Department of Food Science and Technology, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA.
Department of Chemical Engineering, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA.
Sci Rep. 2024 Aug 20;14(1):19298. doi: 10.1038/s41598-024-69867-6.
With the growing popularity of cold brewed coffee comes a need for brewing efficiency while preserving the desirable flavor profile. Despite the wide use of full immersion brewing techniques, the effect of brew time on the dynamic sensory profiles of full immersion brewed coffee remains underexplored. Here, we investigated the relationship between coffee sensory quality and extraction dynamics, measured as Total Dissolved Solids (TDS) and Extraction (E) of full immersion brewed coffee at various roast levels, and brewing temperatures (4 °C, 22 °C and 92 °C), over brew time using a generic descriptive analysis method. Specifically, different brew time points were selected for different temperatures based on five targeted coffee extraction stages. Furthermore, the unique experimental design also explored a sensory-driven engineering research process. Roast level had the greatest impact on the sensory profile of the coffees, followed by brewing temperature, but brew time, especially the longer brew times as TDS plateaued, had subtler impacts than expected. Twenty-five of 28 sensory attributes were significantly different among the 30 coffee samples, indicating a single source green coffee blend can produce a wide range of complex sensory profiles using different combinations of roast level, temperature, and brew time. Specifically, the intensity of sweetness was negatively correlated with TDS, and 19 other attribute intensities were positively correlated with TDS. Interestingly, we found that certain long time cold brews had similar sensory profiles to those of some short time hot brews, suggesting the sensory profiles of certain hot brews and cold brews could possibly be matched through controlled preparation. Overall, our study demonstrated an approach of integrating food engineering and sensory analysis for product development, and our findings provide valuable insights into the extraction dynamics and sensory quality of full immersion brewed coffee and opens new brewing avenues for the coffee industry.
随着冷萃咖啡的日益普及，人们对酿造效率的需求也在不断提高，同时还要保留理想的风味特征。尽管全浸式酿造技术得到了广泛应用，但冲泡时间对全浸式酿造咖啡动态感官特征的影响仍未得到充分探索。在这里，我们研究了咖啡感官质量与提取动力学之间的关系，使用通用描述性分析方法测量了不同烘焙程度、酿造温度（4°C、22°C 和 92°C）和冲泡时间下全浸式酿造咖啡的总溶解固体（TDS）和提取（E）。具体来说，根据五个目标咖啡提取阶段，为不同的温度选择了不同的冲泡时间点。此外，独特的实验设计还探索了一种以感官为导向的工程研究过程。烘焙程度对咖啡的感官特征影响最大，其次是酿造温度，但冲泡时间，尤其是当 TDS 达到稳定状态时的较长冲泡时间，其影响比预期的要微妙。在 30 个咖啡样本中，28 种感官属性中有 25 种存在显著差异，这表明单一来源的混合绿咖啡豆可以使用不同的烘焙程度、温度和冲泡时间组合产生广泛的复杂感官特征。具体来说，甜度的强度与 TDS 呈负相关，19 种其他属性的强度与 TDS 呈正相关。有趣的是，我们发现某些长时间的冷萃咖啡具有与某些短时间热萃咖啡相似的感官特征，这表明某些热萃咖啡和冷萃咖啡的感官特征可能可以通过控制制备来匹配。总的来说，我们的研究展示了一种将食品工程和感官分析相结合的方法，用于产品开发，我们的研究结果为全浸式酿造咖啡的提取动力学和感官质量提供了有价值的见解，并为咖啡行业开辟了新的酿造途径。
