Chemical Activation of Banana Peel Waste-Derived Biochar Using KOH and Urea for CO2 Capture.

This article describes the synthesis and characterization of porous carbon derived from waste banana peels by chemical activation with KOH or by activation KOH and urea modification. The as-synthesized samples were carefully characterized by various techniques. The prepared carbonaceous materials possess highly developed micropore and mesopore structures and high specific surface area (up to 2795 cm2/g for materials synthetized with KOH and 2718 cm2/g for activated carbons prepared with KOH and urea). A series of KOH-activated samples showed CO2 adsorption at 1 bar to 5.75 mmol/g at 0 °C and 3.74 mmol/g at 25 °C. The incorporation of nitrogen into the carbon sorbent structure increased the carbon uptake capacity of the resulting materials at 1 bar to 6.28 mmol/g and to 3.86 mmol/g at 0 °C and 25 °C, respectively. It was demonstrated that treatment with urea leads to a significant increase in nitrogen content and, consequently, CO2 adsorption, except for the material carbonized at 900 °C. At such a high temperature, almost complete decomposition of urea occurs. The results presented in this work could be used in the future for utilization of biomass such as banana peels as a low-cost adsorbent for CO2 capture, which could have a positive impact on the environment and human health protection.

Fluid Mechanics of Droplet Spreading of Chitosan/PVA-Based Spray Coating Solution on Banana Peels with Different Wettability.

The spreading behavior of a coating solution is an important factor in determining the effectiveness of spraying applications. It determines how evenly the droplets spread on the substrate surface and how quickly they form a uniform film. Fluid mechanics principles govern it, including surface tension, viscosity, and the interaction between the liquid and the solid surface. In our previous work, chitosan (CS) film properties were successfully modified by blending with polyvinyl alcohol (PVA). It was shown that the mechanical strength of the composite film was significantly improved compared to the virgin CS. Here we propose to study the spreading behavior of CS/PVA solution on fresh bananas. The events upon droplet impact were captured using a high-speed camera, allowing the identification of outcomes as a function of velocity at different surface wettabilities (wetting and non-wetting) on the banana peels. The mathematical model to predict the maximum spreading factor, ßmax, was governed by scaling law analysis using fitting experimental data to identify patterns, trends, and relationships between ßmax and the independent variables, Weber (We) numbers, and Reynolds (Re) numbers. The results indicate that liquid viscosity and surface properties affect the droplet's impact and spreading behavior. The Ohnesorge (Oh) numbers significantly influenced the spreading dynamics, while the banana's surface wettability minimally influenced spreading. The prediction model reasonably agrees with all the data in the literature since the R2 = 0.958 is a powerful goodness-of-fit indicator for predicting the spreading factor. It scaled with ßmax=a+0.04We.Re1/3, where the "a" constants depend on Oh numbers.

Effect of nickel oxide nanoparticles on bioethanol production by Pichia kudriavzveii IFM 53048 using banana peel waste substrate.

The use of nanomaterials in bioethanol production is promising and on the increase. In this report, the effect of nickel oxide nanoparticles (NiO NPs) on bioethanol production in the presence of a novel yeast strain, Pichia kudriavzveii IFM 53048 isolated from banana wastes was investigated. The hot percolation method was employed for the green synthesis of NiO NPs. The logistic and modified Gompertz kinetic models employed in this study showed a 0.99 coefficient of determination (R2) on cell growth, and substrate utilization on the initial rate data plot which indicate that these model were best suited for bioethanol production studies. As a result, 99.95% of the substrate was utilized to give 0.23 g/L/h-1 bioethanol productivity, and 51.28% fermentation efficiency, respectively. At 0.01 wt% of NiO NPs, maximum production was achieved with 0.27 g/g bioethanol yield. Meanwhile, 0.78 h-1 maximum specific growth rate (µmax) of the microorganism, 3.77 g/L bioethanol concentration (Pm), 0.49 g/L/h production rate (rp.m), and 2.43 h production lag time (tL) were obtained when 0.01 wt% of NiO NPs were used during the bioethanol production process. However, a decrease in bioethanol concentrations occurred at ≥0.02 wt% of NiO NPs. The incorporation of NiO NPs in the simultaneous saccharification and fermentation (SSF) process improved the production of bioethanol by 1.90 fold using banana peel wastes as substrate. These revealed NiO NPs could serve as a suitable biocatalyst in the green production of bioethanol from banana peel waste materials.

Prospects of microbial cellulase production using banana peels wastes for antimicrobial applications.

Microorganisms have been extensively studied and used to produce a wide range of enzymes and bioactive substances for a number of uses. Cellulases have also been widely used for a variety of bioprocessing and biotransformation purposes and are acknowledged as the essential enzymes for industrial applications. Broad industrial applications and huge demand essentially require mass-scale and low-cost production of cellulase enzyme. Nevertheless, low-cost production of cellulase enzyme at industrial-level finds certain issues, and this may be mainly associated with the unavailability of cheap and effective substrate to be utilized in fermentation process. In this context, cellulosic wastes are counted as one of the suitable bioresources and have been well explored for low-cost and highly efficient cellulase enzyme productions. Further, banana peels waste is considered as the high cellulose & sugar containing food wastes which is renewable and hugely available worldwide. Therefore, the present review explores the possible utilizations of banana peels as a potential food waste to be employed as substrate to produce cellulase enzymes. Availability and compositional analysis of banana peels has been explored for the microbial cellulase production based on reported studies. Further, this review explores the applications of cellulase enzymes as antimicrobial agents. Based on the available studies and their evaluation, potential limitations and future suggestions for the production of cellulase enzymes and their applications as antibacterial agents have been provided, which have a high potential for numerous biomedical applications and may offer a new opportunity for industrial utility.

Hydroxymethyl furfural (HMF) a high strength cellulose resin for wood composite laminates.

The organic wastes though biodegradable is harmful and pose a serious threat to the environment. This research focused to; harness the cellulose existing in the peels of vegetables, banana and bagasse to establish Hydroxymethyl furfural (HMF) bioresin. Eleven experiments were performed with different w/w% of DMSO and Sulphuric acid to find the best solvent extract. The FTIR-ATR validated sample 6 extract (10 w/w% at 98 contact h) as the prime compared to the other extracts. The conversion of cellulosic glucose to HMF was performed on 10 ml of sample 6 extract. The filtrate was further concentrated to 90% at 80°C. The HPLC analysis displayed 51% conversion of HMF from glucose. The universal testing machine (UTM) test executed on the HMF resin laid on the wood veneers exhibited good curing and tensile strength (18.5 MPa). The physical property of HMF lies close to the commercially available wood resin in the market.

Control of carbendazim toxicity using banana peel powder in rats.

Carbendazim (CBZ) is a steady benzimidazole fungicide broadly exploited in cultivation for pre- and post-harvest treatment to dominate microorganisms infection on several plants. CBZ causes toxic effects in the different tissues of rat via influencing biochemical and hematological factors causing histopathological alterations in the liver and kidney of rats. Banana peel (BP) makes up about 38% of the whole banana weight, BP is usually disposed of as waste that is considered as an environmental problem. BP comprise bioactive a lot of compounds that can be exploited for their unique biological and pharmacological attributes. The current study was carried out to determine the protective effect of dried banana peels consumption against carbendazim toxicity in rats. The results indicated that banana peels had the ability to counteract the toxic effect of carbendazim on rats which was evident by the improvement in liver and kidney functions, lipid profile and histopathological examination.

Optimization of ultrasound-assisted enzymatic extraction of resistant starch from green banana peels and its structural characterization.

The global consumption of a large quantity of banana generates a huge quantity of banana peels which creates the problem of its disposal and proper management. The utilization of banana peels for the extraction of resistant starch can be a valuable strategy of waste valorization with economic viability at the industrial level. Green techniques like ultrasound can be efficacious in terms of increasing the extraction efficiency and yield of resistant starch. In this study, ultrasound assisted enzymatic extraction of resistant starch was optimized using response surface methodology. The optimum yield (60.6%) of resistant starch was obtained at 35 °C temperature, 30:1 liquid to solid ratio after a treatment time of 9 min. The results showed that a combination of ultrasound treatment with enzymatic extraction of resistant starch can be an efficient approach for the valorization of banana peels. Resistant starch holds application as a valuable supplement in functional food development in the fields of dairy, bakery, beverages, etc.

Potential use of banana peel (Musa cavendish) as ingredient for pasta and bakery products.

The consumption of fruits and vegetables involves the disposal of the inedible parts, conveying challenges such as waste management and environment pollution. In recent years, there have been multiple studies aimed at finding alternatives that reduce the negative impact of food/agricultural waste. Since most studies done with by-products recommend their careful selection, the aim of this study was to verify if discarded banana peels could be disinfected until microbiologically safe and to determine if they could still provide nutrients to formulate food products with sensory characteristics acceptable to a consumer market after disinfection. Banana peels were collected from markets, restaurants, and greengrocers. They were disinfected, dried, and pulverized to obtain a flour which was subjected to microbiological and proximal analysis. Once its microbial safety was assured, this flour was incorporated into bakery and pasta products, replacing wheat flour with 5-20% banana peel flour (BPF). The sensory evaluation of the different products was carried out and, after verifying that the products were sensory acceptable, the proximal analysis was implemented. The formulated products were suitable for the addition of BPF up to 10%, in which the Acceptability Index was higher than 80% and significant increases in fiber and fat were achieved. We conclude that waste banana peel flour can be incorporated into bread and pasta products for human consumption to provide nutrients which might contribute to reduce this type of waste and to recover nutrients from otherwise disposed banana peels.

Anti-diabetic effect of banana peel dietary fibers on type 2 diabetic mellitus mice induced by streptozotocin and high-sugar and high-fat diet.

We used a high-fat diet (HFD) and streptozotocin (STZ) to induce type 2 diabetic mellitus (T2DM) mice and evaluated the effect of banana peel dietary fibers (BP-DFs) as potential hypoglycemic agents. After 5 weeks of intervention with banana peel dietary fibers (BP-DFs), food intake was reduced, body weight was increased, blood lipids and glucose were reduced, fasting insulin and GLP-1 levels were increased, and liver and pancreatic tissue damage was reduced. Banana peel soluble dietary fiber (BP-SDF) has the most significant effect. The results of fecal microbiota analysis showed that BP-DFs could ameliorates gut microbiome dysbiosis, and all three types of dietary fibers have obvious effects. The results of fecal short-chain fatty acids (SCFAs) showed that the content of fecal SCFAs was increased after BP-DFs dietary intervention, and BP-SDF had the most obvious effect. RT-PCR experiment results show that BP-DFs can up-regulate the mRNA expression levels of PI3K, AKT, IRS-1, and FOXO1 in the liver of diabetic mice, which indicates that BD-DFs may play a role in improving insulin resistance and insulin signal transduction via the IRS/PI3K/AKT pathway, improving insulin resistance and insulin signal transduction. Our research may be extended to BP-DFs, especially BP-SDF, as the basis for potential dietary intervention to prevent or treat type 2 diabetic mellitus. This work supports future research studies of the anti-diabetic properties of BP-SDF in humans. PRACTICAL APPLICATIONS: Diabetes can lead to a variety of complications that have a huge impact on health. Dietary fiber may help in lowering blood sugar. Our experimental results showed that banana peel dietary fibers have the effect of reducing food intake, blood sugar, improving liver and pancreas function, increasing the abundance of intestinal flora, and improving the IRS/PI3K/AKT pathway in T2DM mice. Therefore, this study could provide a theoretical basis for the development of functional foods with banana peel dietary fiber.

Effect of Banana (Musa sp.) Peels Extract in Nanoemulsion Dosage Forms for the Improvement of Memory: In Vitro & In Vivo Studies.

BACKGROUND: Banana (Musa sp.) is a plant rich in phytochemical compounds, especially antioxidants, which are hypothesized to inhibit the activity of acetylcholinesterase, an enzyme associated with Alzheimer's Disease. OBJECTIVE: This research aimed to study nanoemulsion preparations of Kepok banana (KEP-NE) and Tanduk banana (TAN-NE) peel extracts for their activities as antioxidants, acetylcholinesterase as well as tyrosinase inhibitors, and as agents to improve short-term memory. METHODS: Nanoemulsion was prepared using a combination of high shear homogenization and ultrasonication. The antioxidant activity test was carried out using DPPH and ABTS methods. Meanwhile, memory improvement was studied in a mouse model with memory impairment induced by alloxan (120 mg/kg b.w) using the Y-maze apparatus. ELISA performed determination of acetylcholinesterase and tyrosinase inhibition. RESULTS: Characterization of the nanoemulsion was performed to include particle size, antioxidant activity, acetylcholinesterase, and tyrosinase inhibition. The particle size and polydispersity index (PI) of KEP-NE and TAN-NE were 84.2 nm (PI: 0.280) and 94.1 nm (PI: 0.282), respectively. The antioxidant activity of DPPH showed that the respective IC50 values of KEP-NE and TAN-NE were 0.64 µg/mL and 1.97 µg/mL. At the same time, the values with the ABTS method were 1.10 µg/mL and 1.72 µg/mL, respectively. The IC50 of KEP-NE on acetylcholinesterase inhibition was 108.80 µg/mL, and that on tyrosinase inhibition was 251.47 µg/mL. The study of short-term memory in the Y-maze revealed that the groups Kepok peel extracts 100 and 300 mg/kg b.w and KEP-NE 100 and 300 mg/kg b.w significantly (P < 0.05) improved short-term memory. CONCLUSION: This study suggests that the nanoemulsion dosage form of Kepok banana peel extract has antioxidant and acetylcholinesterase inhibition and tyrosinase inhibition activities and could potentially be an adjunct alternative treatment for memory disorders. Modifying the smaller drug particle size contributes to the delivery system. The nanoemulsion can increase pharmacological activity.

The Potential Use of Orange and Banana Peels to Minimize the Toxicological Effects of Silver Nanoparticles in Oreochromis Niloticus.

To evaluate the effectiveness of orange peels (OP) and banana peels (BP) in reducing the toxicity of silver nanoparticles (Ag-NPs), Oreochromis niloticus were exposed to Ag-NPs, Ag-NPs + OP, and Ag-NPs + BP for 24, 48, and 96 h. Time-dependent toxicological impacts of Ag-NPs were recorded. The maximum Ag accumulation was in hepatic and renal tissues after 96 h. A marked decrease in red blood cell count, hemoglobin content, hematocrit ratio, and mean corpuscular hemoglobin concentration was observed after 48 and 96 h of Ag-NPs exposure. Silver accumulation resulted in severe histological alterations (ex: congestion, vacuolization, and necrotic degeneration) in gills, livers, and kidneys. The adsorptive capacity of both peels could reduce the bioavailability of Ag-NPs as indicated by decreased Ag content in tissues, insignificant change in the hematological parameters with control groups, and regressive histological alterations based on the frequency of alterations' existence and the extent of affected parts.

Stability of biochar derived from banana peel through pyrolysis as alternative source of nutrient in soil: feedforward neural network modelling study.

Biochar derived from banana peels can be used as an alternative nutrient in the soil that can promote crop growth while reducing fertiliser usage. Biochar stability has proportional relationship to biochar residence time in the soil and potassium is one of the vital nutrients needed for plant growth. This research aims at providing optimum pyrolysis operating conditions like temperature, residence time, and heating rate using banana peels as feedstock. An electrical tubular furnace was used to conduct the pyrolysis process to convert banana peels into biochar. The elemental compositions of biochar are potassium, oxygen (O), and carbon (C) content. The O:C ratio was used as the biochar stability indicator. Analysis of results showed that operating temperature has the most remarkable effect on biochar yield, biochar stability, and biochar's potassium content. In addition, a multilayer feedforward artificial neural network model was developed for the pyrolysis process. Eleven training algorithms were selected to model the multi-input multi-output neural network (MIMO). The most suitable training algorithm was identified through four performance criterions which are root mean square error (RMSE), mean absolute error (MSE), mean absolute percentage error (MAPE), and regression (R2). The results show that the Levenberg-Marquardt backpropagation training algorithm has the lowest error. From the chosen training algorithm, neural network was trained, and optimum operating parameters for banana peel were predicted at 490 °C, 110 min, and 11 °C/min with a high yield of 47.78%, O/C ratio of 0.2393, and 14.04 wt. % of potassium.

Synthesis and characterization of nanoparticles from neem leaves and banana peels: a green prospect for dye degradation in wastewater.

Nanoparticles have excellent catalytic, adsorptive, and reactive properties, which led to their application for wastewater treatment. The current study focuses on silver nanoparticle synthesis using neem leaf and banana peel extract and its application as an antimicrobial and dye degrading agent for wastewater treatment. The use of these extracts led to a rapid, simple, and environment-friendly method for the biosynthesis of silver nanoparticles (AgNPs). UV-Vis spectroscopy showed absorption bands at 473 and 423 nm for AgNPs synthesized from neem leaf and banana peel extracts, respectively. The AgNPs were further characterized using XRD, FTIR, ESEM, EDX, and DLS methods. XRD data confirmed the crystalline nature of the synthesized AgNPs. ESEM images revealed the synthesized nanoparticles were spherical. From DLS analysis the average diameter of the AgNPs was found to be 168.7 nm from banana peel and 206.4 nm from neem leaf extract. Antibacterial activity of synthesized nanoparticles at 0.025 mg/ml concentration was tested against Escherichia coli (E.coli), Bacillus subtilis (B.subtilis), Staphylococcus aureus (S.aureus), and Klebsiella sp. using disk diffusion method and the zone of inhibitions observed were 10-13, 3-4, 2-3, and 1-3 nm respectively. 99% degradation of model dye malachite green was observed using banana peels-derived nanoparticles at a concentration of 0.06 mg/ml within 4.5 h. This study provides an eco-friendly and economic approach to AgNP synthesis and its potential application in the removal of hazardous dye from wastewater.

Production of Polysaccharides and Single-Cell Protein by Some Local Isolates of Trichoderma spp.

<b>Background and Objective:</b> Polysaccharides and Single-cell protein are one of the best essential natural products of microorganisms, they are excreted by different microorganisms such as yeast, fungi, bacteria and algae. This study was carried out to detect the ability of four local fungal isolates of <i>Trichoderma </i>spp. to produce polysaccharides and Single-cell protein. <b>Materials and Methods:</b> Standard Czapek Dox Broth Medium was used to detect the ability of fungal isolates to produce polysaccharides and Single-cell protein, with modified the components of medium for improved production using banana peels as a source of carbon and different nitrogen sources at different concentrations and the factorial experiment was carried out using a completely randomized design <b>Results:</b> The highest dry weight and polysaccharides production and protein content have been achieved for the fungus <i>T. reesei</i> with rates of (2.15, 0.276 and 0.94) g/100 mL, respectively, in comparison with the other treatments, the use of ammonium phosphate at concentration 0.6 g L¹ has given the highest dry weight and production of polysaccharides and protein content with rates of (3.75, 0.364 and 2.77) g/100 mL, respectively, also the use of banana peels extract at concentration 40 mL L¹ has given the highest dry weight and production of polysaccharides and protein content with rates of (5.21, 0.539 and 3.63) g/100 mL, respectively. <b>Conclusion:</b> The possibility of using the local isolate of <i>T. reesei</i> in the production of polysaccharides and Single-cell protein using some cheap agricultural waste such as banana peels as a carbon source instead of throwing them as waste and pollutants for the environment.

Bio-sorption of a bi-solute system of copper and lead ions onto banana peels: characterization and optimization.

PURPOSE: Banana peel was used as a low-cost adsorbent for the removal of Cu and Pb ions from aqueous solution in a binary system. METHODS: The interactive effects of the operating parameters such as initial concentration, pH, adsorbent dosage and particle size were studied in a batch mode using central composite design. The characterizations of banana peels were done using point of zero charge (pHpzc), Fourier infrared transform (FTIR), scanning electron microscopy (SEM) and elemental composition (EDS). RESULT: The point of zero charge of banana peels was determined to be 4.83. The FTIR, SEM and EDS showed the functional groups, surface morphology and elemental composition respectively before and after the adsorption process. The analysis of variance (ANOVA) showed a good fit of coefficient of determination (R2) for Cu and Pb being 0.998 and 0.988 respectively. The percentage removal of Cu and Pb increased with increasing adsorbent dosage, however, the bio-sorption capacity of Pb was greater than Cu. The optimized variable conditions for the bio-sorption of Cu and Pb using banana peel gave 99.79% and 88.94% removal for Pb and Cu respectively with initial concentration of 100 mg/L, pH 5, adsorbent dosage of 1 g and particle size of 75 µm. The above condition gave desirability of 0.959, which denotes that the optimum conditions are acceptable. CONCLUSION: The regression model and the agreement between the experimental and predicted values confirmed the validity of second-order polynomial equation for the bio-sorption of Cu and Pb using banana peels. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40201-021-00632-x.

Evaluation of the physicochemical properties of pectin extracted from Musa paradisiaca banana peels at different pH conditions in the formation of nanoparticles.

Colombia is one of the major producers and exporters of banana Musa paradisiaca. Its consumption is high then its agro-industrial wastes are important source to extract pectin. In the present study, inorganic acids (nitric acid and hydrochloride acid) and organic acids (citric acid and acetic acid) were evaluated to extract pectin from banana peels at pH 2 and 3, through acid hydrolysis during 1h at the temperature of 85 °C. The extraction yield, degree of esterification (DE) and intrinsic viscosity of the pectin were characterized. Nitric acid (NA) allowed to obtain higher extraction yield (54 ± 10%) and citric acid (CA) allowed to obtain higher DE (76.7 ± 2%). Additionally, the effect of polymer concentration and degree esterification, low degree of esterification (LDE, 33.1%) and high degree of esterification (HDE, 76.7%) were evaluated in the pectin nanoparticles formation. The pectin with HDE formed stable nanoparticles with a particle size of 255 ± 11 nm and the zeta potential value of -45 ± 3 mV, independently of the polymer concentration. Morphology analysis showed aggregated of the pectin nanoparticles.

Development of antioxidant chitosan film with banana peels extract and its application as coating in maintaining the storage quality of apple.

In the present study, the antioxidant chitosan (CS)-banana peels extract (BPE) composite film was developed. The different content of BPE (4%, 8% and 12%) was added to the CS film not only as the antioxidant but also as the cross-linking. The CS, CS-4% BPE, CS-8% BPE and CS-12% BPE films were characterized by scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD) and thermogravimetric analysis (TGA). The physical and mechanical properties possessed by the CS and CS-BPE films were compared as well, and the CS-4 %BPE composite film exhibited the most excellent properties. The decline in moisture contents, water solubility and water vapor permeability of CS-BPE composite film indicated the reduced hydrophilicity. Moreover, the CS-BPE composite film exhibited excellent antioxidant activity in different food simulants. Finally, the optimal concentration of CS-BPE coating treatment was identified and applied to apple fruit, and the results showed that CS-BPE coating was more capable of improving the postharvest quality of apple fruit than CS coating. This study evidences the promising nature of CS-BPE composite film and coating as a desirable alternative for active packaging and it is believed as conducive to valorization of banana peel by-products for allied applications.

Valorization of agricultural wastes could improve soil fertility and mitigate soil direct N2O emissions.

The emerging need for sustainable management of the increasing quantities of urban and industrial organic wastes creates opportunities for the development of alternative strategies for the improvement of degraded soils. The current study was performed to examine the effects of agricultural wastes application on soil bacterial community as well as CO2 and N2O direct gas emissions. Untreated soils were compared with soils, which received the same amount of N (100 µg/g soil) in the form of ammonium nitrate and organic agricultural waste. In particular, soils were incubated with three different organic agricultural wastes, orange (OP), mandarin (MP) and banana peels (BP) and ammonium nitrate (F) after adjusting soil water at 70% of its holding capacity. In the current study, soil chemical characteristics, quantitative PCR of denitrifiers (nirK, nirS, nosZI and nosZII) and16s rRNA amplicon sequencing were assessed to examine the links between the soil microbial communities and short-term soil direct N2O emissions when treated with agricultural wastes. The highest soil direct N2O emissions were recorded in soils received ammonium nitrate while soils received agricultural wastes exhibited substantially lower soil direct N2O emissions. On the contrary, agricultural wastes stimulated CO2 accumulation as well as the growth of copiotrophic bacterial groups like Proteobacteria and Firmicutes. Interestingly, direct soil N2O emissions were decoupled from the density of denitrifier community while agricultural wastes caused a substantial reduction of the relative abundance of bacterial taxa associated with N2O emissions in the soil. This study proves evidence that agricultural wastes could be integrated in a waste management strategy, which inter alia includes their direct use in agricultural ecosystems resulting in reduced N2O emissions.

Utilization of extracts of Musa paradisica (banana) peels and Dolichos lablab (Indian bean) seeds as low-cost natural coagulants for turbidity removal from water.

In this study, aqueous extracts of Musa paradisica (banana) peels and Dolichos lablab (Indian beans) seeds were prepared and tested as natural coagulants for turbidity removal from simulated turbid water. Effects of extraction time (15, 30, and 45 min), dosage (0.2 to 1.0 mL/L), and water pH on turbidity removals by the natural coagulants were evaluated. In both cases, the extraction time of 45 min for the preparation of aqueous extract and dosage of 0.6 mL/L gave the best results in terms of turbidity removal. Natural coagulants from M. paradisica peels powder could efficiently remove turbidity (> 83%) at all tested pH values (3.0 to 12.0) with maximum turbidity removal of 98.14% at pH 11. In the case of D. lablab seeds, low turbidity removal (71-74%) was observed at pH between 5.0 and 9.0. The maximum turbidity removal (98.84%) was obtained at pH 11. The scanning electron microscopy (SEM) analysis of the settled flocs revealed that more compact flocs formed using M. paradisica peels extract than those developed using D. lablab seeds extract. The chemical analysis and Fourier transform infrared (FTIR) spectroscopy of the extracts revealed that polymeric substances (carbohydrate and proteins) having functional groups -OH, C-N, C-C, -COOH, and N-H might be responsible for the coagulation activity. The zeta potential measurements of natural coagulants revealed that the possible coagulation mechanism would be adsorption and bridging between particles. This study demonstrated the potential use of aqueous extracts of M. paradisica peels and D. lablab seeds as low-cost natural coagulants for turbidity removal.

Characterization of pectin extracted from banana peels of different varieties.

Pectins were extracted from banana peels of five different varieties using citric acid solution. The chemical characteristics of banana peel pectins were investigated and compared with citrus peel and apple pomace pectins which were extracted under the same extraction conditions to assess the potential of banana peels as an alternative source of commercial pectin. The yield of banana peel pectins ranged from 15.89 to 24.08%. The extracted banana peel pectins were categorized as high methoxyl pectin with the degree of esterification between 63.15 and 72.03% comparable to those of conventional pectin sources from citrus peel (62.83%) and apple pomace (58.44%). The anhydrouronic acid (AUA) content of banana peel pectins varied from 34.56 to 66.67%. Among various banana varieties being studied, pectin from Kluai Nam Wa variety had the highest AUA content (66.67%) which met the criteria for food additive pectin indicating its commercial significance as an alternative pectin source.