Use of Student's t statistic as a phenotype of relative consumption preference of wheat (Triticum aestivum L.) grain

Whole-grain wheat (Triticum aestivum L.) products provide essential nutrients to humans, but bran attributes may hinder consumption. Differences in grain attributes including flavor/aroma can be identified using the house mouse (Mus musculus L.) as a model system. A potential application of this model system is to identify genes or quantitative trait loci (QTLs) conferring consumption-related traits using genetic mapping. These analyses require a quantitative phenotype to test marker–trait associations. Two-choice feeding trials are common in consumption studies, but do not provide an independent, quantitative phenotype. The objective of this study was to examine the use of ‘check’ varieties against which to compare sample varieties to generate Student's t values for use as phenotypic values. Two checks, which had previously been identified as “Yummy” and “yucky” (Y, y) were compared against each sample variety. The resulting t values provided an independent quantitative phenotype of the sample varieties.     

Application of extra sulfur to high-sulfur soils does not increase pungency and related compounds in shortday onions

Sulfur (S) nutrition has a strong influence on onion pungency, and the production of sweet onions in the high-sulfur soil of Texas is a challenge to growers. This study was performed to determine the effects of S applications to fields already having sufficient levels of soil S on pungency and related compounds in four shortday onion cultivars. The onion cultivars ‘Cougar’, ‘Legend’, ‘Texas Early White’, and ‘Texas Grano 1015Y’ were grown in three commercial fields at Edinburg, Mercedes, and Weslaco of the Rio Grande Valley of South Texas with applications of sulfur at 0, 13, and 26 kg S/ha. Pyruvic acid, bulb weight, extractable S in soil and total S in bulb, soluble solids content (SSC), flavor precursor compounds [also called S-alk(en)yl-l-cysteine-sulfoxides (ACSOs)], and total sugars were measured. The pyruvic acid level of onions was not increased by the S applications and showed no significant correlation with soil S levels in any of the cultivars at locations having 30 or 235 ppm S. The SSC, total S in bulbs, total sugars, and total ACSO content also showed no correlation with the S applications and soil S levels. Onion pungency and content of flavor precursor compounds were significantly influenced by cultivar and cultivar × location interaction. We conclude that onion pungency is not increased by application of extra S fertilizer to commercial fields already containing sufficient levels of soil sulfur.     

白灵菇风味成分的GC-MS分析

采用水蒸气蒸馏法提取白灵菇中风味成分,然后利用气相色谱-质谱(GC-MS)联用技术进行分析,得到白灵菇总离子流色谱图中共75个峰,经过NIST谱库联机检索,鉴定出35种化合物,约占色谱流峰总面积的79.75%。结果表明,白灵菇风味成分中含量最多的一类化合物为胺类化合物,相对百分含量为43.19%。在胺类化合物中(Z)-9-十八烯酰胺含量最高,相对含量为22.47%。     

稻米食味品质的相关性研究

统一鉴定南方稻区大面积推广的51个早籼稻品种的稻米品质后,进行了稻米食味品质与其他品质性状间的相关分析、逐步回归分析及通径分析。结果表明,稻米脂肪含量较其他品质性状对稻米食味品质有更大的影响,食用优质米的品质评价指标增加脂肪含量似更准确和完善。脂肪含量高、直链淀粉含量中等偏低、糊化温度低、胶稠度软或中等偏软、米粒延伸性好的稻米,食味品质好,这种品质性状的组合方式应该成为水稻品质育种的选择目标.本研究指出,提高脂肪含量、降低直链淀粉含量是改良稻米食味品质的关键,但直链淀粉含量并非越低越好。通过选择,将好的外观与优良的蒸煮、食味品质相结合是完全可能的.     

不同品种鸡汤风味品质比较研究

分别以苏北土鸡、雪山鸡和817肉鸡为原料加工鸡汤,研究其感官品质、游离氨基酸和核苷酸的变化,试验结果表明:相同品种的鸡宰后分别成熟0.5 h与24 h的样品煲汤,在感官风味上没有明显差异,但不同种类鸡汤之间感官差异显著,其中苏北土鸡汤的整体滋味及香气较好,雪山鸡汤滋味略有不足但肉质更好,817肉鸡汤总体评价相对较差;在游离氨基酸含量方面,随着鸡肉宰后成熟时间的延长,所制成的汤中游离氨基酸含量有增加的趋势,且不同品种差异显著;在核苷酸含量方面,不同品种鸡汤中的核苷酸CMP、IMP和AMP差异较大,其含量按照由高到低的顺序依次是苏北土鸡汤、雪山鸡汤、817肉鸡汤。由此可知,苏北土鸡煲汤的整体风味最佳,雪山鸡次之,817肉鸡煲汤风味较差,不适合作煲汤类产品。     

真空回潮工艺参数对烟叶香味物质含量的影响

[目的]研究真空回潮过程对烟叶中香味物质含量的影响。[方法]以WZ-003-YX型真空回潮机为研究对象,选择2个工作周期的抽空温度、加湿温度、保温时间等6个因素,采用均匀设计法设置了10种不同的工艺参数组合,对云南中烟某牌号配方烟叶进行处理,分别测定真空回潮前后烟叶中香味物质含量并对数据进行分析。[结果]试验表明,烟叶经过真空回潮处理后总香味物质含量显著升高,平均升高12.01μg/g,且这种变化趋势不受工艺参数的影响。[结论]研究可为卷烟生产加工中合理制定工艺条件提供参考。     

基于HS-SPME/GC-MS和感官分析技术的单菌发酵对咖啡果酒风味影响研究

为探讨单菌发酵对果酒风味的影响,利用GC-MS分析对风味影响的物质基础,利用电子感官（电子鼻和电子舌）和人为感官判定菌种对咖啡果酒整体风味的影响,研究结果为酿造优质风味咖啡果酒筛选最佳菌种组合提供理论参考。实验结果表明,4 种酵母中B和D酿成的果酒中乙醇的相对含量高于其他2 种,C损失略高于其他3 种酵母。GC-MS分析共检出化合物26 种,其中酯类15 种、醇类7 种、其他化合物4 种;所检化合物除酸类物质外,均具有令人愉悦的风味;醇类均为高级醇,主要是异戊醇和苯乙醇;酵母D峰面积明显高于其他3 种,而醇酯比C(8.61)>A(4.17)>B(1.16)>D(1.05)。电子感官检测发现,电子鼻和电子舌的第1 主成分的贡献率均达到98%以上,但大多存在交叉,区分效果较差,说明风味和口感较为接近;人为感官区分结果与电子感官结果一致。     

香料线滤棒爆口探索及其解决方案研究

为解决香料线滤棒(橙味香料)的爆口问题,进行滤棒成型试验。结果表明:橙味香料中的桔子油和甜橙精油会溶解滤棒搭口粘合剂热熔胶,从而引起滤棒爆口。针对此问题,采用了搭口冷热双胶线技术和伺服同步可调胶量的泵压式供胶系统,并结合对不同厂家提供的冷胶进行筛选,最终有效地解决了橙味香料引起的滤棒爆口。同时,为滤棒爆口和高透成形纸渗胶2个技术难题提供了解决思路。     

超高效液相色谱-串联质谱联用法测定香精香料中的香豆素和黄樟素

[目的]准确快速地测定香精香料中的香豆素和黄樟素。[方法]以60%乙醇水溶液为溶剂,样品经振荡萃取后,提取液经0.22μm滤膜过滤,采用超高效液相色谱-串联质谱联用法(UPLC-MS/MS)测定香豆素和黄樟素。[结果]该方法回收率的结果在95.0%~99.4%,日内、日间测定结果的变异系数分别小于6%和8%,香豆素和黄樟素的定量限分别为77.0和68.1μg/kg。[结论]该方法可有效去除杂质干扰,分析时间短,具有高灵敏度、高精密度、高准确度等优点,适用于香精香料中的香豆素和黄樟素的测定。     

不同萃取头萃取萝卜风味物质的GC-MS分析

采用PDMS/DVB和DVB/CAR/PDMS两种萃取头,以固相微萃取(SPME)法提取萝卜风味物质成分,经气相色谱-质谱联用(GC-MS)对风味物质成分进行鉴定,分析比较两种萃取头提取的风味物质成分差别,以确定适宜的萃取头。结果表明:两种萃取头的固相微萃取共检测到29种风味成分,PDMS/DVB提取数量为17种,DVB/CAR/PDMS为27种;PDMS/DVB萃取头所萃取的醇类、异硫氰酸酯类的数量比DVB/CAR/PDMS萃取头少2种,烷烃类少3种,杂环类少1种,酯类、酮类均未检测到;DVB/CAR/PDMS萃取异硫氰酸酯类、烷烃类、醛类、杂环类、酮类、醚类及醇类的灵敏度高,PDMS/DVB萃取芳香族类的灵敏度高。因此,根据获得风味物质数量、种类以及灵敏度,供试萃取头中,DVB/CAR/PDMS比PDMS/DVB更适于提取分析萝卜风味物质成分。