage temperatures. Increases in CO2 concentrations provided greater inhibition of aerobic and psychrotrophic populations as compared to low CO2 levels. The effect of CO2 on survival of C. jejuni and growth rate of aerobic, psychrotrophic, and lactic acid bacteria was more pronounced at 4°C. Campylobacters were isolated from inoculated turkey roll held under all atmospheres by enrichment procedures on the 18th day and 48th hour of storage at 4 and 21°C, respectively, with an initial population of log 6.0 Campylobacter s/g. However, no Campylobacters were isolated by 18 d of storage at 4°C by direct plating.

scholarly journals Bacteriology and Meat Quality of Moisture Enhanced Pork from Retail Markets in Canada

2017 ◽  
Vol 6 (1) ◽  
pp. 95
Author(s):  
Karola R. Wendler ◽  
Francis M. Nattress ◽  
Jordan C. Roberts ◽  
Ivy L. Larsen ◽  
Jennifer Aalhus
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Meat Quality ◽  
Quality Characteristics ◽  
Retail Markets ◽  
Brochothrix Thermosphacta ◽  
Colour Saturation ◽  
Meat Samples ◽  
Water Holding

Packages of moisture-enhanced and conventional pork chops were collected from six Canadian retail stores on five sampling days. The composition of injection brines differed between retailers, but all contained polyphosphates and salt as main ingredients. Meat quality characteristics and bacteriology were analyzed from collected meat samples. Moisture enhanced chops had a higher pH and a higher water holding capacity than conventional. Juiciness and overall tenderness were improved in moisture enhanced chops. The surfaces of moisture enhanced chops were discoloured; the chops were darker and displayed less colour saturation. Total numbers of aerobes, psychrotrophs and lactic acid bacteria were not affected by moisture enhancement but numbers of Enterobacteriaceae, pseudomonads and Brochothrix thermosphacta, bacteria frequently associated with microbial spoilage, were approximately 1 log CFU·g-1 higher in moisture enhanced samples. This work shows moisture enhancement with injection brines containing salt and phosphates can result in a more palatable product. 

Bacteriology and Retail Case Life of Pork After Storage in Carbon Dioxide

1993 ◽  
Vol 56 (8) ◽  
pp. 689-693 ◽  
Author(s):  
G. G. GREER ◽  
B. D. DILTS ◽  
L. E. JEREMIAH
Keyword(s):  
Carbon Dioxide ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Storage Time ◽  
Aerobic Growth ◽  
Aerobic Conditions ◽  
Controlled Atmospheres ◽  
Brochothrix Thermosphacta ◽  
Retail Display

The effects of prolonged, anoxic storage, under CO2 at −1.5°C, upon the bacteriology and case life of pork on its subsequent transfer to the aerobic conditions of simulated retail display at 8°C was examined. Brochothrix thermosphacta, lactic acid bacteria, enterics, and pseudomonads were enumerated. Panel scores for odor and appearance acceptability were used to quantify retail case life. Lactic acid bacteria were the only bacteria found during loin storage in CO2 for up to 24 weeks. Those organisms reached maximum number of 107 CFU/cm2 within 9 weeks. The number of lactic acid bacteria initially found on the freshly cut surfaces of loin chops increased linearly during the first 9 weeks of loin storage in CO2. Thereafter, they continued to grow on the chops and dominated the spoilage flora during retail display. The pseudomonads grew rapidly and emerged as the next most numerous organism, while B. thermosphacta and enterics showed only limited aerobic growth. The acceptability of pork chop appearance and odor was adversely affected by loin storage time. Each 6-week interval of loin storage produced a 1 d reduction in case life. Should controlled atmospheres be a practicable means of meat distribution to the retail marketplace, efforts will be necessary to assure a maximum case life after their removal from preservative packagings.

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