Comparison of chemical compositions, antioxidant activities, and acetylcholinesterase inhibitory activities between coffee flowers and leaves as potential novel foods

Xiaojing Shen; Fanqiu Nie; Haixian Fang; Kunyi Liu; Zelin Li; Xingyu Li; Yumeng Chen; Rui Chen; Tingting Zheng; Jiangping Fan

doi:10.1002/fsn3.3126

Comparison of chemical compositions, antioxidant activities, and acetylcholinesterase inhibitory activities between coffee flowers and leaves as potential novel foods

Food Sci Nutr. 2022 Nov 5;11(2):917-929. doi: 10.1002/fsn3.3126. eCollection 2023 Feb.

Authors

Xiaojing Shen^{1

2

3}, Fanqiu Nie¹, Haixian Fang⁴, Kunyi Liu^{5

6}, Zelin Li¹, Xingyu Li¹, Yumeng Chen¹, Rui Chen¹, Tingting Zheng⁷, Jiangping Fan¹

Affiliations

¹ College of Food Science and Technology, College of Science Yunnan Agricultural University Kunming China.
² Yunnan Key Laboratory of Pharmacology for Natural Products Kunming Medical University Kunming China.
³ Yunnan Organic Tea Industry Intelligent Engineering Research Center Key Laboratory of Intelligent Organic Tea Garden Construction in Universities of Yunnan Province Kunming China.
⁴ Quality Standardizing and Testing Technology Institute, Yunnan Academy of Agricultural Sciences Kunming China.
⁵ College of Wuliangye Technology and Food Engineering Yibin Vocational and Technical College Yibin China.
⁶ Research Platform for Innovation and Utilization of Medicine Food Homology and Fermented Food Yibin Vocational and Technical College Yibin China.
⁷ Pu'er Institute of Pu-erh Tea Pu'er China.

Abstract

This study aimed to compare chemical compositions, antioxidant activities, and acetylcholinesterase inhibitory activities of coffee flowers (ACF) and coffee leaves (ACL) with green coffee beans (ACGB) of Coffea Arabica L. The chemical compositions were determined by employing high-performance liquid chromatography-mass spectroscopy (HPLC-MS) and gas chromatography-mass spectroscopy (GC-MS) techniques. Antioxidant effects of the components were evaluated using DPPH and ABTS radical scavenging assays, and the ferric reducing antioxidant power (FRAP) assay. Their acetylcholinesterase inhibitory activities were also evaluated. The coffee sample extracts contained a total of 214 components identified by HPLC-MS and belonged to 12 classes (such as nucleotides and amino acids and their derivatives, tannins, flavonoids, alkaloids, benzene, phenylpropanoids, and lipids.), where phenylpropanoids were the dominant component (>30%). The contents of flavonoids, alkaloids, saccharides, and carboxylic acid and its derivatives in ACF and ACL varied significantly (p < .05) compared to similar components in ACGB. Meanwhile, 30 differentially changed chemical compositions (variable importance in projection [VIP] > 1, p < .01 and fold change [FC] > 4, or <0.25), that determine the difference in characteristics, were confirmed in the three coffee samples. Furthermore, among 25 volatile chemical components identified by GC-MS, caffeine, n-hexadecanoic acid, 2,2'-methylenebis[6-(1,1-dimethylethyl)-4-methyl-phenol], and quinic acid were common in these samples with caffeine being the highest in percentage. In addition, ACL showed the significantly highest (p < .05) DPPH radical scavenging capacity with IC₅₀ value of 0.491 ± 0.148 mg/ml, and acetylcholinesterase inhibitory activity with inhibition ratio 25.18 ± 2.96%, whereas ACF showed the significantly highest (p < .05) ABTS radical scavenging activity with 36.413 ± 1.523 mmol trolox/g Ex. The results suggested that ACL and ACF had potential values as novel foods in the future.

Keywords: acetylcholinesterase inhibitory activity; antioxidant activity; chemical composition; coffee flower; coffee leaf.