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1.
The effect of alginate-based edible coating containing Vitamin C (Vc) and tea polyphenols (TP) for shelf-life extension of bream (Megalobrama amblycephala) was evaluated over a 21-day storage at refrigerated temperature (4 ± 1 °C). Bream were left untreated (CK), or were treated with alginate–calcium coating (T1), alginate–calcium coating incorporating 5% Vc (T2), or alginate–calcium coating incorporating 0.3% TP (T3). The fish samples were analyzed periodically for water loss, microbiological (total viable count), chemical (pH, total volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA), K-value) and sensory characteristics. The results indicated that coating treatments retarded the decay of fish compared to uncoated bream. T2 more efficiently inhibited the growth of total viable counts than did T1 or T3 (p < 0.05). Coating treatments predominantly reduced chemical spoilage, reflected in TVB-N, pH, and TBA, retarded water loss (p < 0.05) and increased the overall sensory quality of fish compared to uncoated bream.  相似文献   

2.
The effects of rosemary extract (RE) combined with nisin (N) on the quality of pompano (Trachinotus ovatus) were assessed throughout 15 days of storage at 4 ± 1 °C. Physicochemical (peroxide value, thiobarbituric acid, total volatile basic nitrogen, trimethylamine, pH, K value, texture, and color), sensory, and bacteriological characteristics of fish fillet were all periodically analyzed. RE + N treatment effectively improved physicochemical quality parameters and the sensory, and reduced microbial growth as compared with either treatment of RE or N alone or the control, which resulted in a significant extension in the shelf life of pompano fillet. Therefore, rosemary extract combined with nisin treatment may be a promising method of maintaining the storage quality and extending shelf life of pompano fillet during chilled storage.  相似文献   

3.
The coating effects of tea polyphenol (TP) and rosemary extract (R) combined with chitosan (Ch) respectively on the quality of large yellow croaker (Pseudosciaena crocea) during refrigerated storage at (4 ± 1 °C) were evaluated. A solution of TP (0.2%, w/v) and R (0.2%, w/v) was used for dip pretreatment, and Ch (1.5%, w/v) was used for the coating. Microbiological (total viable count), physicochemical (pH, TVB-N, K value, PV, TBARS), and sensory attributes were periodically assessed over 20 days. The results indicated that the two dip pretreatments combined with chitosan coating could more effectively maintain the good quality and could extend the shelf life by 8-10 days compared with the control group during the refrigerated storage.  相似文献   

4.
The aim of this study was to evaluate the effects of oregano natural extract added to sheep burgers packaged in a modified atmosphere for 20 days at 2 ± 1 °C, seeking antioxidant properties and healthiness appeal. Antioxidant capacity of the oregano extract was determined by Folin-Ciocalteau, DPPH and FRAP methods. Three treatments of burgers were prepared: without antioxidant (control, CO), with 50 ppm BHT and with 1000 ppm oregano extract (ORE). The proximate composition (moisture, fat, protein and ash) of the meat product was determined and its stability was assessed through physicochemical (pH value, colour, lipid and protein oxidation, free fatty acids and volatile compounds profile), microbiological [total viable counts (TVC), Pseudomonas spp., Enterobacteriaceae, lactic acid bacteria (LAB)] and sensory analysis (5-point rating scale). ORE treatment presented similar counts of TVC and LAB and, also, an equivalent capacity to slow lipid and protein oxidation after 20 days, in comparison to BHT. The total amount of volatile compounds increased during storage (P < 0.01) and all treatments showed a decrease (P < 0.001) on a* value. However, ΔE0–20 was higher (P < 0.05) for CO treatment, indicating visual colour changes perceived by consumers. The presence of natural extract prevented the loss of sensory qualities in sheep burgers up to 15 days of storage, being that changes in off-odour were consistent with the microbial results that indicate burgers spoilage. In conclusion, oregano extract presented antioxidant effects quite similar to BHT and thus, can be considered a viable solution for the production of sheep burgers with a healthier appeal.  相似文献   

5.
A new fermented fish sausage product, based on monkfish, was developed by using an accelerated drying process, the QDS process®. To evaluate food safety, a challenge test was performed, in which the raw materials were inoculated with low levels of Listeria monocytogenes and Salmonella enterica (≤150 CFU/g). The product was manufactured, fermented, QDS dried, and half of the samples were pressurized (600 MPa, 5 min, 13 °C). Pathogens, technological microbiota, spoilage indicator bacteria from fish (hydrogen sulphite producing bacteria, coliforms and Escherichia coli) and physicochemical parameters were monitored during manufacturing and after 6, 13, 20 and 27 days of refrigerated storage at 4 and 8 °C. Results showed that in the finished product, pathogens and spoilage indicator bacteria could not grow but decreased and E. coli was not detected during storage. Pressurization had an important reducing effect on technological microbiota, and eliminated L. monocytogenes, S. enterica, hydrogen sulphite producing bacteria and coliforms immediately after production and during refrigerated storage.  相似文献   

6.
《Food Control》2007,18(5):430-435
Physicochemical, microbiological and sensorial qualities of cooked pork patty coated with pectin-based material containing green tea leaf extract powder were studied. Cooked pork patties were separated into three groups; uncoated control (C), coated with pectin-based materials (CP), and coated with pectin-based materials containing 0.5% green tea powder (CGP). The prepared patties were irradiated at 0 and 3 kGy using cobalt-60 gamma rays. Lipid oxidation, free radical scavenging effects, moisture content, total plate count, and sensory properties were evaluated during storage for 14 days at 10 °C. Lipid oxidation decreased (p  0.05) and radical scavenging (p  0.05) increased in the pork patties in CGP or CP relative to those of the controls when vacuum packaged. Coated patties contained higher moisture contents than the controls in both air- and vacuum packagings. The numbers of total aerobic bacteria were significantly reduced by the coating treatments as well as by irradiation. No difference were detected in sensory characteristics due to gamma irradiation or coating treatments.  相似文献   

7.
The aim of the present study was to evaluate the applicability of Quillaja saponaria extract (QSE) and Nα-lauroyl-l-arginine ethyl ester (LAE) as antimicrobial wash water additives in fresh-cut lettuce processing. Antibacterial activities of LAE and QSE against selected strains of the foodborne pathogens Salmonella enterica, Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, and Listeria monocytogenes were examined in vitro. Minimum inhibitory concentrations determined by broth microdilution assay demonstrated that LAE exhibited a strong antimicrobial activity with MICs between 4 and 32 μg/mL against all tested strains, whereas QSE showed a weaker antimicrobial activity with MICs >512 μg/mL. On a pilot-plant scale, the effects of warm water washing at 45 °C for 120 s with and without 40 mg/L QSE or 100 mg/L LAE as well as cold water washing at 4 °C for 120 s with QSE or LAE, respectively, of shredded endive (Cichorium endivia L.) were investigated regarding microbiological and sensory quality as well as physiological properties. Samples were analyzed for headspace O2 and CO2 levels, phenylalanine-ammonia-lyase activity and contents of nitrite and nitrate during nine days of cold storage at 4 °C. By analogy to its antimicrobial effect against the foodborne pathogens in vitro, LAE allowed up to 4 log10 cfu/mL reduction of the microbial load in the washing water of the pilot plant, and might therefore reduce cross-contamination while saving water. The addition of LAE to warm washing water impaired sensory properties of fresh-cut endive during storage, which was predicted by chlorophyll fluorescence imaging analyses. QSE treatment combined with warm water washing best retained sensory appearance throughout our study, being possibly suitable for the production of premium products.  相似文献   

8.
A novel antimicrobial packaging system, as active coating on a commercial Poly(ethylene terephthalate) (PET) film, was formulated and tested in vitro against the spoilage bacteria of Mozzarella cheese. It is based on layered double hydroxide (LDHs) intercalated with salicylate and carbonate anions dispersed in a solvent-based heat seal. The population of spoilage microorganisms (total coliforms, Pseudomonas, fungi), along with the functional microbiota of Mozzarella cheese (lactic acid bacteria) was characterized. Microbial shelf life was evaluated at 18 °C, to simulate thermal abuse. Experimental results show an increase in the microbial shelf life of the packaged Mozzarella cheese of about 20 days, confirming that the investigated active coating may exert an inhibitory effect on the microorganisms responsible for spoilage phenomena, without affecting the functional microbiota of the product.  相似文献   

9.
Minimally processed fruit are susceptible to microbial proliferation and to a fast loss of sensory quality. In this experimental work, in order to increase shelf-life and quality parameters (texture and colour) maintenance of sliced apples (Malus communis, var. Golden delicious), the use of natural antimicrobials was proposed as alternative to the traditional sanitization methods. Citron EO, hexanal, 2-(E)-hexenal, citral and carvacrol, alone or in combination, were employed. As control, apples washed only with 0.5% of ascorbic and 1% of citric acid were used. The apples were dipped with traditional or natural antimicrobial solutions according to a defined protocol. After the treatment, apples were packaged in active modified atmosphere (7% O2 and 0% CO2), into medium permeability bags. The products were stored at 6 °C and, immediately after washing and during storage, the yeast cell loads were monitored until the spoilage threshold (6 log CFU/g). In addition, the volatile profiles, electronic nose analyses, colour and texture analyses were monitored during the storage. In all the samples the spoilage yeast threshold was not attained within the 35 days of storage independently on the substance or mixture of substances supplemented. Samples treated with the combinations citral/2-(E)-hexenal and hexanal/2-(E)-hexenal showed a good retention of colour parameter during storage. Among investigated samples, hexanal/2-(E)-hexenal treatment promoted the best retention of firmness throughout 35 days of storage. These results evidence the potentiality of dipping treatment based on these natural antimicrobials to strongly prolong the shelf-life of fresh-cut apples.  相似文献   

10.
The influence of nanoemulsion (AUSN-4) on the microbiological, proximal, chemical, and sensory qualities of Indo-Pacific king mackerel (Scomberomorus guttatus) steaks stored at 20 °C was studied for a time period of 72 h. AUSN-4 treatment showed initial reduction (P > 0.05) in the heterotrophic, H2S and lactic acid bacterial populations in 12 h, followed by a gradual increase in their respective populations. Irrespective of treatments, reduction in total carbohydrate, protein, and fat contents were observed in all samples with an increase in storage time (h), with AUSN-4 treated steaks having the lowest reduction. AUSN-4 treatment significantly (P < 0.05) decreased the values of chemical indicators of spoilage throughout the storage period. Organoleptic evaluation revealed that AUSN-4 treated steaks showed an extension of shelf life of 48 h, when compared with control and antibiotic treated samples, respectively. Based on the results obtained in our present study we conclude that sunflower oil based nanoemulsion preservative technique is able to extend the shelf life and maintain the quality of S. guttatus steaks during storage.  相似文献   

11.
The objective of this study was to evaluate the combined effect of sugar content (66–70 °Brix) and pH (2.0–3.5) on the growth of a wild strain of Zygosaccharomyces rouxii B-WHX-12-54 by response surface (RS) methodology. Experiments were performed in concentrated apple juice inoculated with this strain at standard storage condition (isothermal, 25 °C) for 60 days. Results show that pH was the most significant limiting factor that affects the growth parameters (potential maximum growth rate and lag phase duration), although the effect of sugar content was also significant. In a second experiment, the time for spoilage (TFS) by this strain in concentrated apple juice was assessed under isothermal (25 °C) and non-isothermal conditions, in an attempt to simulate standard storage and overseas shipping temperature conditions, respectively. Results show that pH was again the environmental factor with the highest effect on delaying the spoilage of the product caused by this strain. Although concentrated apple juice stored under non-isothermal condition showed lower microbial stability (evidenced in lower TFS values) than that stored under standard isothermal condition, a pH value below 2.3 was sufficient to extend the shelf life of the product to more than 60 days under both temperature conditions. The results obtained in this study could be used by producers and buyers to predict and control the growth and TFS of Z. rouxii strain B-WHX-12-54 in concentrated apple juice.  相似文献   

12.
While current food science research mainly focuses on microbial changes in food products that lead to foodborne illnesses, meat spoilage remains as an unsolved problem for the meat industry. This can result in important economic losses, food waste and loss of consumer confidence in the meat market. Gram-negative bacteria involved in meat spoilage are aerobes or facultative anaerobes. These represent the group with the greatest meat spoilage potential, where Pseudomonas tend to dominate the microbial consortium under refrigeration and aerobic conditions. Identifying stress response genes under different environmental conditions can help researchers gain an understanding of how Pseudomonas adapts to current packaging and storage conditions. We examined the gene expression profile of Pseudomonas putida KT2440, which plays an important role in the spoilage of meat products. Gene expression profiles were evaluated to select the most differentially expressed genes at different temperatures (30 °C and 10 °C) and decreasing glucose concentrations, in order to identify key genes actively involved with the spoilage process. A total of 739 and 1269 were found to be differentially expressed at 30 °C and 10 °C respectively; of which 430 and 568 genes were overexpressed, and 309 and 701 genes were repressed at 30 °C and 10 °C respectively.  相似文献   

13.
The combined effects of high hydrostatic pressure (HHP) and a commercial liquid antimicrobial edible coating consisting of lactic and acetic acid, sodium diacetate, pectin and water (“articoat-DLP”) followed by modified atmosphere packaging (MAP) on the shelf-life of chicken breast fillets were evaluated.All samples were held at 4 °C under MAP (30% CO2/70% N2) conditions and these were assigned to the following treatments: (i), control untreated fillets (C-MAP); (ii), fillets dipped in articoat-DLP (A-MAP); (iii) HHP (300 MPa) treated fillets followed by MAP (HP-MAP) and (iv) HHP (300 MPa) treated fillets after dipping in articoat-DLP (A-HP-MAP). During storage, packages were tested at intervals for CO2 and O2 concentrations, colour (CIE L* a* b*), pH, oxidative stability (TBARS), cooking loss, Warner-Bratzler shear force measurement and sensory analysis (colour, tenderness, juiciness, chicken aroma, oxidised flavour, off-flavours and overall acceptability). Total viable counts and numbers of Pseudomonas, lactic acid bacteria (LAB), Brochothrix thermosphacta, coliforms and Escherichia coli were also determined.The A-HP-MAP combination was the most efficient in extending the durability of chicken breast fillets, which maintained their sensory and microbiological quality for up to 28 days. At the time of rejection, total counts were 6.3 ± 0.7 log cfu/g, with LAB being dominant (100%). For A-MAP and HP-MAP fillets, the storage life was estimated to be two weeks while that of the untreated fillets (C-MAP) was estimated to be one week.Colour, tenderness and overall acceptability were the best maintained sensory attributes during storage for A-HP-MAP samples. The synergistic effect of this high-pressure-based hurdle strategy was higher than those previously reported when applying several combined hurdles to poultry meat.  相似文献   

14.
《Food Control》2007,18(5):535-540
The essential oil and methanol extract obtained from aerial parts of Ziziphora clinopodioides Lam. harvested in the Eastern part of Turkey were evaluated for their chemical composition and antibacterial activity against 52 Gram-positive and Gram-negative bacteria. The GC–MS analyses allowed 18 compounds to be determined; the main constituents of the essential oils were (+)-pulegone (31.86%), 1,8-cineole (12.21%), limonene (10.48%), menthol (9.13%), β–pinene (6.88%), menthone (6.73%), piperitenone (5.30%) and piperitone (4.18%) The essential oil and methanol extract had a broad-spectrum antimicrobial activity against pathogens in broth microdilution bioassays. Maximum activity of essential oil (>22 mm) and methanol extract (>11 mm) was observed against Acidovorax facilis, Bacillus flexus, Bacillus spp, Bacillus sphaericus, Brevibacillus brevis, Corynebacterium ammoniagenes, Enterobacter sakazakii, Erwinia carotovora carotovora, Moraxella catarrhalis and Xanthomonas arboricola.  相似文献   

15.
High pressure processing (HPP) comprises the application of pressures between 100 and 1000 MPa to foods for microbial inactivation and food preservation. HPP has been commercially applied to pasteurize fruit juices with the advantage of retaining its bioactive constituents and original organoleptic properties. Alicyclobacillus acidoterrestris has been suggested as a reference in the design of pasteurization for high-acid fruit products, due to spore resistance and spoilage incidents in fruit juices. In this study, A. acidoterrestris spore inactivation by 600 MPa combined with mild heat (35–65 °C) in malt extract broth adjusted to 10, 20 and 30 °Brix was carried out and the inactivation was modeled.The soluble solids increased the resistance of the spores to 600 MPa-thermal process, while the temperature decreased its resistance. Although the nonlinear Weibull model gave better fittings, the first-order kinetic parameters were also determined. For example for 600 MPa at 55 °C D10°Brix = 4.2 min, D20°Brix = 7.6 min, D30°Brix = 13.7 min, and zT-values were 20–21 °C. The z-values for the effect of soluble solids on DT-values were 39–40 °Brix for 45 and 55 °C 600 MPa HPP. The results obtained with broth were validated with fruit juices and concentrates. The combination of HPP with heat was an effective alternative to conventional thermal processing for the inactivation of A. acidoterrestris spores in juices up to 30 °Brix, allowing the use of less 30–40 °C of temperature for the same microbial inactivation, which potentially results in more nutritious, fresher and tastier juices/concentrates.  相似文献   

16.
《Food Control》2013,32(2):553-559
This paper reports on the use of different citrus extracts (biocitro, lemon extract and neroli) for the inhibition of the spores of two strains of Alicyclobacillus acidoterrestris; the research included 3 steps. First, the bioactivity of citrus extracts was assessed under in vitro conditions using a modified micro-dilution method; the concentration of extracts was from 20 to 500 ppm. Then, biocitro and lemon extract (0–80 ppm) were combined with two different thermal treatments (at 70 and 80 °C for 3–6 min) through a fractional factorial design and finally a treatment at 80 °C for 6 min was combined with either biocitro (80 ppm) or lemon extract (80 ppm) and tested in apple juice. Biocitro and lemon extract showed MIC values (Minimal Inhibitory Concentration) from 160 to 500 ppm; their effect could be enhanced by a thermal treatment at 80 °C for 3–6 min, both under in vitro conditions and in apple juice. Finally, biocitro or lemon extract could be added before and after the thermal treatment without any significant loss of their bioactivity.  相似文献   

17.
《Food Control》2007,18(4):292-300
The effect of initial head-spaces of atmospheric air, vacuum and modified atmospheres packaging (50% CO2/50% N2) on microbiological, physicochemical and sensory changes of chub mackerel (Scomber colias japonicus) was studied at 3 and 6 °C. The microbial flora of chub mackerel comprised mainly lactic acid bacteria, Brochothrix thermosphacta (Gram-positive flora) and secondly pseudomonads, Shewanella putrefaciens, Enterobacteriaceae (Gram-negative bacteria). The spoilage of chub mackerel stored under modified atmosphere was delayed compared with those samples stored under vacuum or air. The concentrations of moisture, ash, protein, fat and polyunsaturated fatty acids were not affected during the storage period compared to the pH values and the concentrations of lactate and ammonia that showed significant differences.  相似文献   

18.
The effect of addition of extract from shiitake by-products (0, 0.3, and 0.6%) on the quality characteristics, lipid oxidation and microbial stabilities of fermented sausages was studied during storage up to 30 days at 15 °C, and its effect was also compared with those produced with synthetic antioxidant, BHT (0.02%) or nitrite (0.01%). The addition of natural extract resulted in lower ultimate pH values with higher number of lactic acid bacteria, lower lipid oxidation level and spoilage bacteria count in the products during storage as compared with those of the control or BHT and nitrite treatments (P < 0.05). Storage time significantly increased the lipid oxidation level, however, the increasing rate after 30 days storage in the following order: Control (increased by 1.22 mg MDA/kg) > 0.02% BHT (increased by 0.43 mg MDA/kg) > 0.01% nitrite/nitrate (increased by 0.42 mg MDA/kg) > 0.3% SSE (increased by 0.34 mg MDA/kg) > 0.6% SSE (increased by 0.18 mg MDA/kg). Furthermore, extract of fermented sausages fortified with 0.6% shiitake stipes extract also showed strong antimicrobial activity against 3 foodborne bacteria such as Staphylococcus aureus (minimum inhibitory concentrations (MIC) = 2.08 mg/mL), Listeria monocytogenes (MIC = 4.16 mg/mL) and Escherichia coli O157 (MIC = 8.33 mg/mL). Additionally, the addition of the extract did not cause defects of color, texture and sensory quality in the products. Our results clearly suggest that the shiitake by-product extract represents a functional ingredient to be used (at level of 0.6%) for improving lipid oxidation and microbial stabilities as well as controlling the growth of pathogens in fermented sausages.  相似文献   

19.
The qualities of Penaeus vannamei that are prone to spoilage have a significant impact on its economic profitability. To extend the shelf life of shrimp, this study formulated a novel composite preservative with pullulan and protoilludane sesquiterpene aryl esters (melleolides). Two melleolide compounds, namely armillarin and armillaripin, were identified using high-performance liquid chromatography-triple quadrupole time-of-flight mass spectrometry (HPLC–Q-TOF-MS/MS) analysis of the ethyl acetate extract of Floccularia luteovirens. The antibacterial activity of melleolides was investigated through the disc diffusion method, and it exhibited the most potent effect against methicillin-resistant Staphylococcus aureus (MRSA) among the tested bacteria, producing an inhibition zone diameter of 15.6 mm. The composite preservative displayed competitive inhibition of polyphenol oxidase, with an IC50 value achieved at a melleolides content of 6.27%. Furthermore, the effects of the composite preservatives on shrimp quality were evaluated through sensory, colour, pH, TVB-N, APC, and TBARS assessments. The results indicated that S-PM8 treatment group inhibited the growth of the APC in shrimp from 8.98 log CFU/g (S–C) to 7.48 log CFU/g. The TVB-N content was maintained within 28.7 mg/100 g throughout the storage period. The content of TBARS was 0.97 mg MDA/kg at Day 12, which was significantly lower than that of the control group. Additionally, the composite preservatives substantially improved sensory scores and colour retention during storage. These findings demonstrate the potential of pullulan-melleolides composite preservative to extend the shelf life of P. vannamei.  相似文献   

20.
This study evaluated the efficacy of the individual treatments (slightly acidic electrolyzed water [SAcEW] or fumaric acid [FA]) and their combination to reduce Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus, and Salmonella Typhimurium in fresh pork as well as to study the shelf life and sensory quality (color, odor, and texture) of pork during storage at 4 and 10 °C. The inoculated pork samples (10 g) were dipped for 3 min in each treatment (tap water [TW], SAcEW, strong acidic electrolyzed water [StAEW], 0.5% FA, or SAcEW + 0.5% FA) with or without mild heat (40 °C). Decontamination of fresh pork with SAcEW +0.5% FA at 40 °C for 3 min showed greater bactericidal effect compared to other treatments, which significantly (P < 0.05) reduced E. coli O157:H7, L. monocytogenes, S. aureus, and S. Typhimurium by 2.59, 2.69, 2.38, and 2.99 log CFU/g, respectively. This combined treatment significantly (P < 0.05) yielded in a longer lag time of naturally occurring bacteria (TBC) on pork stored at 4 °C. This combined treatment also prolonged the shelf life of pork up to 6 days and 4–5 days when stored at 4 °C and 10 °C, respectively, compared to those of the untreated pork. The results suggest that the combined treatment of SAcEW + 0.5% FA has potential as a novel method to enhance the microbial safety and quality of fresh pork.  相似文献   

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