Antibacterial Activity of Green Tea Leaf Extract Against Dairy-Associated Bacteria and Its Application in Pasteurized Milk

Vania Glory Falensia Putri Loa, Charis Amarantini, Tri Yahya Budiarso

Abstract

Bacterial contamination in pasteurized milk remains a potential cause of milk-borne diseases. Pasteurization may not eliminate all bacteria, thereby posing health risks. This study evaluated the potential of green tea leaf extract as an antibacterial agent to enhance pasteurization treatment by reducing contaminant bacteria and assessing its effect on milk flavor after treatment. Green tea leaves were extracted using the decoction technique. Antibacterial activity was evaluated using the agar well diffusion method, and bacterial reduction after pasteurization was measured using the total plate count (TPC) test. Panelist acceptance was assessed organoleptically based on color, aroma, and taste. The results showed that green tea leaf extract at a concentration of 5% had a very strong inhibitory effect (≥ 20 mm) against Staphylococcus aureus ATCC 25923 and Staphylococcus aureus SM 3.2.3, reducing bacterial counts by 5.2 log CFU ml-1. Organoleptic testing of pasteurized milk treated with 1 to 5% extract showed consistently favorable scores for color, aroma, and taste. These findings indicate that green tea leaf extract has considerable potential to reduce S. aureus contamination and enhance the effectiveness of pasteurization for commercial application.

Keywords

Camellia sinensis; food safety; milk quality; natural antimicrobial; sensory evaluation

Full Text:

PDF

References

Ahmad, S., Rahman, H., Qasim, M., Nawab, J., Alzahrani, K. J., Alsharif, K. F., & Alzahrani, F. M. (2022). Staphylococcus epidermidis pathogenesis: Interplay of icaADBC operon and MSCRAMMs in biofilm formation of isolates from pediatric bacteremia in Peshawar, Pakistan. Medicina, 58(11), 1510. https://doi.org/10.3390/medicina58111510

Aladhadh, M., & Abdallah, E. M. (2025). Comparative analysis of microbial growth in raw and pasteurized cow and camel milk during chilled storage. Journal of Pure and Applied Microbiology, 19(1), 323–332. https://doi.org/10.22207/JPAM.19.1.23

Alghamdi, A. I. (2023). Antibacterial activity of green tea leaves extracts against specific bacterial strains. Journal of King Saud University - Science, 35(5), 102650. https://doi.org/10.1016/j.jksus.2023.102650

Amirdivani, S., & Baba, A. S. H. (2015). Green tea yogurt: Major phenolic compounds and microbial growth. Journal of Food Science and Technology, 52(7), 4652–4660. https://doi.org/10.1007/s13197-014-1670-6

Balouiri, M., Sadiki, M., & Ibnsouda, S. K. (2016). Methods for in vitro evaluating antimicrobial activity: A review. Journal of Pharmaceutical Analysis, 6(2), 71–79. https://doi.org/10.1016/j.jpha.2015.11.005

Bastam, M. M., Jalili, M., Pakzad, I., Maleki, A., & Ghafourian, S. (2021). Pathogenic bacteria in cheese, raw and pasteurised milk. Veterinary Medicine and Science, 7(6), 2445–2449. https://doi.org/10.1002/vms3.604

Bikheet, M. M., Hassan, H. M., Omar, M. O., Abdel-Aleem, W. M., Galal, S. M., Korma, S. A., ... & Nassar, K. S. (2025). Effects of clove (Syzygium aromaticum) extract on antibacterial activity, phytochemical properties, and storage quality of flavored milk beverages. Journal of Dairy Science, 108(4), 3300–3313. https://doi.org/10.3168/jds.2024-26023

Bishop, J., & McCue, P. M. (2021). Microbiology: Gram stain. Equine Reproductive Procedures (1st ed., pp. 59–60). https://doi.org/10.1002/9781119556015.ch15

BPOM. (2019). Peraturan badan pengawas obat dan makanan nomor 13 tahun 2019 tentang batas maksimal cemaran mikroba dalam pangan olahan (13 tahun 2019). Indonesian Food and Drug Authority. Retrieved from https://standarpangan.pom.go.id/storage/documents/pedoman/Pedoman_Penerapan_Peraturan_Badan_POM_Tentang_Cemaran_Mikroba_dalam_Pangan_Olahan-2019.pdf

BSN. (2021). SNI 8984:2021 Susu cair plain (SNI 8984:2021). Indonesian National Standard. Retrieved from https://akses-sni.bsn.go.id/dokumen/2021/SNI%208984-2021/#p=1

Calahorrano-Moreno, M. B., Ordoñez-Bailon, J. J., Baquerizo-Crespo, R. J., Dueñas-Rivadeneira, A. A., Montenegro, M. C. B., & Rodríguez-Díaz, J. M. (2022). Contaminants in the cow’s milk we consume? Pasteurization and other technologies in the elimination of contaminants. F1000Research, 11, 91. https://doi.org/10.12688/f1000research.108779.1

Chang, G., Li, Q., Wang, T., Zhang, B., Wu, W., Lv, C., ... & Wang, X. (2024). Characterization of Pseudomonas spp. contamination and in situ spoilage potential in pasteurized milk production process. Food Research International, 188, 114463. https://doi.org/10.1016/j.foodres.2024.114463

Chavez-Esquivel, G., Cervantes-Cuevas, H., Ybieta-Olvera, L. F., Castañeda Briones, M. T., Acosta, D., & Cabello, J. (2021). Antimicrobial activity of graphite oxide doped with silver against Bacillus subtilis, Candida albicans, Escherichia coli, and Staphylococcus aureus by agar well diffusion test: Synthesis and characterization. Materials Science and Engineering: C, 123, 111934. https://doi.org/10.1016/j.msec.2021.111934

CLSI. (2024). Performance standards for antimicrobial disk susceptibility tests (14th ed., CLSI standard M02). Clinical and Laboratory Standards Institute. Retrieved from https://clsi.org/shop/standards/m02/

Coleman, M. E., Oscar, T. P., Negley, T. L., & Stephenson, M. M. (2023). Suppression of pathogens in properly refrigerated raw milk. PLOS ONE, 18(12), e0289249. https://doi.org/10.1371/journal.pone.0289249

Desye, B., Bitew, B. D., Amare, D. E., Adane Birhan, T., Getaneh, A., & Gufue, Z. H. (2023). Quality assessment of raw and pasteurized milk in Gondar City, Northwest Ethiopia: A laboratory-based cross-sectional study. Heliyon, 9(3), e14202. https://doi.org/10.1016/j.heliyon.2023.e14202

Du, B., Meng, L., Wu, H., Yang, H., Liu, H., Zheng, N., ... & Wang, J. (2022). Source tracker modeling based on 16S rDNA sequencing and analysis of microbial contamination sources for pasteurized milk. Frontiers in Nutrition, 9, 845150. https://doi.org/10.3389/fnut.2022.845150

Elbassiony, T. A. (2021). Prevalence of some spore forming food poisoning bacteria in milk and some milk products. Journal of Advanced Veterinary Research, 11(4), 243–246. Retrieved from https://advetresearch.com/index.php/AVR/article/view/770

FDA. (2001). BAM media M24: Brain Heart Infusion (BHI) Broth and Agar. U.S. Food and Drug Administration. Retrieved from https://www.fda.gov/food/laboratory-methods-food/bam-media-m24-brain-heart-infusion-bhi-broth-and-agar-equivalent-media-are-available-difco-and-bbl

FDA. (2025). Bacteriological analytical manual chapter 3: Aerobic plate count. U.S. Food and Drug Administration. Retrieved from https://www.fda.gov/food/laboratory-methods-food/bam-chapter-3-aerobic-plate-count

Fusco, V., Chieffi, D., Fanelli, F., Logrieco, A. F., Cho, G. S., Kabisch, J., ... & Franz, C. M. (2020). Microbial quality and safety of milk and milk products in the 21st Century. Comprehensive Reviews in Food Science and Food Safety, 19(4), 2013–2049. https://doi.org/10.1111/1541-4337.12568

Hariadi, H., Susilo, A., Sulistyawati, E. Y. E., Fauziyyah, A., Ikrawan, Y., & Judiono, J. (2023). Effect of green tea extract addition on antioxidant activity, physicochemical, and organoleptic properties of functional beverages. Open Global Scientific Journal, 2(2), 60–65. https://doi.org/10.70110/ogsj.v2i2.18

Hazaa, I. K. K., & Khalil, N. K. (2025). Foodborne pathogens in raw milk: A review of risks and control measures. International Journal of Veterinary Sciences and Animal Husbandry, 10(5), 112–119. https://www.doi.org/10.22271/veterinary.2025.v10.i5b.2247

Hirose, S., Ohya, K., Yoshinari, T., Ohnishi, T., Mizukami, K., Suzuki, T., ... & Hara-Kudo, Y. (2023). Atypical diarrhoeagenic Escherichia coli in milk related to a large foodborne outbreak. Epidemiology and Infection, 151, e150. https://doi.org/10.1017/S0950268823001395

Hoffmann, V., Simiyu, S., Sewell, D. K., Tsai, K., Cumming, O., Mumma, J., & Baker, K. K. (2022). Milk product safety and household food hygiene influence bacterial contamination of infant food in peri-urban Kenya. Frontiers in Public Health, 9, 772892. https://doi.org/10.3389/fpubh.2021.772892

Hwang, H.-J., Kim, Y.-G., & Chung, M.-S. (2021). Improving the extraction of catechins of green tea (Camellia sinensis) by subcritical water extraction (SWE) combined with pulsed electric field (PEF) or intense pulsed light (IPL) pretreatment. Foods, 10(12), 3092. https://doi.org/10.3390/foods10123092

Jalloul, A. B., Ayadi, N., Klai, A., & Abderrabba, M. (2022). Functionalization of pasteurized milk using rosemary, thyme, and ammoides aqueous extracts for better microbial quality and an improved antioxidant activity. Molecules, 27(12), 3725. https://doi.org/10.3390/molecules27123725

Kapoor, S., Goel, A. D., & Jain, V. (2023). Milk-borne diseases through the lens of one health. Frontiers in Microbiology, 14, 1041051. https://doi.org/10.3389/fmicb.2023.1041051

Khan, A., Shabir, D., Ahmad, P., Khandaker, M. U., Faruque, M. R. I., & Din, I. U. (2021). Biosynthesis and antibacterial activity of MgO-NPs produced from Camellia-sinensis leaves extract. Materials Research Express, 8(1), 015402. https://doi.org/10.1088/2053-1591/abd421

Khan, I., Abbas, T., Anjum, K., Abbas, S. Q., Ibtesam, B., Shah, S. A. A., & Akhter, N. (2019). Antimicrobial potential of aqueous extract of Camellia sinensis against representative microbes. Pakistan Journal of Pharmaceutical Sciences, 32(2), 631–636. Retrieved from https://pubmed.ncbi.nlm.nih.gov/31081776/

Lim, S. H., Chin, N. L., Sulaiman, A., Tay, C. H., & Wong, T. H. (2022). Sensory analysis for cow milk product development using high pressure processing (HPP) in the dairy industry. Foods, 11(9), 1233. https://doi.org/10.3390/foods11091233

Liu, S., Zhang, Q., Li, H., Qiu, Z., & Yu, Y. (2022). Comparative assessment of the antibacterial efficacies and mechanisms of different tea extracts. Foods, 11(4), 620. https://doi.org/10.3390/foods11040620

Manandhar, S., Luitel, S., & Dahal, R. K. (2019). In vitro antimicrobial activity of some medicinal plants against human pathogenic bacteria. Journal of Tropical Medicine, 2019(1), 1895340. https://doi.org/10.1155/2019/1895340

Martin, N. H., Boor, K. J., & Wiedmann, M. (2018). Symposium review: Effect of post-pasteurization contamination on fluid milk quality. Journal of Dairy Science, 101(1), 861–870. https://doi.org/10.3168/jds.2017-13339

Medjahdi, K., Didouh, N., & Araujo, R. (2025). Pasteurized milk: A highlight on potential sources of contamination by aerobic spore-forming bacteria. Food Control, 171, 111134. https://doi.org/10.1016/j.foodcont.2025.111134

Mengstu, B., Tola, A., Nahusenay, H., Sisay, T., Kovac, J., Vipham, J., & Zewdu, A. (2023). Evaluation of microbial hygiene indicators in raw milk, pasteurised milk and cottage cheese collected across the dairy value chain in Ethiopia. International Dairy Journal, 136, 105487. https://doi.org/10.1016/j.idairyj.2022.105487

Mladenović, K. G., Grujović, M. Ž., Kiš, M., Furmeg, S., Tkalec, V. J., Stefanović, O. D., & Kocić-Tanackov, S. D. (2021). Enterobacteriaceae in food safety with an emphasis on raw milk and meat. Applied Microbiology and Biotechnology, 105(23), 8615–8627. https://doi.org/10.1007/s00253-021-11655-7

Mushemesh, N., Mahmoud, A., Ressan, D., Abdel-Baqi, Z., & Jassim, S. (2023). The biological activity of some medicinal plant aqueous extracts in inhibiting the growth of pathogenic Gram-negative and Gram-positive bacteria. DYSONA-Life Science, 4(2), 66. https://doi.org/10.30493/dls.2023.412545

Nascimento, J. C. N., Salgado, M. J. G., Gutierrez Alzate, K., de Alencar, J. C. G., Rosario, I. L. D. S., da Silva, J. G., ... & da Costa, M. P. (2023). Effect of sonication associated with pasteurization on the inactivation of methicillin-resistant Staphylococcus aureus in milk cream. Applied Sciences, 13(22), 12093. https://doi.org/10.3390/app132212093

Oliveira, A. S., Saraiva, L. M., & Carvalho, S. M. (2023). Staphylococcus epidermidis biofilms undergo metabolic and matrix remodeling under nitrosative stress. Frontiers in Cellular and Infection Microbiology, 13, 1200923. https://doi.org/10.3389/fcimb.2023.1200923

Orita, T., Chogahara, S., Okuda, M., Sakao, K., Miyata, T., & Hou, D.-X. (2023). Extraction efficiency and alpha-glucosidase inhibitory activities of green tea catechins by different infusion methods. Foods, 12(13), 2611. https://doi.org/10.3390/foods12132611

Pearce, L. E., Smythe, B. W., Crawford, R. A., Oakley, E., Hathaway, S. C., & Shepherd, J. M. (2012). Pasteurization of milk: The heat inactivation kinetics of milk-borne dairy pathogens under commercial-type conditions of turbulent flow. Journal of Dairy Science, 95(1), 20–35. https://doi.org/10.3168/jds.2011-4556

Pratiwi, G. Y., Mandalas, H. Y., & Sugiaman, V. K. (2022). The effect of Indian jujube leaves extract in inhibiting the growth of Porphyromonas gingivalis. Padjadjaran Journal of Dentistry, 34(1), 57–65. https://doi.org/10.24198/pjd.vol34no1.33007

Qin, S., Li, R., Chen, M., Zeng, F., Dai, Y., Wu, G., ... & Li, J. (2023). Oat milk tea model system: Exploring the stability of milk tea and the bioaccessibility of green tea polyphenols. Foods, 12(7), 1402. https://doi.org/10.3390/foods12071402

Rafique, S., Murtaza, M. A., Hafiz, I., Ameer, K., Qayyum, M. M. N., Yaqub, S., & Mohamed Ahmed, I. A. (2023). Investigation of the antimicrobial, antioxidant, hemolytic, and thrombolytic activities of Camellia sinensis, Thymus vulgaris, and Zanthoxylum armatum ethanolic and methanolic extracts. Food Science & Nutrition, 11(10), 6303–6311. https://doi.org/10.1002/fsn3.3569

Ruengdech, A., Mishra, D. K., & Siripatrawan, U. (2025). Multifaceted roles of foam-mat freeze-dried catechins nanoencapsulation to enhance catechins stability and bioaccessibility, and quality of green tea catechins-fortified milk. Food Chemistry: X, 27, 102391. https://doi.org/10.1016/j.fochx.2025.102391

Salimnejhad, Z., Hassanzadazar, H., & Aminzare, M. (2023). Epinecidin‐1 (an active marine antimicrobial peptide): Effects on the survival of inoculated Escherichia Coli O157:H7 and Staphylococcus aureus bacteria, antioxidant, and sensory attributes in raw milk. Food Science & Nutrition, 11(9), 5573–5581. https://doi.org/10.1002/fsn3.3514

Sessa, R. (2022). Gram-negative bacteria exhibit unique biochemical characteristics important for their survival, adaptability, and pathogenicity. International Journal of Infection, 6(2), 35–39. Retrieved from https://www.biolife-publisher.it/iji/wp-content/uploads/2024/11/issue-IJI_2022_62.pdf#page=2

Sharifi, S., Sohrabvandi, S., Mofid, V., Khanniri, E., Khorshidian, N., Esmaeili, S., ... & Mortazavian, A. M. (2021). Determination of lead level in pasteurized milk and dairy products consumed in Tehran and evaluation of associated health risk. International Journal of Cancer Management, 14(9), e115541. https://doi.org/10.5812/ijcm.115541

Silva, B. N., Coelho-Fernandes, S., Teixeira, J. A., Cadavez, V., & Gonzales-Barron, U. (2023). Dynamic modelling to describe the effect of plant extracts and customised starter culture on Staphylococcus aureus survival in goat’s raw milk soft cheese. Foods, 12(14), 2683. https://doi.org/10.3390/foods12142683

Sobeih, A., AL-Hawary, I., Khalifa, E., & Ebied, N. (2020). Prevalence of Enterobacteriaceae in raw milk and some dairy products. Kafrelsheikh Veterinary Medical Journal, 18(2), 9–13. https://doi.org/10.21608/kvmj.2020.39992.1009

Taherpour, A., Hashemi, A., Erfanimanesh, S., & Taki, E. (2016). Efficacy of methanolic extract of green and black teas against extended-spectrum β-lactamase-producing Pseudomonas aeruginosa. Pakistan Journal of Pharmaceutical Sciences, 29(4), 1257–1261. Retrieved from https://pjps.pk/uploads/pdfs/29/4/Paper-22.pdf

Taye, Y., Degu, T., Fesseha, H., & Mathewos, M. (2021). Isolation and identification of lactic acid bacteria from cow milk and milk products. The Scientific World Journal, 2021(1), 4697445. https://doi.org/10.1155/2021/4697445

Triandini, I. G. A. A. H., Wiranto, W., & Wangiyana, I. G. A. S. (2024). Sensory evaluation of cookies formulated with rhizopora propagules flour using 9-point hedonic scale. Journal of Agritechnology and Food Processing, 4(2), 60. https://doi.org/10.31764/jafp.v4i2.28256

Wahyuni, D. S., Putri, R. K., Arniyanti, A., Audita, S. H., Choiri, S., Hadi, S., ... & Ainurofiq, A. (2025). Metabolomic study on Indonesian green tea (Camellia sinensis L.) cultivation. Pharmacognosy Journal, 17(3), 331–341. https://doi.org/10.5530/pj.2025.17.43

Wali, M. K., Abed, M. M., AL-Geheeshy, D. A., Salah, A. H., & Abbas, S. M. (2020). Antimicrobial activity of green tea against Staphylococcus aureus and Pseudomonas aeruginosa isolated from milk. Indian Veterinary Journal, 97(06), 20–23. Retrieved from https://www.researchgate.net/publication/361378006_Antimicrobial_Activity_of_Green_Tea_Against_Staphylococcus_aureus_and_Pseudomonas_aeruginosa_Isolated_from_Milk

Wang, S., Yu, Z., Wang, J., Ho, H., Yang, Y., Fan, R., ... & Han, R. (2021). Prevalence, drug resistance, and virulence genes of potential pathogenic bacteria in pasteurized milk of Chinese fresh milk bar. Journal of Food Protection, 84(11), 1863–1867. https://doi.org/10.4315/JFP-21-094

Wang, W., Guo, Y., Wang, J., Liang, Y., Tian, M., Li, Y., ... & Hao, H. (2026). Camel milk-derived Lentilactobacillus parabuchneri L-185 produces acid-associated metabolites that inhibit MRSA growth and biofilm formation in milk. International Journal of Food Microbiology, 456, 111748. https://doi.org/10.1016/j.ijfoodmicro.2026.111748

Weinstein, E., Lamba, K., Bond, C., Peralta, V., Needham, M., Beam, S., ... & Kimura, A. (2025). Outbreak of Salmonella typhimurium infections linked to commercially distributed raw milk—California and four other states, September 2023–March 2024. Morbidity and Mortality Weekly Report, 74(27), 433–438. Retrieved from https://www.cdc.gov/mmwr/volumes/74/wr/mm7427a1.htm

Wijegunawardhana, D., Wijesekara, I., Liyanage, R., Truong, T., Silva, M., & Chandrapala, J. (2024). Process-induced molecular-level protein–carbohydrate–polyphenol interactions in milk–tea blends: A review. Foods, 13(16), 2489. https://doi.org/10.3390/foods13162489

Xu, F., Xie, Y., Yu, W., & Wang, Z. (2026). Breaking the outer membrane barrier: Structure, targets, and antimicrobial strategies for Gram-Negative bacteria. Frontiers in Microbiology, 17, 1734749. https://doi.org/10.3389/fmicb.2026.1734749

Zhang, Z. (2022). Hacking the permeability barrier of Gram-negative bacteria. ACS Central Science, 8(8), 1043–1046. https://doi.org/10.1021/acscentsci.2c00750

DOI: https://doi.org/10.20961/agrihealth.v7i2.125546

Refbacks

  • There are currently no refbacks.