Phytochemical Composition, Antioxidant Activity, and Untargeted LC-HRMS Fingerprinting of Coffee Pulp under Different Extraction Approaches
Muhammad Eriansyah Al Hakim(a*), Sandi Darniadi(a,b), Anil Kumar Anal(a)

(a) Food Innovation Bioprocessing Nutrition and Health, Asian Institute of Technology, Thailand
*st125014[at]ait.asia
(b) National Research and Innovation Agency (BRIN)

Abstract

Coffee pulp, a major by-product of coffee processing, represents a promising yet underutilized
source of bioactive phytochemicals. The efficiency and selectivity of compound recovery from
such biomass are highly dependent on extraction strategy. This study compared the conventional
heating, ultrasound assisted extraction (UAE), and microwave assisted extraction (MAE) to
determine its methods influence on phenolic recovery, antioxidant potential, and molecular
fingerprinting of coffee pulp extracts. The best performing extraction condition from each method
was selected and assessed through total phenolic content (TPC), total flavonoid content (TFC),
total soluble sugar (TSS), antioxidant activity (DPPH assay), and untargeted LC-HRMS profiling.
The results revealed that each methods showing a clear difference in phytochemical profiles and
antioxidant response. MAE demonstrated the most phenolic and flavonoid recovery which also
have a more enhanced antioxidant activity, indicating a more efficient extraction of bioactive
constituents. UAE exhibited intermediate performance, while conventional extraction showed
lower enrichment of antioxidant-related compounds. Interestingly, the untargeted LC-HRMS
analysis indicated that conventional extraction produced broader chemical feature richness,
suggesting extensive co-extraction of matrix components. In contrast MAE generated a more
selective molecular fingerprint which reflects a more targeted recovery of phenolic subclasses
rather than the other methods. Major phenolic compounds, including chlorogenic acid derivatives
and dicaffeoylquinic acid-related structures were consistently detected across al extraction
approaches, confirming that extraction method did not alter the core phytochemical composition
but rather modulated extraction selectivity and recovery efficiency. Overall, the findings
emphasize that each extraction methods significantly shapes both of phytochemical^s profiles and
functional antioxidant properties of coffee pulp. MAE in particular, demonstrates strong potential
as a selective and efficient approach for valorizing coffee processing by-products within
sustainable and green chemistry frameworks.

Keywords: Coffee pulp, extraction methods, phenolic compounds, antioxidant activity, LC HRMS, phytochemical profiling

Topic: Analytical Chemistry