腐乳白点控制生产工艺参数的研究

腐乳白点常见于成品腐乳,无食用安全问题,但严重影响产品外观和销售。该研究以白腐乳为研究材料,通过单因素试验及正交试验考察腐乳生产过程中发花温度、发花相对湿度、发花时间、摆胚间距、毛霉接种量对腐乳白点及氨基酸态氮含量的影响。结果表明,腐乳最佳生产工艺参数为:摆坯间距2.0 cm、毛霉接种量(显微镜单视野下孢子数)5个、发花温度28℃、发花相对湿度90%、发花时间38 h。在此优化工艺条件下,腐乳氨基酸态氮含量为1.09 g/100 g,未见腐乳白点产生。

Effect of Short-term Forest Bathing in Urban Parks on Perceived Anxiety of Young-adults: A Pilot Study in Guiyang, Southwest China

Forest can be taken as a natural therapy to alleviate perceived anxiety of visitors. Given the geographical difference between urban and rural forest environments, little is known about the urban forest therapy effect of anxiety alleviation with reference to the rural forest. In this study, forty-three university students(aged from 19 to 23) were recruited as participants to visit the forest parks at urban and rural areas of Guiyang City on 21 and 23 December 2016. The forest experience was separated by four sceneries. Participants were asked to complete questionnaires by self-evaluating specific anxiety change from 12 questions with scores from 1 to 10 at both entrance and exit of the parks. The Wilcoxon signed-rank test and paired t-test were used to compare the change of anti-anxiety scores during forest bathing and between urban and rural forests, respectively. Results revealed that forest bathing in the urban park can alleviate the anxiety from financial state(P = 0.0028), exam-pass pressure(P = 0.0040) and love-affair relationship(P = 0.0286). Although rural forest bathing can also alleviate the anxiety from financial state(P = 0.0222), meanwhile, it maintained the anxiety about campus life(P < 0.0001). Forest tree richness tended to be higher in the rural forest park than in the urban one, which in contrast decreased the anxiety alleviation from inter-communication in the rural forest park(P = 0.0487). Principle component analysis indicated that participants tended to perceive more decline of anxiety from social contact in the urban forest. In conclusion, university students were recommended to pay a short visit to the urban forest with partners if they felt anxious about personal affairs and felt necessary to talk with others. For general people's visiting, urban forest trees can be controlled in diversity to some extent to look orderly and alleviate perceived anxiety.

威宁豆酱纯种发酵工艺优化及挥发性风味物质分析

采用枯草芽孢杆菌(Bacillus subtilis)DX-9和异常威克汉姆酵母菌(Wickerhamomyces anomalus)DZ-3分别发酵制备威宁豆酱,以氨基酸态氮含量和感官评分为评价指标,优化制曲条件、辅料添加量及后发酵条件,并采用气相色谱-质谱联用(GC-MS)技术检测豆酱中的挥发性风味物质。结果表明,菌株DX-9和DZ-3的最佳制曲条件:接种量2%和3%、温度38℃和34℃、时间12 d和18 d;辅料最适添加量:食盐10%、辣椒5%、五香粉1.5%;菌株DX-9和DZ-3的最佳后发酵条件:温度40℃和36℃、时间均为90 d。纯种发酵豆酱的品质优于自然发酵豆酱,且菌株DX-9比DZ-3发酵的豆酱品质更佳。自然发酵、菌株DX-9和DZ-3发酵豆酱中挥发性风味物质分别检出73、50和64种,共有物质为23种,主要风味物质分别为醇类(27.36%)、酸类(75.68%)和烯烃类(64.21%)。通过主成分分析(PCA)得出威宁豆酱主要挥发性风味物质为烃类和酸类。

基于i-Tree模型的贵阳市行道树组成与生态服务功能研究

为了解贵阳市行道树的组成结构现状及其生态服务功能价值,应用i-Tree模型的Street模块对贵阳市三类城区的行道树结构和生态服务功能进行分析。结果表明:观山湖区调查街道有行道树24种,南明区和云岩区调查街道有行道树18种,花溪区调查街道有行道树17种。花溪区和老城区的行道树品种少,行道树数量比差距大,物种重要值差距大,观山湖区行道树品种较丰富,数量比差距小,物种重要值差距大。老城区街道行道树覆盖率小,花溪区和观山湖区街道行道树覆盖率大。花溪区调查街道年截留雨水35 116m^3,年能源总效益24 772美元,年空气质量总效益8 050美元,年CO_2总效益4 592美元,年储存CO_23 414 060kg;观山湖区调查街道年截留雨水144 842m^3,年能源总效益80 000美元,年空气质量总效益31 735美元,年CO_2总效益15 580美元,年储存CO_29 266 104kg;老城区调查街道年截留雨水147 550m^3,年能源总效益107 496美元,年空气质量总效益34 336美元,年CO_2总效益19 439美元,年储存CO_215 774 505kg。