首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
采用高、低两种阻隔包装材料及真空、普通两种包装方式包装鲜鱼肉,研究了在不同的贮存温度下,包装鲜草鱼肉挥发性盐基氮(TVB-N)的增加量随存放时间的变化规律及数学关系式。结果表明,不同贮存温度下,包装鲜草鱼肉的TVB-N增加量(Y)与贮存时间(t)符合Y=A·tB关系式,其中系数A、B与包装方式和贮存温度有关,且与温度T符合A=c+f·EXP(T/g),B=a+b·EXP(lnQT/d)关系式,系数c、f、a、b均与温度和包装方式有关,系数g只与包装方式有关,系数d与贮存温度和包装材料的透氧量有关。   相似文献   

2.
The concentrations of seven essential trace elements in 149 freshwater fish from eight fish species (European eel, bream, common carp, European catfish, roach, perch, pike and pikeperch) from five different French fishing areas from contaminated and control sites were measured by inductively coupled plasma mass spectrometry after microwave digestion under pressure. Differences in the concentration of elements in the muscles of these species were examined and the mean levels were compared for each species with previous French and European studies. The condition factor and the differences between the control and contaminated sites and between predatory and non-predatory groups, with respect to the concentration of these elements, were also studied.  相似文献   

3.
为了提高冻藏鲷鱼品质并利用其生产优质鱼糜,研究复合抗冻剂中磷酸盐配比对黄鳍棘鲷抗冻效果的影响.采用差示扫描量热仪测定鱼肉冰点和相变焓,在单因素实验的基础上运用正交试验法优化复合抗冻剂中的磷酸盐配比.正交实验优化的复合抗冻剂磷酸盐最佳配比为3%焦磷酸钠、3%三聚磷酸钠、1%六偏磷酸钠,此时鱼肉冰点和相变焓分别为-2.3℃...  相似文献   

4.
为初步了解中国鱼类产品中香港海鸥菌(Laribacter hongkongensisgen.nov.,sp.nov.)的污染情况,2005年8~10月对广西、广东、福建、浙江和河北5个沿海省份的水产品批发市场、零售市场和饭店采集的鱼类产品进行了香港海鸥菌的监测。在5省1097份鱼类样本中,草鱼247份、鲤鱼248份、其他淡水鱼431份和海水鱼171份。草鱼的检出率为7.69%(19/247),鲤鱼为0.81%(2/248),其他淡水鱼为0.23%(1/431),海水鱼中未检出(0/171)。我国沿海省份淡水鱼类产品中存在香港海鸥菌的污染,应加强对香港海鸥菌的监测。  相似文献   

5.
以新鲜宰杀的草鱼为原料,采用普通包装的方式进行包装,并分别于8℃和20℃条件下贮藏,研究不同贮藏温度下,鲜鱼块的比表面积对其挥发性盐基氮(TVB-N)和硫代巴比妥酸值(TBA)的影响。结果表明,不同温度下,鲜鱼块的比表面积越大,TVB-N值和TBA值的增量随贮藏时间的增速越大。8℃和20℃贮藏条件下,包装鲜鱼块的TVB-N值的增量与贮藏时间及比表面积分别符合方程Y8=(0.00385+0.00000356)·S·t1.525和Y20=(0.00795+0.0000294·S)·t2.06。  相似文献   

6.
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   

7.
The flesh of spaghetti squash separates into strands when cooked. The purpose of this paper is to investigate the cause of strand separation (during cooking) by soaking for 24 h at 35 ℃ in solutions with three kinds of pectin extractant. The changes in strand separation, firmness, histological structure and the pectin of flesh during soaking in 0.01 N HCI solution (pH 2.0), 0.035 M ammonium oxalate solution (pH 4.0) or 2% sodium hexametaphosphate solution (pH 4.0) were investigated. When flesh was soaked in the HCI solution, the separation into strands and removal of calcium and magnesium were greater than that soaked in other pectin extractants. High methoxyl pectin was extracted by soaking in HC1 solution (pH 2.0) due to removal of polyvalent cations. This result shows that high methoxyl pectin glues strands together in the flesh of spaghetti squash. The shape of the cells which constituted strands was round; on the other hand, that of cells surrounded strands was elongated. When cooked in boiling water or soaked at pH 2.0, the shape of the former cells was maintained, but the latter cells, which contributed to adhesion between strands, broke down. Thus, the flesh separated into strands. When flesh was boiled for 15-30 min, pectin degraded and dissolved in the cooking solution; consequently, the flesh separated into strands and also the middle lamella of cell walls of strands separated. However, pectin remaining in strands maintained their crispness.  相似文献   

8.
Fusarium species commonly occur in maize are fungal pathogen which produce mycotoxins, such as fumonisin, trichothecene and zearalenone. In this study, Fusarium species were isolated from maize kernel from Tretep, maize producer region and were identified based on microscopic- and macroscopic characters as well as molecular characters using PCR assays and the partial sequence of TEF 1-α gene (Translation Elongation Factor 1-α. The fumonisin-producing ability of these Fusarium was determined by growing them in corn medium and analyzed their fumonisin by ELISA (enzyme-linked immuno assay). Among 9 isolates, three of them were identified as Fusarium verticillioides, two as Fusarium temperatum, two as Fusarium globosum, one as Fusarium proliJeratum and one as Fusarium subglutinans. Fusarium temperatum is similar morphologically to F. subglutinans, however, both of their differences can be found by molecular analysis. Fumonisin-producing abilities of Fusarium were determined in concentrations 20.51 pg/g-1,109.74 pg/g medium with the highest producer was identified as F. globosum.  相似文献   

9.
Since Korea-Japan annexation in 1910, Japan has promoted the migration and/or tourism into colonial Chosun (old Korea) as an efficient cultural strategy for extending imperialism into Korean peninsula. In many tour guide books, the gisaeng (Korean female entertainers) was not only a symbol of Chosun tradition, but a main icon of Chosun tourism. The high class Korean-styled restaurants (yorijoem) were established as tourist attraction for Japanese inlanders, with singing and dancing gisaengs, ondol (Korean heating floor) house and Korean authentic cuisine, etc. The aim of this paper is firstly to explore the existential change of gisaengs in the yorijoem through its spatial significance in the 1930s, and secondly to explore the identity of Seoul local food culture and its metamorphosis under the colonial modernity.  相似文献   

10.
Changes in nib acidity, protein and sugar concentration during roasting of pulp pre-conditioned and fermented cocoa (Theobroma cacao) beans were investigated. A 4 - 4 full factorial design with the principal experimental factors as pod storage (0, 3, 7 and l0 d) and roasting time (0, 15, 30 and 45 min) were used. The roasted samples were evaluated for pH, titratable acidity, protein content and sugars concentrations using standard methods. Increasing pod storage caused consistent increases in pH with concomitant decreases in titratable acidity, whereas increasing roasting time caused only marginal and insignificant changes in pH but significantly decreased the titratable acidity. The protein content decreased significantly (P 〈 0.05) with increasing pod storage and roasting time. Reducing sugars increased marginally with increasing pod storage treatments whiles increasing roasting time significantly (P 〈 0.05) decreased the reducing sugars of the beans for all pod storage. The non-reducing sugar and total sugar content of the beans decreased significantly from 3.493 mg/g to 2.641 mg/g and from 9.284 mg/g to 8.891 mg/g, respectively, for pods stored from 0 to 10 days while roasting time caused slight decreases in non-reducing sugars with a considerable decrease in total sugars. Pod storage up to seven days decreased considerable the nib acidity (non-volatile acids), non-reducing sugars and total sugars while roasting up to 45 min at 120 ℃ caused dramatic decreases in the nib acidity and reducing sugars with only marginal decreases in non-reducing sugars and total sugars.  相似文献   

11.
In recent years, research on biopolymer based-coating containing natural antimicrobial agents is developing significantly. The objective of this study was to evaluate the antimicrobial efficiency of six formulations containing pre-selected natural antimicrobial compounds against Listeria monocytogenes, Escherichia coli O 157:H7, Salmonella typhimurium, the total bacteria and total yeasts and molds in cauliflower. Each formulation was subjected to a sensory test in parallel to microbiological analysis and the efficiency during storage at 5 ℃ was evaluated for the two best formulations, based on their ability to eliminate the target microorganisms. Both formulations were able to reduce all pathogens and total flora below detectable levels after 24 h of storage at 5 ℃. Using washing or spraying treatments, the two formulations were able to reduce Listeria to undetectable levels for 3 d. This efficiency was extended to 7 d when the formulations were incorporated into an edible coating. Washing treatment with the two formulations was also able to limit the growth of yeast and molds at levels lower than 2 log, for more than 7 d. The population of E. coli was reduced to below the detection limit during 14 d of storage, after washing treatment with the two formulations. The spraying treatment of cauliflower with the formulations allowed the use of very small amounts of antimicrobials while maintaining a fairly good efficiency, greatly reducing the potential costs of implementing this method in the industry. Future research may focus on development of nanoemulsion of antimicrobial formulations based on the developed antimicrobial formulations in this study to improve the better coating efficiency.  相似文献   

12.
Aspergillus flavus maize colonization leads to crop contamination by toxic secondary metabolites and carcinogens called aflatoxins (AF); it has negative effects in public health and has caused economic losses in agricultural activities. Eleven genotypes of immature maize grain frequently used in Mexico were inoculated in vitro with two indigenous toxigenic strains ofA. flavus. The size of inoculum, temperature, humidity and presence of other phytopathogens were assessed. Genotypes Popcorn, C-526, Garst 8366, As910 and 30G40 showed resistance to rating of fungal colonization (FC) and AF accumulation, while 3002W, 30R39, Creole, C-922, HV313 and P3028W genotypes were less resistant. AFB~ had the highest concentrations (26.1 mg/kg ± 14.7 mg/kg), while AFB2, AFG1 and AFG2 showed only residual concentrations 1.6, 2.0 and 4.0 ~tg/kg, respectively. Concerning FC and AF, there were significant differences (P 〈 0.01) between strains and genotype. Both strains showed significant association (P 〈 0.01) between FC and the concentrations of AFB1 and AFB2 (R2: 99.5% and 93.2%; 87.2% and 73.2%, respectively). Results suggest that the level of resistance to fungus infection and AF accumulation is related to maize genotype. It emphasizes the relevance of developing A. flavus resistant maize genotypes as an alternative to control contamination in foodstuff intended for human and animal consumption.  相似文献   

13.
The term "biogenic amines" defines decarboxylation products such as histamine, putrescine, serotonin, tyramine, phenylethylamine, tryptamine and also aliphatic polyamines. They can be detected in both raw and processed foods. In the recent years, there is a great interest in biogenic amines as they are associated with quality, safety and freshness of some foods, particularly fermented foods. The presence of biogenic amines in foods can also be used as an indicator of hygienic quality. Biogenic amines also cause health hazards due to their toxic effects especially in sensitive individuals. It is therefore important to control and reduce the biogenic amines. The reduction can be brought about by the use of high pressure, irradiation, packaging, additives, starter cultures and by reduction of decarboxylase activity and temperature. This review summarizes the significance, function, occurrence and formation of biogenic amines in different foods and their reduction by different methods.  相似文献   

14.
Zinc (Zn) deficiencies are currently thought to cause chronic metabolic derangement leading to or exacerbating immune deficiencY, gastrointestinal problems, endocrine disorders, neurologic dysfunction, cancer, accelerated aging, degenerative disease, and more. Zn deficiency caused by malnutrition and foods with low bioavailability, aging, certain diseases, or deregulated homeostasis is a far more common risk to human health than intoxication. Higher dose of Zn should be limited to short-term use because of an increased risk of gastrointestinal adverse effects, copper deficiency, anemia, and genitourinary complications. This review has detonated the literature on the spectrum of health effects of Zn status, ranging from symptoms of Zn deficiency to excess exposure.  相似文献   

15.
Roes of yellowfin tuna (Thunnus albacares) and red snapper (Lutjanus champecanus) are considered as abundant and underutilized by-product in Indonesia. The production of roe protein concentrate (RPC) is expected to increase the economic value and potency of their usage. Tuna and red snapper RPC was defatted using etano195% with one, two, three and four times of repetition. Both RPC made with four times repetition of defatting had the highest protein content (79.90% and 80.72%), showed high emulsion activity (97.46% and 99.62%) and emulsion stability (97.10% and 99.48%), and decreased the interfacial tension of 51% and 55.9%, respectively. Mayonnaise was made with 0, 25, 50, 75 and 100% substitution level of each RPC with four times repetition ofdefatting. The physical, chemical and organoleptic properties of mayonnaise were studied. The best mayonnaise formulation was obtained from 50% substitution level of tuna and red snapper RPC. Mayonnaise with tuna and red snapper RPC had good viscosity (5,920 cPs and 5,845 cPs), high emulsion stability (90.5% and 91.73%) and small fat globule size (±2.5 lam and ± 2.25 lam), respectively. These mayonnaises also showed high score of spreadability and low intense of fishy odor. However they still had quite strong of fishy flavor based on scoring test.  相似文献   

16.
In spite of receiving a significant amount of food aid, achieving food security has been a major problem in Ethiopia. The claim is evidenced from the 2010 Global Hunger Index where the country fared dismally, coming only fourth from the bottom. There are several factors attributing to this problem of food insecurity in a country like Ethiopia which depends highly on agriculture and allied activities. Some of the factors can be linked to low food production and productivity thereby leading to pervasive poverty. In order to assess these factors, the study was conducted on some selected members of agro-pastoral communities of Somali and Oromia regions in Ethiopia. Using availability of food in the household for the last one month as a proxy for food security, the estimated results of a logistic regression model indicated that the most significant factors affecting household food security are educational level of the spouse and that of the household head, size of farm land, availability of household assets including livestock, peace and security. The paper suggests some leads to how these amenities and resources can be provided to household members as they endeavor to reduce food insecurity.  相似文献   

17.
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   

18.
19.
Avocado oil is a relatively new oil in the market and is highly appreciated by the consumers because of its fine aroma, pleasant taste and health benefits. A study on the characterization of commercial avocado oils produced in Chile was conducted in order to discuss their quality parameters. The study was applied to two marketed avocado oils. The main analytical parameters evaluated to the oils were: fatty acid composition, total chlorophylls, total carotenoids, tocopherols, acid value, peroxide value, total phenolic compounds, polar compounds, oil stability, UV absorption and 3.5-stigmastadiene content. The fatty acid compositions of the studied oils were according with oil composition of pulp pure of avocado fruit. The analysis of tocopherols by high performance liquid chromatography (HPLC) revealed significant differences between the avocado oils studied. Total phenolic compounds, oil stability, UV Absorption characteristics, peroxide value, acid value, tocopherols content, total chlorophylls, total carotenoids and polar compounds were also significantly different between the commercial studied oils. All the above results show a different quality between both commercial avocado oils, showing that the sample C has worse values for the parameters of quality as those required by legislation in many countries. Also, 3.5-stigmastadiene content shows high concentration for one of the commercial avocado oil evaluated which demonstrates the presence of refined oil or that the oil has been submitted to high temperatures. On the other hand it is remarkable that despite the fact that there are many differences in quality parameters, both oils are labeled and marketed as extra virgin quality oils, demonstrating the need to regulate the classification of appreciated oils by the consumers.  相似文献   

20.
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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号