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1.
The effect of slurry ice on the quality of Skipjack tuna (Katsuwonus pelamis) during chilling storage was investigated and compared to flake ice. Slurry ice‐treated samples showed significantly higher springiness and chewiness variables than the blank and flake ice‐treated samples (P < 0.05). The growth of microorganisms in tuna muscle treated with slurry ice was also down significantly (P < 0.05), and the total aerobic counts didn't reach higher scores than 5.0 log CFU/g during the whole chilling storage. Additionally, the myofibrillar protein, Ca2+‐ATPase activity, and total sulfydryl (SH) content in muscle treated with slurry ice were all significantly higher than the blank and flake‐iced samples (P < 0.05). This was probably due to the faster cooling, subzero final‐temperature, and larger heat exchange derived from slurry ice. Standard error of mean and sodium dodecyl sulfate–polyacrylamide gel electrophoresis results also confirmed that slurry ice treatment could effectively retard the degradation of myofibrillar proteins and showed a positive effect on the stability of tissue structures.  相似文献   

2.
The influence of iced storage of two species of bigeye snapper, Priacanthus tayenus and P macracanthus, on the gel‐forming ability of the resulting surimi was investigated. Upon iced storage, whole fish underwent deterioration faster than beheaded/eviscerated fish. Total volatile base and trimethylamine contents of whole fish were higher than those of beheaded/eviscerated fish, particularly after 9 days of storage (P < 0.05). P macracanthus muscle was more susceptible to proteolytic degradation than P tayenus muscle. Ca2+‐ATPase activity decreased as the storage time increased (P < 0.05), indicating the denaturation of myosin. A marked decrease in Ca2+‐ATPase activity was found in whole fish kept for more than 6 days in ice (P < 0.05). Breaking force and deformation of surimi gels from both species decreased, with a concomitant decrease in whiteness, as the storage time increased (P < 0.05). Beheading and evisceration of fish retarded the deterioration. However, the gel‐forming ability of surimi produced from both species decreased continuously throughout iced storage (P < 0.05), probably owing to the denaturation and degradation of myofibrillar proteins. © 2002 Society of Chemical Industry  相似文献   

3.
Carbon monoxide (CO) has been used to stabilize the color of fish muscle during frozen storage and distribution. This study compared changes in the quality profiles of CO‐treated and untreated (UT) tilapia fillets stored at 21 to 22 °C (room temperature), 4 to 5 °C (refrigerated), and 0 °C (iced). Samples (n = 3) were analyzed at different time intervals for chemical, lipid oxidation, microbiological, color, and expert sensory profiles. CO samples contained greater (P < 0.05) apparent ammonia and total volatile base nitrogen (TVB‐N) at day 0, with greater (P < 0.05) TVB‐N throughout refrigerated and iced storage. At time 0, peroxide values (POV) and thiobarbituric‐acid‐reactive substances were lower (P < 0.05) for CO samples and continued to have lower trends throughout all storage temperatures. Microbiological analysis at time 0 did not show any differences between UT and CO samples. Redness (a*) color values were greater (P < 0.05) in CO tilapia at time 0; however, treated product showed a more rapid decline in a* throughout all storage temperatures. While expert sensory evaluation showed no statistical differences between UT and CO tilapia at time 0, CO product failed sensory assessment sooner than UT product when stored refrigerated and in ice.  相似文献   

4.
Cobia (Rachycentron canadum) steaks held in cold store (?18 °C) were analysed aseptically in triplicates for the sensory, total aerobic bacterial count, proximate composition, pH, thiobarbituric acid‐reactive substance (TBA‐RS), formaldehyde, total volatile base nitrogen (TVB‐N), trimethyl amine‐nitrogen (TMA‐N), salt soluble nitrogen (SSN), nonprotein nitrogen (NPN), sodium dodecyl sulphate‐poly acrylamide gel electrophoresis (SDS‐PAGE) pattern. Steaks were sensorially acceptable up to 5 months of storage and the total bacterial counts did not exceed 6 log CFU counts. There were no significant changes in the pH values. TBA‐RS values increased significantly (P < 0.05) and reached 7.34 mg of malonaldehyde kg?1 fat at the end. Formaldehyde content remained constant upto 4th month and later increased to 2.06 μg g?1 (P < 0.05). TVB‐N and TMA‐N values did not exceed the acceptable limits. NPN contents showed no change, while SSN contents increased to 1.24% after 5 months. SDS‐PAGE pattern indicated no protein denaturation in the fish tissue. Results indicated that TBA‐RS value can only be considered as the valuable indicator in determining the quality of fish steaks held in cold stores.  相似文献   

5.
BACKGROUND: Sea urchin gonads are highly valued seafood that degenerates rapidly during the storage period. To study the influence of dissolved oxygen concentration on quality changes of sea urchin (Strongylocentrotus nudus) gonads, they were stored in artificial seawater saturated with oxygen, nitrogen or air at 5 ± 1 °C for 12 days. RESULTS: The sensory acceptability limit was 11–12, 6–7 and 7–8 days for gonads with oxygen, nitrogen or air packaging, respectively. Total volatile basic nitrogen (TVB‐N) values reached 22.60 ± 1.32, 32.37 ± 1.37 and 24.91 ± 1.54 mg 100 g?1 for gonads with oxygen, nitrogen or air packaging at the points of near to, exceeding and reaching the limit of sensory acceptability, indicating that TVB‐N values of about 25 mg 100 g?1 should be regarded as the limit of acceptability for sea urchin gonads. Relative ATP content values were 56.55%, 17.36% and 18.75% for gonads with oxygen, nitrogen or air packaging, respectively, on day 2. K‐values were 19.37%, 25.05% and 29.02% for gonads with oxygen, nitrogen or air packaging, respectively, on day 2. Both pH and aerobic plate count values showed no significant difference (P > 0.05) for gonads with the three treatments. CONCLUSION: Gonads with oxygen packaging had lower sensory demerit point (P < 0.05) and TVB‐N values (P < 0.05), and higher relative ATP content (P < 0.01) and K‐values (P < 0.05), than that with nitrogen or air packaging, with an extended shelf life of 4‐5 days during storage in artificial seawater at 5 ± 1 °C. Copyright © 2011 Society of Chemical Industry  相似文献   

6.
Filleting effect of refrigerated bonito with and without ice on the quality changes and food safety was investigated. Significant variations occurred (P < 0.05) in sensory, chemical and microbiological values amongst groups. The best sensory results were found for filleted bonito with ice (FBRI) with a shelf‐life of 13 days. While sensory values decreased significantly during storage, opposite situation occurred for both chemical and microbiological results (P < 0.05). The lowest total volatile basic nitrogen value was also observed with FBRI and was within the acceptable levels for 15 days as 17.86 mg 100 g?1. All samples contained acceptable trimethylamine levels for 15 days despite unacceptable sensory values after certain days. Although filleting seemed to increase the lipid oxidation, ice application resulted in lowering thiobarbituric acid content. Histamine results closely supported sensory values in terms of legally permitted levels usually by set FDA. While WBR contained histamine value over EU permitted level as 113.78 ppm on the 7th day, the value for FBRI was 56.13 ppm on the 15th day. Histamine‐forming bacteria counts supported histamine formation in most groups, while total bacteria counts were in agreement with sensory results. This study suggests that using ice and filleting can improve shelf‐life of bonito stored at refrigerated temperatures in terms of food quality and safety.  相似文献   

7.
Ice storage of dressed pink perch (Nemipterus japonicus) and Indian oil sardine (Sardinella longiceps) for 16 and 20 days, respectively, resulted in a decrease in emulsifying capacity (EC), protein solubility (PS), relative viscosity (RV) of salt‐soluble proteins (SSP) and water‐soluble proteins (WSP), water binding capacity (WBC) in terms of absorbed moisture in water (AMw), absorbed moisture in brine lpar;AMb), retained moisture in water (RMw) and retained moisture in brine (RMb), WSP and SSP, and increase in cook loss (CL). Decrease in protein solubility influenced the EC, RV, CL and WBC in both the species of fish. Significant (P<0.05) correlations existed among various functional properties analysed, in both the fishes during the ice storage. © 1999 Society of Chemical Industry  相似文献   

8.
Effect of lucerne preservation method on the feed value of forage   总被引:1,自引:0,他引:1  
BACKGROUND: Natural climatic wilt (NCW) and induced industrial wilt (IIW) are widely used as preservation methods for lucerne. Both of these methods reduce the quality of green forage due to respiration under NCW and heat damage under IIW. We compared the influence of these two preservation methods on nutritive value across a wide range of harvest conditions. RESULTS: Cell wall content and cell wall‐linked nitrogen values were higher (P < 0.05) in IIW than NCW. The preservation methods differed significantly (P < 0.05) in terms of soluble fraction, insoluble potentially degradable fraction of dry matter and effective degradability of dry matter. Nitrogen disappearance kinetics showed that the interactions of preservation by cut and preservation by phenological state were significant for the effective degradability of nitrogen. Organic matter digestibility was higher in lucerne preserved by NCW than IIW whereas cell wall digestibility was higher in lucerne preserved by IIW than NCW. Digestible organic matter intake did not differ between preservation methods (P > 0.05). CONCLUSION: Natural climatic wilt forage hay presents similar feed value to the induced industrial wilt alfalfa. Copyright © 2009 Society of Chemical Industry  相似文献   

9.
ABSTRACT: Changes in physicochemical and dynamic viscoelastic properties of ribbonfish ( Trichiurus spp) meat during different periods of ice storage were investigated. The differential scanning calorimetry profile of fresh ribbonfish meat revealed transitions at 33.17 °C, 48.85 °C, and 60.96 °C, indicating denaturation temperature of different protein fractions. The effect of cornstarch or tapioca starch at 9% level on the viscoelastic properties of ribbonfish meat stored in ice for different periods was also evaluated. Total volatile basic nitrogen (TVBN) increased significantly ( P < 0.05) during ice storage for 24 d. However, the myosin heavy chain concentration was unaltered during the ice storage period, as revealed by sodium dodecyl sulphate-polyacrylamide gel electrophore-sis (SDS-PAGE) pattern. A significant ( P < 0.05) decrease in protein solubility (in phosphate buffer 50 m M , pH 7.5, containing 1 M NaCl), calcium-activated adenosine triphosphatase (ATPase) activity, and an increase in reduced viscosity at a protein concentration of 5 mg/mL was observed after 10 d of ice storage indicating protein denaturation and aggregation. The addition of tapioca and cornstarch enhanced storage modulus values of fresh ribbonfish meat. The gelatinization temperature of tapioca starch solution was found to be in the range of 60 °C to 65 °C and for cornstarch 67 °C to 70 °C, as revealed by the differential scanning calorimetry (DSC) profile and dynamic rheological testing. The viscoelastic properties of ribbonfish meat was altered significantly ( P < 0.05), both due to the addition of starch and ice storage period as revealed by frequency sweep of prepared gels.  相似文献   

10.
Caseinmacropeptide (CMP) is a C‐terminal glycopeptide released from κ‐casein by the action of chymosin during cheese‐making. It is recognised as a bioactive peptide and is thought to be an ingredient with a potential use in functional foods. CMP occurs in sweet cheese whey and whey protein concentrate (WPC). Its composition is variable and depends on the particular whey source and the fractionation technology employed in the isolation. There were no significant (P < 0.05) differences in the relative apparent viscosities between species of CMPs (cow, ewe and goat). Analyses at different pH (2, 4, 7, 10), ionic strength (0, 0.2, 0.4 and 0.7 as NaCl molarity) and protein concentration (50, 100 and 200 g kg?1) at temperatures from 10 to 90 °C carried out found pH 7 and high protein concentration (200 g kg?1) conditions to be the best for CMP solutions to keep low and constant relative viscosity values with increasing temperature up to 75 °C. The viscoelastic properties–storage modulus, loss modulus and phase angle–of the different CMPs and WPC solutions were determined. Heat‐induced rheological changes in CMP solutions occurred at moderate temperatures (40–50 °C) with no appreciable differences in viscosity. Gelation took place significantly (P < 0.05) earlier in goat CMP (41 °C), followed by cow CMP (44 °C), ewe CMP (47 °C) and WPC (56 °C). Heating at 90 °C showed that WPC required significantly (P < 0.05) longer times to form gels (>5 min) than the CMPs (<5 min). WPC gels had higher (>20°) phase angle than CMP (<20°), which could be associated with untidy structures, limiting elastic properties of the gel. Copyright © 2006 Society of Chemical Industry  相似文献   

11.
This study aimed to determine effects of setting condition, fish freshness and storage time of frozen surimi on properties of red tilapia surimi gel. To investigate the effect of setting condition, a combination of eight setting temperatures (35–70 °C) and four setting times (30–120 min) was used. Maximum breaking force, deformation and gel strength were obtained after the gel had been set at 40 °C for 90 or 120 min. Setting at 65 °C resulted in the lowest obtained gel strength, because of proteolytic degradation of myosin heavy chain. Increasing storage time of raw fish material in ice caused a significant decrease in gel strength of the resultant surimi gel (P < 0.05). Gels produced from surimi kept in frozen storage for up to 9 months also exhibited reduced gel strength, with a concomitant increase in the expressible drip, with increasing storage time (P < 0.05).  相似文献   

12.
Effects of furcellaran, powder (FURP) and solution (FURS), incorporation (2-8% based on surimi solid content) on gel properties of sardine (Sardinella albella) surimi were investigated. Breaking force, hardness, gumminess, chewiness, and whiteness of gels increased with increasing FURP or FURS contents (P < 0.05), where the highest values were observed in gel containing 8% FURS (P < 0.05). Expressible moisture content of gel decreased as levels of furcellaran increased (P < 0.05). The gel deformation, springiness, and cohesiveness were not affected by furcellaran (P > 0.05) as well as the polymerization of myosin heavy chain as visualised by SDS-PAGE. FURP and FURS could enhance the interconnection between chains during heating as indicated by the higher G′. Addition of furcellaran, especially FURS, up to 6% increased sensory property of resulting gel (P < 0.05). Anywise, an abatement in overall likeness score was found in gel with 8% FURS. Finer and denser microstructural network was observed in gel containing 6% FURS when compared to control. Therefore, furcellaran, prepared as solution, at an appropriate level can improve the overall quality of sardine surimi.  相似文献   

13.
Effect of turmeric and lemongrass essential oils (Eos) and their mixture on quality of green mussel stored at 4 °C was investigated. The mixture of 0.25% turmeric and 0.25% lemongrass Eos could lower microbiological and chemical deterioration of mussel as evidenced by the lower microbial counts, total volatile base, ammonia, trichloroacetic acid‐soluble peptide contents and thiobarbituric acid‐reactive substances, compared with the control (P < 0.05). It indicated that a mixture of turmeric and lemongrass Eos in mussel showed synergistic effect on the retardation of bacterial growth and lipid oxidation. However, samples treated with 0.5% lemongrass oil exhibited the higher likeness score for odour and flavour, compared with the samples treated with other Eos throughout the storage of 15 days. Samples treated with turmeric essential oil caused the changes in odour and flavour. Therefore, lemongrass treatment was shown to be the promising means to prevent the deterioration and maintain the odour and flavour attributes of mussel during prolonged refrigerated storage.  相似文献   

14.
Abstract: The biogenic amines (tyramine, histamine, cadaverine, and puterscine) and microbiological properties (mesophilic, psychrotrophic, and Pseudomonas spp.) of whole pike‐perch (Sander lucioperca) was investigated during 2 d prestorage icing and 90 d frozen storage (−24 °C). At the end of ice storage, a noticeable increase only was found for puterscine level (P < 0.05), and microbial loads of fish increased in comparison with fresh fish (P < 0.05). During the frozen storage, as time passed, a continuous increase of biogenic amines and decrease of bacterial load (except for Pseudomonas spp. at the last 30 d) was detected (P < 0.05). The total contents of biogenic amines ranged from 6.24 to 91.76 μg/g during the investigated period. Puterscine was the major amine detected in pike‐perch and its concentration varied between 1.75 and 56.95 μg/g; due to a more step‐wise increase it was a good quality indicator. At the end of storage, all of the obtained values are below the tolerable maximum amounts based on available regulations. Based on biogenic amines content and microbial load, it could be concluded that pike‐perch can be consumed without any health risks after 2 d icing condition and 90 d frozen storage. Practical Application: Biogenic amines as one of the commonest forms of food intoxication occur in protein‐rich food such as fish. Short‐time icing during transportation is the simplest method to fish preserving for processing or long‐term storage. In this study formation of biogenic amines and bacterial changes in ungutted pike‐perch as highly demanded fish species for human consumption, during transportation and frozen storage was investigated. The results of the research can be advantageously used by fish industry. These findings suggest that the production and storage practices of fish in the retails condition could have acceptable food quality level.  相似文献   

15.
A storage study of deep‐fat‐fried banana chips was carried out for 8 weeks at ambient temperature (27 °C), using four types of packaging material: laminated aluminium foil (LAF), oriented polypropylene (OPP), polypropylene (PP) and low‐density polyethylene (LDPE). The physicochemical and sensory characteristics of the stored banana chips were analysed at weeks 0, 2, 4, 6 and 8. The quality parameters determined were moisture content, water activity (aw), thiobarbituric acid‐reactive substances (TBARS), texture (breaking force), colour and sensory attributes. The moisture content, aw, TBARS and breaking force values of all samples increased during storage. The colour also changed during storage, showing higher L and lower a and b values. Samples packed in LAF had the lowest moisture content, aw, TBARS and breaking force values. The most notable sensory change that occurred during storage was a decrease in crispness. Samples packed in LAF had higher scores than the other three samples, whilst LDPE gave the lowest scores for crispness as well as product colour. There were no significant differences (P > 0.05) in rancid odour among samples packed in OPP, PP and LDPE. However, there were significant differences (P < 0.05) between samples packed in LAF and the other three samples, with LAF giving the lowest rancid odour. © 2002 Society of Chemical Industry  相似文献   

16.
Effect of freezing and frozen storage on gel‐forming ability of muscle from fresh water fish, common carp (Cyprinus carpio), was investigated. Fresh carp meat had good gel‐forming ability as revealed by large strain test (gel strength of 1027 g·cm) and dynamic viscoelastic behavior. Freezing and frozen storage at ?18C for 180 days significantly (P < 0.01) reduced the gel‐forming ability of common carp meat. Reduction in protein solubility and calcium‐activated adenosinetriphosphatase enzyme activity of common carp meat during frozen storage was also significant (P < 0.05). Structural change of proteins during frozen storage was evident from reduced viscosity and gel filtration profile. Higher drip loss and reduction in gel‐forming ability of carp meat is attributed to denaturation of proteins during frozen storage.  相似文献   

17.
The effect of four different gas mixtures on several characteristics of Merino fresh lamb meat quality was studied. Merino lamb meat was packed under four different atmospheres (Batch 1: Ambient air; Batch 2: 70% O2 + 30% CO2; Batch 3: 80% O2 + 20% CO2 and Batch 4: 30% CO2 + 69.6% Ar + 0.4% CO) and stored in darkness and under refrigeration (3 ± 1 °C) for 12 days. pH values and weight losses of lamb meat showed no significant changes during 12 days storage (P > 0.05) and were not affected by the different used atmospheres (P > 0.05). Lightness (L*) was not significantly affected by gas atmospheres until day 12 of storage, lamb meat packed in contact with air (Batch 1) showing the lowest lightness (P < 0.001). Samples in contact with ambient air, presented the lowest a*‐values during most of the storage period (P < 0.001). Batch 4 (30% CO2 + 69.6% Ar + 0.4% CO) showed the highest a*‐values after 7 days storage. Batches 2, 3 and 4 presented a lower microbial count of total aerobic bacteria and Enterobacteriaceae than batch 1 (P < 0.05), whereas for lactic acid bacteria counts there were not significant differences (P > 0.05).  相似文献   

18.
Ganxet protein isolates (GPI) were assessed for antioxidant and functional properties including emulsifying and foaming capacity. The protein content and water activity (aw) value of GPI were 91.08 ± 4.15% and 0.248 ± 0.008%, respectively. The oil- and water-holding capacities of GPI were calculated as 2.76 ± 0.33 and 1.25 ± 0.11 g g−1 of GPI, respectively (P < 0.05). Foaming and emulsifying properties were found to be pH-dependent (P < 0.05). The highest foaming capacity values were observed at pH 8.0 and 10.0 and were calculated as 86.25 ± 5.30% and 78.75 ± 1.77%, respectively. In addition, the generated emulsions were found to be stable, especially at pH 8.0 and 10.0 with emulsion stability values of 94.1 ± 0.0 and 93.9 ± 0.1, respectively (P < 0.05). Results obtained in the current study demonstrate the potential applications of Ganxet-derived proteins as techno-functional ingredients for the development of novel foods.  相似文献   

19.
Ultrasound-assisted freezing (UF) has proven to be a method that can effectively increase the freezing rate of frozen food and improve its quality. The functional properties of myofibrillar proteins (MP) are important factors that affect the further processing quality of meat products. At present, the effect of UF on the functional properties of frozen MP is not yet clear. Therefore, in the present study, changes in the functional properties (emulsifying and gel properties) of MP in common carps (Cyprinus carpio) frozen with UF at different power levels were investigated. The results revealed that, compared with immersion freezing (IF), UF at 175 W (UF-175) effectively inhibited the decrease in protein solubility, absolute Zeta potential, emulsion activity index, storage modulus (G'), and loss modulus (G'') caused by freezing. UF-175 sample had lower protein turbidity, and smaller protein particle size than any other frozen samples (P < 0.05), which suggested that UF-175 inhibited protein aggregation induced by freezing. In addition, shorter T21 and T22 relaxation times were obtained in UF-175 sample than other frozen samples, indicating that UF-175 reduced the mobility of immobilized and free water. Accordingly, UF-175 sample had higher gel strength and water holding capacity than other frozen samples (P < 0.05). A denser and more uniform gel network structure was also found in UF-175 sample than other frozen samples. In general, improved functional properties of common carp MP can be achieved by optimal UF.  相似文献   

20.
ABSTRACT Vacuum‐packaged ground ostrich meat patties containing 2% sodium lactate (SL), 0.2% rosemary extract as oleoresin (RE), or their mixture (MIX) were evaluated and compared with control for their storage stability at 3 ± 1 °C in the dark by measuring pH, 2‐thiobarbituric acid‐reactive substance (TBARS) values, sample color (CIE L*, a*, b*, Hue and Chroma), and microbiological content. The pH values of ostrich patties, ranging from 6.03 to 6.13, were not affected by treatment (P < 0.05). At 9 d of storage, TBARS concentration for control samples containing no additives was 1.64 mg malonaldehyde/kg meat. Addition of RE to the ground ostrich meat inhibited lipid oxidation during storage at 3 ± 1 °C (P < 0.05). TBARS values of SL‐added samples were lower than control samples (P < 0.05); addition of SL also delayed the oxidation. It was found that RE had a protective effect on color, whereas addition of SL decreased CIE a* values (P < 0.05). SL, either alone or with RE, was effective in inhibiting total aerobic bacteria (TAB), coliforms, lactic acid bacteria (LAB), and Brochothrix thermosphacta in ostrich patties (P < 0.05) and provided a 2‐log reduction in microbial population during storage. In addition, RE did not have a significant effect on microbial growth at the concentration used in this study.  相似文献   

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