Valorization of Spent Coffee Grounds as a Natural Source of Bioactive Compounds for Several Industrial Applications—A Volatilomic Approach

Abstract

Coffee is one of the most popular beverages worldwide, whose production and consumption result in large amounts of waste, namely spent coffee grounds, constituting an important source of compounds for several industrial applications. This work focused on the establishment of the volatile fingerprint of five spent coffee grounds from different geographical origins using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME/GC-MS), as a strategy to identify volatile organic metabolites (VOMs) with potential application in the food industry as antioxidant, anti-inflammatory, and antiproliferative agents. One hundred eleven VOMs belonging to different chemical families were identified, of which 60 were found in all spent coffee grounds analyzed. Furanic compounds (34%), nitrogen compounds (30%), and esters (19%) contributed significant to the total volatile fingerprint. The data obtained suggest that spent coffee grounds have great potential to be used as raw material for different approaches in the food industry towards the development of new food ingredients or products for human consumption, in addition to pharmaceutical and cosmetic applications, namely as antioxidant (e.g., limonene, carvacrol), antimicrobial (e.g., pyrrole-2-carboxaldehyde, β-myrcene) and anti-inflammatory (e.g., furfural, 2-furanmethanol) agents, promoting their integral valorization within the circular bioeconomy concept.

Few case studies as ideas for zero-waste from food production and processing

“…Remarkably, the preparation of 1 kg of soluble coffee yields 2 kg of SCG, and a staggering 650 kg of SCG is obtained from one ton of green coffee beans converted into a coffee drink (Vandeponseele et al, 2021;Brekalo et al, 2023). It is reported that about 6 million tons of SCG are collected annually worldwide (Dordevic et al, 2023). Regrettably, the entirety of these SCGs often finds its way to landfills without proper composting, posing a significant environmental and economic challenge.…”

“…Coffee oil, extracted from spent coffee grounds, is rich in bioactive compounds like esters, fatty acids, and phenols, endowing it with diverse pharmacological properties such as anti-aging, antioxidant, and anti-cancer effects. Notably, the applications of coffee oil extend across various industries, including cosmetics, food, and pharmaceuticals (Dordevic et al, 2023). Within the cosmetic industry, coffee oil has found utility due to its skin-friendly properties.…”

“…Derived from diverse sources such, biopesticides offer targeted and effective pest control without the associated risks of residual effects, ensuring a safer and more ecofriendly approach to agriculture and pest management.The spent coffee ground residue, post-extraction, can be repurposed as a nutrientrich soil amendment, promoting sustainable agricultural practices (Santos et al, 2017). The extracted oils might also serve as bio-based additives in the production of biodegradable polymers, contributing to the development of sustainable packaging materials (Dordevic et al 2023).…”

Characterization of the Volatilomic Fingerprint of Culinary Aromatic Herbs: A Comparative Study Based on Chemometric Analysis

“…In this context, gas chromatography-mass spectrometry (GC-MS) stands out as the gold standard instrumental methodology for analyzing VOMs across various samples. However, prior sample preparation is crucial to concentrate the VOMs and eliminate any interference, especially in complex samples like food matrices [16]. To address this, headspace solid-phase microextraction (HS-SPME) is a widely used technique that effectively characterizes the volatile profile of fruits and vegetables [17][18][19].…”

Efficiency of Lactiplantibacillus plantarum JT-PN39 and Paenibacillus motobuensis JT-A29 for Fermented Coffee Applications and Fermented Coffee Characteristics

“…To increase the product's economic value, specialty coffee production by animal feeding and gut fermentation are globally known to create unique aromas and flavors that lead to a higher product price. However, due to issues related to animal cruelty in laboratories, many reports have focused on replacing animal utilization with microbial fermentation [2,3]. The mixed culture of bacteria or bacteria and yeast were described in many previous studies for their ability to generate animal fermentation-like coffee or increase coffee market profitability.…”