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1.
In this work two potential new species for forest plantation projects in Northern Brazil were evaluated for their suitability in particleboard production. The main evaluated parameters of the laboratory boards were pH value and buffer capacity of the particles, compaction ratio, thickness swelling, modulus of elasticity (MOE), modulus of rupture (MOR) and internal bond (IB). The results showed that both species are highly suitable for particleboard production as they presented low densities (400–430 kg/m³), light color, good compressibility and no apparent adverse reactions after UF-resination.  相似文献   

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In this study, shrimp larvae diets were microencapsulated using as wall materials gum arabic, mesquite gum and maltodextrin at pH values of 4.0 and 8.0 and in a diet-to-wall material ratio of 1:2 and 1:3. The microencapsulated diets were then put in seawater in order to determine their dissolution and floatability rates. The experimental dissolution data followed a first-order kinetics model, whilst the experimental floatability data followed a first-order decay kinetics model. As a result, it was determined that the best microcapsules could be selected by using the characteristic dissolution and floatability parameters as screening criteria, without having to carry out cumbersome bioassays with all the experimental diets.  相似文献   

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Phase change materials (PCMs) are widely being used in thermal energy storage systems for solar engineering, building materials, heat pumps, spacecraft, and in textile field especially smart and technical textiles. There are large numbers of organic and inorganic PCMs that possess a wide range of melting and solidifying temperature which attracts researcher’s attention for their applications in different fields. This review paper summarizes the investigation and analysis of the available organic and inorganic PCMs, different encapsulating techniques, characterization techniques, incorporation into fiber and pad application on textiles with practical applications in the field of smart textiles.  相似文献   

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The purpose of this study was to compare the essential oil composition of Inula viscosa leaves by hydrodistillation (HDE), ultrasonic (UDE) and solvent (SE) extractions followed by hydrodistillation. The total polyphenol and flavonoid contents and their antioxidant effects were studied by different solvent of extraction: ethanol (ET), ethyl acetate (EA), methanol (ME) and aqueous (AE). The principal compounds for HDE were: 2-hexenal (3.70%), caryophyllene oxide (3.11%), γ-selinene (3.09%), 3-hexen-1-ol (2.00%), eugenol (1.70%) and trans-caryophyllene (1.34%), while for UDE were: γ-selinene (5.68%), caryophyllene oxide (4.87%), trans-caryophyllene (1.99%) and nerolidol (1.74%). The oil obtained by SE was shown to contain tridecane (3.89%), dodecane (3.08%), trans-caryophyllene (2.94%), caryophyllene oxide (2.56%) and nerolidol (2.53%). Significant changes on phenolic contents were found between the different solvent of extraction. ME and AE extracts led to the highest total polyphenol (PHL) and flavonoid (FL) amounts. The anti-radical activity and reducing power were maximal in AE and ME extract. HPLC examination established that the ferulic acid as major phenolic acid in ME and AE fractions, whereas luteolin was the main compound of EA and ET fractions.  相似文献   

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This study focused on investigating quality changes of thermally processed kale purée using an integrated targeted and untargeted approach. Low, medium, and high processing intensities (carried out at 70, 90, and 128 °C) were selected based on predetermined shelf-life targets: frozen-thawed, refrigerated, and ambient storage, respectively. The results show that that physicochemical properties determining consumer acceptability were largely dependent on the treatment intensity. The high intensity treatment resulted in the least favorable quality characteristics (distinct brown color, chlorophyll and vitamin C destruction as well as a phase separation after storage). Enzymes were inactivated with increasing thermal load. Regarding taste related compounds, there was no clear effect of processing and storage on acidity and sugar profiles. The untargeted GC–MS approach showed that increasing the processing intensity resulted in an increase of the formation of furans and sulfides. Storage clearly affected the formation of volatiles that could be, depending on the thermal treatment, attributed to lipid and/or carotenoid oxidation, continuation of Maillard reactions, and enzyme catalyzed reactions.Industrial relevanceCompared to other Brassicaceae vegetables such as as broccoli, cauliflower and different types of cabbages, kale so far has received little attention from an industrial processing point of view. However, kale has been reported to contain high nutritional value due to its important content of minerals, bioactive compounds and fibre. With the growing health awareness of consumers and increasingly busy lifestyles, the demand for more convenient fruit and vegetable products with high nutritional content has increased. Therefore, research to obtain more insight on the effect of processing and storage on kale purée is important.  相似文献   

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The effects of dietary enrichment of pig diets with DHA from a marine source (Algatrium®) and α-tocopheryl acetate on the nutritional and sensory characteristics of pork and pork products were evaluated. Raw and cooked hams, and dry-cured shoulders from pigs fed with three diets (control, control supplemented with 0.3% DHA plus 50 ppm α-tocopheryl acetate and control with 200 ppm α-tocopheryl acetate) were used. The treatments did not cause any significant differences in proteolytic and antioxidant enzyme activities, except on catalase (CAT) which increased significantly in raw hams from pigs fed DHA supplemented diets. Vitamin E accumulated in samples with α-tocopheryl acetate supplementation. DHA added to the diet increased the DHA level by 87% compared with the control treatment in both raw and dry-cured shoulders, and exceeded 82% in cooked hams. In consequence, the incorporation of the n − 3 source in the diet significantly reduced the n − 6/n − 3 ratio in all products. The ratio reduction ranged from 51% in dry-cured shoulders to 65% in cooked and raw hams.  相似文献   

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The aim of this study was to assess the hygienic quality of raw milk used in the manufacture of S?o Jorge, a Protected Denomination of Origin Portuguese semihard cheese, as well as to ascertain the sanitary conditions prevailing during its processing. Viable counts of Enterobacteriaceae and Micrococcaceae were accordingly obtained, pertaining to 21 independent batches (including samples of raw milk, curd, and cheeses after 1, 3, and 4 months of ripening), from 7 dairy farms. Standard plate counts (log CFU per milliliter or per gram) ranged from 6.1 to 8.6 in raw milk, whereas they ranged from 7.0 to 8.0 in 4-month-old cheeses. Viable counts of Enterobacteriaceae ranged between 5.9 and 7.0 in raw milk and between 0.0 and 1.3 in 4-month-old cheeses. Species identified within this family encompassed Klebsiella oxytoca, Klebsiella cloacae, Klebsiella pneumoniae, Enterobacter sakazakii, and Escherichia coli; Klebsiella ornithinolytica, Klebsiella terrigena, and Serratia odorifera were detected only in raw milk. No Salmonella whatsoever could be detected in any of the samples. Viable counts of Micrococcaceae ranged between 4.7 and 5.9 and between 1.3 and 3.3 in raw milk and 4-month-old cheeses, respectively. Species identified within this family encompassed Staphylococcus sciuri, Staphylococcus epidermidis, Staphylococcus saprophyticus (which was found mainly in ripened cheeses), and Staphylococcus aureus (which was not detected in 4-month-old cheeses). Accompanying physicochemical analyses included determination of moisture, salt, and pH. Statistical analyses revealed a negative correlation between salt content and viable numbers of Enterobacteriaceae in cheese, whereas in the case of Micrococcaceae, a more negative correlation was found between viable numbers and moisture content than between viable numbers and pH. The results of our study indicate, in general, poor milk handling conditions in all farms, given that the indicators total mesophile and Enterobacteriaceae counts were high, between 100- and 1,000-fold those enforced by international standards pertaining to the matrices in question. However, by the time of regular consumption (i.e., after 4 months of ripening), S?o Jorge cheeses exhibit low levels of contamination by Enterobacteriaceae and S. aureus, as well as absence of Salmonella.  相似文献   

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Bovine leukemia virus (BLV) infection, endemic in North American dairy herds, has production-limiting effects. A literature review of available papers published since 1995 concerning BLV transmission and its control was conducted. Although confirmed transmission routes were reviewed (blood, natural breeding, in utero, colostrum, and milk), there is still a lack of detailed information on other specific risks for transmission (e.g., contact transmission and hoof-trimming knives). Eradication of BLV has been achieved by combined management, segregation, and culling approaches. In contrast, although sole implementation of best management practices aimed at prevention of BLV transmission has decreased within-herd BLV prevalence, it has not eradicated BLV from a herd. Therefore, control and eradication of BLV by best management practices only should be further investigated. Additionally, the role of proviral load in infected cattle was investigated. Cattle with a high proviral load seem to be more likely to infect others, whereas those with a very low proviral load seem to have low risks of transmitting BLV. Information on proviral load could be taken into account when controlling BLV in high-prevalence herds. In conclusion, there is a need for detailed, large-scale studies investigating roles of specific transmission routes, knowing proviral load of infected individuals.  相似文献   

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《Journal of dairy science》2022,105(6):5349-5369
The objectives were as follows: (1) establish cow-level thresholds for prepartum nonesterified fatty acids (NEFA) and postpartum NEFA, β-hydroxybutyrate (BHB), and haptoglobin (Hp) concentrations associated with negative health events; (2) evaluate cow-level associations between biomarkers and 305-d mature equivalent milk at the fourth test day (ME305) and reproductive performance; and (3) identify herd-alarm levels (proportion of cows sampled above the critical threshold) for biomarkers that are associated with herd-level changes in disorder incidence (displaced abomasum and clinical ketosis), reproductive performance, and ME305. In a prospective cohort study, 1,473 cows from 72 farms were enrolled from the northeastern United States. Blood samples were collected from the same 11 to 24 cows per herd during the late-prepartum and early-postpartum periods. Whole blood was analyzed for postpartum BHB concentrations; plasma was analyzed for prepartum and postpartum NEFA and postpartum Hp concentrations. Critical thresholds for the biomarkers associated with health events for all cows were established using a receiver operating characteristic curve analysis. Poisson, linear mixed effects, and Cox proportional hazards models investigated the association of the biomarkers with health and performance. The prepartum NEFA and Hp threshold associated with culling was ≥0.17 mmol/L and 0.45 g/L, respectively. The postpartum NEFA and BHB thresholds associated with diagnosis of metritis, displaced abomasum, or clinical ketosis were ≥0.46 mmol/L and ≥0.9 mmol/L, respectively. Multiparous cows with prepartum NEFA concentration ≥0.17 mmol/L produced 479 kg less ME305. Multiparous and primiparous cows with postpartum NEFA concentration ≥0.46 mmol/L produced 280 kg less and 446 kg more ME305, respectively. Cows with BHB concentration ≥0.9 and ≥1.1 mmol/L produced 552 kg more ME305 and had a 20% decreased risk of pregnancy within 150 d in milk, respectively; however, multiparous cows with BHB concentration ≥1.5 mmol/L produced 376 kg less ME305. Cows with Hp concentration ≥0.45 g/L produced 492 kg less ME305 and had 28% decreased risk of pregnancy within 150 DIM. Cows with Hp concentration ≥0.45 g/L had 19% decreased pregnancy risk to first service (PRFS). Herds above the herd-alarm levels for prepartum NEFA had a 6.0-percentage unit increase in disorder incidence and a 6.0-percentage unit decrease in 21-d pregnancy rate (PR) for multiparous cows, a 3.9-percentage unit increase in PR and a 5.8-percentage unit increase in the probability of pregnancy for primiparous cows. Herds above the herd-alarm levels for postpartum NEFA had a 5.8- and 4.2-percentage unit increase in disorder incidence for multiparous and primiparous cows, respectively, a 789 kg decrease in ME305 for multiparous cows, and a 6.8- and 6.3-percentage unit decrease and increase in PR and PRFS for multiparous cows, respectively. Herds above the herd-alarm levels for BHB had an 8.5-percentage unit increase in disorder incidence, a 332 and 229 kg increase in ME305 for primiparous and multiparous cows, respectively, and a 3.2-, 5.2-, and 7.0-percentage unit decrease in PR, probability of pregnancy, and PRFS, respectively. Herds above the herd-alarm levels for postpartum Hp had a 5.3-percentage unit increase in disorder incidence. At the cow level and herd level, elevated biomarker concentrations were associated with an increased disorder risk and varied performance responses.  相似文献   

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Salpicão de Vinhais and Chouriça de Vinhais are traditional dry-fermented meat sausages produced in the North of Portugal. The microbiological profile during production of both products was followed in three small processing units. Lactic acid bacteria were the most prevalent microorganisms, with enhanced growth during the smoking process and a consequent decrease of pH.This study demonstrated that when highly contaminated raw ingredients are used, pathogens might not be eliminated during processing (from seasoning until the end of smoking). Therefore, it is important to highlight that to produce safe Salpicão and Chouriça following traditional recipes and methodologies it is necessary to work under hygienic conditions using raw materials of good microbiological quality.Industrial relevancePreservation of pork meat in the form of semi-dry, fermented and smoked products having a long shelf-life, is an age-old artisanal process that is still practiced in many areas of the world. In many rural communities production has a significant impact on the local economy and food supply, but these products are now becoming increasingly popular in urban areas. In a more widespread distribution of such artisanal products, it is important that consumers are not exposed to undue risks of food-borne infections or intoxications. This study investigates the evolution of the microflora and microbiological safety during the production processes of two such traditional products in the North of Portugal, and during storage of the final products.  相似文献   

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《Journal of dairy science》2023,106(8):5197-5217
Mammalian colostrum, known as “liquid gold,” is considered a valuable source of essential nutrients, growth factors, probiotics, prebiotics, antibodies, and other bioactive compounds. Precisely for this reason, bovine colostrum (BC) is an emerging ingredient for the feed, food, and pharmaceutical industries, being nowadays commercially available in a variety of forms in several countries. Moreover, quite a large number of functional foods and supplements for athletes, human medicines, pet nutrition plans, and complementary feed for some livestock categories, such as piglets and calves, contain BC. The amount of BC yielded by a cow after calving represents approximately 0.5% of the yearly output in dairy breeds. For its nutritional properties and low availability, BC is characterized by a greater market value and an increasing demand compared with other by-products of the dairy sector. However, information regarding the market size of BC for the food and pharmaceutical industries, as well as future developments and perspectives, is scarcely available in the scientific literature. This lack can be attributed to industrial secrecy as well as to the relatively small scale of the BC business when compared with other dairy products, which makes the BC market limited, specific, and intended for a restricted audience. From a legal perspective, regulations assign BC to the large family of milk-derived powders; thus, collecting specific production data, as well as import-export trend information, is not straightforward and can result in unprecise estimates. Given that the interest in BC is increasing in different fields, it is important to have an overview of the production steps and of pros and cons of this emerging ingredient. The present narrative review discloses why BC has started to be considered a product rather than a by-product of the dairy industry. Moreover, the present document aims to summarize the existing methodologies used to assess BC quality in terms of immunoglobulin concentration, the different applications of BC in the industry, and the BC processing technologies. Finally, a panoramic view of the current international market is provided for the first time for this dairy product.  相似文献   

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The effect of addition of amino acids, other than asparagine, on the kinetics of acrylamide formation and elimination reactions was investigated under low moisture conditions using equimolar asparagine-glucose-amino acid model systems, heated at temperatures between 120 and 200 °C. To this end, glutamine and cysteine were selected. A mechanistic model was proposed, composed of the basic reactions occurring in an asparagine-glucose control system on the one hand and of extra reactions in which the additional amino acids are assumed to be involved. Using this model, multiresponse modelling was applied on the responses measured (the same as before plus the concentration of the second amino acids added). In order to test the consistency of the basic model and to elucidate the mechanism(s) by which the additional amino acids act on acrylamide formation and elimination, the kinetic parameters for the different reaction steps of the basic model were fixed to the values estimated for the control system. Addition of glutamine had a slightly increasing effect on the yield of acrylamide, resulting in a significant increased rate constant for acrylamide formation and elimination. Cysteine on the contrary, had a pronounced reducing effect (>99%) on the acrylamide yield, which can mainly be attributed to an additional acrylamide elimination reaction which is dependent on the cysteine concentration.  相似文献   

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