Frozen Chicken Meat Research Articles

Antioxidative mechanisms of tea catechins in chicken meat systems

Abstract The effects of dietary tea catechins (TC) supplementation at levels of 50 (TC50), 100 (TC100) 200 (TC200), and 300 (TC300) mg/kg feed on oxidative stability and on protection of α-tocopherol (VE) in long-term frozen stored (−20 °C×12 months) chicken breast and thigh meat were investigated. Dietary TC (TC200) showed inhibiting effects on lipid oxidation equivalent to dietary α-tocopheryl acetate (VEA200) for long-term frozen stored chicken meat. The level of VE in long-term stored frozen chicken meat from TC dietary treatments (TC50, TC100, TC200 and TC300) was significantly ( P 2+ -chelating and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging were also examined. Added TC showed significantly ( P 2+ , TC showed strong scavenging capacity for the DPPH free radical. The strong free radical-scavenging ability plus the iron-chelating effects of TC provide a plausible mechanism for the antioxidant effects of added TC in the in vitro meat system.

Significant increase in antibiotic resistance of Salmonella isolates from human beings and chicken meat in Thailand

A total of 1715 Salmonella strains, including 600 S. enteritidis, 290 S.derby, 257 S. Weltevreden, 122 S. 1,4,5,12:i:-, 235 S. anatum, and 211 S. typhimurium, originating from 1308 human beings and 407 frozen chicken meat specimens collected in 1993 and 1994 were tested for antibiotic resistance. The disk diffusion method was used with nine disks of chloramphenicol, ceftriaxone, amikacin, kanamycin, ampicillin, sulfamethoxazole plus trimethoprim, nalidixic acid, gentamicin and ofloxacin. The resistance rates of human beings isolates in 1994 to ceftriaxone, amikacin and kanamycin were, respectively, 10.7%, 8.6%, 17.8% in S. enteritidis; 23.1%, 17.3% 33.0% in S. derby; 30.9%, 40.2%. 60.4% in S. weltevreden; 16.1%, 17.7%, 70.9% in S. 1, 4, 5, 12:i:-; 25.7%, 21.6%, 24.7% in S. anatum; 18.9%, 15.7% 37.8% in S. typhimurium, while those isolates in 1993 to the same three antibiotics were, respectively, 1.8%, 0.6%, 3.7% in S. enteritidis; 0.8%, 0%, 9.1% in S.derby; 1.8%, 2.7%, 10.8% in S. weltevreden; 3.8%, 0%, 23.0% in S.1, 4, 5, 12:i:-; 2.2%, 2.2%, 6.7% in S. anatum; 4.5%, 1.5%, 10.6% in S. typhimurium. It was shown that the resistance rates in 1994 were significantly higher than those in 1993. All isolates were susceptible to ofloxacin with the exception of one isolate.

Studies on Vitamin E and Meat Quality. 2. Effect of Feeding High Vitamin E Levels on Chicken Meat Quality

The objective of this work was to study the influence of vitamin E (as all-rac-α-tocopheryl acetate) supplementation on the sensory quality of frozen chicken meat. Two dietary treatments were compared as follows: (1) the control group received a diet containing respectively 30, 20, and 15 mg of α-tocopheryl acetate/kg of feed for the age periods of 0−20, 21−38, and 38−45 days; (2) the supplemented group received a starter diet containing 30 mg of α-tocopheryl acetate/kg of feed from 0 to 20 days and a finisher diet containing 200 mg/kg of feed from 21 to 45 days. HPLC analyses showed that muscle α-tocopherol levels of the chickens on the supplemented diet were 6−7-fold higher than those of the chickens on the control diet. Meat quality was evaluated by sensory as well as by instrumental techniques, such as induced thiobarbituric acid values (TBA) and gas chromatography−mass spectrometry. It was shown that vitamin E supplementation had a beneficial effect on the sensory data and the oxidative stability of...

Gamma irradiation as a means to eliminate Listeria monocytogenes from frozen chicken meat

AbstractCells of Listeria monocytogenes ATCC 35152 were sensitive to gamma irradiation in phosphate buffer, pH 7.00 (D10, dose required for 10% survival—0.15 kGy) at 0–5°C. The cells showed higher radiation survival when irradiated under frozen condition, with a D10 of 0.3 kGy. The protection offered by shrimp/chicken/kheema homogenates (100 g litre−1) was evidenced by even higher D10 values (0.5 kGy) at both 0–5°C and cryogenic temperature. Boneless chicken meat samples were artificially inoculated with L monocytogenes ATCC 35152 cells at low (5 × 103) colony‐forming unit (cfu) g−1 and high (5 × 106 cfu g−1) concentrations and irradiated at 1, 3, 4, 6 kGy doses under cryogenic conditions. The efficacy of the radiation process was evaluated by detecting L monocytogenes during storage at 2–4°C in the irradiated samples. These studies, when repeated with three other serotypes of L monocytogenes, clearly suggested the need for a dose of 3 kGy for elimination of 103 cfu cells of L monocytogenes g−1 from air‐packed frozen chicken meat.

Efficacy of selected media for recovery of Escherichia coli O157:H7 from frozen chicken meat containing sodium chloride, sodium lactate or polyphosphate

The viability of Escherichia coli O157:H7 in frozen chicken meat (CM) containing sodium chloride (NaCl), sodium lactate, or polyphosphate over an 18 month period was determined. Additionally, several recovery media were evaluated. Ground CM (10 g) was inoculated (10 6 cfu g -1) with E. coli O157:H7, then held at -20°C. Surviving cells were enumerated monthly using a nonselective medium, tryptic soy agar (TSA). After 11 months, seven additional recovery media were also used to evaluate the ability to recover freeze/NaCl-injured cells. In all treatments, the initial population decreased (P < 0·05) during storage. In CM with no additives, E. coli O157:H7 decreased by 0·6 log 10 cfu g -1 in 18 months. Addition of NaCl and sodium lactate resulted in reductions (P < 0·05) ranging from 1·4-2·4 log 10 cfu g -1 over the same period. Addition of polyphosphate did not affect recovery (P < 0·05). Recovery of E. coli O157:H7 was least (P < 0·05) from CM containing 8% NaCl, and recovery was least efficient (P < 0·05) on selective media (i.e. MacConkey sorbitol agar, MSA). The addition of Mg 2+ to MSA did not enhance recovery. Highest recoveries (P < 0·05) occurred on TSA, TSA plus 1% pyruvic acid and phenol red sorbitol agar (PRSA). E. coli O157:H7 survived (≥18 months) well in frozen poultry, and selective media such as MSA were inadequate for recovering freeze/NaCl-injured cells.

HYGIENIZATION OF INDIAN CHICKEN MEAT BY IONIZING RADIATION

ABSTRACT Both fresh and frozen chicken meat were evaluated for microbiological status by screening for total bacterial counts and for the presence of pathogens like Enterobacteria, Bacillus cereus, coagulase positive Staphylococci and Salmonella spp. Most of the samples exhibited heavy bacterial contamination (1.2 × 105 ‐ 2.6 × 106/g), mainly with Staphylococcus spp. (1.5 × 104 ‐ 2.8 × 105/g). All the chicken samples also showed the presence of Salmonellae (3 × 101 ‐ 2.1 × 102/g). Among the different serotypes observed in chickens. S. typhimurium was common in fresh as well as frozen chicken. Radicidation at 2 kGy at cryogenic conditions (−40°C) was efficient in eliminating the natural pathogenic contamination of the poultry. Salmonella spp. viz. S. seftenberg and S. typhimurium differed in radiation sensitivity, the D10 values in phosphate buffer (pH 7.2) being 0.25 kGy and 0.12 kGy, respectively. Chicken homogenate (10%) offered approximately 2‐fold protection to these cells. Chicken samples artificially inoculated with a heavy inoculum (108 cells/g) of these 2 serotypes required higher gamma radiation doses of 4–5 kGy. The findings suggested that a dose of 2 kGy is adequate for normally contaminated chicken samples, but for the heavily contaminated chicken a dose of 4–5 kGy, depending upon the predominating Salmonella serotype present, is required.

Evaluation of the precision of the modified Fitch method for thermal conductivity measurement of foods

A device was developed for measurement of thermal conductivity of solid food materials above and below freezing. The system is a modification of the Fitch apparatus. A disc-shaped sample with a constant thickness is placed in the compartment between a copper rod and a copper disc. The disc and rod act as a heat source and sink. The instrument was tested and calibrated by measuring the thermal conductivity of ice, frozen chicken meat (white), fresh potato and apple.

Efficacy of some methods and media for detecting and enumerating Campylobacter jejuni in frozen chicken meat.

Four of five strains of Campylobacter jejuni survived in chicken meat stored at -18 degrees C for 12 months. Direct plating of samples was superior to the most probable number technique for enumerating C. jejuni. Enrichment culture using the Doyle & Roman enrichment method resulted in the highest rates of detection. Packaging under an atmosphere of CO2 did not substantially influence survival.

Effect of polyphosphates on the survival of pre-stressed Salmonella typhimurium cells in frozen chicken meat

Six different commercial polyphosphate preparations were evaluated for their lethal efficacies against inoculated pre-stressed stationary phase cells of Salmonella typhimurium LT 2 in frozen comminuted poultry meat subsequently stored at −18°C for 28 days. At the 0·3% wt/wt concentration used, Puron 6040 was found most potent, achieving approximately 2 log cycle viability reduction, closely followed by Fibrisol N7 and sodium tripolyphosphate with 94·7% and 84·5% viability reductions, respectively. Curaphos 700 instant and tetrasodium pyrophosphate No. 7 both exhibited similar potency magnitudes of approximately 70% viability reduction each, while acid sodium pyrophosphate was the least potent. The polyphosphates slightly altered sample pH values and aided fluid retention without any detectable influence on the a w value. The findings demonstrate the potential antimicrobial benefits derivable from polyphosphates incorporation coupled with the conferrable textural advantages. It is considered that the observed potencies are influenced by chemical factors including chain length, pH and the subsequent relative stabilities of the polyphosphates in the menstruum system.

Survival of aerobic and anaerobic bacteria in chicken meat during freeze-dehydration, rehydration, and storage.

Total and anaerobic counts were ascertained on boneless, cooked, cubed, frozen chicken meat. We determined survival of aerobes and anaerobes in the natural flora after the meat was freeze-dehydrated and rehydrated at room temperature for 30 min and at 50, 85, and 100 C for 10 min. Total and anaerobic counts of bacteria in the rehydrated meat were established during storage of samples at 4, 22, and 37 C-until a spoilage odor was detected. Samples were also inoculated with Clostridium sporogenes and were dried and rehydrated at 100 C and stored at 37 C. Approximately 21% of the aerobes and 37% of the anaerobes survived drying and rehydration at room temperature. Many genera of aerobes, anaerobes, and facultative anaerobes survived drying and rehydration at 50 C; only sporeformers survived rehydration at 85 or 100 C. Low-temperature (4 C) storage of rehydrated meat produced ample shelf life (over 20 days), whereas storage at the higher temperature resulted in a shelf life of less than 30 hr. Approximately 81% of the C. sporogenes cells survived rehydration at 100 C and grew to over 10(7) cells within 40 hr. Our study presents additional data for adequate microbiological control in processing of freeze-dehydrated meat. Also, it points out the natural selection for sporeformers at high temperature of rehydration, stressing the need for consumer education in product handling for safety purposes.

Survival of Aerobic and Anaerobic Bacteria in Chicken Meat During Freeze-Dehydration, Rehydration, and Storage1

Total and anaerobic counts were ascertained on boneless, cooked, cubed, frozen chicken meat. We determined survival of aerobes and anaerobes in the natural flora after the meat was freeze-dehydrated and rehydrated at room temperature for 30 min and at 50, 85, and 100 C for 10 min. Total and anaerobic counts of bacteria in the rehydrated meat were established during storage of samples at 4, 22, and 37 C-until a spoilage odor was detected. Samples were also inoculated with Clostridium sporogenes and were dried and rehydrated at 100 C and stored at 37 C. Approximately 21% of the aerobes and 37% of the anaerobes survived drying and rehydration at room temperature. Many genera of aerobes, anaerobes, and facultative anaerobes survived drying and rehydration at 50 C; only sporeformers survived rehydration at 85 or 100 C. Low-temperature (4 C) storage of rehydrated meat produced ample shelf life (over 20 days), whereas storage at the higher temperature resulted in a shelf life of less than 30 hr. Approximately 81% of the C. sporogenes cells survived rehydration at 100 C and grew to over 10(7) cells within 40 hr. Our study presents additional data for adequate microbiological control in processing of freeze-dehydrated meat. Also, it points out the natural selection for sporeformers at high temperature of rehydration, stressing the need for consumer education in product handling for safety purposes.

A fluorescent-antibody technique for the rapid detection of Salmonellae in foodstuffs.

SYNOPSISThe development of a rapid, indirect fluorescent‐antibody technique for the detection of Salmonella; in dried egg powder, frozen chicken meat, and frozen chicken stock is described. Experiments using the technique in parallel with a conventional cultural technique have shown the results to be comparable and it is concluded that, provided the fluorescent‐antibody technique is used in conjunction with such a cultural technique, the small incidence of false positive results encountered does not constitute a great disadvantage in routine work.

Biochemical and Quality Changes Occurring During Freezing of Poultry Meat

SUMMARY—Comparative studies on muscle from fresh (unfrozen) and freshly frozen chickens showed that freezing caused small, but detectable changes in eating quality and that changes in muscle proteins during freezing depended on freezing rate. Slow freezing caused a larger loss of drip on thawing, a larger loss of nitrogenous constituents and nucleic acid derivatives to the drip, and a larger loss of water‐holding capacity of meat, than fast freezing. In addition, slow freezing, as compared to fast freezing, increased proteolysis and caused a greater decrease in the adenosine‐triphosphatase activity of myofibrillar proteins. Taste panel comparisons of fresh and frozen chicken meat showed that freezing caused a significant change in the odor of uncooked breast and leg meat and a decrease in tenderness of cooked breast meat. The results suggest that rapid freezing preserves the integrity of muscle proteins to a greater extent than slow freezing.