Activity of drimane antifeedants and related compounds against aphids,and comparative biological effects and chemical reactivity of (−)- and (+)-polygodial

A series of natural drimanes and related synthetic compounds was tested for antifeedant activity against aphids. Polygodial and warburganal were the most active. The synthetic compounds methyl 9-hydroxydrimenoate and 9-hydroxydrimenal, although active against lepidopteran larvae, were inactive against aphids. Natural (–)-polygodial and the synthetic (+) isomer showed similar levels of activity as aphid antifeedants and in phytotoxicity, fish toxicity, and human taste tests, but reacted at different rates with enantiomers of 1-phenylethylamine.     

虾夷扇贝活力变化对其呈味特性的影响研究

目的 研究虾夷扇贝活力变化对于呈味特性的影响。方法 将活品虾夷扇贝在4℃干藏0、6、24 h后,其分别处于不同的活力状态。通过扇贝组织形态、扇贝闭壳肌中三磷酸腺苷（Adenosine triphosphate,ATP）及其关联化合物、腺苷酸能荷（Adenylate energy charge,AEC值）、线粒体活性、能量代谢物水平等指标分析活力;对加热熟制后的各样品进行感官评价,测定呈味化合物含量、计算味觉活度值;最后分析扇贝活力变化对呈味特性的影响。结果 干藏期间扇贝外套膜收缩,活力轻微下降,但ATP及其关联化合物、AEC值均无显著变化。线粒体活性由85.59%显著下降至59.21%,线粒体功能下降。另外,干藏导致糖酵解代谢物糖原由4.32 g/100 g下降至3.14 g/100 g,同时葡萄糖1-磷酸、果糖6-磷酸、磷酸二羟丙酮等代谢物含量显著上升,三羧酸循环（Tricarboxylic acid,TCA）代谢物丙氨酸含量由0.44 mg/g增加至0.71 mg/g。干藏导致扇贝中呈味化合物谷氨酸含量由0.93 mg/g下降至0.51 mg/g,精氨酸含量由9.05mg/g上升至10.56 mg/g,滋味中鲜味降低、苦味上升。结论 虾夷扇贝活力下降导致了谷氨酸含量的下降和精氨酸含量的上升,进而造成扇贝滋味中鲜味的下降和苦味的上升。     

适宜口感下的红茶品饮冲泡技术

目的:探究适宜口感下的红茶冲泡上限及其技术参数。方法:以一芽二叶红茶为原料,将感官审评方法制备的茶汤梯度稀释并由50名志愿者品饮,在确定适宜口感浓度的基础上,以适宜口感下水浸出物、茶黄素、茶红素质量浓度为考察指标,优化筛选红茶每次品饮冲泡的技术参数以及适宜口感下的冲泡次数。结果:红茶茶汤中水浸出物、茶黄素、茶红素质量浓度分别为1.40,0.04,0.60 mg/mL时,具有适宜的品饮口感;第1次冲泡采用茶水比(m_茶∶V_水)1∶100 (g/mL)、82℃纯水冲泡4.5 min,第2次冲泡采用茶水比(m_茶∶V_水)1∶50 (g/mL)、86.0℃纯水冲泡3.5 min,两次所得的茶汤均具有适宜的品饮口感并达到适宜口感的水浸出物、茶黄素、茶红素质量浓度;但第3次冲泡采用茶水比(m_茶∶V_水)1∶50 (g/mL)、97.3℃纯水冲泡6.4 min后,所得茶汤口感过淡,同时水浸出物、茶黄素也未能达到适宜口感下的质量浓度要求。结论:适宜口感下的红茶品饮冲泡以冲泡2次...     

On the Effect of Tastant Excluded Fillers on Sweetness and Saltiness of a Model Food

ABSTRACT: In this study, the effect on taste due to the addition of air bubbles to a water-based gel was investigated. The gel phase contained either sucrose to give a sweet taste or sodium chloride to give a salty taste. For the sweet gels, taste intensities were evaluated for samples with different volume fractions of the air bubbles (up to 40%, v/v) and different concentrations of the sucrose. For the salty gels, samples were evaluated at 40% volume fraction of air bubbles. It was found that a reduction of the sodium chloride or sucrose by the same weight percentage as the volume fraction of the air bubbles in the samples gave equal taste perception as the nontastant-reduced samples. Moreover, saltiness and sweetness perception were clearly enhanced at 40% volume fractions of air bubbles if the sodium chloride or sucrose was not reduced. Thus, the overall tastes of the samples appeared to depend mainly on the concentration levels of the salt or the sucrose in the aqueous phase irrespective of the volume fraction of the air bubbles. However, the air bubbles were found to change the texture and appearance of the samples. It has been demonstrated that the inclusion of air bubbles offers scope for the reduction of sodium chloride or sucrose in food products.     

Perception of Beer Flavour Associates with Thermal Taster Status

Beer flavour, and thus much of the consumer experience of beer, is determined by the sensations elicited when it is taken into the mouth. Thus, individual differences in the perception of these oral sensations may contribute to the variation in consumer behaviour. A new taste phenotype shown to associate with the intensity of oral sensations elicited by simple solutions is thermal taster status (TTS). Thermal tasters (TTs) perceive ‘phantom’ tastes with thermal stimulation of the tongue, while thermal non‐tasters (TnTs) do not. Here, we investigate the effect of TTS on the perceived intensity of bitterness, sourness, sweetness, fullness, carbonation and overall flavour intensity elicited by seven beers representing classic styles — wheat beer, brown ale, pale ale, low‐alcohol lager, standard lager, high‐alcohol lager and stout. A strong trend was observed for TTs (n = 20) to rate attributes higher than TnTs (n = 20) for all beers except the stout, with these differences significant in many instances (ANOVA or binomial analysis). It is concluded that TTS may be an important determinant of individual differences in the perception of beer flavour, but beer liking and preference are more complex phenomena than can be accounted for by this phenotype alone.     

黄山头大曲酒独特醇甜型风格成因初探（一）

从黄山头酒业所处地理位置的自然生态环境、有机原料基地的建设、生产工艺特点、民俗习惯、现代生物技术的应用与传统工艺的改进、酒体微量成分与人体健康等六个方面探讨了黄山头大曲酒的＂绵、甜、爽、净、香＂风格特征的成因。决定黄山头大曲酒醇甜型风格的六大主要因素为自然生态环境、原辅料、微生物区系、糖化发酵剂、酿酒工艺、储存设备与环境。     

中国小说叙述视角的语言审美功能--小说语言美学系列之二

小说叙述语言因叙述视角的不同而呈现不同的审美功能,像全能视角的叙述语言注重讲故事的传奇性和超越性,提供全方位的审美感知。而外部视角和内部视角的叙述语言则注重叙事的外在客观真实性和内在主观真实性,追求典型、深刻、细腻、传神的本真效果,是拓展型的审美品味和原生态的审美透视。中国小说叙述语言在这些方面显示了突出而又独到的特点。     

不同包装对籼粳杂交大米及其蒸煮米饭品质的影响

为明确籼粳杂交大米在不同包装内的品质变化规律,以甬优15大米为原料,研究在室温下(20～25℃),编织袋、PE袋、真空包装、牛皮纸袋4种包装对其大米及蒸煮米饭品质的影响.结果表明,随着贮藏时间的延长,籼粳杂交大米的脂肪酸值、直链淀粉含量、米饭硬度逐步增加,而大米新鲜度值、大米食味值、米饭黏度、米饭食味值等逐渐降低,各品...     

技术美学对当代景观设计的影响及发展趋向

阐述了技术美学的来源及拓展,探讨了技术美学与当代景观设计的关系。同时从新材料、新技术、新结构和新设备等4个方面的运用来论述技术美在当代景观设计中的渗透和体现。并总结了技术美学在当代景观设计中的三个发展趋向,即情感化、乡土化、生态化的审美趋向。