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1.
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.  相似文献   

2.
This study investigated the effects of different cooking methods, namely water bath cooking (WB), short time ohmic cooking (STOH) and long time ohmic cooking (LTOH) on color, cooking loss, shear force value and proteome changes in beef M.longissimus dorsi at the same endpoint temperature of 72 °C. The cooking loss and shear force value of the ohmically cooked meat were significantly lower (P < 0.05) and redness a* value was significantly higher than that of the WB cooked samples. Proteomics analysis showed that ohmically cooked meat had less protein damage than those of WB cooked ones. Seventeen protein spots of differential abundance in two-dimensional gel electrophoresis (2-DE) image between STOH and WB cooked samples were successfully identified, and thirteen protein spots between LTOH and WB cooked samples were identified. Most of them belong to myofibrillar and sarcoplasmic proteins and may be related to changes of meat quality parameters.Industrial relevanceDuring thermal processing, proteins, the primary constituents of meat, undergo structural modifications such as oxidation, degradation, denaturation and aggregation. These changes of proteins have important effects on the quality of the final meat products, such as color, tenderness and flavor, and ultimately affect meat palatability and acceptability. Nowadays, innovation is necessary in developing new cooking methods to meet the industrial demand for more efficient production and consumer's demand for higher quality and safer meat products. Ohmic cooking, also known as electric resistance cooking, relies on the heat that is generated when electrical current passes directly through conductive foodstuff to cook the food. Compared to conventional cooking, ohmic cooking has the advantages of much shorter cooking time, higher yield and more uniform heating distribution, and ohmically cooked meat has superior color, higher tenderness, etc. Therefore, as a potential food processing technology, ohmic heating not only increases energy efficiency, but also improves meat quality. In this study, two-dimensional gel electrophoresis and tandem mass spectrometry were used to investigate the quality and proteome changes of beef M.longissimus dorsi following ohmic cooking and water bath cooking, and the results indicated that protein damages in ohmically cooked meat were much less than that of water bath cooked ones, and this might contribute to the lower cooking loss, higher tenderness and better color in ohmically cooked meat. The results of the study suggested that ohmic cooking has a great potential in industrial production of meat products.  相似文献   

3.
Restructured meat is made by binding individual pieces of meat together. To study the effect of mechanical work on the meat binding process, a standard cooking protocol must be established. This paper details the establishment of a standard cooking protocol for the cooking process using untreated beef semitendinosus muscle. The effect of different cooking temperatures and applied loads during cooking were investigated. Meat samples were cut in 20 mm cubes size from beef semitendinosus muscle and two pieces were held together with the muscle fibre parallel to each other by wrapping them with a plastic food wrap. Then the samples were placed inside square steel tubes, that act as a mold for cooking, and different weights (0, 250, 500, 750 and 1000 g) were placed on top of the meat cubes during cooking. The temperatures used for cooking were 60, 70 and 80 °C. There was a significant temperature effect, with increases noted between 60 °C and 70 °C and between 70 °C and 80 °C. At 60 °C neither myosin nor collagen has gelatinized, leading to low binding strengths. At 70 °C the myosin component will have gelatinized. At 80 °C the collagen component will be contributing to the bond. To keep the collagen effect to a minimum the meat should be cooked at 70 °C. The effect of applied cooking load was significant at all cooking temperatures once sufficient load had been applied against no load to ensure good contact at the joint. There was a significant effect of applied load noted at 80 °C with increases up to 750 g and a drop occurring between the 750 and 1000 g loadings. The drop has been attributed to collagen being squeezed out of the joint as a bead of white material was noted around the joint.  相似文献   

4.
《Meat science》2009,81(4):1205-1211
The influence of ageing and cooking on the Raman spectrum of porcine longissimus dorsi was investigated. The rich information contained in the Raman spectrum was highlighted, with numerous changes attributed to changes in the environment and conformations of the myofibrillar proteins.Predictions equations for shear force and cooking loss were developed from the Raman spectra of both raw and cooked pork. Good correlations and standard errors of prediction were obtained for both WB shear force and cooking loss, with the raw and the cooked samples showing almost identical results R2 = 0.77, root mean standard error of prediction (RMSEP)% of mean = 12% for shear force; R2 = 0.71, RMSEP% of mean = 10% for cooking loss. The Raman spectra were also able to predict the extent of cooking that occurred within the pork (R2val = 0.94, RMSEP% of range = 5.5%).Raman spectroscopy has considerable potential as a method for non-destructive and rapid determination of pork quality parameters such as tenderness. Raman spectroscopy may provide a means of determining changes during cooking and the extent to which foods have been cooked.  相似文献   

5.
《Meat science》2010,84(4):651-656
Accumulation of fluorescent pigments in cooked bovine meat (M. Longissimus thoracis) was studied in relationship with the heating parameters (time and temperature). Muscles were aged at 4 °C for 11 days under vacuum before cooking. Meat cooking was performed by applying jets of steam. Three different heating treatments were tested: two with constant surface temperatures of 65 and 96 °C for 300 s, and one with a continuously increasing surface temperature up to 207 °C. After extraction in water/dichloromethane/ethanol, fluorescence pigments were distributed between the apolar phase (emission 420–440 nm after excitation at 360 nm) and the polar phase, where two emission peaks were seen (emission 410–430 and 515 nm after excitation at 360 nm). Fluorescence in the two phases was little affected by heating at the two constant temperatures while it increased exponentially after 1 min of treatment, as the varying temperature reached 141 °C. The maximum fluorescence increases, measured in the extreme conditions of cooking (207 °C/300 s), were of 5000% in the apolar phase and 1700% in the polar phase. Thiobarbituric acid reactive substances (TBARS) and protein carbonyls were measured in parallel. The correlations between these two parameters and the fluorescence emission demonstrated that the interaction between proteins and aldehyde products of lipid peroxidation was mainly involved in the production of fluorescent pigments in cooked meat.  相似文献   

6.
《Meat science》2007,75(4):644-647
In this investigation, the effect of cooking treatments (60 min at 150 °C, 40 min at 200 °C, and 20 min at 250 °C) on aluminium contents of meats (beef, water buffalo, mutton, chicken and turkey) baked in aluminium foil were evaluated. Cooking increased the aluminium concentration of both the white and red meats. The increase was 89–378% in red meats and 76–215% in poultry. The least increase (76–115%) was observed in the samples baked for 60 min at 150 °C, while the highest increase (153–378%) was in samples baked for 20 min at 250 °C. It was determined that the fat content of meat in addition to the cooking process affected the migration of aluminium (r2 = 0.83; P < 0.01). It was also found that raw chicken and turkey breast meat contained higher amounts of aluminium than the raw chicken and turkey leg meat, respectively. Regarding the suggested provisional tolerable daily intake of 1 mg Al/kg body weight per day of the FAO/WHO Expert Committee on Food Additives, there are no evident risks to the health of the consumer from using aluminium foil to cook meats. However, eating meals prepared in aluminium foil may carry a risk to the health by adding to other aluminium sources.  相似文献   

7.
The relationship between the activities of endogenous enzymes in milled rice and accumulation of chemical components in the rice grains during cooking was investigated. Maltose and soluble starch were optimally hydrolyzed around 60 °C by both crude extracts and purified α-glucosidases of milled rice. Gelatinization onset temperature of rice flour was determined to be 63 °C with DSC analysis under usual cooking condition. Hydrolytic activities on carbohydrates and proteolytic activities of milled rice were enhanced at pH 5 compared to pH 7 at the range of 4–80 °C. When rice was cooked at pH 5, glucose and amino acids highly accumulated with soaking for 16 h before heating. We propose a new method of cooking with prolonged soaking at acidic pH, which is effective for increasing the amounts of chemical components in cooked rice.  相似文献   

8.
《Food microbiology》1998,15(4):367-378
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 g1)or high (105 cfu g1)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 g1less 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.  相似文献   

9.
《LWT》2005,38(2):111-118
Hamburger patties are prepared from ground beef and cooked to obtain a safe product before consumption. Cooking process eliminates microbial hazards and results in certain quality changes (e.g., cooking loss, textural changes). All these changes can be used as an objective function to achieve an optimum cooking process, but their effects on decision variable (e.g. process temperature profiles) of the optimization should be known. The use of different objective functions (minimization of cooking losses, hardness, chewiness, and shear to work) was compared to see their effects on plate temperature profiles for double-sided contact cooking. Modified Complex Method was applied as the optimization procedure. Lower and higher limits of grill temperatures (177–220°C) were explicit constraints while lethality and temperature at the patties center (F0⩾15 s; Tc⩾71°C) were implicit constraints. The objective functions and implicit constraints were determined using a previously developed numerical heat transfer simulation model. Constant temperature profiles (decision variables) for different objective functions at different processing times (121 and 130 s) were determined. Same decision variables were found regarding the different objective functions (198.3°C and 184.1°C) for the given processing times.  相似文献   

10.
《Food microbiology》2005,22(4):321-327
Substantial numbers of aerobic bacteria but few coliforms or Listeria spp. and no Escherichia coli were recovered from both swab samples and brines circulated in cleaned equipment used for injecting pork loins. After meat was processed for 30 or 60 min, the numbers of aerobic bacteria in brines had increased by >1 log unit, to about 4.5 log cfu ml−1, but coliforms were <2 and E. coli and Listeria spp. were <1 log cfu ml−1. The numbers of bacteria on the surfaces of pork loins before and after injection of the meat were similar. No bacteria were recovered from the deep tissues of the uninjected meat, but aerobic bacteria were recovered at log-mean numbers of 2.1 log cfu g−1 and coliforms at log-total numbers of 1.2 log cfu 25 g−1 from 25 samples of deep tissues of injected meat. Aerobic bacteria were recovered at log total numbers of 1.0 log cfu 25 g−1 from 25 samples of injected pork cooked to a central temperature of 61 °C, but no bacteria were recovered from the deep tissues of meat cooked to 70 °C. The findings suggest that moisture-enhanced pork cooked to a medium rare condition can be microbiologically safe.  相似文献   

11.
The study was aimed to evaluate the physicochemical effects of three cooking methods i.e. sous-vide (SV), cook-vide (CV) and traditional cooking (TC) on carrots and green peas. SV and CV were performed at 60–90 °C for various time periods (SV: green peas 50–100 min, carrots 90–150 min; CV: green peas 30–70 min, carrots 20–60 min) with respect to peroxidase test. These vegetables were also cooked at atmospheric pressure for 15, 30, 45 and 60 min and the results were compared with those obtained from SV and CV. Antioxidant activity, total phenolic and vitamin C analyses reflected less harm to the green peas in CV as compared to SV and TC. However, carrots were approximately half degraded during SV than in CV and TC as shown by the antioxidant activity. Moreover, total phenolic content of carrots was highly protected when cooked in SV method. The color change values (∆ E) of green peas were slightly lower in TC when compared to CV and SV, while in carrots, they were very close to each other's in all three methods. CV-cooked green peas and carrots provided the highest general acceptance for the sensorial properties. As a conclusion, TC had more adverse effects on the quality characteristics on green peas and carrots.  相似文献   

12.
《Food microbiology》2005,22(1):47-52
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.  相似文献   

13.
Water absorption as a new method of cooking quality (hard cooking or mealy cooking) of yam and cassava cultivars determination was studied by cooking eight (08) cultivars. 30 g of each were boiled in 500 ml of water during 20 minutes and dried at 70 °C for 15 hours and 103 °C for 3 hours in a vacuum oven. Results showed that cassava and yam have different cooking quality. Dry matter content does not influence the cooking quality of yam and cassava. Mealy cooking quality of yam absorbs less water (6.6%) during cooking but looses more soluble dry matter (9.5%) during the same process. Hard cooking quality of yam absorbs much water (23.5%), but looses less soluble dry matter (3.9%). The soluble dry matter is the main parameter to determine the quality of D. alata. It stands at 9.5% ± 2.9 for mealy cooking quality and 3.9 ± 0.73 for hard cooking quality cultivars of D. alata. Water absorbed by mealy cooking cassava (27.6%) is significantly (p < 0.05) higher compared to water absorbed of hard cooking cassava (12.4%). Water absorbed during cooking is the main parameter in determining the quality of cassava cultivars. Water absorbed stands at 27.6% ± 8.8 for mealy cooked quality and 12.4% ± 1.9, for hard cooked quality of cassava cultivars. A close relation between water absorption and cooking quality was revealed to contribute to a better selection procedure for cultivars in the frame of food security.  相似文献   

14.
High pressure–low temperature (HPLT) processing was investigated to achieve Escherichia coli O157:H7 inactivation in non-intact, whole muscle beef while maintaining acceptable quality characteristics. Beef semitendinosus was internally inoculated with a four strain E. coli O157:H7 cocktail and frozen to − 35 °C, then subjected to 551 MPa for 4 min (HPLT). Compared to frozen, untreated control (F), HPLT reduced microbial population by 1.7 log colony forming units (CFU)/g on selective media and 1.4 log on non-selective media. High pressure without freezing (551 MPa/4 min/3 °C) increased pH and lightness while decreasing redness, cook yield, tenderness, and protein solubility. Aside from a 4% decrease in cook yield, HPLT, had no significant effects on quality parameters. It was demonstrated that HPLT treatment reduces internalized E. coli O157:H7 with minimal effect on quality factors, meaning it may have a potential role in reducing the risk associated with non-intact red meat.Industrial relevanceIn the current work, high pressure (551 MPa, 4 min) was applied to beef semitendinosus while it was at subfreezing temperatures (<− 30 °C). Most studies utilizing this high pressure–low temperature (HPLT) process employ subzero capable thermostatic high pressure equipment, which currently has no commercial equivalent. Successful HPLT runs were completed in this study using more conventional temperature control (1–3 °C) on pilot scale (20 L) high pressure processing equipment. The process yielded E. coli O157:H7 reductions of 1.4–1.7 log colony forming units (CFU)/g, which, while lower than conventional high pressure processing (HPP), may be sufficient to eliminate O157 populations typical of non-intact, whole muscle beef. Various quality factors, including color, purge losses and cooked tenderness, were unaffected by HPLT, while an equivalent HPP process at nonfreezing temperatures (551 MPa, 3 °C) induced color change (loss of redness), increased cook losses and decreased cooked tenderness compared to the control and HPLT beef. Producers of non-intact, whole muscle (blade tenderized or brine injected) meat, especially those that ship and sell frozen products, may look to HPLT processes to improve food safety.  相似文献   

15.
《Meat science》2013,93(4):409-416
In this work, the effect of pre-incubation conditions (temperature: 10, 15, 37 °C; pH 5.5, 6.5 and water activity, aw: 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 aw (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 aw 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/aw 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.  相似文献   

16.
After being cooked, newly harvested brown rice becomes a pasty mass and swells only slightly. To modify these undesirable brown rice properties, the paddy needs to be stored for at least 3–6 months. However, problems arise since brown rice has short shelf-life (3–6 months) due to accumulation of free fatty acids (FFA) leading to rancidity during storage. In the present study, high-temperature fluidized-bed drying technique in combination with tempering step was tested to alleviate the above-mentioned problems. The quality of rice dried at temperatures of 130 and 150 °C and tempered for 30 up to 120 min was compared to that of brown rice stored at ambient temperature (approximately 30 °C) for 7 months. The experimental results showed that the cooking and eating properties of the fluidized bed dried brown rice, i.e., hardness, solid loss, volume expansion and elongation ratio, changed in a similar fashion to those of the conventionally aged brown rice. The drying temperature and tempering time affected significantly the brown rice properties. The texture of cooked thermally treated brown rice was significantly firmer than that of the conventionally aged brown rice. In addition, it was found for the thermally treated brown rice that the contents of free fatty acids increased only slightly during storage while the glycemic index reduced from high to low-medium level.  相似文献   

17.
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.  相似文献   

18.
Radio frequency (RF) cooking is a form of dielectric heating in which products are heated by subjecting them to an alternating electromagnetic field between two parallel electrodes. Although similar in some respects to Microwave heating, RF has been proposed to be more suitable for industrial heating of meats because of the greater penetration depths possible with this technology. In this study an RF cooking protocol was developed and its effect on selected quality attributes of pork based white pudding was examined. Whilst cooking of the product in air proved unfeasible due to arcing, use of a polyethylene cell with circulating hot water (80 °C) facilitated successful heating of the product. Application of RF using an optimised cooking protocol (RF power = 450 W, cell volume = 500 ml and continuous circulation) resulted in a mean end-point temperature of 73 °C after 7 min 40 s. Similar mean end-point temperatures in water bath and steam oven heated products were achieved after 29 and 33 min, respectively. A factorial experiment was conducted to assess selected quality attributes of the cooked puddings. Results show that RF heated puddings were not significantly different (P > 0.05) from water bath and steam oven heated products with regard to instrumental colour, instrumental texture (Kramer shear and texture profile analysis) and expressible fluid. Furthermore, results of a sensory similarity test involving 60 panellists indicated that panellists were not able to detect differences between puddings cooked by RF and conventional methods. Overall this suggests that RF heating technology could have potential in pasteurisation of meat products though further work is needed to verify this.  相似文献   

19.
Comminuted and gelled, fat-containing meat products such as frankfurters and luncheon meats are commercially processed by heating relatively slowly (for up to 2 h or more) to an endpoint of about 70 °C prior to cooling. This study compared such a slow, ramp heating regime (0.5 °C/min), terminated at 70 °C, to rapid, square-wave cooking (one step: rapid 100 °C/min heating to 70 °C endpoint, plus isothermal holding prior to cooling, or two-step: rapid heating to 50 °C, holding, then rapid heating to 70 °C plus holding prior to cooling) on meat batter gel properties (fracture and small strain rheology, microstructure, cook loss, and expressible water). The results indicated that a rapid cooking process, with its inherent advantages of reduced process time, lower equipment footprint, and more efficient use of energy, can produce a product nearly equivalent in textural properties and cook yield to one processed by traditional smokehouse cooking when the cook value of the processes is similar and an intermediate (near 50 °C) holding step is included (two-step rapid heating). One-step rapid heating negatively affected gel structural homogeneity and water/fat holding properties of fat-containing gels.  相似文献   

20.
Since 2002, it has been well-known that carbohydrate-rich foods have a high level of acrylamide (AA). Some researchers have drawn attention on the formation of AA in coated and fried chicken meat products in recent years. From this viewpoint, the purpose of the present study was to mitigate acrylamide formation in fried chicken drumsticks (CDs) and chicken wings (CWs) using green tea extract (GTE) alone or combined with microwave pre-cooking (MPC) by decrease frying time. In brief, CDs and CWs marinated for one day were divided into eight groups. Four of those were first covered with batter and breading, including 0%, 0.5%, 1.5% and 3% GTE and deep fried in fat for 8.5 min for CDs and 3.5 min for CWs at 175 °C and 8 psi of pressure. In the second step, the remainder of the marinated CDs and CWs were subjected to MPC for 7 min and 5 min, respectively. Then, they were covered with batter and breading including 0%, 0.5%, 1.5% and 3% GTE and deep fried in fat for 5.5 min for CDs and 2.5 min for CWs at 175 °C and 8 psi for pressure. With increasing levels of GTE, the AA concentration decreased gradually in CDs and CWs. In addition, MPC also decreased AA formation in CWs due to the shorter frying time. Moreover, MPC was more efficient at reducing AA formation in CWs when it was combined with GTE. A lighter and more yellowish color was measured in CDs as a consequence of the shorter frying time. It is crucial to state that the incorporation of GTE into the breading or MPC did not negatively affect the sensory properties of CDs and CWs, while it reduced AA formation. In conclusion, it can be stated that GTE alone or combined with MPC is an effective and practical mitigation strategy for AA formation.  相似文献   

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