Survey of Meat Collected from Commercial Broiler Processing Plants Suggests Low Levels of Semicarbazide Can Be Created during Immersion Chilling.

ABSTRACT: Semicarbazide (SEM) is routinely employed as an indicator for the use of nitrofurazone, a banned antimicrobial. The validity of SEM as a nitrofurazone marker has been scrutinized because of other possible sources of the compound. Nonetheless, a U.S. trade partner rejected skin-on chicken thighs because of SEM detection and suspected nitrofurazone use. Because nitrofurazone has been banned in U.S. broiler production since 2003, we hypothesized that incidental de novo SEM formation occurs during broiler processing. To assess this possibility, raw leg quarters were collected from 23 commercial broiler processing plants across the United States and shipped frozen to our laboratory, where liquid chromatography-mass spectrometry was used to quantitatively assess for SEM. Leg quarter samples were collected at four points along the processing line: hot rehang (transfer from the kill line to the evisceration line), prechill (before the chilling process), postchill (immediately following chilling), and at the point of pack. Thigh meat with skin attached was removed from 535 leg quarters and analyzed in triplicate for SEM concentrations. The concentrations ranged from 0 to 2.67 ppb, with 462 (86.4%) of 535 samples below the regulatory decision level of 0.5 ppb of SEM. The 73 samples over the 0.5-ppb limit came from 21 plants; 53 (72.6%) of positive samples were in meat collected after chilling (postchill or point of pack). The difference in both prevalence and concentration of SEM detected before and after chilling was highly significant (P < 0.0001). These data support our hypothesis that SEM detection in raw broiler meat is related to de novo creation of the chemical during processing.

Effect of spaghetti meat abnormality on broiler chicken breast meat composition and technological quality.

The effects of spaghetti meat (SM) myopathy and sampling location on chicken breast meat physical traits, composition, and protein functionality were investigated using 30 normal (N) and 30 SM boneless fillets. Weight, drip loss, pH, and color traits were determined on intact fillets. Proximate composition, water holding capacity, mineral profile, SDS-PAGE, myofibrillar, and sarcoplasmic protein solubility, and emulsifying properties were assessed on both the superficial (S) and deep (D) layers of the breasts. SM fillets were heavier (P < 0.0001) and exhibited greater drip loss (P = 0.0131) and higher b* index on the skin side of the muscle (P < 0.0001). Muscle condition by layer interaction effect revealed that the superficial portion of SM fillets (SM-S) exhibited the highest moisture (P = 0.0003) and fat contents (P = 0.0011) coupled with the lowest protein (P < 0.0001) and ash contents (P = 0.0458). Total and soluble collagen amounts were higher in N-S and SM-S groups compared with N-D and SM-D (P < 0.0001). SM-S group exhibited the highest calcium (P = 0.0035) and sodium (P < 0.0001) levels. Overall, the myopathy had only minor impacts on protein profiles, while the muscle layer exerted a more remarkable effect. SM fillets exhibited higher pH but a lower myofibrillar protein solubility (P < 0.0001). Salt-induced water uptake, cooking loss, and final yield values suggested a potential impairment of water-holding capacity in SM-affected meat. Sarcoplasmic and myofibrillar emulsion activity indexes were similar between the 2 muscle conditions, but the stability of the emulsions was lower in SM meat. Overall, significant layer and muscle condition by layer effects were not observed in the functional properties of the breast meat. SM exerted a profound and negative impact on breast meat composition that led to detrimental consequences on functionality traits. Given the fundamental role of protein quality for meat processing, these data suggest that a further step toward the understanding of this myopathy should be the investigation of intrinsic protein characteristics.

Neutralization of Bactericidal Activity Related to Antimicrobial Carryover in Broiler Carcass Rinse Samples.

Studies were conducted to examine the ability of three chemicals to neutralize residual antibacterial activity of commercial antimicrobial chemicals used in poultry processing. Chemical antimicrobial interventions used in poultry processing may have potential for carryover into whole poultry carcass buffered peptone water (BPW) rinses collected for monitoring Salmonella contamination. Such carryover may lead to false-negative results due to continuing bactericidal action of the antimicrobial chemicals in the rinse. To simulate testing procedures used to detect Salmonella contamination, studies were conducted by separately adding test neutralizers (highly refined soy lecithin, sodium thiosulfate, or sodium bicarbonate) to BPW and using these solutions as carcass rinses. Control samples consisted of BPW containing no additional neutralizing agents. One of four antimicrobial solutions (cetylpyridinium chloride, peroxyacetic acid, acidified sodium chlorite, and a pH 1 hydrochloric:citric acid mix) was then added to the rinses. The four antimicrobial solutions were prepared at maximum allowable concentrations and diluted with modified BPW rinses to volumes simulating maximum carryover. These solutions were then inoculated with a mixed culture of five nalidixic acid-resistant Salmonella serovars at 106 CFU/mL. The inoculated rinse was stored at 4°C for 24 h, and Salmonella was enumerated by direct plating on brilliant green sulfa agar supplemented with nalidixic acid. Results indicate that incorporation of optimal concentrations of three neutralizing agents into BPW neutralized the demonstrated carryover effects of each of the four antimicrobial solutions tested, allowing recovery of viable Salmonella at 106 CFU/mL (P > 0.05), equivalent to recovery from carcass rinses with no antimicrobial carryover. Incorporation of these neutralizers in BPW for Salmonella monitoring may reduce false-negative results and aid regulatory agencies in accurate reporting of Salmonella contamination of poultry.

In-Package Inactivation of Pathogenic and Spoilage Bacteria Associated with Poultry Using Dielectric Barrier Discharge-Cold Plasma Treatments.

The goal of this study was to test the efficacy of in-package dielectric barrier discharge-cold plasma (DBD-CP) treatment to inactivate poultry-associated spoilage (Pseudomonas fluorescens) and pathogenic (Salmonella enterica Typhimurium, Campylobacter jejuni) bacteria. Liquid cultures of the bacterial isolates were sealed within packages containing ambient air (Trial 1) or modified air (65% O2:30% CO2:5% N2; Trial 2). The packages were subjected to treatment times ranging from 30 to 180 s, and after 24 h incubation at 4 °C, bacterial titers were determined. The DBD-CP system completely inactivated the four isolates tested, although the in-package gas composition and treatment times were isolate-specific. Both C. jejuni isolates were completely inactivated between 30 s (modified air) and 120 s (ambient air), while modified air was required for the complete inactivation of S. typhimurium (90 s) and P. fluorescens (180 s). This DBD-CP system is effective for inactivating major poultry-associated spoilage and pathogenic bacteria in liquid culture, and through this study, system parameters to optimize inactivation were determined. This study demonstrates the potential for DBD-CP treatment to inactivate major bacteria of economic interest to the poultry industry, thus potentially allowing for reduced spoilage (e.g., longer shelf life) and increased safety of poultry products.

Effect of Simulated Sanitizer Carryover on Recovery of Salmonella from Broiler Carcass Rinsates.

Numerous antimicrobial chemicals are currently utilized as processing aids with the aim of reducing pathogenic bacteria on processed poultry carcasses. Carryover of active sanitizer to a carcass rinse solution intended for recovery of viable pathogenic bacteria by regulatory agencies may cause false-negative results. This study was conducted to document the potential carryover effect of five sanitizing chemicals commonly used as poultry processing aids for broilers in a postchill dip. The effect of postdip drip time on the volume of sanitizer solution carryover was first determined by regression of data obtained from 10 carcasses. The five sanitizer solutions were diluted with buffered peptone water at 0-, 1-, and 5-min drip time equivalent volumes as determined by the regression analysis. These solutions were then spiked to 10(5) CFU/ml with a mixture of five nalidixic acid-resistant Salmonella enterica serovars, stored at 4°C for 24 h, and finally enumerated by plate count on brilliant green sulfa agar containing nalidixic acid. At the 0- and 1-min drip time equivalents, no Salmonella recovery was observed in three of the five sanitizers studied. At the 5-min drip time equivalent, one of these sanitizers still exhibited significant (P ≤ 0.05) bactericidal activity. These findings potentially indicate that the currently utilized protocol for the recovery of Salmonella bacteria from postchill sanitizer interventions may lead to false-negative results due to sanitizer carryover into the carcass rinsate.

Effect of Sample Preparation on the Discrimination of Bacterial Isolates Cultured in Liquid Nutrient Media Using Laser-Induced Breakdown Spectroscopy (LIBS).

Laser-induced breakdown spectroscopy (LIBS) is used as the basis for discrimination between two genera of gram-negative bacteria and two genera of gram-positive bacteria representing pathogenic threats commonly found in poultry processing rinse waters. Because LIBS-based discrimination relies primarily upon the relative proportions of inorganic cell components including Na, K, Mg, and Ca, this study aims to determine the effects of trace mineral content and pH found in the water source used to isolate the bacteria upon the reliability of the resulting discriminant analysis. All four genera were cultured using tryptic soy agar (TSA) as the nutrient medium, and were grown under identical environmental conditions. The only variable introduced is the source water used to isolate the cultured bacteria. Cultures of each bacterium were produced using deionized (DI) water under two atmosphere conditions, reverse osmosis (RO) water, tap water, phosphate buffered saline (PBS) water, and TRIS buffered water. After 3 days of culture growth, the bacteria were centrifuged and washed three times in the same water source. Bacteria were then freeze dried, mixed with microcrystalline cellulose, and a pellet was made for LIBS analysis. Principal component analysis (PCA) was used to extract related variations in LIBS spectral data among the four bacteria genera and six water types used to isolate the bacteria, and Mahalanobis discriminant analysis (MDA) was used for classification. Results indicate not only that the four genera can be discriminated from each other in each water type, but that each genus can be discriminated by water type used for isolation. It is concluded that in order for LIBS to be a reliable and repeatable method for discrimination of bacteria grown in liquid nutrient media, care must be taken to insure that the water source used in purification of the culture be precisely controlled regarding pH, ionic strength, and proportionate amounts of mineral cations present.

Quantitative analysis of cotton (Gossypium hirsutum) lint trash by fluorescence spectroscopy.

The presence of cotton plant botanical components, or trash, embedded in lint subsequent to harvesting and ginning is an important criterion in the classification of baled cotton by the U.S. Department of Agriculture Agricultural Marketing Service. The trash particles may be reduced in size to the point that specific trash types are not identifiable by image or gravimetric analysis, and it is desirable to quantify different trash types so that processing lines may be optimized for removal of the most problematic trash to enhance processing performance and cotton lint quality. Currently, there are no methods available to adequately quantify cotton lint trash based on botanical origin. The present work attempts to address this issue through the analysis by fluorescence spectroscopy of dimethyl sulfoxide extracts of mixtures of six botanical trash types. The fluorescence data are subsequently subjected to chemometric analysis. The resulting 6 partial least-squares calibration models obtained from 128 mixtures are demonstrated in the case of leaf and hull to be capable of predicting individual trash component concentrations with a high degree of confidence.

Variation in surface chemical constituents of cotton (Gossypium hirsutum) fiber as a function of maturity.

Modern cotton yarn production technology has made it imperative that new predictors of yarn spinning efficiency be determined. Surface frictional forces play a large role in spinning efficiency, yet little is known about the chemical constituents comprising the cotton fiber surface or their respective roles in inter-fiber frictional behavior. Major cotton fiber surface chemical components including pectin, wax, soluble salts, and sugars were quantified, and their respective relationships to cotton fiber maturity, as measured by micronaire, determined for 87 cotton samples exhibiting large variations in age, micronaire, genetics, and growing region. In the case of pectin and wax, inverse relationships with micronaire were found, whereas salts and sugars exhibit linear relationships with micronaire. Using these mathematical relationships, it will be possible to develop predictive models of whether spinning performance of different cottons is affected by deviations of the chemical constituents from the determined relationships.