Water Chestnut Research Articles

Physicochemical, nutritional and organoleptic characteristics of cookies based on water chestnut (Trapa natans) and wheat

The water chestnut flour has massive potential to replace the white flour for the development of value-added food products. In the present research work water chestnut flour was combined with white flour at different levels, i.e. 0 (T0), 15 (T1), 30 (T2), 45 (T3) and 60 % (T4), to develop nutritional cookies. The influence of the water chestnut flour concentration on the obtained cookie's physiochemical features was investigated. The cookie's diameter and thickness exhibited a significant increase as a result of the replacement. The fiber and ash contents progressively increased from 2.8 ± 0.1 % and 1.3 ± 0.1 % in the case of T0, to 6.1 ± 0.1 % and 2.2 ± 0.1 % for T4, respectively. Meanwhile, the moisture, protein and fat contents of cookies decreased. A significant increase in K, Mg, Zn, Fe, P and Cu was observed with values 98.3 ± 0.1, 21.5 ± 0.2, 2.0 ± 0.2, 3.0 ± 0.2, 48.6 ± 0.4 and 2.3 ± 0.02 mg/100 g, respectively in T4 cookies. The organoleptic analysis showed that control cookies got the highest scores for all these parameters, whereas cookies with 60 % water chestnut flour got the lowest scores. For T1 and T2 formulations, acceptable scores were collected, justifying that a 15 to 30 % replacement level of water chestnut flour with white flour could be proposed to develop good quality nutritious cookies.

Formulation and Characterization of Novel Cereal Gluten-Free Pasta from Semi-Popped Makhana, Water Chestnut, and Potato

Formulation and Characterization of Novel Cereal Gluten-Free Pasta from Semi-Popped Makhana, Water Chestnut, and Potato

Chromium(VI) removal from water using different bio-adsorbents: Comparison and scope in the treatment of local water bodies with economic analysis

Tannery industries are an important part of India’s economy. India has huge production and consumption of footwear in the world. Leather goods and footwear exports in India were set to reach $5.26 billion in 2022–23. These tannery industries require 40m3 of fresh water per ton of raw material.The water released by these industries are highly contaminated with Cr(VI). Apart from tannery industries,other industrial processes like electroplating, pigmentation also release chromium into the environment. Cr(VI) has adverse effects on humans health, animals and plants. Bio-absorbents exhibit good absorption capacity for Cr(VI). Five different bio-adsorbents have been used,which were collected from wastes.There is hardly any research that shows relation between percentage removal of chromium with respect to size of bio-adsorbents.This study is presented in the same direction. A stock solution was prepared in the laboratory that had similarity in chromium concentration with tannery effluent.Titration (quantitative analysis) was used.On comparison, it was found that pomegranate peel and water chestnut shell showed better Cr(VI) absorption capacity upto 97.83%. A schematic idea has been proposed for the removal of Cr(VI) from drinking water used in rural areas. Economic analysis of the use of these bio-absorbents has proven it to be a better option for Cr(VI)capture.

Widely targeted metabolomics analysis reveals the potential metabolic network of high-pressure carbon dioxide regulating fresh-cut Chinese water chestnut yellowing

In this study, we applied widely targeted metabolomics and physiological analysis to investigate the non-volatile metabolites changes and regulatory mechanisms of high-pressure carbon dioxide (HPCD) treatment on the yellowing of fresh-cut Chinese water chestnut (CWC). A total of 349 non-volatile metabolites were identified and subjected to principal component analysis (PCA), OPLS-DA and KEGG enrichment analysis. The results showed that the yellowing of fresh-cut CWC was related to membrane lipid metabolism and flavonoid biosynthesis. Damage stress induced membrane lipid metabolism and flavonoid biosynthesis in surface tissues, and the increase of phenylalanine ammonia-lyase (PAL) activity in flavonoid biosynthesis might be triggered by signaling molecules from membrane lipid metabolism. On the one hand, HPCD treatment could directly inhibit the activity of PAL, and reduce the biosynthesis of flavonoids in the damaged tissues. On the other hand, HPCD could indirectly inhibit the generation and accumulation of potential signaling molecules by regulating membrane lipid metabolism, thus preventing signaling molecules from triggering flavonoid biosynthesis. This study proposed a potential network of HPCD regulating the yellowing of fresh-cut CWC and established the foundation for further control of yellowing in fresh-cut CWC.

Comprehensive Characterization of Starch from Diverse Sources: Physicochemical, and Functional Properties

AbstractThe present study is based on the comprehensive characterization of starches from pearl millet, sorghum, mango kernel, and water chestnut. The starches are analyzed to observe the difference in physicochemical, pasting, rheological, Fourier transform infrared spectroscopy (FTIR), and X‐ray diffraction (XRD) properties. The amylose content from diverse sources ranges from 17.3 to 26.3%. The swelling power and solubility of the starches are influenced by the increase in temperature. It is observed that an increase in temperature results in increased swelling power and solubility. At 90 °C, mango kernel starch shows the highest swelling power while pearl millet starch shows the lowest. The botanical sources influence the pasting and rheological properties, and a significant difference (p < 0.05) is observed in all the parameters recorded. The peak viscosity (PV) of starches ranges from 1256 to 2101 cP. All the starches possess almost similar and typical starch FTIR spectra. The starches from all sources show prominent peaks at 15.2, 17, 18.3, and 23 (2θ), corresponding to a typical A‐type starch crystallinity organization.

Probing the Potential of Water Chestnut Powder (Trapa bispinosa) in Improving the Shelf Life of Buttermilk

Buttermilk, a valuable by-product of butter production, faces challenges in commercialization due to its limited shelf life and susceptibility to fungal growth. This study aimed to explore the use of water chestnut powder (WCP) as a means to extend the shelf life of buttermilk. The investigation involved evaluating the physicochemical properties, antioxidant activity, antifungal properties, and stabilizing effects of WCP in buttermilk. Buttermilk samples were prepared with varying concentrations of WCP (0%, 0.5%, 1%, 1.5%, and 2%) and stored at 4 °C for one month. The analysis of physicochemical properties showed that the concentration of WCP had a significant impact on the protein percentage, ash content, pH, and acidity of the Water Chestnut Buttermilk (WCBM). Assessment of antioxidant activity using the phosphomolybdenum method showed that, on the 21st day of storage, WCBM3 and WCBM4 exhibited total antioxidant capacities of 0.57±0.12 and 0.60±0.32, respectively, compared to the control with a capacity of 0.48±0.07. The antifungal activity of water chestnut powder buttermilk was evaluated using a qualitative method, which demonstrated inhibition of fungal growth. In the control and WCBM1 and WCBM2 treatments, the observed inhibition ranged from 1-4 mm. However, as the concentration of water chestnut powder increased in WCBM3 and WCBM4, the level of inhibition also increased. Textural analysis further indicated the stabilizing effect of WCP on buttermilk. Overall, the incorporation of WCP in buttermilk yielded promising results in terms of enhancing its physicochemical properties, antioxidant activity, antifungal potential, and textural stability. This study highlights the potential of water chestnut as an ingredient to improve the shelf life and quality of buttermilk, creating opportunities for its commercial utilization in the dairy industry.

Origin of domesticated water chestnuts (Trapa bispinosa Roxb.) and genetic variation in wild water chestnuts.

The water chestnut Trapa bispinosa Roxb. has been domesticated in China and has been reported as the only domesticated species of this genus. To understand the origin of T. bispinosa and its evolution pathway, we compared the genetic similarity and seed morphology of domesticated water chestnut T. bispinosa with three wild species T. natans, T. incisa, and T. japonica along with archeological seed samples from the Tianluoshan site (approximately 7000-6300 cal BP) in China. The largest seed size was observed only in the domesticated species, whereas other wild species showed smaller size including T. natans L. genetically close to the domesticated type, and T. incisa was the smallest in size. The volumes of the seed capsule and endosperm were measured using X ray CT scans, showing the ratios of total volumes between T. bispinosa and wild species ranged from 4.2 to 4.5. The ratios of endosperm volume ranged from 3.3 to 3.7. Both measurements showed domesticated species have larger seed volume. Genome size was indirectly estimated by flow cytometry. Domesticated species with larger seed size was estimated as diploid, as were the wild species except for tetraploid species T. japonica. Domesticated species clearly showed the largest edible organs, but it was not a result of ploidy level changes. Maternal lineages traced using complete whole chloroplast sequences, suggested that T. natans is the closest to T. bispinosa, both of which are close to T. japonica. The result was confirmed by PCR genotyping with chloroplast insertion/deletion (cpINDEL) markers developed in the study. T. incisa showed distinct plastid types within the species, and T. japonica showed a unique plastid genotype. Our study concludes the largest volumes for the edible endosperm have been accomplished through nearly 6000 years of artificial selection, but the domestication did not involve ploidy level changes.

Scalable, bio-inspired and self-floating bi-layer polyurethane foam solar evaporator with excellent capillary hydrodynamic effect

Solar photothermal interfacial evaporation is one of the most promising strategies in seawater desalination and wastewater treatment, but its efficiency is limited by the trade-off between salt circulation and thermal positioning. Therefore, how to effectively control salt circulation and heat transfer to achieve high efficiency in a solar evaporator (SE) is a problem worthy of attention. Herein, inspired by water chestnut, a self-floating bi-layer foam consisting of a photo-thermal polypyrrole (PPy) coating and a lightweight polyurethane-carbon nanotube (PU/CNTs) foam matrix was constructed by simple liquid-phase in-situ polymerization and continuous in-situ polyurethane foaming technology. Based on the hydrodynamic effect of capillary wicking, the flow velocity control of aqueous solution in porous SE is realized by means of the bi-layer structure of macropores and micropores, and the heat transfer from the top photothermal zone to bulk water is slowed down without setting a separate thermal insulation layer. With the novel structure employed, an evaporation flux of 2.66 kg m−2 h−1 is achieved under 1 sun illumination. In addition, the SE with the length and width enlarged to 3 m and 1 m can be continuously evaporated in salt-saturated wastewater for 20 days without manual maintenance, and there is no obvious salt accumulation in the macroporous photothermal layer.

Optimization of water chestnut (Trapa bispinosa) starch, fructo-oligosaccharide and inulin concentrations for low-fat flavoured yogurt consisting of a probiotic Lacticaseibacillus rhamnosus strain

A low-fat flavoured probiotic yogurt consisting of Lacticaseibacillus rhamnosus, mango pulp and water chestnut starch as a fat replacer together with prebiotics was formulated with better shelf life (15 days), technological and sensory properties.

Evaluation of acetic acid treatment of fresh-cut water chestnuts using gray-correlation analysis based on the variation-coefficient weight.

The demand for fresh-cut water chestnuts, a convenient and nutritive vegetable, is increasing in market. However, the slicing of water chestnuts can cause mechanical damage to tissue, which results in quality deterioration. We aimed to select the optimal treatment through a comprehensive comparison of the preservation effect of acetic acid, which could prolong the shelf life of fresh-cut water chestnuts and improve their storage quality. A comprehensive evaluation was conducted using the gray-correlation method based on the variation-coefficient weight to observe the treatment of 0, 2 and 5% acetic acid. Their effects on color, weight loss rate, and the content of ascorbic acid, total sugar, reducing sugar, soluble protein, and free amino acid were determined. The color, weight loss rate, and nutritional content of fresh-cut chestnuts varied under different processing and storage times. When stored for more than 4 days, the b* value, and the content of total sugar and soluble protein in CK were higher than those in 2% or 5% acetic acid, but the weight loss rate, and the content of ascorbic acid and free amino acid in CK were less than those in acetic acid treatments. Considering various indicators, it was difficult to determine which treatment to choose for fresh-cut water chestnut preservation. The gray-correlation analysis results indicated that when stored for 8, 12, or 16 days, the gray-correlation degree of 5% acetic acid was the highest, while that of the control was the lowest. It could be directly concluded by the gray-correlation degree that when the storage time exceeded 4 days, acetic acid could be used to improve storage quality, and 5% acetic acid had a better preservation effect than 2%. Fresh-cut water chestnuts can be stored for 4 days without the need for acetic acid treatment. These findings could provide information and comprehensive evaluation methods for the preservation of fresh-cut fruits and vegetables. The next step is to evaluate the preservation effect of acetic acid by measuring its effects on other indicators of fresh-cut water chestnuts (e.g., flavonoids, and microorganisms), providing ideas for the research of preservatives.

Mechanism of exogenous methyl jasmonate in regulating the quality of fresh-cut Chinese water chestnuts.

Fresh-cut Chinese water chestnuts (CWCs) are susceptible to yellowing and browning during storage due to mechanical damage and the loss of protective outer skin, adversely affecting their marketability and shelf life. Methyl jasmonate (MeJA) is currently extensively used for food preservation, but it has not been used in Chinese water chestnuts. This study investigated the effect of MeJA treatment on the quality of fresh-cut CWCs. Fresh-cut CWCs immersed in 20 μM MeJA solution for 10min and stored at 10°C for 5d effectively delayed the yellowing process, reduced the respiration rate, and minimized the weight and soluble solids loss during storage. In addition, MeJA treatment induced the activities of superoxide dismutase (SOD) and catalase (CAT), which improved the antioxidant capacity of fresh-cut CWCs and inhibited the generation of reactive oxygen species (ROS). Meanwhile, MeJA treatment inhibited the activities of phenylalanine aminotransferase (PAL), polyphenol oxidase (PPO) and peroxidase (POD). The results of quantitative real-time PCR (qRT-PCR) showed that MeJA down-regulated the expression of CwCHS1, CwCHS2, CwCHS3 and CwCHI2 in freshly cut CWCs and inhibited the accumulation of flavonoids, thus delaying the surface discoloration of freshly cut CWCs.

Assessment of agronomic crops-based residues for growth and nutritional profile of Pleurotus eryngii.

Among edible mushrooms, Pleurotus eryngii is unique due to its flavor, admirable medicinal and nutritional profiling. Pakistan is an agricultural country diverse in various crops. However, the residues of the horticultural and agronomic crops are wasted without utilization in the food chain. Hence, a study was performed to assess the performance of relatively low-cost, easily available crops residues i.e. cotton, rice, wheat, mustard and water chestnut for yield and nutrition enhancement of Pleurotus eryngii strains P9 (China) and P10 (PSU-USA). The results revealed that morphological attributes i.e. mycelium run, fruit development, yield and biological efficiency were significantly higher by using cotton waste as compared to other substrates. Regarding biochemical attributes i.e. total soluble solids (12.67 °Brix), phenolics (259.6 mg/100g), moisture (92.3%) and ascorbic acid contents (2.9 mg/100ml) were also significantly higher by using cotton waste. Whereas, acidity (0.30%), reducing sugar (7.67%), non-reducing (4.33%) and total sugars contents (12%) were found highest by using mustard straw. Nutrient analysis of substrates showed that nutrient levels were increased after harvesting of crop as compared to before harvesting levels. Overall results revealed that cotton waste and mustard straw are promising substrates for Pleurotus eryngii better growth and have potential in yield and nutrition enhancement. Moreover, P10 strain performed better as compared to P9.

Controlled atmosphere storage of krypton, xenon and oxygen inhibits yellowing and maintains quality of fresh peeled water chestnuts (Eleocharis dulcis)

Yellowing and quality (including total soluble solid (TSS), titratable acid (TA) and ascorbic acid (AA)) deterioration are the main reasons for affecting shelf life of fresh peeled water chestnuts (FPWCs). The use of controlled atmosphere (CA) storage of krypton (Kr), xenon (Xe) and O2 to keep food fresh has not been studied. The purpose of this study was to determine the effect of CA storage of Kr, Xe and O2 on the shelf life of FPWCs. FPWCs were treated with CA storage (Kr 40.4%, Xe 40.4%, O2 19.2%) (CA-(Kr, Xe, O2)). The N2 content, Kr content, Xe content, O2 content, CO2 content, degree of yellowing, eriodictyol and naringenin contents, polyphenol oxidase (PPO) activity, peroxidase (POD) activity, phenylalanine lyase (PAL) activity, weight loss, TSS content, TA content, AA content, texture and microbe of FPWCs were measured. The results indicate that CA-(Kr, Xe, O2) reduces the degree of yellowing by inhibiting the eriodictyol content, maintains the quality by reducing the weight loss and increasing TSS, TA and AA contents. In addition, it was found that CA-(Kr, Xe, O2) maintains the texture by increasing the hardness, springiness, gumminess and chewiness, and inhibits the growth of mesophile, yeast and mold. The results provide a new method for extending shelf life of FPWCs.

Technological, quality and nutritional characteristics of Ramen noodles with wheat flour partially substituted by water chestnut flour

Ramen noodles were prepared by partially supplementing traditional wheat flour with water chestnut flour (WCF) at 30, 40 and 50% levels w/w. The composition, pasting and farinograph indices of flour blends were studied. Noodles were analysed for colour, radical scavenging and functional characteristics. Time for dough development, stability and farinograph quality number declined significantly from 5.250±0.07 to 1.20±0.01 min, 6.45±0.07 to 1.31±0.01 min and 81.50±0.71 to 18.50±0.71, respectively, after replacement. Statistically significant increment in pasting temperature (60.91±0.01 to 72.05±0.07°C), peak viscosity (1094.05±0.07 to 1099.25±0.35 Brabender Unit, BU), breakdown (310.05±0.07 to 376.05±0.07 BU), hot paste (782.05±0.07 to 996.10±0.14 BU) and cold paste viscosities (1548.10±0.14 to 1701.25±0.35 BU) were found with the addition of WCF. Non-traditional ramen exhibited significantly improved fibre, antioxidant potential and mineral content with significant reduction in % fat and caloric count. The colour variation data in ramen noodles were: L* (66.35–57.86); a* (0.24–2.08); and b* (4.03–4.47). Texture hedonic scores varied between 8.38 and 7.57 with chestnut flour level increment. Hardness of Ramen noodles samples ranged between 13.9 and 19.8 N.

Development of Sasirangan Liquid Waste Treatment System Using Ozonization Method Using Composite Ceramic Filter Media Based on Water Chestnut (Eleocharis Dulcis)

Sasirangan Liquid Waste (SLW) contains heavy metals and chemicals with BOD and COD concentrations exceeding the waste water quality standards in accordance with the Minister of Environment and Forestry Regulation Number P.16 of 2019. The aim of this research is to design and develop a SLW processing system using filter media and composite ceramics made from water chestnut (Eleocharis dulcis). Based on previous research, using the filtration method; filtration and adsorption; filtration, adsorption, sedimentation and ozonization. Filtration method can remove solid particles and sediment from water, so the water appears clearer. The water purification process that involves a filtration method using slow sand filter (SSF), which additional processes are needed either before or after the SSF is carried out. Meanwhile, the use of water chestnut has been carried out by several researchers due to its high active carbon content, namely 50.68%. In this research, we combine several methods including filtration, sedimentation, and ozonization. Water chestnut has a bound carbon content of 84.53% after being activated with an H2SO4 activator, where the largest porosity is found in ceramics with activated charcoal composite materials with variations of the H2SO4 activator. Apart from that, chestnut also has a cellulose content of 35.32% so it has the potential to be effective as a ceramic composite material in sasirangan liquid waste processing filters, especially as an adsorbent. The benefits obtained from the results of this research can be a scientific reference for the use of water chestnut as a filter media and composite ceramic.

Effect of addition of methionine and histidine on physicochemical and rheological characteristics of water chestnut starch as revealed by molecular dynamic simulations

The effect of addition of amino acids including methionine (Met) and histidine (His) at selected concentrations (2, 6, 10, and 15%) on the physicochemical, pasting, and rheological properties of water chestnut starch (WS) was evaluated. A higher quantity of amino acids considerably (p < 0.05) inhibited the ability of starch-amino acid blends to expand their solubility index and swelling capacity. The addition of amino acids also significantly decreased peak viscosity (952.33–540.67 cP), hot paste viscosity (917–528 cP), cold paste viscosity (1209.67–659 cP), and setback (277.67–131 cP) of WS. Addition of amino acids enhanced the stability ratio (SR) of WS. All the studied samples displayed storage moduli (G′) values higher than loss moduli (G′′) but rheologically weak gel characteristics. Molecular dynamics simulation studies revealed that interactions between amino acids and water greatly reduced the number of starch–water hydrogen bonds while preserving a higher number of starch-starch intramolecular interactions. This study could provide important insights for better understanding of modification of water chestnut starch functionality under the influence of amino acid residues.

Use of Pesticides and Health Risks to Chinese Water Chestnut Farmers in Suphanburi Province, Thailand.

We aimed to study the relationship between the use of pesticides and the health risks faced by Chinese water chestnut farmers in this country. This cross-sectional survey was conducted among 425 farmers in Sriprachan district, Suphanburi Province, Thailand in 2021. Samples were recruited using the cluster sampling method, and data collection took place through questionnaires. The questionnaire consisted of 3 parts, 76 items, namely personal information of farmers (12 items checklist), the use of pesticides by chemical risk assessment was a 5-point rating scale (40 items), and health risk assessment exposure to pesticides was a 5-point rating scale (24 items). The content validity index for scale (S-CVI) was 0.963 and the reliability with Cronbach's alpha coefficient was 0.904. Data were analyzed using descriptive statistics, chi-square, relative risk, and 95% CI. The overall pesticide use among farmers was at a moderate level (Mean=3.26, SD=0.60). Farmers' signs and symptoms of exposure were compared to their use of pesticides. The pesticide use increased health risks by 15.57 (95% CI: 12.33 to 18.14). Hazard identification was 10.79 higher (95% CI: 8.19 to 13.40). Dose-response assessment was -16.23 higher (95% CI: -17.63 to -14.82). Exposure assessment was 11.49 higher (95% CI: 9.87 to 13.10) and the risk characteristic was -7.46 (95% CI: -8.49 to -6.44). It was statistically significant at <.001. Careless and incorrect use of pesticides by Chinese water chestnut farmers can lead to health risks from exposure to toxic substances.

Synergistic co-catalytic nanozyme system for highly efficient one-pot colorimetric sensing at neutral pH: Combining molybdenum trioxide and Fe(III)-Modified covalent triazine framework

This study investigates the co-catalytic capabilities of MoO3 nanosheets in enhancing the enzyme-like catalytic activity of a two-dimensional ultrathin Fe(III)-modified covalent triazine framework (Fe-CTF) under neutral pH conditions. The unique physicochemical surface properties and two-dimensional structures of Fe-CTF enable the direct immobilization of native enzymes (glucose oxidase (GOD) and xanthine oxidase (XOD)) through adsorption, eliminating the need for chemical processes. Efficient immobilization of the native enzymes within the Fe-CTF/GOD(XOD) hybrid is achieved through multipoint attachment involving various interactions. The Fe-CTF/MoO3 co-catalytic system exhibits enzyme-mimicking activity at neutral pH and, when combined with the high catalytic activity of the immobilized native enzymes, enables the development of a colorimetric method for glucose detection. This method demonstrates excellent facilitation, rapidity, sensitivity, and selectivity, with a linear detection range of 50–1000 μM and a limit of detection of 8.8 μM for glucose. Furthermore, a straightforward one-pot colorimetric method is established for screening XOD inhibitors. The inhibitory potential of a crude extract derived from Chinese water chestnut peel on XOD activity is evaluated using this method. The findings of this study pave the way for the utilization of nanozyme/native enzyme hybrids in pH-neutral conditions for one-pot colorimetric sensing. This work contributes to the advancement of enzyme-based sensing technologies and holds promise for various applications in biosensing and biomedical research.

Ultimate Analysis of Water Chestnut (Trapa natans Var. bispinosa Roxb) Affected by Various Inorganic and Organic Sources

The present investigation aimed to know the impact of various organic and inorganic fertilizers on the Ultimate parameters of water chestnuts. The ultimate analysis included the percentage of nitrogen, hydrogen, carbon, sulfur, protein, carbon-hydrogen ratio, and carbon–nitrogen ratio from kernels, fruit peel, and chestnut plants. For kernels, T4 (Nano-Urea @ 4.0%) had the greatest percentages of Nitrogen (1.99), Carbon (41.95), Hydrogen (6.767), Sulphur (0.244), Carbon-Hydrogen ratio (6.20), and Protein (12.44). T2 (½ RDF Nutrient + DAP) had the highest Carbon-Nitrogen ratio (23.26). The largest percentages of nitrogen (2.51), sulfur (0.342), and protein (15.69) were found in T5 (Jivamrut @ 10%) for peel estimate, whereas T1 (Control) exhibited the highest ratios of carbon to nitrogen (21.27) and carbon-hydrogen (7.22). T2 (½ RDF -Urea + DAP) had the highest proportion of hydrogen (5.53), whereas T6 (RDF) had the highest percentage of carbon (39.33). In contrast, T6 (RDF) had the largest percentages of carbon (36.75), hydrogen (5.29), and carbon-hydrogen ratio (19.02) for the chestnut plant. T5 (Jivamrut @ 10%) had the highest percentages of nitrogen (2.68), sulfur (0.588), carbon-hydrogen ratio (6.93), and protein (16.75).

Water Chestnut (Eleocharis dulcis) Microfiber Reinforced Composite with NaOH Modification

This study aimed to obtain the physical and mechanical properties of a composite made from water chestnut microfiber and e-glass with a polyester matrix. Using water chestnut (Eleocharis dulcis) as reinforcement for composite materials is a good way to utilize local materials and increase the economy of local people. It would need a modified treatment to improve the mechanical properties of water chestnut fiber-reinforced composites. The water chestnut fiber was modified by treating it with 5% volume NaOH solution and continued with 5% volume H2O2 bleaching, 50% volume H2SO4 hydrolysis, and ultrasonication. Then it was washed with water and dried in the oven for 12 hours to obtain the microfiber. The size of the water chestnut microfiber obtained was about 3-9 µm. Composite was produced using the compression molding method at a pressure of 2 MPa and a temperature of 25°C. The variations in the volume fraction of the polyester composite, water chestnut microfiber, and e-glass fiber with Volume Fraction (%) were 60%:40%:0% (sample A), 60%:0%:40% (sample B), 50%:25%;25% (sample C), 60%:40%:0% (sample D) and 70%:15%:15% (sample E). The physical characterization of composites showed that the lowest composite density and water content on samples B and A were 1.22 g/cm3 and 0.59%. In contrast, the mechanical characterization of composites showed the highest MoR and MoE on samples A and C of 87.86 MPa and 10.43 Gpa, respectively. Composite made from water chestnut (Eleocharis dulcis) modified microfiber reinforcing material with 5% volume NaOH solution and e-glass with a polyester matrix at a volume fraction composition of 50%:25%:25% is recommended.