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 15 毫秒
1.
2.
3.
4.
In order to evaluate the suitability of signal detection theory methods for assessing the discriminability of foods and beverages, the discriminability of two dairy milk products that differed in fat content was measured with two detection-theoretic methods: the single-interval rating method, and the same-different method. The nominal fat contents of the milk products were 0.1 and 1.6%. Measures of discriminability for three observers were derived by fitting receiver operating characteristics (ROCs) based on equal-variance normal models to the ratings of each observer with a procedure that combined jackknifing and maximum-likelihood estimation. The fitted ROCs provided a good fit to the data indicating that the equal-variance models were appropriate for these tasks. The best-fitting estimates of d' obtained for each task were not significantly different, demonstrating that d' is a measure of sensitivity that is largely independent of the task from which it is determined. However, estimates of proportion correct obtained for each task were shown to be significantly different.  相似文献   

5.
The effect of three pleasant fine women's fragrances on the mood of women was assessed. The three fragrances had similar hedonic values but different sensory characteristics. The fragrances elicited nonspecific effects on mood. All three fragrances’ impact on mood was influenced by initial mood and lasted up to three hours, i.e., as long as the scent was still noticeable. Trends revealed that all three fragrances decreased negative affect and increased vigor. Also, independent of their hedonic value, the three fragrances elicited specific mood patterns. With the “woody citrus coniferous” scent, respondents experienced higher hostility and tension. The “floral chypre citrus” fragrance decreased anger and confusion. The “floral woody” scent had the lowest Total Mood Disturbance score and lowered depression, tension and confusion.  相似文献   

6.
微生态调节剂对鲤生长及肠道菌群的影响   总被引:8,自引:0,他引:8  
应用微生态调节剂(JY10、JY31复合制剂),作为饲料添加剂饲养鲤后,进行肠道菌群定位,定量及定性分析,并以投喂常规饵料的鲤作为对照。实验结果表明:微生态调节剂饲养后鲤肠道中JY10、JY31制品菌群量明显增加,大肠菌群量明显减少,定植效果良好;同时其生长指标明显优于对照组,说明该微生态调节剂对鲤肠道菌群的调整查和促进新陈代谢及生长均有明显作用。  相似文献   

7.
Caffeine contributes to the flavor profiles of beverage and food products, and other bitter compounds, such as quinine, cannot replicate caffeine's bitterness. Research also has indicated caffeine's ability to enhance desirable tastes, such as sweetness and saltiness, in beverages by modifying neurological pathways. Caffeine may reduce potential " off-flavors" by solubilizing some compounds, while having little effect on other compounds considered important in beverage flavor profiles. Exposure to caffeine may enhance cognition and potentially heighten the capacity for smell and taste. Thus, use of caffeine in beverages may positively affect flavor profiles and the experience of beverage consumption.  相似文献   

8.
生态制品对鲤生长的影响及其作用机理的研究   总被引:5,自引:2,他引:5  
本文根据微生态学原理,从正常健康鲤的肠道中分离、筛选出无毒无害正常菌群Jy10、Jy31制成生态制品,作为鲤的饲料添加剂,用以饲养鲤,其应用结果表明,鲤生态制品饲养组的增重率、能量同化率、生态生长效率(K_1),组织生长效率(K_2)以及多项生理生化指标(Rbc、Hb、血糖量、血浆总蛋白量、红细胞脆性、肌肉含蛋白质率等)均高于或优于对照组。本文对生态制品的促长作用机理进行了初步分析。  相似文献   

9.
10.
The sensory profiles of the most common chilled and frozen salmon products available to consumers on the Danish market were studied. A sensory profiling was made on 12 salmon products varying in salmon species, origin, storage method and time. Samples stored in ice between 7 and 16 days, frozen for 1 month or stored in modified atmosphere for 5 days all had sensory profiles dominated by sea/seaweed odor, juicy and oily texture, fresh fish oil, and sweet and mushroom flavor. Marked differences in the sensory profiles of the frozen samples were found to correlate to differences in storage time. Frozen storage for 6 months resulted in firm texture, discolored appearance and rancid flavor. The samples stored in modified atmosphere for 7 days had a sensory profile with marked rancid and sour odor.  相似文献   

11.
多巴胺能药物对鲤鱼促性腺激素分泌活动的影响   总被引:7,自引:0,他引:7  
王黎  林浩然 《动物学报》1997,43(1):74-79
研究多巴胺(DA)及其激动剂阿扑吗啡(APO)和拮抗剂Domperidone(DOM)对不同性腺发育时期和不同年龄雌鲤促性腺激素(GtH)分泌活动的影响。结果表明:鲤鱼基础GtH分泌具有明显的季节性变化,表现为血清GtH含量在性腺发育早期较低,性腺成熟期升高,到性腺退化期又降低。DA和APO对GtH分泌的抑制作用及DOM对GtH分泌的刺激作用在不同性腺发育时期为:性腺发育早期〉性腺成熟期〉性腺退化  相似文献   

12.
13.
60种食药两用中药抗菌防腐作用研究   总被引:30,自引:1,他引:30  
本实验利用无菌24-孔板采用连续稀释法对60味食药两用中药进行了抗19种常见食品腐败菌的快速筛选,得到有明显抗菌作用的中药5种:丁香、花椒、高良姜、甘草、乌梅。其中:丁香、花椒、高良姜为香料,有较强的抗真菌作用;乌梅对所测细菌有较强抑制作用,将丁香、花椒、高良姜等等量组成复方进行抗菌实验,得出该复方的醇提物抗菌作用强于水提物,在浓度为1/80时对所有被测菌均有抑制作用。  相似文献   

14.
Capsaicin burn was induced by a one percent solution of Tabasco TM sauce in spring water. Four foods, rice, water, butter, and pineapple juice, warmed to 35°C, were used to reduce the burn. A no food treatment was used as a control. Subjects recorded perceived burn intensity by placing slash marks on line scales at set time intervals throughout the tests. Burn was significantly reduced while the foods were in the mouth but increased after the foods were expectorated. The decreased burn may be due to the very presence of a food in the mouth.  相似文献   

15.
导入外源DNA对小麦基因表达的影响   总被引:7,自引:0,他引:7  
用(SDS)PAGE对外源豌豆DNA导入小麦体的不良变异后代种子蛋白质和酯酶同工酶(EST)、超氧化物歧化酶(SOD)、过氧化同工酶(POD)进行分析,发现变异小麦的种子蛋白质消减4个组分带,EST和POD消减2条酶谱带,SOD的活性明显降低,并且变异小麦植株的发育生长表型呈现出脆弱,早衰迹象,表明导入外源DNA抑制了某些基因的表达,同时分析导致这种负作用的原因。  相似文献   

16.
By scanning and transmission electron microscopy we have shown that insulin rapidly reversed changes in surface membrane conformation and polysome profile induced by the transfer of actively growing Balb/c 3T3 fibroblasts from a serum-containing to a serum-free medium. Morphometric analysis of polysome profiles revealed a 94% aggregation of total f ribosomes during logarithmic growth. This figure fell to 78% after 18 h of serum starvation. The number of f ribosomes per unit area of cytoplasm also fell. 1 h of insulin treatment restored aggregation to 92% and increased the number of f ribosomes per unit area of cytoplasm by 22%. Scanning electron microscopy of logarithmically growing cells revealed an abundance of surface microvilli, whereas serum starvation promoted a smooth surface with few microvilli. After 1 h of insulin treatment, microvilli reappeared with a distribution and subcellular organization characteristic of exponential growth. This study shows the combined and rapid effect of insulin on the regulation of polysome formation and the promotion of a specific surface membrane conformation in cultured cells. The observations are consistent with the knowledge that insulin, acting on the surface membrane, can influence such parameters as membrane transport, and the rates of protein and RNA synthesis.  相似文献   

17.
This research characterized the time-intensity (TI) profiles of monosodium glutamate (MSG), disodium 5'-inosinate (IMP), and disodium 5'-guanylate (GMP). Twenty subjects rated total taste intensity of single solutions of 2.5, 5 and 10 mM MSG, 0.63 and 2.5 mM IMP and GMP, and some of their mixtures, using the TI method. The profiles generated were atypical of other taste modalities. Time to maximum intensity waslong (16–20s), followed by a plateau at maximum intensity, and a persistent aftertaste (50–96s duration). Maximum intensities of the samples varied (p < 0.001), with mixtures of 10 and 5 mM MSG with 2.5 mM IMP or GMP yielding the highest intensities. Similar differences were found for total duration and area under the curve. These results indicate that flavor potentiators may increase total flavor during consumption. Synergism between flavor potentiators was demonstrated.  相似文献   

18.
19.
仔鱼的开口摄食期及其饵料综述   总被引:22,自引:0,他引:22  
鱼类的受精卵在完成胚胎发育的正常过程后经过脱膜孵化成为仔鱼。此时,初孵仔鱼(newly hatched larvae)一般消化道尚未与外界相通,均有较大的卵黄囊作为孵化后一段时间内继续发育的营养来源。但随着卵黄物质的逐渐消耗,消化管与口腔接通以后,仔鱼必需从外界环境中摄取必要的营养物质,以便进一步发育与生长,这就是仔鱼的开口摄食期。    相似文献   

20.
The effects of intensive Tsetse Control hunting operations on a duiker population (Sylvicapra grimmia) were investigated in a 200 sq. mile area in Eastern Zambia. Two years of hunting were insufficient to reduce this population so significantly that a marked shift of its age composition towards the juvenile age classes resulted. There were, however, indications of beginning accelerated population growth through increased breeding and inclusion of more juveniles in the reproduction process, as a first response to the hunting pressure. Although general availability of duiker did not diminish, they became increasingly difficult to shoot because of behavioural adaptation and changing periods of feeding activity. Neither hunting nor various other human disturbances provoked emigration from the area or a change of the seasonal pattern of localised movement. The studied hunting operation failed to remove more than the annual increment to the duiker population and in respect of this species was thus ineffective as a means of Tsetse Control. Implications of the results of this study for the management of duiker for sustained meat production are discussed.  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