高级检索

    干燥方式对烟花有机酸含量的影响及判别分析

    Effects of Drying Methods on Organic Acid Contents of Tobacco Flowers and Discriminant Analysis

    • 摘要: 为开发烟草花序(简称烟花)在烟用香料方面的利用价值,并建立基于关键有机酸的烟花干燥方式判别模型,利用GC/MS检测,分析7种干燥方式下烟花有机酸含量的差异,应用偏最小二乘-判别分析(PLS-DA)筛选出关键差异有机酸,并应用Fisher判别分析建立烟花干燥方式的判别模型。结果表明,(1)不同干燥方式烟花挥发酸为具有特征香气的苯甲酸、苯乙酸、3-甲基戊酸,总量为116~181 μg/g;非挥发酸总量为59.7~77.0 mg/g,草酸、苹果酸、柠檬酸含量之和占92.5%~97.8%;高级脂肪酸总量为22.4~65.2 mg/g,不饱和脂肪酸(油酸、亚油酸、亚麻酸)占58.7%~76.6%。(2)干燥方式对烟花有机酸含量影响显著:烟花挥发酸总量以晾干最高,其次是程序升温干燥和晒干,冷冻干燥最低;非挥发酸总量以冷冻干燥最高,恒温65 ℃干燥最低;高级脂肪酸总量以冷冻干燥最高,晾干最低。(3)应用PLS-DA可将7种干燥方式分为5类:冷冻干燥、程序升温干燥、恒温干燥、晒干、晾干,并基于PLS-DA模型VIP值,筛选出不同干燥方式的7种关键差异有机酸(戊二酸、油酸、硬脂酸、草酸、柠檬酸、肉豆蔻酸、苯乙酸),由此建立了5类烟花干燥方式的Fisher判别模型,其训练集和测试集的判别正确率分别为96.7%、100%。综上,晾干、晒干或程序升温(至59 ℃)干燥的烟花有机酸组成更适用于烟用香料,有机酸可作为烟花资源干燥方式有效判别的特征化学成分。

       

      Abstract: To explore the utilization of tobacco flower in tobacco flavoring applications and establish discriminant model for drying methods based on key organic acids, GC/MS was employed to analyze the differences in organic acid content across seven drying methods. Partial least squares-discriminant analysis (PLS-DA) was used to identify key differential organic acids, followed by Fisher discriminant analysis to construct a discriminant model for identifying drying methods. Results showed as the follows. (1) Volatile acids in tobacco flowers treated with different drying methods were identified as benzoic acid, phenylacetic acid and 3-methylpentanoic acid (with characteristic aroma), with total content ranging from 116 to 181 μg/g. The total content of non-volatile acids ranged from 59.7 to 77.0 mg/g, with the sum of oxalic acid, malic acid and citric acid content accounting for approximately 92.5% to 97.8% of the total. The total content of higher fatty acids ranged from 22.4 to 65.2 mg/g, with unsaturated fatty acids (oleic acid, linoleic acid, and linolenic acid) accounting for about 58.7% to 76.6% of the total. (2) Drying methods significantly affected organic acid contents: air drying achieved the highest volatile acid content, followed by programmed heating drying and sun drying, whereas freeze drying yielded the lowest. Non-volatile acids reached peak levels during freeze drying, whereas their minimum content were observed in 65 ℃ constant temperature drying. The total content of higher fatty acids was the highest in freeze drying and the lowest in air drying. (3) PLS-DA classified the seven drying methods into five categories: freeze drying, programmed heating drying, constant temperature drying, sun drying, and air drying. Based on the VIP values from the PLS-DA model, seven key differential organic acids, namely glutaric acid, oleic acid, stearic acid, oxalic acid, citric acid, myristic acid, and phenylacetic acid, were identified as characteristic markers. Subsequently, a Fisher discriminant model was established for the five categories of tobacco flower drying methods, with classification accuracies of 96.7% in the training set and 100% in the test set. In summary, the organic acid profiles of tobacco flowers subjected to air drying, sun drying, or programmed heating drying (up to 59 ℃) exhibit greater suitability for tobacco flavoring applications. Organic acids can serve as characteristic chemical components for effectively discriminating tobacco flower resources obtained from different drying methods.

       

    /

    返回文章
    返回