Zhai Xingchen, Yang Mengnan, Zhang Jing, Zhang Lulu, Tian Yarong, Li Chaonan, Bao Lina, Ma Chao, Abd El-Aty A M
Beijing Key Laboratory of Forest Food Processing and Safety, College of Biological Science and Technology, Beijing Forestry University, Beijing, China.
Department of Pharmacology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt.
Front Nutr. 2022 Mar 18;9:849811. doi: 10.3389/fnut.2022.849811. eCollection 2022.
A long extraction time for traditional cold coffee brewing considerably reduces the production efficiency of this type of beverage. Herein, a new ultrasound-assisted cold brewing (UAC) method was established. The feasibility of UAC was assessed by comparison with main physicochemical characteristics, non-volatile and volatile compounds in coffee extracts produced by hot brewing and conventional static cold brewing methods. Compared to the static cold brews, the levels of total dissolved solids, total lipids, proteins, and titrated acids of UAC coffee extracts increased by 6-26%, 10-21%, 26-31%, and 12-15%, respectively. Caffeine, chlorogenic acid, and trigonelline concentrations were also determined by HPLC. Based on the volatile profiles obtained by HS-SPME-GC/MS, the aroma compounds in UAC was significantly different ( < 0.05) from hot brews but similar to static cold ones, suggesting that ultrasonication compensated for the time of the static cold brewing, thereby considerably shortening the extraction time (1 h vs. 12 h). This work demonstrated that the combination of ultrasound-assisted with cold brew could produce coffee with good flavor and increase the extraction efficiency, which may provide an option for the acceleration of the cold brew coffee process.
传统冷萃咖啡的长时间萃取显著降低了此类饮品的生产效率。在此，建立了一种新的超声辅助冷萃（UAC）方法。通过与热萃和传统静态冷萃方法所制咖啡提取物的主要理化特性、非挥发性和挥发性化合物进行比较，评估了UAC的可行性。与静态冷萃咖啡相比，UAC咖啡提取物中的总溶解固体、总脂质、蛋白质和滴定酸含量分别提高了6 - 26%、10 - 21%、26 - 31%和12 - 15%。还通过高效液相色谱法测定了咖啡因、绿原酸和胡芦巴碱的浓度。基于顶空固相微萃取-气相色谱/质谱（HS-SPME-GC/MS）获得的挥发性成分谱，UAC中的香气化合物与热萃咖啡有显著差异（<0.05），但与静态冷萃咖啡相似，这表明超声处理弥补了静态冷萃的时间，从而显著缩短了萃取时间（1小时对12小时）。这项工作表明，超声辅助与冷萃相结合可以生产出风味良好的咖啡，并提高萃取效率，这可能为加速冷萃咖啡工艺提供一种选择。
