基于可解释机器学习方法的茶本酒香气品质预测模型构建

    Predicting study on aroma quality prediction model for tea-flavored liquor using explainable machine learning method

    • 摘要: 为实现茶本酒香气质量等级的精准预测、揭示影响其香气品质的关键挥发性成分,试验以110款茶本酒为研究对象,通过感官分析确定其香气品质等级,利用顶空固相微萃取-气相色谱-质谱测定主要香气成分轮廓,结合13种机器学习(machine learning,ML)算法和Shapley可加性特征解释(shapley additive explanations,SHAP),建立茶本酒香气品质预测模型,识别各等级茶本酒的关键差异性风味化合物并探索其作用模式。结果表明,在32个主要挥发性香气成分中,10种萜烯类物质、10种酯类物质和4种高级醇在不同等级酒样间具有显著差异。模型性能评价表明,径向基支持向量机(radial support vector machine)的曲线下面积最高(0.924),且准确度、精确度、召回率、F1分数均在0.8以上,综合性能优于其他ML算法,是茶本酒香气品质预测的最优模型。SHAP分析显示,里哪醇、茴香脑、水杨酸甲酯、橙花醇、十一酸乙酯、异戊醇的SHAP值高于其他成分,在模型预测中表现出较高的贡献度,是影响茶本酒香气质量等级的关键挥发性成分。其中,里哪醇、茴香脑、水杨酸甲酯、十一酸乙酯对茶本酒的香气品质具有积极影响;橙花醇对香气品质的贡献水平随其含量变化呈先上升后下降的趋势;异戊醇的大量积累则可能降低茶本酒的品质。研究揭示了影响茶本酒香气品质的关键挥发性成分及其潜在作用机制;通过对原料品质的把控,并在生产各环节对上述成分含量进行合理调控,可促进茶本酒风味品质的定向提升。

       

      Abstract: Tea-flavored liquor represents a distinctive category of alcoholic beverages produced through raw material preparation, tea maceration, sugar supplementation, alcoholic fermentation, distillation, aging, and blending, resulting in a distinctive combination of tea and liquor flavors. However, its aroma profile is characterized by pronounced complexity and variability, and the accurate assessment and prediction of aroma quality continue to pose substantial challenges. To address these gaps, this study developed an explainable machine learning (ML) framework for predicting the sensory quality grades of tea-flavored liquor and identified the key volatile compounds underlying quality differentiation. A total of 110 tea-flavored liquor samples were evaluated by a professional tasting panel following standardized sensory assessment protocols. Based on the panel’s evaluation, each sample was assigned to one of three predefined quality grades (Grade A, high quality; Grade B, medium quality; Grade C, low quality). The main aroma compound profiles of tea-flavored liquor were determined using headspace solid phase micro-extraction-gas chromatography-mass spectrometry (HS–SPME–GC–MS). Thirteen ML models were benchmarked, and model performance was assessed using accuracy, precision, recall, F1-score, and the area under the receiver operating characteristic curve (AUC). To enhance interpretability, Shapley Additive exPlanations (SHAP) were employed to quantify the contribution of aroma compounds to model predictions. According to the sensory evaluation results, 28 samples were classified as Grade A, 42 as Grade B, and 40 as Grade C. Among the 32 major volatile aroma compounds, 24 exhibited significant differences (P<0.05) across the three quality grades, including 10 terpenes, 10 esters, and 4 higher alcohols. Samples graded as RANK A and RANK B displayed broadly similar aroma profiles, whereas most compounds in RANK C were present at significantly lower concentrations. Among the 13 ML models tested, the Radial Support Vector Machine (Radial SVM) achieved the best predictive performance, with an AUC of 0.92 and accuracy, precision, recall, and F1-score values all exceeding 0.8. SHAP analysis further revealed that terpenes constituted the largest subgroup among the top 20 most influential compounds, followed by 7 esters and 3 higher alcohols. Key aroma compounds contributing to the model prediction included linalool (floral), anethole (spicy), methyl salicylate (mint-like), nerol (floral), ethyl undecanoate (fruity), and isoamyl alcohol (alcoholic). Linalool, anethole, methyl salicylate, and ethyl undecanoate were found to exert a positive contribution to the sensory quality of tea-flavored liquor. While nerol similarly showed a positive effect, its contribution followed a complex, nonlinear trend: its positive influence first increased, then diminished as concentrations rose. This unique pattern may be hypothesized to result from a synergistic effect between esters and other terpene compounds at lower concentrations, which collectively amplified the sensory perception of nerol. In contrast, the accumulation of isoamyl alcohol appeared to diminish the overall aroma quality of tea-flavored liquor. In conclusion, this study established an accurate and interpretable ML model for sensory quality grading of tea-flavored liquor and identified volatile compounds most critical to quality differentiation. These findings provide a scientific basis for targeted optimization of production processes, quality control, and flavor enhancement in tea-flavored liquor. Future work will focus on exploring the interactions among key aroma compounds to further enrich the theoretical foundation of flavor chemistry in alcoholic beverages.

       

    /

    返回文章
    返回