Kyriakoudi Anastasia, Loukri Anastasia, Christaki Stamatia, Oliinychenko Yelyzaveta, Stratakos Alexandros Ch, Mourtzinos Ioannis
Laboratory of Food Chemistry and Biochemistry, Department of Food Science and Technology, Faculty of Agriculture, Forestry and Natural Environment, School of Agriculture, Aristotle University of Thessaloniki (AUTH), 54124 Thessaloniki, Greece.
College of Health, Science and Society, School of Applied Sciences, University of the West of England, Coldharbour Ln, Bristol, BS16 1QY UK.
Food Anal Methods. 2024;17(10):1484-1496. doi: 10.1007/s12161-024-02661-2. Epub 2024 Aug 5.
In the present study, cold atmospheric plasma (CAP) was employed as a pretreatment method for the extraction of phenolic compounds from spent coffee grounds (SCGs). The impact of CAP treatment conditions, i.e., thickness of the SCGs layer (mm), distance between the plasma source and the SCGs layer (mm) and duration of CAP treatment (min), on the total phenol content, in vitro antioxidant activity, as well as caffeine and chlorogenic acid content of SCGs, was investigated. The process parameters were optimized with the aid of response surface methodology (RSM). After optimizing the CAP pretreatment conditions, the CAP-treated SCGs were subjected to ultrasound-assisted extraction using ethanol as the extraction solvent. The optimum conditions for CAP treatment identified, i.e., thickness, 1 mm; distance, 16 mm; and duration, 15 min, led to a significant enhancement in the recovery of bioactive compounds from SCGs compared to those obtained from untreated SCGs. Total phenolic content and antioxidant activity significantly increased (i.e., TPC from 19.0 ± 0.7 to 24.9 ± 1.4 mg GAE/100 g dry SCGs, A from 106.7 ± 5.01 to 112.3 ± 4.3 μmol Trolox/100 g dry SCGs, A from 106.7 ± 5.01 to 197.6 ± 5.8 μmol Trolox/100 g dry SCGs, A from 17938 ± 157 to 18299 ± 615 μmol Trolox/100 g dry SCGs). A significant increase in caffeine content from 799.1 ± 65.1 mg to 1064 ± 25 mg/100 g dry SCGs and chlorogenic acid content from 79.7 ± 15.3 mg to 111.3 ± 3.3 mg/100 g dry SCGs, was also observed. Overall, CAP pre-treatment can be used to enhance the recovery of bioactive compounds from SCGs.
在本研究中，冷大气等离子体（CAP）被用作从咖啡渣（SCGs）中提取酚类化合物的预处理方法。研究了CAP处理条件，即SCGs层的厚度（mm）、等离子体源与SCGs层之间的距离（mm）和CAP处理持续时间（min）对SCGs的总酚含量、体外抗氧化活性以及咖啡因和绿原酸含量的影响。借助响应面法（RSM）对工艺参数进行了优化。在优化CAP预处理条件后，对经CAP处理的SCGs使用乙醇作为提取溶剂进行超声辅助提取。确定的CAP处理最佳条件为：厚度1mm、距离16mm、持续时间15min，与未经处理的SCGs相比，显著提高了从SCGs中回收生物活性化合物的效率。总酚含量和抗氧化活性显著增加（即总酚含量从19.0±0.7增加到24.9±1.4mg GAE/100g干SCGs，抗氧化活性从106.7±5.01增加到112.3±4.3μmol Trolox/100g干SCGs，抗氧化活性从106.7±5.01增加到197.6±5.8μmol Trolox/100g干SCGs，抗氧化活性从17938±157增加到18299±615μmol Trolox/100g干SCGs）。还观察到咖啡因含量从799.1±65.1mg显著增加到1064±25mg/100g干SCGs，绿原酸含量从79.7±15.3mg显著增加到111.3±3.3mg/100g干SCGs。总体而言，CAP预处理可用于提高从SCGs中回收生物活性化合物的效率。
