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1.
The ingestion of probiotic lactic acid bacteria has been evaluated and noted that it has an effect on the balance of desirable microbiota in the gastrointestinal tract. Lactobacillus gasseri demonstrates good survival in the gastrointestinal tract, and it has been associated with a variety of probiotic activities and roles, including the reduction of fecal mutagenic enzymes, the production of bacteriocins and the stimulation of macrophages immunomodulation. The aim of the study was to evaluate the effects of a pool of L. gasseri strains isolated from the feces of breastfed infants added in the human milk of healthy women. The milk was both pasteurized and unpasteurized, to verify the cell cytotoxicity of macrophages and to quantify the production of immunologic mediators such as IL-4, IL-6, IFN-γ, TNF-α, NO and oxygen intermediary compounds (H2O2). The administration of raw human milk and pasteurized human milk to infants is a regular, encouraged practice in units of intensive therapy (UITs) and our present investigation verified the beneficial effect of addition of a pool of L. gasseri to pasteurized human milk (PHML). Our results show that probiotic supplementation helped to maintain cell viability, reduced IL-6 and IFN-γ production and stimulated TNF-α, NO, H2O2, IL-4 production. Nevertheless, the results indicate that the addition of lactobacillus to human milk was not a determinant in the production of TNF-α. L. gasseri added to breast milk did not present a cytotoxic risk, and the addition ofL. gasseri to pasteurized milk of human milk bank would benefit newborns that depend on milk banks for the colonization of more desirable microbiota.  相似文献   

2.
This study evaluated the effect of carbon dioxide addition on microbiological quality during refrigerated storage of raw milk collected in Curitiba city, Brazil. A three factor-two level full factorial design was used to investigate the effect of the pH (5.8-6.4), storage time (0-10 days) and storage temperature (5-10 ℃), on the responses, namely, mesophiles, psychrotrophs, lipolytic psychrotrophs and proteolytic psychrotrophs counts. Results showed that increase in pH and storage time had significant effect on the microbial count. No significant effect of storage temperature was observed for all the microorganisms studied. All responses were well predicted by selected mathematical models, as denoted by coefficient of determination above 0.95.  相似文献   

3.
Goat milk ice cream was made with various sources of fat ingredients such as cream, soybean oil, rice bran oil and butter with the purpose of seeking the fat ingredient source instead of fat source from cow origin. The physical properties and the sensory evaluation of ice cream were then investigated. The firmness of goat milk ice cream mixed with rice bran oil, butter and cream were not significantly different before aging at 4 ℃ for 8 h. All of them gave the overrun between 51%-63% and the one with butter was the highest. The meltdown rate of all types of fat ingredients are not significantly different, being in the range of 0.86-0.88 g/min. According to sensory evaluation, the cow milk ice cream with cream was mostly accepted in all attributes such as appearance, smoothness, whiteness, melting in mouth and odor while the goat milk with cream and butter are the second and third. Nevertheless, the goat milk ice cream with soybean oil and rice bran oil were moderately accepted in overall preferences.  相似文献   

4.
Soy yogurt has gained significant popularity due to its nutritional health benefits. The objectives of this study were to develop flavored yogurt from soybean milk with reduced soy aftertaste by the addition of 30% (wt/wt) strawberry or orange jam in conjunction with a lactic acid fermentation. Soy milk-based yogurt products were assessed for microbial quality and for acceptability by a panel of Jordanian and Malaysian consumers. Sixty-one individuals, of whom 75.4% (n = 46) were Jordanian and 24.6% (n = 15) were Malaysian, evaluated the plain and flavored soy milk-based yogurt. The overall acceptability of orange and strawberry soy yogurt was rated significantly higher than plain soy yogurt. In general, the orange and strawberry soy yogurt received higher sensory ratings from Malaysian than Jordanian consumers. In addition, formulations with orange jam received higher scores than those flavored with strawberry. Shelf life tests showed that soy yogurt was acceptable for at least 8 d without perceptible spoilage. Therefore, the approach used yielded flavored products with better acceptability and improved sensory attributes, including decreased intensity of off flavor, with suitable shelf life at 4 ℃.  相似文献   

5.
The purpose of this study was to determine the occurrence and antimicrobial resistance of Streptococcus spp. isolated from fresh ewe's milk and consequently to draw conclusions concerning the health condition of the animal flocks and the current trends of antibiotic use in small ruminants. A total of 77 mountainous sheepfolds were investigated representing 10% of all transhumant sheep and goats flocks in the area. Duplicate milk samples were collected from January to February transferred to the laboratory and analyzed for the presence of Streptococcus spp. by using the serial dilution method and plating on the surface of Slanetz and Bartley agar. The isolates were tested against nine antimicrobial agents with the Kirby-Bauer disk diffusion method. The results showed that Streptococcus spp. occurred in 84.4% of the samples and in counts ranged between 1.8 log CFU/mL and 4.6 log CFU/mL. Concerning susceptibility, only 1.3% of the isolates were resistant to all antimicrobials while 27.3% were fully susceptible. Resistance to cefepime was the most common (93.1%) observation followed by resistance to ampicillin (82.1%), ciprofloxacine (58.3%) and meropenem (51.9%). The isolates were vancomycin susceptible at a rate of 83.6%. Multidrug resistance to at least three antibiotics was observed to be 22.1% of Streptococcus spp.. Given the prevalence of Streptococcus spp. and the elevated resistance of isolates to various antibiotics it is concluded that further examinations and even interventions are required in order to pertain the appropriate animal health and milk quality.  相似文献   

6.
The study has been carried out to elucidate what contents of heavy metals were typical for canned milk products - evaporated (TS 25.5-28.5%) sterilized milk and condensed sweetened milk, produced in Lithuania in the period 1983-1997. The influence of storage time upon the level of Sn, Pb, Cu and Zn in the products has also been determined. The results show that the most considerable changes occurred in Cu concentration, which gradually decreased from the maximum level in 1983-1985 (2.23±0.18mg/kg) to the minimum level in the latest years (0.44±0.01 mg/kg). Such variation of copper content in canned milks can be closely connected with its changes in raw milk. Zinc content in canned milk products also was in good agreement with raw milk. The content of tin and lead in the canned products many times exceeded their concentration in raw milk and ranged from 28±2 and 0.093±0.005 to 114±4 and 0.29±0.01 mg/kg, respectively. It has been determined that the dependence of the concentration of tin and lead on the storage time of concentrated (or evaporated) sterilized milk is nearest to the parabolic, and in sweetened condensed milk to the exponential function, whereas the small increase of copper and zinc concentrations can be described by straight-line function. The functional dependence obtained enables one to predict the Sn and Pb level in canned evaporated milk products after storage and to foresee the safe initial concentration of these metals in freshly produced evaporated milk, assigned for storage.  相似文献   

7.
Weekly milk yields of 1022 Holstein heifers from 61 sires were used to derive coefficients of the lactation curves using modified gamma and inverse polynomial functions. The natural logarithm of a modified gamma function was ln(yn) = ln (a) + b ln (n) + cn + u sin (x) + v cos (x), where a, b, c, u, and v are coefficients to be estimated; n is the day of lactation; and x is the day of year. Estimates of a, b, and c were combined to define persistency [-(b + 1) ln c], week of peak yield (b/c), and peak yield [a(b/c)be-b]. The inverse polynomial function was n/yn = A0 + A1n + A2n2, where A0, A1, and A2 are coefficients to be estimated. Variance and covariance components for the coefficients of the lactation curve were estimated by the multitrait restricted maximum likelihood method using canonical transformation. Heritability estimates were ln (a) .11, b .07, c .04 u .01, v .04, A0 .28, A1 .26, A2 .21, persistency .21, week of peak .18, peak yield .23, and 308-d milk yield .41. Genetic correlations indicated that selection for faster rate of increase to peak production would result in higher 308-d milk production, higher peak yield, and greater persistency.  相似文献   

8.
分析了UHT奶非商业无菌的原因。依据GB/T4789.26-2003和ATD细菌生化鉴定义对UHT奶进行检测及细菌鉴定。结果表明,同一品牌不同品种的6种UHT奶中,有5种为非商业无菌;分别检出蕈状芽孢杆菌短小芽孢杆菌。结论:UHT乳质量把关须从原料乳,生产工艺,生长环境控制。  相似文献   

9.
A sensitive and selective method for the determination of six non-steroidal anti-inflammatory drugs (NSAIDs) in bovine plasma was developed. An improved method for the determination of authorised and non-authorised residues of 10 non-steroidal anti-inflammatory drugs in milk was developed. Analytes were separated and acquired by high performance liquid chromatography coupled with an electrospray ionisation tandem mass spectrometer (ESI–MS/MS). Target compounds were acidified in plasma, and plasma and milk samples were extracted with acetonitrile and both extracts were purified on an improved solid phase extraction procedure utilising Evolute? ABN cartridges. The accuracy of the methods for milk and plasma was between 73 and 109%. The precision of the method for authorised and non-authorised NSAIDs in milk and plasma expressed as % RSD, for the within lab reproducibility was less than 16%. The % RSD for authorised NSAIDs at their associated MRL(s) in milk was less than 10% for meloxicam, flunixin and tolfenamic acid and was less than 25% for hydroxy flunixin. The methods were validated according to Commission Decision 2002 European Commission Decision. 2002. Decision(2002/657/EC) of 12 August 2002 implementing Council Directive 96/23/EC concerning the performance of analytical methods and interpretation of results. Off J Eur Commun, L221: 836.  [Google Scholar]/657/EC.  相似文献   

10.
The effect of introduction of milk proteins in a novel homogenized canned meat of the "Kroshka" type for child and dietetic nutrition was studied. It was shown in animal experiments that introduction of sodium caseinate and fat-free curds in a 5% amount into canned meat raises the biological value of canned food and exerts a favourable effect on some metabolic parameters of the growing organism.  相似文献   

11.
2,2-Bis(4-hydroxyphenyl)propane bis(2,3-epoxypropyl) ether (BADGE) is used in the manufacture of lacquers for coating the inside of food and beverage cans. In June 1996 the EC Scientific Committee for Food temporarily increased the specific migration limit applying to BADGE to 1 mg/kg pending consideration of additional toxicological data. In order to find out if there is migration of BADGE from can coatings into foods, a 'worst case' sampling exercise has been conducted to survey those canned foods where the propensity for migration of BADGE was judged to be highest. The foods surveyed include canned fish in oil, meat and milk and, altogether, BADGE was determined in 181 retail samples. Analysis for BADGE was conducted, in duplicate, by HPLC with fluorescence detection with confirmation of BADGE identity by GC/MS analysis using selected ion monitoring. BADGE was found at levels exceeding 1 mg/kg in seven of the 15 canned anchovy samples and five of the 22 sardine samples purchased during the period September 1995-July 1996. Infrared analysis of the can coatings provided strong evidence that the higher BADGE levels found were associated with use of PVC organosol lacquers, although in some cases cans coated with organosols gave low BADGE results. For canned sardine samples found to contain greater than 0.5 mg/kg BADGE in the total contents, a replicate can was opened and separate analyses performed on the drained fish and the oil. The results clearly showed that BADGE concentrations in the oil were about 20 times higher than in the drained fish. Further samples of canned sardines and anchovies were purchased in June/July 1997 and, in all cases, BADGE levels were found to be below 1 mg/kg. In the other retail canned foods, BADGE was not detectable (DL = 0.02 mg/kg) or detected at concentrations well below the temporary SML of 1 mg/kg.  相似文献   

12.
Pasteurisation is a vital unit operation to inactivate the spoilage organisms and enzymes present in the milk. Computational fluid dynamics (CFD) modelling can be used as a tool to determine the temperature distribution pattern inside canned milk during thermal processing. In this study, a CFD model was developed for the pasteurisation process of canned milk at 74°C and 85°C and validated with the experimental measurements. Moreover, the effect of can rotation (5, 50 and 100 rpm) on processing time and pasteurisation value was investigated. This study predicted rotation of can with 5 rpm was more effective than stationary positioned can during pasteurisation.  相似文献   

13.
The cyclic bacteriocin enterocin AS-48 was tested on a cocktail of two Geobacillus stearothermophilus strains in canned food samples (corn and peas), and in coconut milk. AS-48 (7 μg/g) reduced viable cell counts below detection levels in samples from canned corn and peas stored at 45 °C for 30 days. In coconut milk, bacterial inactivation by AS-48 (1.75 μg/ml) was even faster. In all canned food and drink samples inoculated with intact G. stearothermophilus endospores, bacteriocin addition (1.75 μg per g or ml of food sample) rapidly reduced viable cell counts below detection levels and avoided regrowth during storage. After a short-time bacteriocin treatment of endospores, trypsin addition markedly increased G. stearothermophilus survival, supporting the effect of residual bacteriocin on the observed loss of viability for endospores. Results from this study support the potential of enterocin AS-48 as a biopreservative against G. stearothermophilus.  相似文献   

14.
《Food chemistry》2004,88(2):233-236
Fluoride content in black tea in various commodities, packages, and preparation processess was assayed and its safety evaluated. A fluoride ion selective electrode method was used to determine the fluoride content in 20 tea samples, in various black tea commodities, namely stick-shaped, granular, and canned or bottled tea beverage, originally produced in India, Sri Lanka, China, Japan and UK, and milk–tea after addition of milk and sugar. The fluoride content of 5 stick-shaped black teas was 96.9–148 mg/kg, that of 8 granular black tea was 139–223 mg/kg, and that of 3 canned or bottled beverage black tea beverages was 0.70–0.96 mg/l, respectively. Neither the bagged black tea paper nor the addition of milk and sugar affected the ionic fluoride level within the tea. These results suggest that, for heavy black tea drinkers, the fluoride intake in areas with drinking water fluoridation, and also other probable sources of fluoride, may approach or reach the level of risk from chronic fluoride intoxication.  相似文献   

15.
Beef tallow is a byproduct of the slaughter industry. As a consequence, meat producer countries obtain a high amount of this low value-added fatty material. In Uruguay, it is generally used for food purposes or for biodiesel production. Globally, around half of the beef tallow produced worldwide is used for the manufacturing of food. To the best of our knowledge there are no published studies concerning the stability of beef tallow when exposed to high temperatures. The aim of this work was to study some Uruguayan beef tallow brands and compare its stability with that of the most frequently used frying oils in Uruguay (sunflower high oleic, rice bran and sunflower oil) to assess its suitability for frying. Stability was assessed by the oxidative stability index and thermoxidation in absence of food. Even though beef tallow's inherent stability indicated that it should be highly stable to oxidation, the majority of the analyzed samples exhibited a similar or lower stability than sunflower high oleic. This might be explained by a different composition in pro-oxidants and/or antioxidants between the beef tallows and the oils. According to the thermoxidation assays, which are carried out in similar conditions to those of a frying process, three of the beef tallow samples, sunflower high oleic and rice bran oil would be similarly suitable for frying, while sunflower oil and the other two samples of beef tallow evidenced a lower thermoxidative stability, thus not being recommended for this use.  相似文献   

16.
Hyuganatsu is a typical Japanese citrus with desirous smell and edible albedo. The objectives of this study are to establish a method for softening hyuganatsu peel without heating and a process for making a high pressure-induced (HP-) marmalade and to compare with heat-induced (H-) marmalade and citrus shaddock family marmalade. Firmness of peel was (greatest to least) pressurized at 500 MPa for 30 min, soaked in citric acid solution at pH 2.7 for 24 h, and boiled for 10 min, respectively. The cell walls of flavedo and albedo did not loosen after pressurization. However, after soaking or heating, the middle lamella of albedo separated. When flavedo was soaked at pH 2.7, 9.3% of pectin was extracted. The amount of naringin was the least in hyuganatsu 〈 pummelo 〈 grapefruit), and juice sacs 〈 flavedo 〈 segment walls 〈 albedo, respectively. Thus, marmalade was processed. Albedo, segment walls and juice sacs of hyuganatsu were homogenized with citric acid solution (pH 2.7) and mixed with sliced flavedo. Then it was soaked for 24 h at pH 2.7. Sucrose was then added (final sugar 50%), vacuum packed, then pressurized for 30 min at 500 MPa or boiled for 10 min, respectively. There was no significant difference in sensory evaluation between HP- and H-marmalade. However, the color, transparency and total evaluation of HP-marmalade were better than H-marmalade. Consequently, total evaluation of hyuganatsu-HP-marmalade was rated highly. So, hyuganatsu was considered to be more suitable for marmalade because it was more palatable than the others.  相似文献   

17.
The efficiency of using nanostructured silver in technological processes of making red wine has been studied with the purpose of substituting sulfur dioxide. For preparation of research objects, we used dry wine material of red grape variety "Saperavi". After completion of malolactic fermentation, the second racking the wine material off the lees and its treatment with antiseptics were carried out. Sulfur dioxide (Kadifit) and different doses of nanostructured silver were used. Microbiological investigation was performed on the presence of lactic bacteria after completion of malolactic fermentation and racking off the lees. The investigation of phenolic compounds was conducted at the following stages of technological processes: (1) after completion of alcoholic fermentation and racking off the lees; (2) after completion of malolactic fermentation; (3) after the second racking off the lees and treatment with antiseptics. By means of the HPLC analysis, the amounts ofcatechins, phenolcarbonic acids and flavonols were determined. It has been established that after conduction of malolactic fermentation in the process of racking the wine material off the lees and storage, the application of 0.6 mg/L of nano-silver for blocking of lactic-acid bacteria and inhibition of oxidation of phenolic compounds has the same effect as sulfitization with 50 mg/L of Kadifit.  相似文献   

18.
Although many aroma components have been identified in green tea leaves, the aroma compounds contributing to green tea's characteristic odor have not yet been reported. The authors recently reported that aroma components with a matcha-like odor are present in both green tea and black tea prepared from the Sayamakaori tea cuttivar. This matcha-like odor is similar to the odor of commercial available matcha (high-quality powdered green tea), and is a specific odor feature of green tea leaves. At present, the green-tea odor is thought to arise from the combination of a large number of constituents. Recent reports indicate that a complex interaction between olfactory receptors and odorants is important for the evaluation of the odors. Taking into consideration these findings, the authors investigated the aroma profile of green tea, focusing on the characteristic molecular structures of the constituents that give matcha-like odor. Using a combination of organic synthesis and gas chromatography-mass spectrometry plus gas chromatography-olfactometry, the authors identified aroma components with matcha-like odors in five other tea cultivars. This investigation also revealed that several compounds with a formyl group were important constituents of the aroma of green tea leaves, although the odor of each constituent was not individually similar to the tea's overall aroma. The authors found for the first time a group of key components that have the matcha-like odor.  相似文献   

19.
In this study, the target bioactive compounds (e.g., alkaloids, flavonoids, saponins and other polar compounds) in Vietnamese Caricapapaya leaves were extracted. The cytotoxic activities of the papaya leaves extracts on the selected tumor cell lines, such as lung cancer cell line LU-1, carcinoma cell line KB, breast cancer cells MCF7 and leukemia cell line HL-60, were examined. Preliminary findings showed a high inhibitive activity of papaya leave extracts against the four tested tumor cell lines at the concentration of 100 μg/mL. Out of the bioactive compounds in papaya leaves extract, alkaloids showed the highest inhibitive activity (105.95% on MCF7 and 91.86% on LU-1), followed by polar compounds (62.88% on LU-1 and 21.80% on KB), and saponins (59.74% on MCF7 and 25.25% on LU-1). Flavonoids has the lowest inhibitive activity on cell lines (e.g., 45.51% on MCF7 and 20.32% on LU-1). Taken together, the results suggest that alkaloids have a relatively high inhibitive activity on the selected tumor cell lines and their stimulated concentration at 50% (IC50) values for on MCF7 and KB were 24.67 μg/mL and 33.56 μg/mL, respectively. However, the result pointed out the immunostimulatory ability of only polar compounds and saponins which could stimulate the growth of in vitro lymphocytes but not flavonoids and alkaloids. The SC50 (stimulated concentration at 50%) values of polar compounds and saponins were 287.87μg/mL and 192.99 μg/mL, respectively.  相似文献   

20.
The aim of this study was to apply the existing techniques that enable examination ofmacadamia kernels to provide a better understanding of physico-chemical properties of kernels during postharvest processing. These techniques, such as X-ray tomography, could be applied for quality monitoring in the macadamia industry. The objectives of this study were to investigate the browning centre symptoms that usually occur in macadamia nuts-in-shell. The applied techniques included confocal microscopy, X-ray tomography and magnetic resonance imaging (MRI). Five different varieties of macadamia nuts (A38, 246, 816, 842 and Daddow) were selected to include distinct characteristics, such as drop pattern and growing location. Analysis of the microstructure of kernels by confocal microscopy showed the distribution of possible brown pigment compounds as well as the distribution of lipids, carbohydrates and proteins inside macadamia cells. Physical properties data, including shell density and seed to volume ratio, were obtained by X-ray tomography. Magnetic resonance diffusion tensor imaging used in this study showed marked differences in microstructure which indicate that different varieties exhibit different microstructures expressed as fraction ofanisotropy and apparent diffusion coefficient that appear to be related to the occurrence of the brown centre. Hence, the findings of this study have potential to improve the existing postharvest techniques used in the macadamia processing industry. They will be of benefit to the industry in terms of improved quality control and cost reduction.  相似文献   

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