品种和日龄对鸡肉滋味呈味物及香味前体物含量的影响

比较不同日龄石歧黄鸡和AA肉鸡滋味呈味物及香味前体物含量差异。如果表明:日龄对鸡风味相关物含量有显著影响,随着日龄的增加,鸡肉pH值及游离氨基酸、硫胺素含量显著降低(P<0 05),而DM、CP、肌苷酸及其相关物含量显著增加(P<0 05)。品种对鸡肉DM、EE、脂肪酸、游离氨基酸、还原糖、肌苷酸等物质含量具有显著影响(P<0 05),石歧黄鸡游离氨基酸含量显著低于AA肉鸡(P<0 05),其余指标均显著高于AA肉鸡(P<0 05)。在DM、CP及游离氨基酸等指标上观测到日龄与品种的互作效应(P<0 05)。

低温对片烟外观质量及香味前体物的影响

温度是影响烟叶醇化质量的重要因子。为明确低温对烟叶醇化质量的影响,为低温贮存烟叶提供技术支撑,考察了不同低温(0、3、6、9、12和15℃)对贮存片烟外观质量及香味前体物的影响。结果表明:随着温度的增加,片烟贮存24个月期间,片烟外观质量分值、片烟吸光值有增加趋势,片烟多酚总量、叶黄素含量及胡萝卜素含量、片烟常规化学成分(烟碱、还原糖)呈下降趋势,且温度为3℃及以下时,片烟外观质量分值、多酚总量、叶黄素及胡萝卜素含量、常规化学成分及吸光值几乎不变。因此,可以认为3℃为烟叶醇化的起始温度。该研究结果为低温贮存烟叶提供技术支撑。

五指毛桃香味萃取物成分分析

目的分析五指毛桃香味萃取物的化学成分。方法采用亚临界流体萃取技术萃取五指毛桃的香味成分,结合气质联用技术对香味萃取物进行成分分析。结果五指毛桃亚临界萃取率高达2. 2%,香味萃取物中共鉴定16种物质,其中含有量较高的组分有齐墩果烷醋酸酯、补骨脂素、亚麻酸、棕榈酸、佛手柑内酯、油酸、角鲨烯、芥酸酰胺。结论该方法简单快速,可用于五指毛桃香味萃取物的成分分析。

6.用固相微萃取法提取橙汁香味物实验条件的优化

德国波恩Rheinishe Friedrich—Wilhelms大学学者K．Lachenmeier等人在“EjEAFChe，Electronic Journal of Environmental，Agricultural and Food Chemistry”2006，5（3），1380～1388页上用英文发表的文章报道一种实验设计使固相微萃取法从橙汁中提取香味物的条件最优化（同时进行GC和GC／MS分析）。

Identification of Odor Volatile Compounds and Deodorization ofPaphia undulata Enzymatic Hydrolysate

Unfavorable fishy odour is an inevitable problem in aquatic products. In the present study, headspace solid-phase mi- croextraction gas chromatography mass spectrometry （HS-SPME-GC-MS） analysis of volatiles from untreated samples and three deodorized samples （under the optimal conditions） ofPaphia undulata enzymatic hydrolysate revealed that the compounds contrib- uting to the distinctive odor were 1-octen-3-ol, n-hexanal, n-heptanal, 2,4-heptadienal, and 2,4-decadienal, whereas n-pentanal, n-octanal, n-octanol, benzaldehyde, 2-ethylfuran and 2-pentylfuran were the main contributors to the aromatic flavor. The deodoriz- ing effects of activated carbon （AC） adsorption, yeast extract （YE） masking and tea polyphenol （TP） treatment on a P. undulata en- zymatic hydrolysate were investigated using orthogonal experiments with sensory evaluation as the index. The following optimized deodorization conditions were obtained： AC adsorption （35 mg mL-1, 80℃, 40 rain）, YE masking （7 mgmL l, 45 ℃, 30 min） and TP treatment （0.4mgmL-l, 40℃, 50min）. AC adsorption effectively removed off-flavor volatile aldehydes and ketones. YE masking modified the odor profile by increasing the relative contents of aromatic compounds and decreasing the relative contents of aldehydes and ketones. The TP treatment was not effective in reducing the odor score, but it significantly reduced the relative content of alde- hydes while increasing that of alkanes. It is also notable that TP effectively suppressed trimethylamine （TMA） formation in a P. un- dulate hydrolysate solution for a period of 72 h.

Study on Aroma Components of Six Kinds of Plum Fruits

[Objective] The aim was to study the aromas composition of plum fruit. [Method] The aroma components of six kinds of plum fruits were analyzed by SPME, detected and identified by GC-MS.[Result] 85 kinds of aroma substances were separated and identified, including 40 kinds of common components.The experiments had good reproducibility by strictly controlling the desorption temperature, time and sample holding time.The obtained chromatographic peak retention time and the normalized area variation coefficient CV% values were between 0.03% -0.54% and 5.85% -18.08% by experimenting the five precision of AoLi13.The qualitative and quantitative were fully meet repeatability requirements for test samples. [Conclusion] The study provided scientific basis for the development and process of plum industry in China.

Are eavesdroppers multimodal？ Sensory exploitation of floral signals by a non-native cockroach Blatta orientalis

The study of multi-modal communication has only recently been extended to innate and learned interactions between flowers and their animal visitors, and usually only to pollinators. Here we studied the relevance of floral scent and visual display of a night blooming, putatively hawkmoth-pollinated plant Oenothera acaulis （Onagraceae） in the attraction of non-native cockroaches Blatta orientalis （Blattodea： Blattidae）, which function as facultative floral larcenists in coastal habitats of central Chile. We experimentally decoupled visual （corolla） and olfactory （fragrance） stimuli by presenting paper corollas and green mesh bags, with or without a freshly-picked natural flower inside. We then contrasted the behavioral responses of roaches in these treatments with those to the natural combination of traits in actual flowers and their respective control treatments, measuring the roaches＇ frequency of first visits, mean and total residence time spent in each treatment. The roaches primarily used olfactory cues when approaching O. acaulis flowers at two biologically relevant spatial scales. In addition, the presence of conspecific roaches had a strong influence on recruitment to the experimental arena, increasing the statistical differences among treatments. Our results suggest a primacy of floral fragrance over visual stimuli in the foraging responses of B. orientalis. Olfactory cues were necessary and sufficient to attract the roaches, and the visual cues presented in our manipulations only marginally increased their attraction within a 20 cm diameter of the stimulus. The full spectrum of floral visitation behavior was not elicited by the artificial flowers, suggesting the need for additional tactile or contact chemosensory stimuli not provided by paper. Although the nitrogenous scent compounds that we found in O. acaulis flowers are almost exclusively found in hawkmoth-pollinated flowers, the attractiveness of these compounds to a non-native, facultative flower-visiting insect indicates that they do not function as pollinator-specific signals for hawkmoth attraction .

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