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1.
A microencapsulated beta-cyclodextrin and trans-cinnamaldehyde complex (2 g/100 g) was incorporated into a multilayered edible coating made of chitosan and pectin. Fruits were washed, peeled and cut, coated, and stored at 4 °C in Ziploc® trays with Ziploc® lids for 15 days. Uncoated fruits served as controls. Coated fruits were firmer, maintained color, β-carotene content, and showed lower juice leakage (P < 0.05). Coated samples were more accepted (P < 0.05) by the panelists than the controls. Encapsulation of trans-cinnamaldehyde was successful since it had no negative impact on the fruit's flavor. A parallel study evaluated the effect of packaging on the efficacy of the multilayered coating. Coated and uncoated fruits in trays were also covered with Saran® wrap and plain cheese cloth (ambient conditions). The Ziploc® trays with Ziploc® lids were the best packaging method. The Layer-by-layer assembly with incorporation of microencapsulated antimicrobial was effective in extending shelf life and quality of fresh-cut papaya.  相似文献   

2.
Efficacy of nisin‐EDTA treatments as a sanitizing treatment for reducing native microflora of whole melons and extending shelf‐life of fresh‐cut pieces was compared to chlorine treatments. Whole cantaloupe and honeydew melons were washed with water, nisin (10 μg/mL)‐EDTA (0.02 M), or 200 ppm chlorine for 5 min at ~ 20C before fresh‐cut preparation and storage at 5C for 15 days with periodic microbiological sampling. In addition, some fresh‐cut pieces were washed with 10 μg/mL nisin‐EDTA or 50 ppm chlorine for 1 min before storage. Changes in appearance, odor, overall acceptability and the shelf‐life of the minimally processed fresh‐cut melons were investigated. Preliminary studies indicated that water washes, EDTA (0.002 to 0.2 M) or nisin (5 to 10 μg/mL) were not effective in reducing the microflora of whole melon when used individually. Nisin‐EDTA and chlorine treatments were significantly (P < 0.05) more effective in reducing native microflora than water washes. Nisin‐EDTA treatments were significantly (P < 0.05) more effective than chlorine in reducing populations of yeast and mold and Pseudomonas spp. on whole melon surfaces but were not as effective as chlorine treatments for reducing aerobic mesophilic bacteria, lactic acid bacteria and total gram‐negative bacteria. Microbial contaminants on fresh‐cut pieces washed with 50 ppm chlorine or nisin‐EDTA were further reduced. However, microbial populations increased throughout refrigerated storage irrespective of treatments. Odor, appearance, and overall acceptability ratings for cantaloupe and honeydew fresh‐cut pieces treated with nisin‐EDTA or chlorine were not significantly (P > 0.05) different from each other throughout the storage period (15 to 21 days). However, both treatments led to significantly (P < 0.05) improved ratings compared to the controls for the fresh‐cut pieces at 9 to 12 days of storage and thereafter. The results of this study suggest that treatments with nisin‐EDTA before and after fresh‐cut processing would improve the quality and extend the shelf‐life of fresh‐cut melon.  相似文献   

3.
BACKGROUND: The feasibility of using modified atmosphere packaging (5 kPa O2 + 5 kPa CO2) to maintain the antioxidant properties of fresh‐cut tomatoes during shelf‐life was assessed through storage at different temperatures (5, 10, 15 and 20 °C). Health‐related compounds, antioxidant capacity, microbiological counts, physicochemical parameters and in‐package atmosphere of tomato slices were determined. RESULTS: Initial lycopene, vitamin C and phenolic contents and physicochemical parameters of tomato slices were well maintained for 14 days at 5 °C. Lycopene and total phenolic contents were enhanced over time in tomato slices stored at 15 and 20 °C. However, this increase in antioxidant compounds of fresh‐cut tomatoes during storage may be associated with excessive amounts of CO2 (R2 = 0.5679–0.7328) in the packages due to microbial growth. Although keeping tomato slices at temperatures above 10 °C increased their antioxidant content, the shelf‐life of the product was reduced by up 4 days. CONCLUSIONS: A storage temperature of 5 °C is appropriate for maintaining the microbiological shelf‐life of fresh‐cut tomatoes for up to 14 days and also allows the antioxidant properties of tomato slices to be retained over this period, thus reducing wounding stress and deteriorative changes. Copyright © 2008 Society of Chemical Industry  相似文献   

4.
A novel nanopackaging was synthesised by coating polyvinyl chloride (PVC) film with nano‐ZnO powder, and its effects on the preservation quality of fresh‐cut ‘Fuji’ apple were investigated at 4 °C for 12 days. Compared with the control (PVC film), nanopackaging significantly reduced the fruit decay rate (P < 0.05), as well as decreased the accumulation of malondialdehyde (MDA) from 74.9 nmol g?1 in the control to 53.9 nmol g?1 in the nanopackaging. Cutting caused an increase in ethylene level, suggesting wound‐induced ethylene production, which was suppressed in nanopackaging. Both the polyphenoloxidase and pyrogallol peroxidase activities were decreased in nanopackaging fruit. The initial appearance of apple slices was retained, and the browning index was prevented in nanopackaging samples, which was only 23.9, much lower than the control of 31.7 on day 12. These results indicated that nano‐ZnO active packaging could be a viable alternative to common technologies for improving the shelf‐life properties of ‘Fuji’ apples as a fresh‐cut product.  相似文献   

5.
Mango puree is known to have good oxygen barrier properties. Therefore, mango film on its own might be useful to extend the shelf life of fresh‐cut mango. In this study, fresh‐cut mango was wrapped with mango film and packed in modified atmosphere packaging (MAP). Each package was stored at 30 °C or 5 °C and sensory evaluation was performed to determine its quality and shelf life. The shelf life of uncoated and coated fresh‐cut mango pieces was 6 days for each at 5 °C and was 3 and 4 days, respectively, at 30 °C. The sensory evaluation indicated that coated fresh‐cut mango was slower to produce an off‐flavour and maintained better visual quality than uncoated mango at 30 °C. Nonetheless, coated fresh‐cut mango was softer than uncoated mango because of the hydrophilic nature of the mango film. No significant difference in the oxygen and carbon dioxide concentrations was observed between coated and uncoated fresh‐cut mango. Coating fresh‐cut mango with mango film showed a similar effect to MAP in prolonging the shelf life of the fresh produce. The use of the coating will enhance fruit quality and lead to better acceptance by consumers.  相似文献   

6.
Aqueous ozone was first used to take the place of chlorine as fresh‐cut apples sanitiser. Aqueous ozone (1.4 mg L?1) treatments were evaluated for their effectiveness on microbial growth, quality attributes and shelf life of fresh‐cut apples. The results indicated that aqueous ozone treatments for 5 and 10 min achieved accepted microbial quality and, respectively, reduced total bacteria counts by 1.83 and 2.13 log10CFU g?1 compared with the control samples on the 12th day. The ethylene production, polyphenol oxidase and peroxidase activities, and total phenol and malondialdehyde contents were reduced by aqueous ozone treatments. In addition, this sanitiser also delayed the quality deterioration of fresh‐cut apples and enhanced their antioxidant capacity. Therefore, it was recommended to sanitise fresh‐cut apples with aqueous ozone (1.4 mg L?1) for 5 min, which applied to industrial production requirement for both efficiency and costs and could extend the shelf life up to 10 days.  相似文献   

7.
Minimally processed carrots have a short shelf‐life because of white blush formation (caused primarily by surface dehydration) and microbiological spoilage (caused mostly by lactic acid bacteria). The use of polymeric packaging films combined with edible coatings might have an additive or synergistic effect to extend the shelf‐life of minimally processed carrots because of the formation of a double barrier to gases and water vapour. A 3 × 3 factorial experiment using a polymeric packaging film of three different levels of permeability and a cellulose‐based edible coating (Nature Seal®) at different concentrations was conducted on minimally processed carrots to investigate any possible synergistic effect over 12 days of storage at 10 °C. No such effect was found. The polymeric packaging film effectively prevented microbiological growth and spoilage but was unable to control white blush formation. On the other hand, the edible coating partially controlled white blush formation but enhanced microbiological spoilage. The polymeric packaging film functioned primarily as a gas barrier, whereas the edible coating probably functioned as a moisture barrier. White blush formation was found to be the most important shelf‐life determinant for minimally processed carrots. Copyright © 2003 Society of Chemical Industry  相似文献   

8.
The effects of chlorine dioxide (ClO2) on respiration and ethylene synthesis of fresh‐cut melon fruit and the possible mechanisms involved were investigated. Fresh‐cut ‘Hami’ melon fruit fumigated with gas ClO2 in sealed container for 12 h and then stored at 5 °C with 95% relative humidity (RH) for 19 days. Results showed that fruit treated with ClO2 resulted in lower rates of the total respiration, alternative pathway respiration, cytochrome pathway respiration and ethylene production. Furthermore, the expressions of ethylene biosynthesis‐related genes, including CmACS2, CmACO1 and CmACO3 were reduced by ClO2 treatment. Taken together, it is suggested that ClO2 treatment might be an effective way to delay ripening of fresh‐cut ‘Hami’ melon, partially due to the reduced respiration and ethylene biosynthesis.  相似文献   

9.
Buckwheat starch (BS) films containing zinc oxide nanoparticles (ZnO‐N; 0%, 1.5%, 3% and 4.5%) were prepared, and their physical, optical and antimicrobial properties were examined. As ZnO‐N content increased from 0% to 4.5%, TS increased from 14.99 to 19.09 MPa and E decreased from 25.60% to 20.65%. In addition, L* and a* values decreased, whereas b*, ΔE and opacity increased. Regarding antimicrobial activity, the BS/ZnO‐N films had the reductions of 2.96–3.74 log CFU mL?1 against Listeria monocytogenes after 8 h based on viable cell count assay. The BS film containing 3% ZnO‐N, an optimal concentration chosen in this study, was applied to fresh‐cut mushroom packaging, and the film exhibited antimicrobial activity against L. monocytogenes, resulting in a reduction of 0.86 log CFU g?1 after 6 days of storage. Thus, these results indicate that the BS/ZnO‐N film can be used as a biodegradable packaging material.  相似文献   

10.
BACKGROUND: Alternative techniques for cultivation of leafy vegetables such as a floating tray system and unconventional gas mixtures for post‐harvest active modified atmosphere packaging (MAP) could be of interest in the minimally processed vegetable industry. RESULTS: The combined effect of three pre‐harvest fertilisation doses (8, 12 or 16 mmol N L?1) and three post‐harvest MAP conditions (passive, super‐atmospheric or N2O‐enriched) on the main quality attributes of fresh‐cut baby spinach leaves throughout 10 days at 5 °C was studied. After 8 days of shelf life, spinach leaves fertilised with 8 and 16 mmol N L?1 and stored under N2O‐enriched MAP showed the lowest microbial growth, with good sensory quality. Such combined treatments also preserved the total antioxidant capacity sampled at harvest (8 g ascorbic acid equivalent antioxidant capacity kg?1 f.w.). A decrease of 10–20% in total vitamin C content regardless of N fertilisation and packaging treatment was found during shelf life. Total phenolics content at harvest was 2 g gallic acid equivalents kg?1 f.w., which was slightly decreased or preserved during shelf life while total chlorophylls were preserved for all treatments assayed around 550 mg kg?1 f.w. CONCLUSION: No clear effect of fertilisation doses was observed during post‐harvest storage on overall quality of fresh‐cut baby spinach leaves, while N2O‐enriched atmospheres seems to be a promising alternative to passive MAP for extending shelf life. Copyright © 2010 Society of Chemical Industry  相似文献   

11.
This study was aimed at evaluating the effect of coatings with alginate (AL), pectin (PE), carboxymethyl cellulose (CMC) or chitosan (CH) on microbial stability, physicochemical attributes, total phenolics and carotenoids content, antioxidant capacity and sensory properties of fresh‐cut mango during 14 days at 4 ± 1 °C. Coated fresh‐cut mango kept microbial counts below 6 logs CFU g?1, being CH‐coated fresh‐cut mango those that exhibited the lowest microbial counts (1 log CFU g?1) along entire storage. AL, PE and CMC coatings maintained yellow colour of fresh‐cut mango throughout storage. AL and CH coatings, which have different monomers in their chain, improved the content of antioxidant compounds in fresh‐cut mango as related to uncoated. AL‐coated fresh‐cut mangoes were the toughest, among those coated, during 14 days. The highest consumer acceptance was achieved in AL (90.2%) coated fresh‐cut mango. CH would be the most suitable coating to extend the quality of fresh‐cut mango throughout storage.  相似文献   

12.
BACKGROUND: Chitosan can form antimicrobial, semi‐permeable barriers that limit gas exchange and reduces water loss in fruits. Consumer interest in fresh‐cut papaya fruit is leading to increasing demand because of its sensorial and antioxidant properties. However, papaya is a highly perishable product that is prone to loss of weight, loss of firmness and microbial attack. The aim of this study was to evaluate the effect of chitosan coatings on the overall quality of fresh‐cut papaya. Chitosan coatings of low (LMWC), medium (MMWC) and high (HMWC) molecular weights, at concentrations of 0.01 and 0.02 g mL?1, were applied to fresh‐cut papaya cubes. The treated cubes were stored at 5 °C and changes in quality were evaluated. RESULTS: MMWC maintained the highest color values (L* and b*) and firmness. Chitosan coatings suppressed mesophilic plate count, and the growth of molds and yeast, compared to controls. The MMWC coatings at 0.02 g mL?1 resulted in the highest antimicrobial activity and decreased the activity of the enzymes polygalacturonase and pectin methylesterase, followed by low and high MW chitosan coatings at 0.02 g mL?1. CONCLUSION: The application of the MMWC treatment at 0.02 g mL?1 could be used to reduce deteriorative processes, maintain quality and increase the shelf life of fresh‐cut papaya stored at 5 °C. Copyright © 2008 Society of Chemical Industry  相似文献   

13.
With the aim to develop natural preservatives displaying also chemopreventive activity, different Commiphora myrrha (Nees) Engl. extracts were studied. Myrrh essential oils, obtained by steam distillation and microwave‐assisted hydrodistillation, and several other extracts, obtained by sequential procedures with petroleum ether (PE), ethanol, ethyl acetate and butanol, have been screened for their antioxidant (DPPH· scavenging assay) and antiproliferative activity (on both nontumour and colon cancer cell lines) without previous purification. Considering that the colon cancer cell lines were more sensitive to PE and ethanol extracts, the latter of which showed the highest antioxidant activity (EC50 = 0.160 ± 0.008 mg mL?1), both have been selected for further antibacterial/antifungal activity tests using an antimicrobial diffusion test and a growth inhibition test on salads. Results showed that the ethanol extract possessed the higher antibacterial and antifungal activity. Compared to untreated product, fresh‐cut salads treated with these two myrrh extracts displayed a significant lower bacterial growth. Although further investigation is required, these promising results offer hints as how to improve the shelf life of fresh‐cut salad.  相似文献   

14.
Nanoencapsulation can provide a means to effectively deliver antimicrobial compounds and enhance the safety of fresh produce. However, to date there are no studies which directly compares how different nanoencapsulation systems affect fresh produce safety and quality. This study compared the effects on quality and safety of fresh‐cut lettuce treated with free and nanoencapsulated natural antimicrobial, cinnamon bark extract (CBE). A challenge study compared antimicrobial efficacy of 3 different nanoencapsulated CBE systems. The most effective antimicrobial treatment against Listeria monocytogenes was chitosan‐co‐poly‐N‐isopropylacrylamide (chitosan‐PNIPAAM) encapsulated CBE, with a reduction on bacterial load up to 2 log10 CFU/g (P < 0.05) compared to the other encapsulation systems when fresh‐cut lettuce was stored at 5 °C and 10 °C for 15 d. Subsequently, chitosan‐PNIPAAM‐CBE nanoparticles (20, 40, and 80 mg/mL) were compared to a control and free CBE (400, 800, and 1600 μg/mL) for its effects on fresh‐cut lettuce quality over 15 d at 5 °C. By the 10th day, the most effective antimicrobial concentration was 80 mg/mL for chitosan‐PNIPAAM‐CBE, up to 2 log10 CFU/g reduction (P < 0.05), compared with the other treatments. There was no significant difference between control and treated samples up to day 10 for the quality attributes evaluated. Chitosan‐PNIPAAM‐CBE nanoparticles effectively inhibited spoilage microorganisms’ growth and extended fresh‐cut lettuce shelf‐life. Overall, nanoencapsulation provided a method to effectively deliver essential oil and enhanced produce safety, while creating little to no detrimental quality changes on the fresh‐cut lettuce.  相似文献   

15.
BACKGROUND: The fresh‐cut industry commonly uses sodium hypochlorite (NaClO) for disinfection. However, there are certain problems related to its use, and acidified sodium chlorite (ASC) could be an alternative sanitiser to replace it. There is limited research evaluating the effect of ASC on the overall quality of fresh‐cut produce, especially sensory quality. In this study the decontamination efficacy and quality attribute effects of ASC on fresh‐cut tatsoi after application and during storage were investigated. RESULTS: Tatsoi baby leaves were minimally processed at 8 °C and stored under passive modified atmosphere packaging for up to 11 days at 5 and 10 °C. Low to moderate doses of ASC (100–500 mg L?1) showed an initial antimicrobial efficacy on natural microflora and Escherichia coli as effective as that of NaClO. Regarding contact time, ASC was effective in reducting the E. coli population during the first 30 s of washing, and an increase in contact time did not improve the antimicrobial effect. Sensory quality attributes were well kept for up to 11 days at 5 °C but for only 5 days at the abusive temperature of 10 °C. CONCLUSION: ASC provides an alternative sanitising technique to NaClO for maintaining the quality and safety of fresh‐cut tatsoi baby leaves for up to 11 days at 5 °C. Copyright © 2011 Society of Chemical Industry  相似文献   

16.
Fresh‐cut vegetables became more and more popular due to healthy eating habits, with main problem safety of the product because of microbial spoilage as well as visual and nutritional quality changes. Ozone may act as a sanitizer; however, due to its strong oxidant activity care is needed, as in some cases, that is, if the dose being used is too high, the quality of the produce may be reduced. In this study, ozonated water at various concentrations and dipping times (0, 0.4, 0.8, or 1.2 mg/L for 0, 1, 15, or 30 s) were tested. Results revealed that application of ozonated water (0.8 mg/L for 30 s) before packaging reduced yellowing and maintained compositional characteristics of the fresh‐cut spinach leaves, ensuring a shelf‐life extension of 3 days. Moreover, a positive effect on microbial population control was recorded during the first 5 days of storage.

Practical applications

The use of chlorine or other chemicals in fresh‐cut industry is decreasing while alternatives treatments are proposed. Ozone even had remarkable antimicrobial action however because of its oxidation action could be negative for the horticultural products. This work investigated the efficiency of ozone treatment (concentration and dipping time) to control yellowing of fresh‐cut spinach as well as the effect on microbial counts and leaves composition. The information obtained from this study provide the chance to extend the postharvest life of a highly perishable product with an alternative to chemical treatment that could be easily applied in processing line.  相似文献   

17.
In‐package sanitisation was developed using polylactic acid (PLA) films with allyl isothiocyanate (AIT) vapour. Tomatoes were artificially inoculated with Escherichia coli, Geotrichum candidum and Fusarium oxysporum and stored in clamshell boxes with the film fixed to the underside of the lid. The changes in bacterial and fungal populations and the quality of tomatoes during storage at 4 and 10 °C were evaluated. The results revealed that the film treatment (4 × 8 cm2 film in 1 L box) reduced the populations of inoculated bacteria and fungi on tomatoes by 2–3 log CFU g?1, and then significantly (P < 0.05) inhibited their growth during the 21‐day storage period at both temperatures. Tomatoes subject to film treatment had fewer changes in quality (colour, firmness, contents of total soluble solid, titratable acids and vitamin C) than the control samples during storage. The antimicrobial PLA film can be used for in‐package sanitisation to extend the shelf‐life of packaged tomatoes or similar perishable vegetables.  相似文献   

18.
In this study, tuna burgers were subjected to a bio‐preservation treatment combined with modified atmosphere packaging (MAP) in order to prolong the shelf life. After L. reuteri production of reuterin, the antimicrobial compound was microencapsulated and then added to tuna burger formulation. Reuterin content was analysed before and after the spray drying treatment, thus assessing its final concentration. Then, the effects of spray‐dried reuterin on tuna burgers quality were investigated with success on samples packaged under both ordinary and MAP conditions. The efficacy of bio‐control was evident in all the samples. For burgers stored in air, a shelf life of about 7.63 days was recorded for the active samples with respect to the 5.78 days of the reuterin‐free samples. Under MAP, a similar reuterin effectiveness was recorded but a general shelf life improvement was reached, accounting for about 13 days in the active samples and 12 days in the reuterin‐free samples.  相似文献   

19.
Maintaining the quality of a fresh‐cut fruit or vegetable product is a major concern and a priority in the development and in the production of fresh‐cut produce products of the industry. The industry has been searching for alternative methods to protect fresh‐cut produce from decay and to prolong shelf life. The objective of this research is to enhance the quality and the shelf life of fresh‐cut pineapple by exposure to methyl jasmonate (MJ). The exposure of the diced pineapple to a MJ emulsion at a concentration of 10 ?4 M for 5 min in a sealed container decreased microbiological growth by 3 logs after 12 days of storage at 7C, compared with the control pineapple. Methyl jasmonate as vapor or as dip did not affect the firmness or the color of the fruit. Methyl jasmonate may be a practical treatment to ensure the safety and the quality of fresh‐cut pineapple and other fruits and vegetables.  相似文献   

20.
The current study was aimed to study the shelf life of beef meat at refrigeration storage using novel chitosan derivative (Ch‐D). Chitosan was modified with antimicrobial monomethyl fumaric acid (MFA). The chemical structure of the resulting material was characterized by FT‐IR and HR‐XRD. The results confirmed the successful synthesis of conjugate sample. For the shelf life study, following lots were used: control (distilled water), chitosan 0.5%, Ch‐D 0.5%. The samples were kept at 4 °C for 16 days and analyzed at 4‐day intervals. Ch‐D treatment significantly reduced the total viable counts, enterobacteriaceae, lactic acid bacteria, psychrotrophic bacteria, and yeasts–moulds when compared with the chitosan and control during refrigeration storage. The peroxide value (PV) for Ch‐D was 0.19 ± 0.04 meq O2 kg?1 fat and chitosan was 0.21 ± 0.07 meq O2 kg?1 fat and showed no significant difference (< 0.05) at the end of the storage. Thiobarbituric acid reactive substance (TBARs) value for Ch‐D was 0.48 ± 0.02 mg MDA kg?1 and chitosan was 0.57 ± 0.09 mg MDA kg?1, while the carbonyl contents for Ch‐D was 3.16 ± 0.23 nm  mg?1 protein and chitosan was 3.11 ± 0.16 nm  mg?1 protein at 16 days of storage. Values for Ch‐D and chitosan treatments were significantly lower (< 0.05) for all the quality attributes as compared with the control throughout storage. At the end of storage, Ch‐D treatment showed a significant increase (< 0.05) in lightness (L* = 41.54 ± 0.09) and yellowness (b* = 2.23 ± 0.04). The redness for control was high (a* = 6.12 ± 0.09) as compared with the treated samples. Based primarily on microbial counts, Ch‐D treatment extended the shelf life of beef meat by about 8 days, maintaining acceptable quality attributes.  相似文献   

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