Poultry Meat Spoilage Research Articles

High biofilm-forming Pseudomonas strains isolated from poultry slaughterhouse surfaces: Their importance in the persistence of Salmonella enteritidis in slaughterhouses

The surfaces of poultry slaughterhouse equipment are significant sources of contamination with Pseudomonas strains, which leads to spoilage of poultry meat during subsequent refrigerated storage. In this study, Pseudomonas strains with high biofilm-forming ability were isolated from different surfaces of the poultry slaughterhouse equipment, identified based on molecular data, and characterized their biofilm-forming ability. After 24 h of incubation at 25 °C, 54 out of 58 Pseudomonas strains produced biofilm in vitro on polystyrene microplates. Seven isolates with high-ability to produce biofilm were identified as P. fragi (three strains), P. fluorescens (two strains), P. lundensis and P. cedrina. Despite their differences, these strains produced high amounts of biofilm in pure- and dual-species cultures with S. enteritidis on stainless steel surfaces. However, their ability to produce dual-species biofilms with S. enteritidis depends on whether S. enteritidis form the biofilm simultaneously with the Pseudomonas strains or whether Pseudomonas strains have already formed a biofilm. In concurrent inoculation, S. enteritidis participated in biofilm formation with all seven Pseudomonas strains with varying percent contributions. However, in delayed inoculation, S. enteritidis did not contribute in the biofilm formed by P. lundensis R26, P. fragi R39, and P. fluorescens R47. In addition to highlighting the complexity of bacterial interactions associated with Pseudomonas strains, these results showed that Pseudomonas strains can be implicated in Salmonella persistence in poultry slaughterhouses.

Fabrication and validation of CO2-sensitive indicator to monitor the freshness of poultry meat

Three-layer CO2-sensitive intelligent labels consisting of PET as transparent gas impermeable film, the color changing layer with pH dyes (bromothymol blue (BTB) and phenol red (PR)) immobilized with a cellulose-based binder, and a white PE film as the gas permeable inner layer. The intelligent labels were implemented in PA/PE bags for CO2 simulation at concentrations of 0–30 %, and color change (∆E and ∆RGB) was monitored at 4 °C and 25 °C for 24 h. Chicken breast was packaged with PA/PE bags integrated with the intelligent labels and the color change was monitored at 10 °C for 4 days. BTB-based indicators showed a higher color difference than PR-based indicators in simulation and poultry packaging. However, phenol red-based indicators showed a more distinct and noticeable color change. The increase in CO2 correlates well with the color change. PR and BTB-based pH sensitive dyes are successfully used to monitor poultry meat spoilage in real packaging conditions.

Investigation of Pseudomonas Species in Chicken Drumstick Samples

This study aimed to detect the contamination of refrigerated poultry meat with psychrotrophic bacteria, such as Pseudomonas species. Pseudomonas spp. can grow well in the skin and muscle of poultry meat by using carbonhydrates and amino acids at refrigeration temperature (4 °C). They are mainly responsible for the spoilage of poultry meat with their enzymatic activiy. For this purpose, a total of 107 chicken drumstick samples were analyzed for the presence of Pseudomonas species (Pseudomonas fragi, Pseudomonas fluorescens, Pseudomonas putida, Pseudomonas lundensis, Pseudomonas aeruginosa). Of the samples, 92.5% found to be contaminated with Pseudomonas spp. A total of 99 isolates were confirmed as Pseudomonas spp. by PCR, targeting the 16S rDNA gene. Among the 99 isolates, 78.7% were identified as P. fluorescens, whereas P. fragi, P. putida, P. lundensis, and P. aeruginosa were not detected in the study. The findings show that P. fluorescens is the most prevalent species in refrigerated poultry meat, thus posing a potential risk for the spoilage of poultry meat.

Development of a Dye-Based Device to Assess the Poultry Meat Spoilage. Part II: Array on Act.

This work presents a colorimetric dye-based array for naked-eye detection of chicken meat spoilage. The array is obtained by fixing five acid–base indicators, m-cresol purple (1), o-cresol red (2), bromothymol blue (3), thymol blue (4), and chlorophenol red (5), and a sensing molecule specific for thiols, 5,5′-dithiobis(2-nitrodibenzoic acid), called Ellman’s reagent (6), on a cellulose-based support. The dyes, being permanently charged, are fixed on the support via ion-exchange. The entire degradation process of beast poultry meat, at ambient temperature and in a domestic fridge, is followed by the change of the color of the array, placed in the headspace over the meat samples. The device is set after selection of the most suitable starting form, which could be the acidic or the basic color of indicators, being the proper dye concentration and the dimension of the spots already established. Basing on sensors colors, we identified three levels of the degradation process of chicken meat, named SAFE, WARNING, and HAZARD. By instrumental analysis, we demonstrated that sensors response was correlated to volatile organic compounds (VOCs) composition in the headspace and, thus, to meat spoilage progress. We demonstrated that biogenic amines (BAs), commonly considered a critical spoilage marker, are indeed produced into the samples but never present in the headspace, even in traces, during the investigated time-lapse. The VOC evolution nevertheless allows one to assign the sample as WARNING and further HAZARD. Some indicators turned out to be more informative than others, and the best candidates for a future industrial application resulted in a bromothymol blue (3)-, chlorophenol red (5)-, and Ellman’s reagent (6)-based array.

Insights into the Identification of the Specific Spoilage Organisms in Chicken Meat.

Poultry meat deterioration is caused by environmental conditions, as well as proliferation of different bacterial groups, and their interactions. It has been proposed that meat spoilage involves two bacterial groups: one group that initiates the deterioration process, known as specific spoilage organisms (SSOs), and the other known as spoilage associated organisms (SAOs) which represents all bacteria groups recovered from meat samples before, during, and after the spoilage process. Numerous studies have characterized the diversity of chicken meat SAOs; nonetheless, the identification of the SSOs remains a long-standing question. Based on recent genomic studies, it is suggested that the SSOs should possess an extensive genome size to survive and proliferate in raw meat, a cold, complex, and hostile environment. To evaluate this hypothesis, we performed comparative genomic analyses in members of the meat microbiota to identify microorganisms with extensive genome size and ability to cause chicken meat spoilage. Our studies show that members of the Pseudomonadaceae family have evolved numerous biological features such as large genomic size, slow-growing potential, low 16S rRNA copy number, psychrotrophic, and oligotrophic metabolism to initiate the spoilage of poultry meat. Moreover, inoculation experiments corroborated that these biological traits are associated with the potential to cause chicken meat deterioration. Together, these results provide new insights into the identification of SSO. Further studies are in progress to elucidate the impact of the SSO on meat quality and microbiota diversity.

Packaging as a tool to improve the shelf life of poultry meat

In this paper, recent findings about poultry meat spoilage and packaging systems are discussed. Poultry meat is widely consumed and its consumption has been growing for decades. Raw poultry meat is a highly perishable food with short-term shelf life, and thus, novel strategies for maintaining safety and quality must be applied to meet the demands of the modern consumer. The main cause of meat spoilage is bacterial growth and the goal of this paper is to highlight the importance of GHP (Good Hygiene Practice) in the chain of processing, packaging, storage, and distribution of poultry meat in order to avoid economic losses and meet consumer expectations.

Assessing the capability of Fourier transform infrared spectroscopy in tandem with chemometric analysis for predicting poultry meat spoilage.

BackgroundUse of traditional methods for determining meat spoilage is quite laborious and time consuming. Therefore, alternative approaches are needed that can predict the spoilage of meat in a rapid, non-invasive and more elaborative way. In this regard, the spectroscopic techniques have shown their potential for predicting the microbial spoilage of meat-based products. Consequently, the present work was aimed to demonstrate the competence of Fourier transform infrared spectroscopy (FTIR) to detect spoilage in chicken fillets stored under aerobic refrigerated conditions.MethodsThis study was conducted under controlled randomized design (CRD). Chicken samples were stored for 8 days at 4 + 0.5 °C and FTIR spectra were collected at regular intervals (after every 2 days) directly from the sample surface using attenuated total reflectance during the study period. Additionally, total plate count (TPC), Entetobacteriaceae count, pH, CTn (Color transmittance number) color analysis, TVBN (total volatile basic nitrogen) contents, and shear force values were also measured through traditional approaches. FTIR spectral data were interpreted through principal component analysis (PCA) and partial least square (PLS) regression and compared with results of traditional methods for precise estimation of spoilage.ResultsResults of TPC (3.04–8.20 CFU/cm2), Entetobacteriaceae counts (2.39–6.33 CFU/cm2), pH (4.65–7.05), color (57.00–142.00 CTn), TVBN values (6.72–33.60 mg/100 g) and shear force values (8.99–39.23) were measured through traditional methods and compared with FTIR spectral data. Analysis of variance (ANOVA) was applied on data obtained through microbial and quality analyses and results revealed significant changes (P < 0.05) in the values of microbial load and quality parameters of chicken fillets during the storage. FTIR spectra were collected and PCA was applied to illuminate the wavenumbers potentially correlated to the spoilage of meat. PLS regression analysis permitted the estimates of microbial spoilage and quality parameters from the spectra with a fit of R2 = 0.66 for TPC, R2 = 0.52 for Entetobacteriaceae numbers and R2 = 0.56 for TVBN analysis of stored broiler meat.DiscussionPLS regression was applied for quantitative interpretation of spectra, which allowed estimates of microbial loads on chicken surfaces during the storage period. The results suggest that FTIR spectra retain information regarding the spoilage of poultry meat.ConclusionThe present work concluded that FTIR spectroscopy coupled with multivariate analysis can be successfully used for quantitative determination of poultry meat spoilage.

High pressure inactivation of Escherichia coli, Campylobacter jejuni, and spoilage microbiota on poultry meat.

This study evaluated the high pressure inactivation of Campylobacter jejuni, Escherichia coli, and poultry meat spoilage organisms. All treatments were performed in aseptically prepared minced poultry meat. Treatment of 19 strains of C. jejuni at 300 MPa and 30°C revealed a large variation of pressure resistance. The recovery of pressure-induced sublethally injured C. jejuni depended on the availability of iron. The addition of iron content to enumeration media was required for resuscitation of sublethally injured cells. Survival of C. jejuni during storage of refrigerated poultry meat was analyzed in fresh and pressuretreated poultry meat, and in the presence or absence of spoilage microbiota. The presence of spoilage microbiota did not significantly influence the survival of C. jejuni. Pressure treatment at 400 MPa and 40°C reduced cell counts of Brochothrix thermosphacta, Carnobacterium divergens, C. jejuni, and Pseudomonas fluorescens to levels below the detection limit. Cell counts of E. coli AW1.7, however, were reduced by only 3.5 log (CFU/g) and remained stable during subsequent refrigerated storage. The resistance to treatment at 600 MPa and 40°C of E. coli AW1.7 was compared with Salmonella enterica, Shiga toxin-producing E. coli and nonpathogenic E. coli strains, and Staphylococcus spp. Cell counts of all organisms except E. coli AW 1.7 were reduced by more than 6 log CFU/g. Cell counts of E. coli AW1.7 were reduced by 4.5 log CFU/g only. Moreover, the ability of E. coli AW1.7 to resist pressure was comparable to the pressure-resistant mutant E. coli LMM1030. Our results indicate that preservation of fresh meat requires a combination of high pressure with high temperature (40 to 60°C) or other antimicrobial hurdles.

Microbial Growth on Broiler Carcasses Stored at Different Temperatures After Air- or Water-Chilling

Poultry meat has a high risk of contamination during its processing. Storage temperature, type of packaging, and types and numbers of psychrotrophic bacteria are the major factors determining the spoilage of poultry meat. Before packaging, poultry carcasses are chilled by air or water currents in commercial slaughterhouses. The packaging material and methods are other factors influencing the spoilage of poultry meat. Although unpackaged carcasses had lower production costs, they were found to contain high numbers of microorganisms. The unpackaged carcasses are often not recommended for food safety and public health risks. The present study examines the growth of some spoilage microorganisms on unpackaged carcasses and on broiler carcasses packaged in polyethylene bags or synthetic plates. The carcasses examined in this study were collected from the slaughterhouses of the Bolu region of Turkey. All carcasses were subjected to an air or water chilling process in the slaughterhouse and then stored at 0, 4, or 7 degrees C for 14 d. Samples were taken on d 0, 4, 8, 10, and 14 of storage and analyzed for total bacterial count, and for Pseudomonas spp., Enterobacteriaceae, yeasts, and molds. The carcasses packaged in synthetic plates or polyethylene bags and kept at 0 degrees C were microbiologically safer and had longer shelf life, so they are found to be the most reliable for consuming. The shelf life of broiler carcasses could be further increased by improving hygiene and sanitation procedures at the slaughterhouse.

Formation of biogenic amines and relation to microbial flora and sensory changes in smoked turkey breast fillets stored under various packaging conditions at 4 °C

The present study evaluated: (1) the formation of biogenic amines (BAs) in smoked turkey fillets during storage under aerobic and modified atmosphere packaging (MAP) conditions at 4 °C, (2) the relation of BAs to microbial and sensory changes in turkey meat and (3) the possible role of BAs as indicators of poultry meat spoilage. Smoked sliced turkey fillets were stored in air and under vacuum, skin and two modified atmospheres (MAP), M1 (30% CO 2/70% N 2) and M2 (50% CO 2/50% N 2), at 4±0.5 °C, for a period of 30 days. The BAs determined were: tryptamine, tyramine, histamine, putrescine, cadaverine, spermidine and spermine. Low levels of BAs were observed throughout the entire storage period, with the exception of histamine, tyramine and tryptamine, for which higher concentrations were recorded. Values for these three BAs were the highest for air-packaged samples (32.9, 25.0 and 4.1 mg/kg, respectively) and the lowest for skin-packaged samples (11.9, 4.3 and 2.8 mg/kg, respectively) after 30 days of storage. All microorganism populations increased throughout the storage period, except for Pseudomonas spp. and Enterobacteriaceae, in skin-packaged fillets and modified atmosphere M2, which remained under the method detection limit (<1 log CFU/g) until day 30 of storage. Pseudomonas spp. and Enterobacteriaceae for the rest of the packaging treatments remained below 5 log CFU/g throughout storage. On the other hand, lactic acid bacteria were dominant throughout the storage period, regardless of the packaging conditions reaching 8.9 log CFU/g on day 30 of storage. Mesophiles reached 7 log CFU/g after ca. 19–20 days for the air and skin packed samples, 22–23 days for the M2 and vacuum packed samples and 25–26 days for the M1 packed samples. BA values for tryptamine, histamine and tyramine correlated well with both microbiological and sensory analyses data. Tryptamine, histamine and tyramine may be used as chemical indicators of turkey meat spoilage.

Possible role of volatile amines as quality-indicating metabolites in modified atmosphere-packaged chicken fillets: Correlation with microbiological and sensory attributes

The present work evaluated the possible role of volatile amines as indicator(s) of poultry meat spoilage. Fresh chicken meat (breast fillet) was packaged in four different atmospheres: air (A), vacuum (VP) and two modified atmospheres (MAs), namely M1, 30%/65%/5% (CO 2/N 2/O 2) and M2, 65%/30%/5% (CO 2/N 2/O 2). All chicken samples were kept under refrigeration (4 ± 0.5 °C) for a period of 15 days. Of the four treatments, the VP and M1 and M2 gas mixtures were the most effective for delaying the development of aerobic spoilage microbial flora. Pseudomonas spp. in chicken samples stored under M2 gas mixture and VP were significantly lower than all the other samples after 15 days of storage. Of the remaining bacterial species examined, lactic acid bacteria (LAB), Brochothrix thermosphacta, were dominant in the microbial association of both aerobically- and MA-packaged chicken, while yeasts contributed to a much lesser extent in the final microbial flora of chicken meat. On the basis of microbiological data (TVC), shelf-life extensions of 2, 4 and 9–10 days were achieved by VP and M1 and M2 gas mixtures. Results of the present work showed that the limit of sensory acceptability (a score of 6) was reached for the aerobically, vacuum-packaged and M1 gas mixture chicken samples approximately on days 6–7 and 9–10, respectively. Based on sensory (taste) analysis and with regard to chicken spoilage and freshness, TMA-N and TVB-N limit values of acceptability, namely 10.0 mg N/100 g and 40 mg N/100 g for chicken samples stored in air, may be proposed as the upper limit values for spoilage initiation of fresh chicken meat stored aerobically. Interestingly, the M2 gas mixture sample did not reach these limit values throughout the 15 day storage period. The formation of volatile amines during chill storage of chicken meat, under the packaging conditions examined in the present study, seemed to be in good agreement with the increase in microbiological count (TVC) and sensory taste score except for the M2 gas mixture.

Correlation between microbial flora, sensory changes and biogenic amines formation in fresh chicken meat stored aerobically or under modified atmosphere packaging at 4 °C: possible role of biogenic amines as spoilage indicators

This study evaluated the formation of biogenic amines (BAs) in breast chicken meat during storage under aerobic and modified atmospheric packaging (MAP) conditions at 4 degrees C, the correlation of microbial and sensory changes in chicken meat with formation of BAs and the possible role of BAs as indicators of poultry meat spoilage. Poultry breast fillets were stored aerobically or under MAP (30%, CO(2), 70% N(2)) at 4 degrees C for up to 17 days. Quality evaluation was carried out using microbiological, chemical and sensory analyses. Total viable counts, Pseudomonads and Enterobacteriaceae, were in general higher for chicken samples packaged in air whereas lactic acid bacteria (LAB) and Enterobacteriaceae were among the dominant species for samples under MAP. Levels of putrescine and cadaverine increased linearly with storage time and were higher in aerobically stored chicken samples. Spermine and spermidine levels were also detected in both aerobically and MAP stored chicken meat. Levels of tyramine in both chicken samples stored aerobically and or under MAP were low (< 10 mg kg(-1)) whereas the formation of histamine was only observed after day 11 of storage when Enterobacteriaceae had reached a population of ca. 10(7) CFU g(-1). Based on sensory and microbiological analyses and also taking into account a biogenic amines index (BAI, sum of putrescine, cadaverine and tyramine), BAI values between 96 and 101 mg kg(-1) may be proposed as a quality index of MAP and aerobically-packaged fresh chicken meat. Spermine and spermidine decreased steadily throughout the entire storage period of chicken meat under aerobic and MAP packaging, and thus these two amines cannot be used as indicators of fresh chicken meat quality.

Identification of yeasts isolated from poultry meat.

In an assessment of the potential role of yeasts in the spoilage of poultry meat, the population and species diversity of yeasts were determined on 50 commercial raw and processed chicken and turkey product samples. Initial populations (log10 cfu/g) ranged from less than 0.1 to 2.9, and increased by the expiration date to 0.4 to 5.1, respectively. 145 of 152 isolates were identified as belonging to 12 species. Yarrowia lipolytica and Candida zeylanoides were predominant, accounting for 39% and 26% of the isolates, respectively. Six different species of basidiomycetous yeasts were determined representing 24% of the isolates. The ability of the predominant yeast species to grow at refrigeration temperatures and their proteolytic and lipolytic activies suggest that yeasts may play a more significant role than previously recognised in the spoilage of poultry products.

A selective medium for the rapid detection by an impedance technique of Pseudomonas spp. associated with poultry meat.

A new medium for detecting and enumerating Pseudomonas spp. associated with poultry meat spoilage by a rapid impedance technique was developed, after testing potential growth promoters for eight Pseudomonas strains and inhibitors against eight competing strains (Enterobacteriaceae) able to grow on the medium of Mead and Adams (1977). Four basal media (brain heart infusion, brucella broth, Shaedler broth and Whitley impedance broth (WIB)) and a synthetic medium were evaluated. Whitley impedance broth was the best basal medium for detecting variations in impedance in relation to Pseudomonas growth. The efficiency of WIB was improved by adding compounds which enhanced the growth of Pseudomonas on the synthetic medium. Among the incubation temperatures tested, 22 degrees C proved to be the best compromise between growth of Pseudomonas associated with poultry meat spoilage and inhibition of competitors. Among the 15 inhibitory substances evaluated against Pseudomonas competitors, five were chosen for inclusion in the final medium: metronidazole, carbenicilline, cetrimide, cycloheximide and diamide (MCCCD medium). Preliminary results obtained from experiments with beef and pork meat showed that this medium could also be used without diamide and at an incubation temperature of 25 degrees C. The impedance technique using MCCCD medium was then compared with an official method which uses the medium of Mead and Adams (1977) on 106 samples of poultry neck skin. The linear regression coefficient between the two techniques was approximately r = 0.85. Impedance was able to detect 10(3) Pseudomonas g-1 within less than 19 h making it a promising technique for predicting poultry meat spoilage.

Research Note: Relationship of Microbiological Quality and Oxidative Stability of Raw Broiler Meat During Cold Storage

The purpose of this study was to determine whether 2-thiobarbituric acid (TBA) values could be used to predict microbiological spoilage of poultry meat. The TBA values of control and inoculated (cultured breast skin microflora, 105 cells/mL) chicken breast and leg meat were examined at 0, 2, 7, and 14 days storage in slightly adverse storage conditions (6 C) and at 26 and 20 days, respectively, when spoilage occurred (108 cfu/g). Psychrotrophic counts were also obtained on these sampling days for control and inoculated breast and leg meat. Microbiological counts were significantly different for control and inoculated samples on each of the sampling days. However, no significant differences between TBA values of control and inoculated samples were noted on any of the sampling days. No difference was observed between the TBA value of the inoculated product, which had reached spoilage levels (108 cfu/g), and the control product, which was not spoiled (<107 cfu/g). Therefore, the TBA test is not an accurate predictor of microbiological spoilage of poultry meat.

Extending the Shelf-Life of Chicken Broiler Meat

Microorganisms involved in the spoilage of poultry meat stored at —2, 4, and 15 C were identified. The numbers of spoilage organisms on poultry meat after storage for different time periods at the above temperatures were determined. Attempts were made to extend the shelf-life of poultry meat by treatment with two solutions containing citric acid, potassium sorbate, and modified cornstarch. Solution 1 consisted of 10% citric acid, 6% potassium sorbate, and 34% modified cornstarch in water (pH 3.2). Solution 2 consisted of 20% citric acid, 6% potassium sorbate, and 24% modified cornstarch in water (pH 2.4). Chicken broiler wings were dipped in boiling water for 10 sec, dipped in Solution 1 or 2 for 60 sec, drained for 3 sec, and packaged individually in polyethylene bags.Untreated poultry meat samples (portion of wing consisting of ulna and radius with attached skin and muscle) had a shelf-life of less than 1 day at 15 C, 7 days at 4 C, and 14 days when stored at —2 C. Wings treated with Solution 1 had a shelf-life of 4 days at 15 C and 14 days at 4 C. Wings treated with Solution 2 had a shelf-life of 6 days at 15 C and longer than 28 days when stored at 4 C. Wings treated with Solution 1 remained acceptable for 1 day when stored at 25 C, whereas those dipped in Solution 2 were acceptable after 2 days. Pseudomonads were identified as the major organisms responsible for spoilage of both treated and untreated samples. Throughout the study, samples treated with Solution 2 had lower microbial counts than samples treated with Solution 1. Treatment of thighs with Solution 1 had no adverse effect on the sensory characteristics of barbecued samples. Samples treated in Solution 2 were scored lower but were not undesirable. Barbecuing consisted of oven baking and basting with a spicy tomato base sauce.

A selective medium for the rapid isolation of pseudomonads associated with poultry meat spoilage

1. A new selective medium (CFC) has been developed for the rapid isolation of pigmented and non-pigmented pseudomonads associated with the spoilage of poultry meat held under chill conditions. It comprises Difco Heart Infusion Agar supplemented with 50 microgram cephaloridine, 10 microgram fucidin and 10 microgram cetrimide/ml. 2. CFC medium was found to be more selective than three other media which have been used for isolating pseudomonads from foods, when tested with pure cultures of 28 reference organisms. 3. CFC supported the growth of a higher proportion of pseudomonads from freshly-eviscerated carcasses and processing equipment when the organisms were present only in low numbers relative to other genera.

Determination of Pyoverdine on the Surface of Chicken Meat

INTRODUCTIONTHE genus Pseudomonas predominates in the spoilage of poultry meat (Ayres et al., 1950). Some pseudomonads produce a fluorescent pigment, but others do not (Breed et al., 1957). Cotterill (1956) suggested the use of an ultraviolet lamp to detect the fluorescence that accompanies the spoilage of packaged chicken. Silliker et al. (1958) recommended a streaking method for isolation of pseudomonads causing fluorescence, and concluded that the fluorescent strains form a significant proportion of the spoilage flora. Kraft and Ayres (1961) reported that fluorescence was enhanced by the use of films allowing passage of oxygen, but according to Barnes and Shrimpton (1958) odor was not necessarily well correlated with fluorescence.“Pyoverdine” was suggested by Turfreijer (1941) as a name for the fluorescent pigment complex of the pseudomonads. Studies on pyoverdine were reported by Elliott (1958a) and a method for its determination in frozen egg was described (Elliott, 1958b). The method …

Use of Nystatin (Mycostatin) to Retard Yeast Growth on Chlortetracycline-treated Chicken Meat

ABSTRACT THE effectiveness of broad spectrum antibiotics for the control of red meat spoilage has been reported in a series of papers by Cahill et al. (1952), Lepovetsky et al. (1953), Goldberg et al. (1953), and Weiser et al. (1953 (1954). Tarr et al. (1952 (1954), and Tarr (1954) reported that antibiotics can be used to prolong the shelf life of fish as well as red meat. The use of antibiotics for the control of poultry meat spoilage was reported by Kohler et al. (1955) and Ziegler and Stadelman (1955). In studies using chicken halves dipped in chlortetracycline solutions, Ziegler and Stadelman (1955) found that the organisms predominant on the chlortetracycline-treated halves were yeasts having the shape and budding characteristics of the family Saccharomycetacae. Tarr et al. (1952) also reported noticeable yeast growth on meats and fish treated with broad spectrum antibiotics. The purpose of the work reported herein was to . . .

The Efficacy of Chlortetracycline at Several Temperatures in Controlling Spoilage of Poultry Meat

INTRODUCTIONTHE volume of poultry meat moving through market channels is increasing each year. A high percentage of this meat is fryer chickens most of which are delivered to the final consumer without freezing. One of the major problems in handling the fresh fryers is the short keeping time. The spoilage of fresh poultry meat held under refrigeration without freezing is predominantly bacterial. This information has been available for years. Lockhead and Landerkin (1935) reported that spoilage of chicken held at refrigerator temperatures above freezing was due primarily to surface bacteria. Further confirmation comes from the work of Ayres, Ogilvy and Stewart (1950). The appearance of slime nodules and off-odor has been commonly used to determine spoilage, but Ziegler, Spencer and Stadelman (1954) report a rapid microscopic method for this determination. This was the method used in this study.On November 30, 1955, the Federal Food and Drug Administration cleared …