The use of β-glucan as a partial salt replacer in high pressure processed chicken breast meat

The effect of various ingredients such as sodium chloride (NaCl), sodium tripolyphosphate (STPP) and β-glucan (BG) on the biochemical properties of chicken breast proteins during temperature assisted high pressure processing was studied. Total protein solubility revealed that 600 MPa pressure and 40 ^oC are critical for the denaturation of proteins in STPP samples. Increase in reactive sulfhydryl groups with pressure indicate the exposure of buried sulfhydryl groups. Hydrophobicity and sulfhydryl contents revealed that hydrophobic interaction and disulphide bond formation are responsible for gel formation. The study revealed that 40 ^oC and 400/600 MPa pressure is optimum for high pressure processing of chicken breast meat. Addition of β-glucan with reduced NaCl and in the absence of sodium tripolyphosphate could produce gels with similar properties to those with 2.5% NaCl addition. Hence it is proposed that β-glucan can be used to reduce NaCl content of chicken products produced by temperature assisted high pressure processing.     

Influence of cooking conditions on cooking loss and tenderness of raw and marinated chicken breast meat

The influence of different cooking treatments on tenderness and cooking loss, as main quality characteristics of chicken breast meat, was investigated. Industrial skinless chicken breast meat samples were designated as raw and marinated and cooked in the oven by hot air and hot air-steam mixture at 130, 150 and 170 °C, for 4, 8 and 12 min. Cooking losses were evaluated by weight changes before and after cooking, and tenderness changes were determined on cooked samples by measuring shear force using instrumental texture analysis. Results showed that marination, followed by air-steam cooking is the best combination to obtain the most tender chicken breast slices. The time and temperature of cooking showed similar effects on cooking loss and tenderness: short cooking time (4 min) and temperatures of 130–150 °C resulted in lower cooking losses and best meat tenderness, in both not marinated and marinated meat. Statistically significant correlations between tenderness and cooking loss indicated that the cooking loss correlated better with cooking time than with cooking temperature. An opposite phenomenon was observed for meat tenderness.     

Rosemary as antioxidant in pressure processed chicken during subsequent cooking as evaluated by electron spin resonance spectroscopy

The potential of rosemary (Rosmarinus officinalis L.) to inhibiting lipid oxidation in minced chicken breast and thigh muscle processed at 600 MPa for 10 min during subsequent heat treatment was investigated using electron spin resonance (ESR) spectroscopy and electrochemical detection of oxygen consumption. Chicken breast cooked at 95 °C was found to have significantly higher rate of formation of free radicals and oxygen consumption rate than the samples cooked at 70 °C and 120 °C and this intermediate cooking temperature was used to evaluate the effect of pressure on oxidation during subsequent cooking. Rosemary was found effective in retarding lipid oxidation since the pressurized, minced chicken breast and thigh with rosemary added showed lower rate of oxygen consumption and lower tendency of free radical formation following heat treatment than the samples without rosemary. Pressurized chicken thigh showed a higher susceptibility to oxidation than chicken breast upon subsequent heat treatment. Oxidation in pressurized and subsequently heat-treated chicken breast was from a higher tendency of radical formation concluded to be in an earlier phase of oxidation compared to thigh subjected to the same treatment.Industrial relevanceHigh-pressure processing has a great potential for microbial control of raw chicken meat as a “fresh” chill-stored, convenience product for wok cooking. While raw chicken meat is oxidatively stable, high-pressure treatment at 600 MPa and above induces lipid oxidation resulting in off-flavors during subsequent cooking. Addition of 0.1% dried rosemary to minced chicken thighs or breasts prior to high-pressure processing inhibit lipid oxidation during subsequent cooking and could form the basis for product development.     

Efficacy of plant extracts in inhibitingAeromonas hydrophilaandListeria monocytogenesin refrigerated,cooked poultry

Alcohol extracts of angelica root, banana purée, bay, caraway seed, carrot root, clove (eugenol), marjoram, pimento leaf and thyme were applied to cooked chicken to determine their antimicrobial activities against Aeromonas hydrophilaand Listeria monocytogenes.Skinless chicken breast meat was cooked to an internal temperature of 85°C, allowed to cool to c. 5°C, then treated by surface application with plant extracts. Low (10 cfu g⁻¹)or high (10⁵ cfu g⁻¹)populations of A. hydrophilaand L. monocytogeneswere applied and samples were stored at either 5 or 15°C for up to 14 or 7 days, respectively. Eugenol and pimento extracts were most effective in inhibiting growth of both bacteria. A. hydrophilawas the more sensitive to the two treatments, with 4 log₁₀ cfu g⁻¹less growth occurring at 14 days at 5°C on eugenol-treated breast meat than on control samples. These results suggested that plant extracts might be useful as antimicrobials in cooked, ready-to-eat chicken meat.     

Effects of smoking and marination on the sensory characteristics of cold-cut chicken breast filets: A pilot study

This study aimed to determine individual and combined effects of smoking and marination on the sensory characteristics of boneless, skinless chicken breast meat. Four types of cooked, cold-cut chicken breast meat, i.e., marinated cooked, marinated smoked, and controls of non-marinated cooked and non-marinated smoked chicken, were evaluated for 28 sensory characteristics. Marination significantly increased saltiness, sweetness, roasted flavor, smoked flavor, and moistness of the cold-cut chicken breast meat. In addition, smoking significantly enhanced the saltiness, bitterness, roasted flavor, smoked flavor, and moistness of mass. Interestingly, a combination of smoking and marination processes resulted in a synergistic increase in the perceived moistness of mass compared to their individual treatments. In conclusion, this study demonstrates individual and combined influences of smoking and marination on the sensory characteristics of cold-cut chicken breast meat.     

Application of statistical process control,sampling, and validation for producing Listeria monocytogenes-free chicken leg quarters processed in steam followed by impingement cooking

Chicken leg quarters (180–230 g) were processed for 4 min in steam at 99°C and then in an air impingement oven for 24 min at an oven temperature of 232°C, an air velocity of 2 m/s, and a humidity of 60%. The cooked chicken leg quarters were sampled to measure for the end-point internal temperatures. Sampling size in each subgroup for the internal temperature measurements was determined based on a normal distribution at a confidence level of 95%. The process mean, range, and standard deviation at 95% confidence level were 73.9°C, 1.8°C, and 0.9°C, respectively, for the internal temperatures of the cooked chicken leg quarters. The process lethality was validated for up to 7  log₁₀ cfu/g reductions of Listeria monocytogenes in the cooked chicken leg quarters and verified by an inoculation study in which the chicken leg quarters were injected with 0.1 ml of the culture per cm² of the product surface area to contain 7–8 log₁₀ cfu/g of L. monocytogenes. This paper provided an approach for process control, sampling, and validation to reduce pathogens in fully cooked poultry products.     

Lipid Oxidation Potential of Beef, Chicken, and Pork

Beef and pork longissimus dorsi and semimembranosus muscles and chicken breast and thigh muscles were excised 24 hr postmortem from carcasses of marketweight grain-finished feedlot beef cattle, marke-tweight hogs on a typical finishing diet, and broilers on a commercial grain diet. Muscle samples were immediately ground and formed into patties and stored raw or after cooking, at 4°C (cooked) or ?20°C (raw and cooked). TBA values (on sample weight basis) of frozen raw samples were higher for beef and pork than for chicken, as was heme iron content. However, TBA values of cooked samples were highest for chicken thigh muscles, which contained the most polyunsaturated fatty acids, at all storage temperatures.     

Inhibition of Clostridium sporogenes PA 3679 and Natural Bacterial Flora of Cooked Vacuum-Packaged Bratwurst by Sodium Acid Pyrophosphate and Sodium Tripolyphosphate With or Without Added Sodium Nitrite

Survival and growth of inoculated Clostridium sporogenes PA3679 and natural aerobic and anaerobic bacterial flora were studied in refrigerated (5°C) and subsequently temperature abused (24–25°C), cooked, vacuum-packaged bratwurst containing 0.5% sodium acid pyrophosphate (SAPP) or sodium tripolyphosphate (STPP) with or without sodium nitrite. Phosphates alone or combined with nitrite did not affect aerobic bacterial counts but resulted in reduced clostridial and anaerobic counts at 5°C. Upon temperature abuse, inhibition of all bacteria by SAPP was significant (P<0.05) for up to 48 hr and greatly enhanced by 100 ppm but not by 50 ppm sodium nitrite, whereas STPP lost its antimicrobial properties after 24 hr. Soluble orthophosphate levels had a positive correlation with bacterial inhibition in SAPP-treated bratwurst.     

Effect of pre-incubation conditions on growth and survival of Staphylococcus aureus in sliced cooked chicken breast

In this work, the effect of pre-incubation conditions (temperature: 10, 15, 37 °C; pH 5.5, 6.5 and water activity, a_w: 0.997, 0.960) was evaluated on the subsequent growth, survival and enterotoxin production (SE) of Staphylococcus aureus in cooked chicken breast incubated at 10 and 20 °C. Results showed the ability of S. aureus to survive at 10 °C when pre-incubated at low a_w (0.960) what could constitute a food risk if osmotic stressed cells of S. aureus which form biofilms survive on dried surfaces, and they are transferred to cooked meat products by cross-contamination. Regarding growth at 20 °C, cells pre-incubated at pH 5.5 and a_w 0.960 had a longer lag phase and a slower maximum growth rate. On the contrary, it was highlighted that pre-incubation at optimal conditions (37 °C/pH 6.5/a_w 0.997) produced a better adaptation and a faster growth in meat products what would lead to a higher SE production. These findings can support the adoption of management strategies and preventive measures in food industries leading to avoid growth and SE production in meat products.     

Effects of carrageenan on thermal stability of proteins from chicken thigh and breast muscles

Thermal stability of ground chicken meat and myofibrillar proteins mixed with κ-, ι-, and λ-carrageenan (CGN) at different NaCl concentrations was investigated with differential scanning calorimetry. Three transitions, characteristic of myosin head (63.3, 62.2°C), sarcoplasmic proteins/myosin tail (67.7, 68.6°C), and actin (78.3, 81.4°C), were observed for nontreated thigh and breast muscles, respectively. The influence of CGNs on the thermal transitions was dependent on salt concentrations. κ-CGN with 2.5% NaCl decreased (P<0.05) transition temperature (T_max) of thigh myosin head and actin, while all three CGNs with or without 2.5% salt decreased (P<0.05) T_max for breast actin. Total enthalpy of denaturation decreased slightly in the presence of κ-CGN for thigh muscles only. The gum effects on myofibril isolates were variable and were salt-dependent. The results suggested molecular interactions between the gums and meat proteins, but the response of the specific proteins to gums appeared to be muscle type-dependent.     

Effect of Sodium Chloride and Phosphates on the Thermal Properties of Chicken Meat Proteins

Maximum thermal transition (T_max) and denaturation enthalpy (ΔH) of water-washed myofibrils and finely cut chicken breast muscle, treated with 1–4% NaCl and/or 0.25–1% of either pyrophosphate (PP) or tripolyphosphate (TPP), were monitored by differential scanning calorimetry. Increasing the concentration of NaCl destabilized the heat resistance of the proteins in water-washed myofibrils and in meat specimens. Actin showed the greatest reduction of T_max, a 16°C decline in the presence of 4% NaCl. In a meat system, the addition of 4% NaCl resulted in one T_max instead of five transitions, as seen in untreated meat. The presence of PP and TPP, especially in concentrations of 0.25 and 0.50%, enhanced the thermal stability of myosin. Changes in denaturation temperatures of proteins were accompanied by corresponding changes in AH.     

Heat Denaturation and Emulsifying Properties of Egg Yolk Phosvitin

Phosvitin in water at pH 7 had a denaturation temperature (T_d) of 79.7 ± 1.4°C when heated at 10°C/min. When dissolved in 0.1M and 1.0M NaCl, the T_d decreased to 77.7 ± 1.2°C and 77.2 ± 1.3°C, resoectivelv. and in 10 and 20% sucrose there was no change in T_d. Heat treatment of phosvitin solutions at ≥65°C led to decreased emulsifying activity (EA). The emulsion stability (ES) decreased when phosvitim solutioni were heated at 70, 80 or 96°C for up to 60 min. The ES was not affected (p < 0.05) for phosvitin solutions after heating at ≤67.5°C for up to 60 min.     

Antioxidant Efficacy of Oleoresin Rosemary and Sodium Tripolyphosphate in Restructured Pork Steaks

Thiobarbituric acid (TBA) analysis, sensory evaluation and hexanal content (frozen storage only) monitored lipid oxidation. STPP significantly (P<0.01) reduced lipid oxidation in cooked steaks during refrigerated storage (ε4°C) for 8 days, and in raw steaks stored at ? 30°C for 8 mo. Lipid stability was not enhanced by OR/STPP treatments compared to STPP treatments. Water-soluble OR/STPP did not result in significantly (P>0.05) greater lipid stability than oil-soluble OR/STPP treatments. Hexanal content significantly (P<0.01) increased after 8 mo frozen storage.     

SENSORY ATTRIBUTES AND THIAMINE CONTENT OF ROASTING CHICKENS COOKED IN A MICROWAVE, CONVECTION MICROWAVE AND CONVENTIONAL ELECTRIC OVEN

Fresh whole roasting chickens were cooked to an internal temperature of 79°C (175°F) in either a microwave, convection microwave or conventional electric oven. The sensory attributes of breast meat samples from chickens cooked in the three ovens were evaluated by untrained and laboratory panels. Untrained panelists found convection microwave cooked samples to be more acceptable in terms of juiciness than microwave cooked samples. Laboratory panelists rated the chicken cooked in the conventional oven as significantly more tender and juicy but similar in flavor intensity to chicken cooked in the microwave ovens. Thiamine retention on a dry weight basis ranged from 77% in conventionally cooked chicken breasts to 98% in microwave cooked chicken legs.     

Thermal Properties of Proteins in Chicken Broiler Tissues

The thermal behavior of breast and thigh muscles, blood and skin tissues of chicken broilers was evaluated by differential scanning calorimetry (DSC). Onset temperature of transition (T_o), maximum thermal transition (T_max) temperatures, and denaturation enthalpy (ΔH) were evaluated. Breast muscle exhibited a complex thermogram with five endothermic transitions at 57°C, 63°C, 67°C, 73°C, and 78°C at a heating rate of 10°C/min. Thigh muscle exhibited only three major transitions at 60°C, 66°C, and 76°C. Thermal curves of isolated protein fractions indicated that the thermal transitions in muscle corresponded to the denaturation of myosin, sarcoplasmic proteins, collagen and F-actin. An increase in the heating rate from 1.0° to 40°C/min significantly elevated the onset temperature of transition and major transition temperatures, as well as the enthalpy of denaturation. Enthalpy of the muscle system heated to various end-point temperatures, cooled and reheated, showed that myosin was completely denatured at 60°C, sarcoplasmic proteins at 70°C and actin at 80°C.     

EFFECT OF PHOSPHATE AND PECTIN ON QUALITY AND SHELF-LIFE OF MARINATED CHICKEN BREAST

Fresh split chicken breasts were injected with 5% sodium acid pyrophosphate (SAPP), 5% sodium tripolyphosphate (STPP), 2.5% Genu pectin (GENU), or the combination of 5% SAPP with 2.5% GENU and 5% STPP with 2.5% GENU. Calcium lactate (0.1 M) solution was sprayed on the surface of chicken marinated in pectin. Marinated samples were stored at 4C for 7 days to evaluate changes in the psychrotrophic bacterial count and quality. STPP injected chicken breast had highest (α=0.05) marinade pickup, net weight increase, cook yield and moisture content. SAPP injected chicken had intermediate marinade pickup, but lowest retention in the muscle among all treatments. Marinades with pectin or pectin combined with phosphate had lower pickup but higher marinade retention compared with SAPP injected breasts. The water holding capacity (WHC) of STPP and GENU injected cooked chicken breast was higher than SAPP injected samples or control. All marinated chicken breasts had significantly lower shear force than noninjected control. Neither phosphate nor pectin had a significant influence on microbial activity of marinated chicken.     

Thermal Properties of Yak α-Lactalbumin and β-Lactoglobulin: a DSC Study

A differential scanning calorimetry (DSC) method was used to investigate the denaturation temperature of yak α-lactalbumin (α-La), β-lactoglobulin (β-Lg), and a mixture of two proteins and the thermal properties of α-La and β-Lg in the presence of glucose, lactose, sucrose, NaCl, CaCl₂, and at various pH (4.0–10.0). The denaturation temperature (T _d) of α-La increased from 52.1 °C in the absence of β-Lg to 53.9 °C in the presence of β-Lg, while the T _d of β-Lg decreased from 81.4 °C in the absence of α-La to 79.9 °C in the presence of α-La. α-La was thermal stable in the range of pH 4.0–10.0, while β-Lg was more thermal stable in acidic pH than in alkaline pH. Sugars, Na⁺, and Ca²⁺ influenced the stabilization of the two proteins against thermal denaturation with greatly influenced for β-Lg. α-La kept reversibility in the presence of sugars, NaCl, CaCl₂, and over a wide pH range (4.0–10.0), with most of the reversibility values being greater than 90%. In contrast, β-Lg was completely irreversible whether in its native state or in the presence of the additives.     

Heat transfer modeling of chicken cooking in hot water

To calculate the slowest heating point and optimum cooking time of whole chicken cooking in hot water, a 2-dimensional heat transfer model was developed to predict temperature profile and history of the chicken cooked in hot water at 85, 90 and 95 °C. Chickens were divided into 12 sections and the heat transfer model was applied to each cross section. These models were solved with an I-DEAS program. Specific heat and thermal conductivity were measured at temperatures ranging from 25 to 95 °C. The temperature of chicken did not significantly affect the thermal properties. The average values of specific heat of white and dark meats were 3.521 and 3.654 kJ/(kg K), respectively, and the average thermal conductivity values were 0.5093 and 0.4930 W/(m K), respectively. The model was validated against experimental results, and provided an average root mean square error of 2.8 °C. Temperature distributions showed that the slowest heating point was deep in the breast part of the second cross section (3.6 cm far from shoulder) at the symmetric line of the chicken, around 2.1–2.5 cm deep from breast skin. For food safety consideration, the recommended cooking times, for whole chickens in weight range of 2.3–3.2 kg with different initial temperatures (5–30 °C), were around 74–84, 64–74 and 57–67 min for cooking temperatures of 85, 90, and 95 °C, respectively.     

Effects of sodium tripolyphosphate on functional properties of low‐salt single‐step high‐pressure processed chicken breast sausage

Influences of sodium tripolyphosphate (STPP) contents (0.1, 0.2, 0.3 and 0.4%) on water holding capacity (WHC) and texture properties of low‐salt (1.2% NaCl) single‐step high‐pressure processed chicken breast sausages (LSSS‐HPP sausages) were evaluated. Results showed that WHC was improved (4–5%) by the addition of STPP. However, the STPP contents customarily used for cooked sausages (0.3–0.5%) were excessive for LSSS‐HPP sausages, causing a soft and tacky texture. Sausages containing 0.1% of STPP had the best taste according to the sensory evaluations. Chemical interactions plus Raman spectroscopic analysis revealed that STPP addition partly changed native structures of myofibrillar proteins. Furthermore, higher STPP contents in the meat batter prevented those proteins from high pressure denaturing and aggregating in the subsequent single‐step HPP procedure. Increased hydrogen bonds and decreased hydrophobic interactions explained the better WHC and softer texture. Therefore, 0.1% of STPP is the optimal content in the processing of new‐type LSSS‐HPP sausages.     

Influence of Sodium Tripolyphosphate on the Binding and Antimicrobial Properties of Reduced NaCl-Comminuted Meat Products

The binding and antimicrobial properties of comminuted meat products were evaluated at varying levels of NaCl and of sodium tripolyphosphate (STPP). The meat batters were inoculated with Clostridium sporogenes spores (10/g) either before (cans) or after (vacuum packages) thermal (70°C) processing. Product binding was inferior when the NaCl level was reduced to 1.1% (50% reduction). STPP increased pH by 0.17-0.23 units and restored binding of low NaCl products. During storage (20°C) microbial growth and product spoilage were more rapid with decreasing brine level, irrespective of presence or absence of STPP.