Agricultural residues derived from Enset, scientifically classified as Ensete ventricosum and colloquially termed the false banana, represent a viable and technically competitive replacement for petroleum-based synthetic fibers in industrial composites, geotextiles, and technical packaging. In a comprehensive laboratory investigation published in the journal Discover Polymers, researchers Alhayat G. Temesgen, J. Kaufmann, and H. Cebulla presented a multi-technique evaluation of the physicochemical, mechanical, morphological, and thermal degradation characteristics of Enset pseudo-stem fibers sourced from the Gurage and Hadiya highland zones of Ethiopia. The study addressed an ongoing challenge in sustainable materials engineering: while conventional synthetic fibers such as polypropylene, polyester, and glass fiber dominate commercial manufacturing, their production and lifecycle persistence generate persistent microplastic pollution and consume finite fossil energy resources. By analyzing raw fibrous waste generated during traditional food harvesting, the authors established baseline engineering properties and benchmarked Enset performance directly against widely utilized commercial plant fibers including flax, jute, sisal, banana, and abaca.

Ensete ventricosum is an underexplored single-stemmed monocarpic perennial plant that occurs in both wild and cultivated forms across East and Central Africa, sustaining more than twenty million people in the Ethiopian highlands as an essential food security crop. Taxonomically, the genus Ensete comprises seven recognized species distributed across Africa and Asia, including Asian taxa such as Ensete superbum, Ensete glaucum, and Ensete lecongkietii, alongside African taxa including Ensete livingstonianum, Ensete homblei, and the Madagascan species Ensete perrieri. Among all members of the genus, Ensete ventricosum represents the sole species that has undergone agricultural domestication, with cultivation confined strictly to southern and southwestern Ethiopia. Although wild populations of the plant thrive naturally in Uganda, Tanzania, Mozambique, Zambia, and the Democratic Republic of Congo, domesticated farming remains concentrated in Ethiopian highland agroecosystems. During the processing of kocho, a traditional fermented staple food prepared from the starchy corm and pseudo-stem trunk, farmers extract valuable starch while generating massive quantities of fibrous leaf sheaths and outer stem tissues that are routinely abandoned in field piles or incinerated.

To obtain reliable experimental specimens and systematically eliminate operator-induced variations during fiber processing, the investigators implemented a standardized manual extraction protocol. Extraction was conducted by a single trained technician utilizing identical stainless-steel blades set at a fixed scraping angle of thirty degrees, applying a controlled sequence of three to four scraping passes per stem strip directed from the inner surface toward the outer surface. Strict pre-defined quality acceptance criteria were maintained throughout the sampling campaign: any extracted fibers displaying visible kinks, localized cross-sectional narrowing, mechanical surface abrasions, or structural contamination were immediately discarded and replaced. Following extraction, all retained fiber samples underwent thorough purification consisting of three consecutive wash cycles in distilled water at a one-to-twenty weight-to-volume ratio for fifteen minutes per cycle. The purified fibers were subsequently air-dried on specialized mesh racks under controlled laboratory ambient conditions of twenty to twenty-five degrees Celsius and forty to sixty percent relative humidity for forty-eight hours prior to desiccator storage.

Chemical functional group identification performed using Fourier Transform Infrared spectroscopy in attenuated total reflectance mode confirmed the classic spectral signatures of a lignocellulosic structure composed of cellulose, hemicellulose, and lignin. Diagnostic absorption bands were recorded at 3346, 2956, 2876, 1730, 1641, 1463, 1161, and 1033 inverse centimeters across the infrared spectrum. The prominent, broad absorption peak centered at 3346 inverse centimeters corresponds to hydroxyl group O–H stretching vibrations, signaling extensive intermolecular and intramolecular hydrogen bonding within crystalline and amorphous cellulose domains. These hydrogen bonding networks contribute directly to crystalline packing efficiency, elevated tensile strength, and high axial stiffness, while simultaneously imparting hydrophilic characteristics that necessitate surface modification when formulating hydrophobic polymer composites. Absorption peaks identified at 2956 and 2876 inverse centimeters represent asymmetric and symmetric aliphatic C–H stretching vibrations from methyl and methylene groups present in cellulose, hemicellulose, and lignin side chains. The distinct carbonyl band recorded at 1730 inverse centimeters denotes acetyl ester groups associated with the acetylated xylan backbone of hemicellulose, which reduce structural packing between hemicellulose and cellulose microfibrils. Strong polysaccharide C–O stretching bands at 1161 and 1033 inverse centimeters confirmed high cellulose concentrations, aligning with compositional ranges of sixty to sixty-five percent cellulose, ten to twenty percent hemicellulose, and five to ten percent lignin.

Morphological characterization carried out via polarized optical microscopy and scanning electron microscopy demonstrated that Enset fibers possess a distinct hierarchical organization. Elementary fibers naturally aggregate into cohesive technical fiber bundles bound together by an intercellular middle lamella composed predominantly of pectin and hemicellulose. Across fifty individual specimens examined in accordance with ASTM D1577 standards, fiber diameters exhibited substantial biological variation, ranging from a minimum of 70 micrometers to a maximum of 265 micrometers, with a population mean of 156.4 plus or minus 42.8 micrometers and an overall coefficient of variation of 27.4 percent. Multiple digital measurements recorded across five equidistant longitudinal positions along fifty-millimeter fiber segments revealed an average within-fiber diameter coefficient of variation of twelve plus or minus five percent, reflecting natural developmental taper and anatomical growth heterogeneity. Cross-sectional profiles exhibited diverse non-circular geometries, including circular, elliptical, and polygonal shapes, yielding an average circularity index of 0.76 plus or minus 0.12. Furthermore, high-resolution scanning electron micrographs indicated that internal cell lumens occupy fifteen to twenty-five percent of the total fiber cross-sectional area, creating a hollow tubular morphology that influences overall skeletal density and mechanical damping behavior.

The physical density of Enset elementary fibers was established through gas pycnometry using an Anton Paar Ultrapyc 5000 apparatus operating with 99.99 percent pure nitrogen displacement under a stabilized chamber temperature of twenty degrees Celsius and an equilibration pressure of 1.3 bar. Prior to testing, half-gram fiber specimens cut into lengths of five to ten millimeters were thoroughly oven-dried at sixty degrees Celsius for twenty-four hours and cooled inside a desiccator to eliminate moisture effects. Five independent sample batches underwent ten consecutive measurement cycles each, yielding an average skeletal density of 1.476 plus or minus 0.003 grams per cubic centimeter with a coefficient of variation below two percent. Statistical verification indicated a normal distribution of measured values, reflecting high instrument precision and homogeneous skeletal substance. The recorded density is marginally lower than that of pure crystalline cellulose, which ranges from 1.50 to 1.55 grams per cubic centimeter, because of the lower-density amorphous hemicellulose and lignin constituents alongside the fifteen to twenty-five percent internal lumen void space. This density aligns closely with values reported for flax, jute, hemp, and sisal, confirming that Enset fibers offer attractive specific strength-to-weight ratios suitable for lightweight composite structures.

Mechanical performance evaluation via single-fiber tensile testing in accordance with ASTM D3379-75 protocols demonstrated excellent load-bearing capacity. Testing fifty conditioned fiber specimens at twenty-three degrees Celsius and fifty percent relative humidity produced an average breaking force of 9.16 plus or minus 1.7 Newtons, a mean tensile strength of 621 plus or minus 115 Megapascals, and an average elongation at break of 3.24 plus or minus 0.86 percent. Individual tensile strengths ranged from 415 to 900 Megapascals, corresponding to linear specific strengths between 0.28 and 0.61 Newtons per tex, directly rivaling commercial flax at 500 to 900 Megapascals, jute at 350 to 700 Megapascals, banana at 529 to 914 Megapascals, sisal at 400 to 700 Megapascals, and abaca at 300 to 1600 Megapascals. Statistical analysis confirmed that tensile strength data adhere to a two-parameter Weibull weakest-link distribution with a shape parameter modulus of 4.8 and a characteristic scale parameter of 672 Megapascals. Fiber strength displayed a statistically significant inverse correlation with diameter: finer fibers measuring 70 to 120 micrometers achieved average tensile strengths of 742 plus or minus 98 Megapascals, whereas coarser fibers measuring 190 to 265 micrometers averaged only 523 plus or minus 87 Megapascals due to higher defect probabilities and lignification. Increasing gauge length from 10 to 50 millimeters systematically reduced average strength from 698 to 547 Megapascals, matching classical weakest-link flaw probability scaling.

Thermogravimetric analysis performed under a dynamic nitrogen atmosphere at a constant linear heating rate of ten degrees Celsius per minute identified a three-stage thermal decomposition profile characteristic of lignocellulosic biomass. Stage one degradation took place between 23 and 147 degrees Celsius, producing approximately six percent total mass loss attributed entirely to the release of absorbed moisture and volatile plant extractives. Stage two degradation occurred between 147 and 370 degrees Celsius, accounting for approximately sixty-four percent total mass loss driven by the rapid depolymerization and pyrolytic breakdown of hemicellulose and cellulose chains, with the maximum derivative thermogravimetric decomposition peak registered at 298 degrees Celsius. Stage three degradation extended from 370 to 600 degrees Celsius, representing approximately eighteen percent mass loss governed by the slow thermal breakdown of complex cross-linked aromatic lignin structures, leaving an eighteen percent residual char yield at 600 degrees Celsius. The authors clarified that the thermal decomposition signal tail observed near 550 degrees Celsius represents gradual char oxidation and residual lignin decomposition under inert purging rather than a discrete thermal transition of cellulose. Because ten percent mass loss occurs at 237 degrees Celsius and fifty percent mass loss at 326 degrees Celsius, composite manufacturing temperatures must strictly remain below 200 degrees Celsius to prevent hemicellulose degradation.

The structural morphology and physical properties of Enset fibers support diverse industrial use cases spanning traditional textiles, structural composites, and advanced functional materials. Historically, coarse Enset fibers have provided durable material for sacks, ropes, and agricultural storage bags used to handle bulk commodities such as coffee beans and grains. In polymer composites, Enset fibers serve as renewable reinforcements for non-load-bearing and semi-structural components such as architectural ceiling boards, interior building elements, and automotive door panels. Furthermore, the presence of hollow internal cell lumens occupying up to twenty-five percent of the cross-sectional area provides natural acoustic damping behavior. Referenced acoustic testing indicated that Enset fabrics achieve superior sound absorption compared to conventional glass fiber insulation across the high-frequency spectrum between 3000 and 6000 Hertz. Advanced nanostructuring involving enzymatic treatment followed by mechanical micro-disintegration has also been shown to improve sound absorption by forty-seven percent, expanding potential applications into high-performance architectural and transportation acoustic shielding. Biodegradable Enset geotextiles also provide effective soil stabilization, weed control, and erosion mitigation in landscaping applications, completely decomposing via soil microbial action within months to several years without leaving toxic synthetic residue.

Regional agricultural production estimates highlight enormous economic valorization opportunities alongside environmental mitigation benefits for rural farming communities across Ethiopia. Cultivation models formulated by Robert and Chernet estimate that average Enset farming yields 10.8 metric tons of harvested plant biomass per hectare annually based on a planting density of 400 plants per hectare and a selective annual harvest of one-quarter of mature standing plants. Across 287,334 hectares in the Southern Nations, Nationalities, and Peoples’ Region and 26,821 hectares in Oromia, national gross biomass production reaches approximately 2.77 million metric tons annually. Because usable fiber bundles comprise roughly fifteen percent of dry pseudo-stem weight, national agricultural waste generation is estimated at 415,836 metric tons of raw fiber per year. At prevailing market rates of 200 Ethiopian Birr per kilogram for processed fiber, complete commercialization of this residue represents a theoretical gross economic value of 83.2 billion Ethiopian Birr. Even under conservative commercialization scenarios capturing ten percent of the waste stream at half the quoted market price, rural smallholders could generate 4.16 billion Birr annually while preventing uncontrolled open burning and localized sanitation hazards. To transition Enset fiber into large-scale industrial manufacturing, the researchers recommended future investigations focusing on standardized TAPPI chemical quantification, composite interfacial shear adhesion testing, standardized ISO 10534-2 acoustic characterization, and comprehensive lifecycle assessments.

Subject of Research: Physicochemical and mechanical characterization of agricultural Enset pseudo-stem fiber waste for industrial material applications

Article Title: Cellulosic Enset fiber from agricultural waste as sustainable material for industrial application

Article References: Temesgen, A. G., Kaufmann, J., & Cebulla, H. (2026). Cellulosic Enset fiber from agricultural waste as sustainable material for industrial application. Discover Polymers, 3(1), Article 10. https://doi.org/10.1007/s44347-026-00044-w

Image Credits: AI Generated

DOI: 10.1007/s44347-026-00044-w

Keywords: Enset fiber, agricultural waste, lignocellulosic materials, tensile strength, gas pycnometry, thermogravimetric analysis, natural fiber composites, sustainable materials, Weibull modulus, bio-based textiles, Cellulosic, Enset