# Functional Chewing Gum Enriched with Spent Coffee Grounds Extract: Chemical Characteristics and Antimicrobial Potential Against Oral Bacteria

**Authors:** Hanem M. M. Mansour, Elsayed E. Hafez, Mahdy N. Elnaggar, Hager S. A. Alsonpaty, Salim A. Ali, Asteer V. Abd-Elnoor, Amira A. Abdellatef, Omayma E. Shaltout, Marwa G. Allam, Eman M. Abdo

PMC · DOI: 10.3390/foods15040640 · 2026-02-10

## TL;DR

This paper explores using spent coffee grounds in chewing gum to create a sustainable product with antimicrobial properties that may benefit oral health.

## Contribution

The novelty lies in incorporating SCG extract into frankincense-based chewing gum to evaluate its antimicrobial potential against oral bacteria.

## Key findings

- SCG extract has high phenolic content and antioxidant activity.
- T25 gum showed the best antimicrobial effects against S. mutans and E. faecalis.
- The SCG-enriched gum is a promising biodegradable functional product for oral health.

## Abstract

Spent coffee grounds (SCGs), as a by-product, represent a sustainable source of bioactive components. Herein, the ethanol extract of SCGs was examined for its chemical characteristics and antimicrobial effect. The extract was incorporated into novel frankincense-based gums at concentrations of 0% (T0), 15% (T15), 20% (T20), and 25% (T25). The physicochemical properties and the antibacterial activity of the SCG-enriched gums against oral pathogens were assessed. SCG extract showed a total phenolic content of 999.38 ± 2.63 μg/g and demonstrated antioxidant activity with a 50% inhibitory concentration (IC50) of 107.28 ± 1.90 μL/mL. T25 showed the highest phenolic content (256.66 ± 2.93 μg/g) and enhanced scavenging activity IC50 = 211.05 ± 0.65 (DPPH) and 128.52 ± 4.05 μL/mL (ABTS). T25 demonstrated superior antimicrobial effects against Streptococcus mutans and Enterococcus faecalis at 400 µL/mL, with inhibition zones of 33.33 ± 2.89 and 20.33 ± 0.58 mm compared to T0. Both T25 and T0 inhibited Lactobacillus acidophilus similarly. Overall, incorporating SCG extract into natural frankincense-based gum presents a promising biodegradable functional gum with potential oral health benefits.

## Linked entities

- **Chemicals:** ethanol (PubChem CID 702), ABTS (PubChem CID 35688)
- **Species:** Streptococcus mutans (taxon 1309), Enterococcus faecalis (taxon 1351), Lactobacillus acidophilus (taxon 1579)

## Full-text entities

- **Diseases:** endodontic infections (MESH:D011671), caries (MESH:D003731), Cytotoxicity (MESH:D064420), obesity (MESH:D009765), inflammatory (MESH:D007249), injury to (MESH:D014947), enamel (MESH:D003744), carcinoma (MESH:D009369), Alzheimer's (MESH:D000544)
- **Chemicals:** aluminum chloride (MESH:D000077410), CO2 (MESH:D002245), sodium carbonate (MESH:C005686), Frankincense (MESH:D065260), ABTS (MESH:C002502), lipids (MESH:D008055), lipopolysaccharides (MESH:D008070), hydrogen (MESH:D006859), Lecithin (MESH:D054709), DMSO (MESH:D004121), Flavonoid (MESH:D005419), chlorogenic acid (MESH:D002726), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MESH:C022616), H2O2 (MESH:D006861), EMEM (-), caffeine (MESH:D002110), penicillin (MESH:D010406), MTT (MESH:C070243), propolis (MESH:D011429), minerals (MESH:D008903), acetone (MESH:D000096), oil (MESH:D009821), fatty acids (MESH:D005227), potassium persulfate (MESH:C009007), starch (MESH:D013213), water (MESH:D014867), sorbitol (MESH:D013012), essential oils (MESH:D009822), catechin (MESH:D002392), isopropanol (MESH:D019840), KBr (MESH:C039004), NaOH (MESH:D012972), Ethanol (MESH:D000431), formazan (MESH:D005562), Gallic acid (MESH:D005707), sugars (MESH:D000073893), acids (MESH:D000143), carboxylic acids (MESH:D002264), melanoidin (MESH:C011908), sodium nitrite (MESH:D012977), streptomycin (MESH:D013307), carbon (MESH:D002244), agar (MESH:D000362), acetonitrile (MESH:C032159), 2,2, diphenyl-1-picrylhydrazyl (MESH:C004931), esters (MESH:D004952)
- **Species:** Centropomus viridis (species) [taxon 56564], Eucalyptus (genus) [taxon 3932], Bacteria Latreille et al. 1825 (Bacteria stick insect, genus) [taxon 629395], Homo sapiens (human, species) [taxon 9606], Enterococcus faecalis (species) [taxon 1351], Sus scrofa (pig, species) [taxon 9823], Coffea arabica (arabica coffee, species) [taxon 13443], Lactobacillus acidophilus (species) [taxon 1579], Candida albicans (species) [taxon 5476], Clostridium perfringens (species) [taxon 1502], Streptococcus mutans (species) [taxon 1309], Streptococcus mutans ATCC 25175 (strain) [taxon 1257041], Escherichia coli (E. coli, species) [taxon 562], Pseudomonas aeruginosa (species) [taxon 287], Enterococcus faecalis ATCC 19433 = NBRC 100480 (strain) [taxon 1169286], Saccharomyces cerevisiae (baker's yeast, species) [taxon 4932]
- **Cell lines:** WI-38 — Homo sapiens (Human), Finite cell line (CVCL_0579)

## Figures

8 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12939841/full.md

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Source: https://tomesphere.com/paper/PMC12939841