SJA_41_5_118-125

Introduction

Amla (Emblica officinalis), also known as Indian gooseberry, is a tropical fruit famous for its rich content of bioactive compounds such as phenolic acids, flavonoids, tannins, and vitamin C. These compounds contribute to its antioxidant, antimicrobial, and anti-inflammatory properties, making amla a valuable ingredient in traditional medicine and nutraceutical applications (Husna et al., 2024). Amla fruit is rich in various phytoconstituents, including vitamin C, phenolics, flavonoids, alkaloids, flavones, terpenoids, and tannins (Chahal et al., 2019; Tewari et al., 2023). Due to its rich phytochemical composition, amla is recognized for its therapeutic potential in treating skin disorders, gastric ailments, diabetes, hypertension, and cardiovascular diseases (Chaikul et al., 2021; Tewari et al., 2024). Given its pharmacological significance, efficient extraction methods are essential to maximize the recovery of bioactive compound.

Previous studies have explored different extraction techniques to obtain bioactive compounds from amla. Maceration, soxhlet extraction, and hydrodistillation have been widely used but require prolonged extraction times and large solvent volumes, limiting their efficiency. Alternative approaches, such as supercritical fluid extraction and microwave-assisted extraction, have been investigated to improve extraction efficiency, but these methods often involve high operational costs and complex setups (Patra et al., 2022). Ultrasound-assisted extraction (UAE) is a highly effective non-thermal technology that has recently gained significant attention in food processing due to its efficiency, simplicity, portability, and cost-effectiveness (Aslam et al., 2023). UAE operates using high-frequency ultrasonic waves (≥ 20 kHz) to disrupt cell walls, facilitating the release of bioactive compounds. Compared to maceration, UAE offers higher extraction yields, increased mass transfer rates, and the ability to operate at lower temperatures, thereby preserving the integrity of heat-sensitive compounds (Patra et al., 2022).

In recent years, several studies have explored the extraction of bioactive compounds from amla fruit. Manikandan et al. (2019) investigated the production of antioxidant polyphenols from Phyllanthus emblica using the Soxhlet extraction method. Similarly, Raaf et al. (2023) examined the impact of particle size on the yield, phenolic, and flavonoid content of amla extract obtained through maceration. However, research focusing on the optimization of ultrasound-assisted extraction (UAE) parameters for enhancing bioactive compound recovery remains limited. Recent studies, such as Husna et al. (2024), have focused on optimizing UAE conditions; however, a more comprehensive comparison with conventional extraction methods is still needed. The novelty of this study lies in its detailed investigation of the effect of extraction time and solvent ratio on bioactive compound recovery from amla using UAE, along with a comparative analysis to maceration, contributing valuable insights for optimizing UAE in sustainable extraction processes. The findings of this research contribute to advancing sustainable extraction methodologies, aligning with global efforts to reduce industrial solvent usage and energy consumption.

Materials and Methods

Materials

Amla fruit was procured from Aceh Besar District, Indonesia. The chemicals used was purchased from Merck (Indonesia), included ethanol (95% purity), Biuret reagent, petroleum ether (40-60 deg C), CH₃COOK (≥ 99% purity), AlCl3 (98% purity), Folin-C ((≥ 90% purity), and Na₂CO3 (≥ 99% purity). All chemicals were used as received, without any additional purification.

Experimental procedure

The experimental procedure is presented in Figure 1. The experiments were performed on a laboratory scale. A single-factor design was chosen to focus on the effect of individual experimental variables (material-to-solvent ratio and extraction time) on the extraction process. This design is easier to understand, implement, and analyze, as it isolates the impact of each factor. Additionally, a single-factor design requires fewer resources, making it more efficient for conducting a detailed and focused evaluation.

The amla fruit was thoroughly washed under running water to remove impurities. The outer skin was peeled, and the flesh was sliced thinly using a slicer. The slices were dried in an oven at 45°C for 10 hours, ground into powder using a blender, and sieved through 40- and 60-mesh sieves. The fraction retained in the 60-mesh sieve was used for extraction.

Amla fruit powder (6.5 g) was placed in a three-neck flask, and 70% ethanol was added at different material to solvent ratios (1:5, 1:10, 1:15, 1:20, and 1:25 g/mL). UAE was performed at room temperature (28°C) for 2, 4, 5, 6, and 8 minutes using an ultrasonic cleaning bath system (Krisbow, Indonesia) at 47 kHz frequency. The mixture was filtered through Whatman No. 1 filter paper, and the filtrate was concentrated with a rotary vacuum evaporator (100 mbar, 40°C, 100 rpm). The resulting thick extract was weighed, stored in dark vials for further analysis. The experiments were conducted in triplicate to ensure data reproducibility, and the average values of the measured data were reported. The experimental error across all trials was found to be less than 5%, indicating that variations in the collected data under identical conditions were insignificant (Supardan et al., 2019). The extraction yield was calculated using Eq. (1).

Analysis methods

UV-vis spectrophotometer (VIS 722N) was used to determine the quantitative information regarding the content of bioactive compounds in Amla fruit extract. The quantification of bioactive compounds followed the outlined procedures by Oramahi et al. (2024). The utilization of a pre-prepared calibration curve facilitates the determination of bioactive components concentration. Fourier Transform Infrared spectroscopy (FTIR Shimadzu, IRPrestige 21) was used to identify the functional groups of the amla extract. The shape of the spectra presented and the positions of the absorption bands are expressed as wavenumbers and are used to identify the functional groups present in the sample. The spectrum is taken in the wavenumber region of 4000–400 cm-1.

Results and Discussion

Proximate analysis of dried amla powder

Table 1 shows the proximate composition of the dried amla powder. Carbohydrates accounted for the highest proportion (81.9%), while fat content was the lowest (1.23%). These findings align with previous studies reported by Mishra and Mahanta (2014). The slight variation in fat and protein content may be attributed to differences in geographical location and environmental conditions (Okeke et al., 2021). The moisture content (8.85%) was within acceptable limits to prevent microbial growth, as suggested by Zambrano et al. (2021).

Table 1: Proximate analysis of amla fruit powder

Parameter	Amount (%)
Water content	8.85
Ash content	3.07
Fat level	1.23
Protein content	4.95
Carbohydrate levels	81.90

Effect of extraction time and material to solvent ratio on yield

The extraction yield of amla fruit was significantly influenced by both extraction time and material to solvent ratio (Figure 2). The highest yield (31.0%) was obtained at an extraction time 4 minutes and a material to solvent ratio 1:15 g/mL. Initially, increasing extraction time led to greater compound diffusion due to prolonged solvent contact, enhancing mass transfer. However, beyond 4 minutes, a decline in yield was observed, likely due to the degradation of thermosensitive bioactive compounds such as phenolics and ascorbic acid, as reported by Tewari et al. (2024). A comparable research outcome was reported by Li et al. (2023) in their study on the extraction of ursolic acid from apple peel. They observed that the extraction yield declined with longer ultrasonic time, dropping from 1.56% at 30 minutes to 1.35% at 75 minutes. Prolonged ultrasonication raised the extraction temperature, which in turn degraded ursolic acid due to extended exposure to ultrasonic radiation, ultimately reducing the yield.

The material to solvent ratio also played a crucial role in extraction efficiency. A higher material to solvent ratio facilitated greater bioactive compound diffusion, with the highest extraction yield recorded at 1:15 g/mL. Further increases in solvent volume did not significantly enhance the yield, possibly due to dilution effects reducing solvent saturation capacity. This trend supports earlier reports that achieving the proper material to solvent ratio is critical to enable effective compound diffusion and to prevent over-dilution, which may otherwise hinder mass transfer (Li et al., 2023). The combined effect of extraction time and material to solvent ratio highlights the importance of optimizing these parameters to maximize yield while preventing compound degradation.

Effect of extraction time on phenolic and flavonoid content

The effect of extraction time on phenolic and flavonoid content was further investigated at material to solvent ratio 1:15. The total phenolic and flavonoid content varied with extraction time (Figure 3). The highest flavonoid content (12.08 mg QE/g) and total phenolic content (236.72 mg GAE/g) were obtained at 4 minutes. During the initial stage of extraction, sonication effectively facilitates the release of bioactive compounds from plant cells. Ultrasonic waves enhance heat and mass transfer by disrupting or breaking cell walls, thereby improving the extraction efficiency of targeted bioactive components. However, prolonged sonication may lead to the degradation of phenolic compounds, potentially reducing their overall yield (Tiwari, 2015). These results are in agreement with previous findings (Husna et al., 2024; Tewari et al., 2024), indicating that extended extraction initially enhances mass transfer but excessive sonication leads to degradation. A decrease in phenolic content at 8 minutes suggests compound breakdown due to overexposure to ultrasonic waves. Thus, optimizing extraction time is crucial to balancing yield and bioactive compound preservation

Comparison of UAE and maceration

The UAE method demonstrated superior extraction efficiency compared to maceration. Under similar extraction condition (material to solvent ratio 1:15), UAE produced a higher yield (31.0% in 4 minutes) compared to 29.0% in 72 hours for maceration (Figure 4(a)). Thus, UAE increased extraction yield by 6.9%, reducing processing time by 96% compared to maceration. In the maceration method, the transfer of extract compounds to the solvent is much less and the yield is lower. UAE has been recognized as an effective technique for extracting phytochemicals from plants (Tuan et al., 2025). UAE enhances solvent penetration by inducing cell disruption, facilitating faster bioactive compound release. UAE consistently outperformed maceration, confirming its superiority in bioactive extraction. Enhanced solvent penetration in ultrasonic extraction leads to the recovery of greater amounts of phenolic and flavonoid compounds, as shown in Figures 4(b) and 4(c). These findings align with Albuquerque et al. (2025), who compared heat-assisted extraction (HAE) and ultrasound-assisted extraction (UAE) for anthocyanin recovery from Sicana odorifera fruit epicarp. They reported HAE yields of 23% (w/w) extract, while UAE achieved 26% (w/w) in significantly less time (23 vs. 62 min). Likewise, Liu et al. (2024) showed that UAE outperformed conventional extraction methods for phenolics from grape marc, producing higher bioactive yields with reduced processing time. This study further supports UAE as a sustainable, energy- and cost-efficient method that enhances bioactive compound recovery while reducing extraction time.

FTIR analysis was performed to determine the bioactive compounds in the amla extract by examining their functional groups (Figure 5). The FTIR spectra revealed several prominent peaks. The band at 3350–3370 cm-¹ corresponds to O–H stretching (H-bonded), indicating the presence of phenols and alcohols (Nandiyanto et al., 2019). The C–H vibration was observed at 2950–3000 cm-¹, associated with phenolic aromatic compounds. The peak at 1700–1750 cm-¹ represents the C=O stretching of ester groups (Rosalina et al., 2022). Additionally, bands at 1470–1490 cm-¹ and 1620–1650 cm-¹ correspond to C=C–C stretching of aromatic rings and C=C groups of phenolic aromatic compounds, respectively (Öztürk et al., 2018). The presence of polyphenol compounds was confirmed by the functional groups C–O, C=O, and –OH. The ester group further indicates the presence of tannins, saponins, and flavonoids (Raaf et al., 2024). Overall, the FTIR spectra aligned well with previous studies, demonstrating consistency with the findings of Firdous et al. (2021).

The surface morphology of amla powder is illustrated in Figure 6. SEM analysis showed structural changes in amla powder during extraction. Before extraction, intact cell walls were observed (Figure 6a). After 72 hours of maceration, initial cell wall ruptures appeared (Figure 6b), while 8 minutes of UAE caused significant cell disruption (Figure 6c), enhancing

solvent accessibility and facilitating rapid bioactive release. This effect results from ultrasonic vibrations, cavitation waves, and the mechanical impact of ultrasonication, which lead to molecular disruption within the cell wall. Compared to maceration, UAE induced faster and more extensive structural damage, facilitating efficient compound extraction. This phenomenon aligns with the findings by Hsu and Yang (2024), who observed similar results in extraction of polyphenols, cynarin, and chlorogenic acid from Arctium lappa L. roots treated with ultrasound.

Conclusions and Recommendations

This study demonstrates that ultrasound-assisted extraction (UAE) is a superior method for extracting bioactive compounds from amla, outperforming maceration in yield and efficiency. Optimal UAE conditions (4 min, 1:15 g/mL) resulted in a 31.0% extract yield, higher than maceration (29.0% in 72 h), with enhanced flavonoid and phenolic content. FTIR analyses confirmed the presence of key bioactive compounds. These findings establish UAE as a rapid and efficient extraction technique, reducing processing time while preserving bioactive integrity. Its application in nutraceutical and pharmaceutical industries holds significant potential. Future research should explore industrial-scale implementation and alternative solvent systems to further optimize extraction efficiency.

Acknowledgements

We appreciate the financial support of Universitas Syiah Kuala through Professor Research Grant 2023.

Novelty Statement

This study distinctly highlights the comparison with maceration to underscore the advantages of ultrasound-assisted extraction in improving the efficiency of bioactive compound extraction from amla (Emblica officinalis).

Authors’ Contribution

Yanna Syamsuddin: Designed the research and wrote the manuscript.

Nabila Mulya Rahma Rizky and Dini Hayatul Nufus: Conducted the experiment.

Satriana and Auliyaa Raaf: Planned the research, wrote and edited the manuscript.

Muhammad Dani Supardan: Provided guidance throughout the research process and reviewed the manuscript.

Generative AI or AI assisted technology statement

During the preparation of this manuscript, the authors utilized ChatGPT to improve the clarity of the writing. Subsequently, the authors carefully reviewed and edited the content as necessary and take full responsibility for the final publication.

Conflict of interest

The authors have declared no conflict of interest.

References

Albuquerque, B.R., J. Pinela, C. Pereira, R.C. Calhelha, I. Oliveira, S. Heleno, M.B.P.P. Oliveira and L. Barros. 2025. Optimization and comparison of heat- and ultrasound-assisted extraction methods for anthocyanin recovery from Sicana odorifera fruit epicarp. Biomass Convers. Biorefin., 15: 1027–1040. https://doi.org/10.1007/s13399-023-05097-6

Aslam, R., M.S. Alam, A. Ali, Y. Tao and S. Manickam. 2023. A chemometric approach to evaluate the effects of probe-type ultrasonication on the enzyme inactivation and quality attributes of fresh amla juice. Ultrason. Sonochem., 92: 106268. https://doi.org/10.1016/j.ultsonch.2022.106268

Chahal, A.K., G.C. Chandan, R. Kumar, A.K. Chhillar, A.K. Saini and R.V. Saini. 2019. Bioactive constituents of Emblica officinalis overcome oxidative stress in mammalian cells by inhibiting hyperoxidation of peroxiredoxins. J. Food Biochem., 44(2): 1–10. https://doi.org/10.1111/jfbc.13115

Chaikul, P., M. Kanlayavattanakul, J. Somkumnerd and N. Lourith. 2021. Phyllanthus emblica L. (amla) branch: A safe and effective ingredient against skin aging. J. Tradit. Complement. Med., 11(5): 390–399. https://doi.org/10.1016/j.jtcme.2021.02.004

Firdous, A., E. Ringo and P. Elumalai. 2021. Effects of green tea- and amla extracts on quality and melanosis of Indian white prawn (Fenneropenaeus indicus, Milne Edwards, 1837) during chilled storage. Aquac. Fish., 6(6): 617–627. https://doi.org/10.1016/j.aaf.2020.09.003

Hsu, Y.C. and C.Y. Yang. 2024. Assessment of ethanolic extraction of chlorogenic acid, cynarin, and polyphenols from burdock (Arctium lappa L.) roots under ultrasound. Molecul., 29(21): 5115. https://doi.org/10.3390/molecules29215115

Husna, N.E., E. Noor, F. Fahma and T.C. Sunarti. 2024. Optimization of ultrasound-assisted extraction of amla (Emblica officinalis) fruit using response surface methodology and identification of phenolic compounds. Food Res., 8: 257–270. https://doi.org/10.26656/fr.2017.8(6).589

Li, H., Y. Liu, S. Guo, M. Shi, S. Qin and C. Zeng. 2023. Extraction of ursolic acid from apple peel with hydrophobic deep eutectic solvents: Comparison between response surface methodology and artificial neural networks. Food., 12(2): 310. https://doi.org/10.3390/foods12020310

Liu, Z., H. Wu, B. Holland, C.J. Barrow and H.A.R. Suleria. 2024. An optimization of the extraction of phenolic compounds from grape Marc: A comparison between conventional and ultrasound-assisted methods. Chemosens., 12(9): 177. https://doi.org/10.3390/chemosensors12090177

Manikandan, A.S.P., S. Akila and K. Prabu. 2019. Production of polyphenol from Phyllanthus emblica using soxhlet extraction process. Int. J. Recent Technol. Eng., 8(4): 5010–5012. https://doi.org/10.35940/ijrte.D8170.118419

Mishra, P. and C.L. Mahanta. 2014. Comparative analysis of functional and nutritive values of amla (Emblica Officinalis) fruit, seed and seed coat powder. Am. J. Food Technol., 9(3): 151–161. https://doi.org/10.3923/ajft.2014.151.161

Nandiyanto, A.B.D., R. Oktiani and R. Ragadhita. 2019. How to read and interpret FTIR spectroscope of organic material. Indones. J. Sci. Technol., 4(1): 97–118. https://doi.org/10.17509/ijost.v4i1.15806

Okeke, H.C., O. Okeke, K.O. Nwanya, C.R. Offor and C.C. Aniobi. 2021. Comparative assessment of the proximate and mineral composition of Cucumis sativus L. and Solanum aethiopicum L. fruit samples grown in South Eastern and North Central Regions of Nigeria respectively. Natur. Resour., 12(8): 237–249. https://doi.org/10.4236/nr.2021.128017

Oramahi, H.A., T. Maurisa, Nurhaida, H. Darwati and S. Rifanjani. 2024. Optimization and characterization of liquid smoke produced by Terminalia catappa wood pyrolysis and its in vitro antifungal activity. Sci. Technol. Indones., 9(1): 207–214. https://doi.org/10.26554/sti.2024.9.1.207-214

Öztürk, M., I. Bulduk, S.E. Korcan, R. Liman, F.K. Çoban, M. Kargıoğlu and M. Konuk. 2018. Total phenolics, flavonoids contents, antioxidant activity and DNA protective effect of Lenten rose (Helleborus orientalis). Asian J. Biochem. Genet. Mol. Biol., 1(4): 1–12. https://doi.org/10.9734/ajbgmb/2018/v1i430047

Patra, A., S. Abdullah and R.C. Pradhan. 2022. Review on the extraction of bioactive compounds and characterization of fruit industry by-products. Bioresour. Bioproce., 9(14): 1–25. https://doi.org/10.1186/s40643-022-00498-3

Raaf, A., F. Mulana, Y. Syamsuddin, N. Arpi and M.D. Supardan. 2023. Effect of particle size on the phenolic and flavonoid contents of amla (Indian gooseberry) extract. IOP Conf. Ser.: Earth Environ. Sci., 1266: 012065. https://doi.org/10.1088/1755-1315/1266/1/012065

Raaf, A., F. Mulana, Y. Syamsuddin, N. Suriaini and M.D. Supardan. 2024. Effect of drying pretreatment methods on amla (Emblica officinalis) extracts obtained through maceration using ethanol as solvent. Int. J. Technol., 15(4): 917–926. https://doi.org/10.14716/ijtech.v15i4.5669

Rosalina, Y., E. Warsiki, A.M. Fauzi and I. Sailah. 2022. Study of anthocyanin extraction from red banana (Musa sapientum L. var Rubra) waste and characteristics of light effects. Sci. Technol. Indones., 7(4): 522–529. https://doi.org/10.26554/sti.2022.7.4.522-529

Supardan, M.D., E. Misran, Mahlizar, Satriana and W.A.W. Mustapha. 2019. Effect of material length on kinetics of essential oil hydrodistillation from lemongrass (Cymbopogon citratus). J. Eng. Sci. Technol., 14(2): 810–819.

Tewari, R., V. Kumar and H.K. Sharma. 2023. Thermal and nonthermal processing of an underutilized fruit Emblica officinalis (amla): A sustainable approach. Sustain. Food Technol., 1(5): 658–680. https://doi.org/10.1039/D3FB00058C

Tewari, R., V. Kumar and H.K. Sharma. 2024. Effect of ultrasonication on the quality of amla pulp (Emblica officinalis): Optimization and comparison with the thermal processing. Food Chem. Adv., 4: 100663. https://doi.org/10.1016/j.focha.2024.100663

Tiwari, B.K. 2015. Ultrasound: A clean, green extraction technology. Trac Trend Anal. Chem., 71(1): 100-109. https://doi.org/10.1016/j.trac.2015.04.013

Tuan, P.M., T.H.D. Nguyen, N.T. Ngan and D.C. Vu. 2025. Comparative analysis of phenolics and in vitro bioactivities of Sphagneticola calendulacea (L.) Pruski extracts obtained by conventional solvent, ultrasonic agitation, and enzyme assisted extractions. J. Ind. Chem. Soc., 102(1): 101556. https://doi.org/10.1016/j.jics.2024.101556

Zambrano, M.V., B. Dutta, D.G. Mercer, H.L. Maclean and M.F. Touchie. 2021. Assessment of moisture content measurement methods of dried food products in small-scale operations in developing countries: A review. Trends Food Sci. Technol., 88: 484–496. https://doi.org/10.1016/j.tifs.2019.04.006