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1.
Lowtemperatureplasmatreatmentofwoolinducedchemicalandphysicalchangesob viouslyonfibersurface .Thesechangeswillcausethechangesofdyeing property .Itwillbedifferentfromuntreatedwoolintermsofthe propertiesofdyepenetrationandthebindingforcewithdyes .Alotofstu…  相似文献   

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In this study, we compared the effect of basil essential oil (EO) and various packaging conditions on “Anthotyros,” a Greek whey cheese. This cheese was stored at 4 °C under aerobic (A), vacuum (V), and modified atmosphere (M, 40%/60%; CO2/N2,) conditions, without or with (AB, VB, and VM) basil EO added to the cheese samples to a final concentration of 0.4% (v/w). The quality characteristics and the shelf life of both untreated and basil EO-treated cheese were assessed using microbiological, physicochemical, and sensory parameters. Microbiological results revealed that either modified atmosphere/vacuum packaging (MAP/VP) singly or in combination with basil EO delayed microbial growth as compared to the control (A) samples. The sensory and microbiological data showed that the combined use of MAP and VP with added basil EO extended the shelf life of fresh Anthotyros (4 °C) by approximately 10–12 days (treatment MB) and 6 days (treatment VB) as compared to aerobic packaging (A). Under these treatments, whey cheese samples maintained good sensory characteristics. This study has shown that the combined use of either VP or MAP, and basil EO, can extend the shelf life of whey cheese and maintain the freshness and the sensorial characteristics of the product.  相似文献   

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Effects of modified atmosphere and polymeric packaging material on the physical (mass loss, color, firmness), chemical (pH, total titratable acidity, total soluble solid, total phenolic content, total anthocyanin content), and sensory quality of “Napoleon” cherry (Prunus avium L. “Napoleon”) were studied. While lightness (L*) remained fairly unchanged, redness (a*), yellowness (b*), and chroma (C*) decreased during a 42-day storage period, resulting in darker fruit. Firmness did not differ significantly from the initial values (P ≤ 0.05) after 42 days of storage at 0°C. pH increased for all treatments over the storage period. In general, total titratable acidity increased during the first 2 weeks, and then decreased afterwards. Packaging significantly reduced mass losses, which were 24.08%, 0.50%, 0.39%, and 0.81% for control (unpackaged), polypropylene tray/biaxially oriented polypropylene film (PP/BOPP), polypropylene tray/cast polypropylene film, and polyvinyl chloride-polyethylene tray/polyethylene terephthalate-polyethylene films, respectively. Modified atmosphere packaging was found beneficial on extending the shelf life of fruit during storage. The shelf life of “Napoleon” cherries was suggested as 28 days for packaged samples and 14 days for unpackaged samples at 0°C. Samples packaged with PP/BOPP under 21% O2 79% N2 preserved their physical, chemical, and sensory quality better than other treatments.  相似文献   

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Residues of pesticides in food are influenced by processing such as fermentation. Reviewing the extensive literature showed that in most cases, this step leads to large reductions in original residue levels in the fermented food, with the formation of new pesticide by-products. The behavior of residues in fermentation can be rationalized in terms of the physical-chemical properties of the pesticide and the nature of the process. In addition, the presence of pesticides decrease the growth rate of fermentative microbiota (yeasts and bacterias), which provokes stuck and sluggish fermentations. These changes have in consequence repercussions on several aspects of food sensory quality (physical-chemical properties, polyphenolic content, and aromatic profile) of fermented food. The main aim of this review is to deal with all these topics to propose challenging needs in science-based quality management of pesticides residues in food.  相似文献   

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This review represents systematic and integrated picture of pesticide exposure to plant and its effect on growth and metabolism. Decades ago, agrochemicals were introduced aiming at enhancing crop yields and protecting crops from pests. Due to adaptation and resistance developed by pests to chemicals, every year higher amounts and new chemical compounds are used to protect crops, causing undesired side effects and raising the costs of food production. Biological chemical free agriculture is gaining also more and more support but it is still not able to respond to the need for producing massive amounts of food. The use of agrochemicals, including pesticides, remains a common practice especially in tropical regions and South countries. Cheap compounds, such as DDT, HCH, and Lindane, that are environmentally persistent, are today banned from agriculture use in developed countries, but remain popular in developing countries. As a consequence, persistent residues of these chemicals contaminate food and disperse in the environment. Therefore, the thrust of this paper was to review the application of pesticides effect early from germination to growth of the plant, leading to alteration in biochemical, physiological and different enzymatic and non-enzymatic antioxidants which ultimately affect the yield and resulted in residues in plant, vegetables, and fruits.  相似文献   

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Colour compounds of rosé wines can be very sensitive to storage conditions because of the low levels of naturally-occurring protective compounds. This article deals with the effects of storing rosé wines under different temperature and light conditions, with regard to their colour characteristics and anthocyanin profile. Samples were taken seven times altogether over a period of 582 days. At the end of the storage period, the resulting differences in the wines were studied by μLC/MS. It was found that storing rosé wine at room temperature caused a reduction of 50% in the levels of anthocyanins compared to storing them at 3°C. Increasing the storage temperature to 45°C caused the total decomposition of all anthocyanins. Furthermore, during the maturation of the wine, a loss of sugar moiety, hydration of aglycone, and the formation of the corresponding chalcone or diketone were observed. Levels of pyranoanthocyanins in the wines were studied as well. Vitisins A and B, hydroxyphenyl-pyranomalvidin-3-glucoside, dihydroxyphenyl-pyranomalvidin-3-glucoside, and methoxyhydroxyphenyl-pyranomalvidin-3-glucoside were identified. The highest levels of both chalcones and pyranoanthocyanins were found in samples stored at room temperature. The effect of irradiation on the pigments also appeared to be significant but less important than the effect of high temperature.  相似文献   

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Drying uniformity, microstructure, apparent density, rehydration, and texture properties were measured to evaluate the quality of stem lettuce slices dried in a pulse-spouted bed microwave freeze dryer. Drying was carried out in a 5-cm (o.d.) vacuum chamber at 80?±?5 Pa, mean microwave power level of 3.2 W?g?1 and pulse-spouting time interval of 10 min. Results show that microwave freeze-dried products in the pulse-spouted mode dried more uniformly as compared to those dried in steady spouted bed mode. Pulse-spouted bed mode also resulted in dried stem lettuce slices with lower discoloration, more uniform and compact microstructure, higher rehydration capacity (RC) as well as greater hardness after rehydration over shorter drying time relative to those obtained in a steady spouting condition.  相似文献   

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Understanding the influence of processing operations such as drying/dehydration, canning, extrusion, high hydrostatic pressure, pulsed electric field, and ohmic heating on the phytochemicals of fruits, vegetables, and grains is important in retaining the health benefiting properties of these antioxidative compounds in processed food products. Most of the previous investigations in the literature on the antioxidants of fruits, vegetables, and grains have shown that food-processing operations reduced the antioxidants of the processed foods, which is also the usual consumer perception. However, in the last decade some articles in the literature reported that the evaluation of nutritional quality of processed fruits and vegetables not only depend on the quantity of vitamin C but should include analyses of other antioxidant phytochemicals and antioxidant activity. Thermal processing increased the total antioxidant activity of tomato and sweet corn. Most importantly, analysis also depends on the condition, type, and mechanism of antioxidant assays used. This review aims to provide concise information on the influence of various thermal and nonthermal food-processing operations on the stability and kinetics of health beneficial phenolic antioxidants of fruits, vegetables, and grains.  相似文献   

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Besides the positive effects, γ-irradiation and heat treatment of foods usually lead to changes in their structure or composition, thus influencing their quality. In view of the fact that herbs and spices are important source of antioxidants in a human diet, any kind of treatment can have an impact on their antioxidant status, as well. In this contribution, we review the effects of γ-radiation and heat treatment on some constituents and antioxidant properties of culinary herbs and spices. Both methods of treatment result in some common qualitative changes in herbs and spices, mostly in the content of polyphenols or volatile components. The results of antioxidant testing assays are sometimes contradictory in observed effect or trends, in dependence on the manner of treatment and character of spice matrix. Based on this review, the effects of γ-radiation or heat processing on antioxidants, or the vitamin content in herbs and spices is still lacking, which makes the direct assessment of the effect of treatment on the antioxidant status of herbs and spices practically impossible. However, the changes in composition that have been observed to date suggest that they have only a small effect on the behavior of herbs and spices in a real food matrix.  相似文献   

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A mixture design approach was employed to determine the effect of κ - and λ-carrageenans of Oaxaca cheese fat reduction on melting (Schreiber and Melt Area), color, protein, moisture, and yielding. Melting was affected mainly by the fat content, but κ -carrageenan seems to improve this property. Color was affected by fat content, with a relatively profiting effect of λ-carrageenan, related to higher moisture content and higher cheese yielding. Incorporation of low concentrations of carrageenans allowed a considerable fat reduction with no detrimental effect on Oaxaca cheese overall quality.  相似文献   

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The effect of nisin alone and in combination with Microgard? on the natural microbial flora of ricotta cheese and in post-process contamination with Listeria innocua was studied. Microbial groups studied were mesophilic, psychrotrophic, proteolytic, lactic acid and coliform bacteria, and total molds and yeasts. Considering the evolution of all microbial groups and failure criteria adopted for mesophilic and coliform bacteria, this product reached the end of its shelf life before 5 days, which is insufficient time for product commercialization. The combined use of nisin and Microgard? proved to be more effective than the individual application on these microbial groups, resulting in a 13 days shelf life extension. Additionally, the combined treatment reduced the growth of L. innocua as a post-process contamination.  相似文献   

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ABSTRACT: A novel nano-packing material with lower relative humidity, oxygen transmission rate and high longitudinal strength was synthesized by blending polyethylene with nano-powder (nano-Ag, kaolin, anatase TiO2, rutile TiO2), and its effect on preservation quality of strawberry fruits (Fragaria ananassa Duch. cv Fengxiang) was investigated during storage at 4 °C. Results showed that nano-packaging was able to maintain the sensory, physicochemical, and physiological quality of strawberry fruits at a higher level compared with the normal packing (polyethylene bags). After a 12-d storage, decreases in the contents of total soluble solids, titratable acidity, and ascorbic acid of nano-packing were significantly inhibited. Meanwhile, decay rate, anthocyanin, and malondialdehyde contents were decreased to 16.7%, 26.3 mg/100g, 66.3 μmol/g for nano-packing and 26.8%, 31.9 mg/100g, 75.4 μmol/g for normal packing; polyphenoloxidase (PPO) and pyrogallol peroxidase (POD) activities were significantly lower in nano-packing than the control. These data indicated that the nano-packaging might provide an attractive alternative to improve preservation quality of the strawberry fruits during extended storage. Practical Application: Nano-packing exhibited identified quality benefits applicable to the preservation of fresh strawberry. Furthermore, nano-packing has the advantages of simple processing and feasibility to be industrialized in contrast with other storages. Thus, the utilization of nano-packing will likely assist commercial producers and retailers in extending the shelf life of products over a broader range in the future.  相似文献   

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In recent years, mainly due to the specific health benefits associated with (1) the discovery of bioactive peptides in protein hydrolysates, (2) the reduction of protein allergenicity by protein hydrolysis, and (3) the improved protein digestibility and absorption of protein hydrolysates, the utilization of protein hydrolysates in functional foods and beverages has significantly increased. Although the specific health benefits from different hydrolysates are somewhat proven, the delivery and/or stability of these benefits is debatable during distribution, storage, and consumption. In this review, we discuss (1) the quality changes in different food protein hydrolysates during storage; (2) the resulting changes in the structure and texture of three food matrices, i.e., low moisture foods (LMF, aw < 0.6), intermediate moisture foods (IMF, 0.6 ≤ aw < 0.85), and high moisture foods (HMF, aw ≥ 0.85); and (3) the potential solutions to improve storage stability of food protein hydrolysates. In addition, we note there is a great need for evaluation of biofunction availability of bioactive peptides in food protein hydrolysates during storage.  相似文献   

17.
The effects of high-pressure (HP) treatment (400?MPa at 42 °C for 5 min) and pulsed electric field (PEF) processing (25 kV/cm at 57 °C for 280 μs) on ascorbic acid, total carotenoids, total phenolic compounds and total antioxidant capacity (TEAC and ORAC) of an orange juice–milk (OJ-M) beverage along the storage time at 4 °C were compared with a conventional heat preservation technology used in industry (90 °C for 15 s). During storage, ascorbic acid, total carotenoids and antioxidant capacity (TEAC) depleted with time regardless of the treatment applied. Instead, total phenolic content and antioxidant capacity measured by the ORAC method increased at the end of the storage. Non-thermal-treated beverage had less non-enzymatic browning than the thermally pasteurized one. There were no significant variations in the hidroxymethylfurfural (HMF) content of the HP- and PEF-treated OJ-M, whilst a significant increase was obtained after thermal treatment. During refrigerated storage, HMF was always below the maximum values established. The HP treatments reduced the L* value of the treated beverages immediately after processing and during refrigerated storage and induced an increase in total colour differences of beverages treated by HP compared with PEF and thermally processed orange juice–milk. Hence, alternative methods such as HP and PEF may give new opportunities to develop orange juice–milk with an equivalent shelf life to that of thermally treated orange juice mixed with milk in terms of microbial, physicochemical and nutritional characteristics.  相似文献   

18.
Sev,” savory prepared from chickpea flour is a popular snack item for its appealing flavor and texture. Mapping and positioning of market samples consisting different varieties like Small (S1, S2, S3), Medium (M1, M2, M3), and Big (B1, B2, B3, B4) were carried out using principal component analysis. Samples were subjected to sensory profiling resulting in small variety samples were crisper compared to other varieties. Texture measurement indicated breaking strength was higher in big variety samples. Color analysis showed significant difference in L*, a*, and b* values. Principal component analysis results indicated that S1 and S2 were associated with crispness, uniform texture, and typical fried oil aroma. Commercially available sev samples were significantly different in their quality parameters, which was indicated by the study. Study showed that small variety (S3) had the highest overall quality among all the samples, which also had high sensory scores for crispness.  相似文献   

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