Durian Rind Research Articles

Extraction and Characterization of Microcrystalline Cellulose (MCC) from Durian Rind for Biocomposite Application

The scientific community has become interested in cellulose extraction from agro-industrial wastes because they contain large quantities of cellulose and are being researched globally due to their application. Cellulose extracted from these wastes offers varying characteristics and structures depending on the specific source. In this study, microcrystalline cellulose (MCC) was extracted from different parts of the durian husk through acid hydrolysis with various concentrations of oxalic acid and cellulose-to-acid ratios. The durian husk underwent a pretreatment method involving bleaching and alkaline treatment. The characteristics of MCC, such as functional group, morphology, and crystallinity, were studied. The findings indicated that lignin was successfully removed through pretreatment. However, traces of hemicellulose were still detected in a few samples. The extracted MCCs demonstrated a diameter range from 6.237 to 25.38 μm and crystallinity within the range of 71.43–78.30%. Polycaprolactone (PCL)-based biocomposites with different MCC weights (0.2, 0.5, and 1.0 wt%) were fabricated, and the performance was evaluated through tensile testing and biodegradability tests. The addition of 1.0 wt% MCC enhanced the tensile strength by 22%. SEM analysis revealed the cross-section fracture surface of the biocomposite, indicating the contribution of the MCC during pull-out. Meanwhile, the biodegradability of the biocomposite increased with the addition of MCC, indicating that the MCC-based biocomposite was fully biodegradable.

Durian rind pectin blended with nisin coating to preserve egg quality and reduce bacteria

In the absence of refrigerated storage, coating materials may offer effective alternatives for preserving egg shelf life. Durian rind, rich in pectin, seals eggshell pores, while nisin, a natural antimicrobial peptide, helps reduce bacteria. This study investigated the effectiveness of durian rind pectin combined with nisin to preserve egg quality and reduce bacterial contamination. Eggs were divided by treatment: (1) uncoated or control; (2) durian rind pectin coated; and (3) coated with durian rind pectin and nisin. All eggs were kept at room temperature (25–30 °C) for five weeks and evaluated weekly for weight loss, Haugh unit (HU), yolk index (YI), egg white pH, and total bacterial count on eggshells and egg content. Results were that durian rind pectin coating, with or without nisin, significantly reduced weight loss (8.5–8.7 % in coated eggs versus 10.5 % in uncoated eggs by day 35); maintained Grade A HU until day 28 (uncoated eggs dropped to Grade B by day 14); and preserved a higher YI with a lower egg white pH compared to uncoated eggs. The total bacterial count on eggshells was lowest in eggs coated with durian rind pectin and nisin (4.06 log10 CFU/mL), compared to durian rind pectin alone (5.15 log10 CFU/mL) and uncoated eggs (5.85 log10 CFU/mL) at day 35. These findings suggest that durian rind pectin coating may extend egg shelf life up to 28 days by maintaining a Grade A HU and an egg white pH under 9.2. Adding nisin enhances antibacterial activity, reducing bacterial count on eggshells.

Effect of feeding durian fruit peel in kacang goats on production performance and physiological parameters

The durian fruit (Durio zibethinus Murr.) peels can be used as animal feed. This study aimed to determine the effect of feeding durian fruit peel on body weight, feed conversion ratio and physiological parameters and reproduction performance of female kacang goats. The research method uses the 3 x 3 factorial randomized block design (RBD). The main components were dose D1 = ASP dose of 100 g/liter of water; D2 = ASP dose of 200 g/liter of water, and D3 = ASP dose of 300 g/liter of water, and the next variable is the soaking time, namely: P1 = Soaking durian rind for 24 hours; P2 = Soaking durian rind for 48 hours; and P3 = Soaking durian rind for 72 hours and each repeated four times as a group. The analysis of variance showed that giving durian fruit peels soaked in rice husk ash filtrate solution at different doses did not give a significant difference (p>0.05) in body weight gain, use of dry matter and the effectiveness of using proportions, breath waves and heartbeat waves of female kacang goats, but had a significant effect (p<0.05) on the edible carcass weight and very significant (p<0.01) on the non-edible carcass level of female kacang goat giving durian fruit peels by immersing rice husk ash filtrate solution with different soaking time variations had a significant effect (p<0.05) on body weight gain and productivity using the proportion of female kacang goats, did not have a large effect (p>0.05) on physiological parameters. Durian skin waste has the potential to be used as animal feed, has nutritional content, and can increase the body weight of kacang goats, but requires further processing such as soaking in a solution of rice husk ash filtrate.

NMR fingerprinting of depolymerised durian rind pectin and its antibacterial activity

This study investigated the effect of commercial sterilisation treatment (121 °C for 15 min) on durian rind pectin. The change of structure was observed by NMR (nuclear magnetic resonance) and the antibacterial activity was assessed by microdilution method to obtain the minimum inhibitory concentration (MIC) value. NMR spectra revealed the rhamnogalacturonan-I and homogalacturonan structure, with lower methyl-ester in sterilised pectin. Native pectin was unable to inhibit Escherichia coli and Staphylococcus aureus at the highest tested concentration (MIC > 25 mg/mL), but sterilised pectin showed inhibitory effect against E.coli (MIC 12.5 mg/mL) and S. aureus (MIC 6.25 mg/mL). Membrane filtration to obtain fraction < 20 kDa enhanced the inhibition against S. aureus further, but not for E.coli. The antibacterial effect was possibly correlated to the decrease of molecular weight (MW) and degree of esterification (DE) of durian rind pectin. E. coli was more resistant to pectin than S. aureus.

Tropical Fruit Waste Management: Developing Pectin-based Biopolymer from Durian Rind (Durio zibethinus)

Durian (Durio zibethinus) is a popular native tropical fruit and is largely produced in Southeast Asia. In Indonesia, 1.71 million metric tons of durian were produced in 2022. However, this high production may lead to organic waste issues due to the large amount of durian rind generation. About 60 – 75% of the durian is the rind, which is mostly discarded, hard to be decomposed, and not utilized optimally. Meanwhile, the durian rind poses as a potential reservoir containing high concentrations of cellulose and pectin. Therefore, this research aimed to (1) extract pectin content from durian rind and (2) synthesize and characterize pectin-based biopolymer films. First, the pectin was extracted from dried durian rind powder using acid extraction and alcoholic precipitation methods. Then, biopolymer synthesis was done by mixing formulations of pectin, chitosan, ethylene glycol, and glycerol solutions to form thin films. About 0.13 – 0.71 g of pectin (0.46% of the pectin yield) was extracted per 100 g of dried durian rind powder. The FTIR spectroscopy results of the extracted pectin confirmed the presence of the O - H groups at 3327.83 cm-1, which indicated the pyranose ring, the main characteristic of pectin. Pectin-based biopolymer films were produced with thickness, transparency, and tensile strength of 0.01 – 0.07 mm, 7.40 - 40.50, and 1.26 – 2.69 MPa, respectively. The findings of the soil burial degradation test for biodegradability showed that the biopolymer experienced weight loss of up to 62% in 14 days. Considering the potential utilization of the durian rind for developing biopolymers as value-added bioproducts from agricultural biomass, tropical fruit waste management should be done properly in the future. This also can be offered as one of the alternative solutions for plastic substitution with proper development in the future.

The Organoleptic Evaluation of Chicken Meatball Preservation by Liquid Smoke Powder from Durian Rinds (Durio ziberthinus murr.)

Durian rind contains lignocellulosic biomass, such as cellulose, hemicellulose and lignin, which can be converted into liquid smoke powder. Thanks to the phenolic compounds and acetic acid in the smoke powder, it has antimicrobial effects and can be used as an alternative to food preservatives. The purpose of this study was to investigate the potential of liquid smoke powder from durian rind as a chicken meatball preservative through organoleptic analysis (aroma, texture and colour). Spray drying was used to convert durian rind liquid smoke into smoke powder, and two types of bacteria, Escherichia coli and Salmonella typhimurium, were used to test the antibacterial properties of the smoke powder. Organoleptic test data were analysed using the SPSS version 16 and one-way ANOVA, followed by the least significant difference (LSD) test. The results of antibacterial tests on the E. coli and Salmonella bacteria indicated that the smoke powder had an inhibition zone of 10.55 ± 1 and 8.130 ± 12 mm, respectively. The organoleptic evaluation of aroma, texture and colour suggested that the meatballs could be preserved for 64 h. Meanwhile, the pH test results indicated that the meatballs could only be stored for 60 h.

PENGARUH KOMPOS KULIT DURIAN DAN NPK ORGANIK TERHADAP PRODUKSI TANAMAN PARE (Momordica charantia L.)

The Effect of Compost Durian Peel and Organic NPK on the Production of Bitter Gourd (Momordica charantia L)”. The purpose of this study was to determine the interaction effect as well as the main effect of durian rind compost and organic NPK on bitter melon production. The research was carried out on the agricultural land of the Food Crops Seed Center, Kuantan Singingi Regency, Jalan Perintis Kemerdekaan KM 2, Pulau Godang Village, Kuantan Tengah District, Kuantan Singingi Regency. The study was conducted for 4 months, from December to March 2023. This study used a factorial Completely Randomized Design consisting of 2 factors, namely the first factor of durian peel compost (K) consisting of 4 treatment levels, namely 0, 1, 2 and 3 kg per plot. The second factor was the dose of Organic NPK (N) which consisted of 4 treatment levels, namely 0, 5, 10 and 15 gram plants. Parameters observed were flowering age, harvesting age, number of fruit per plant, fruit weight per plant, fruit weight per fruit, largest fruit diameter, longest fruit length and number of remaining fruit. Observational data were analyzed statistically and continued with the BNJ test at the 5% level. The results showed that the interaction of durian rind compost and Organic NPK significantly affected the parameters of flowering age, harvesting age, number of fruits per plant, fruit weight per plant, fruit weight per fruit and longest fruit length. The best treatment was a dose of 3 kg of durian peel compost per plot and 15 grams of organic NPK per plant. The main effect of real durian peel compost on all observation parameters. The best treatment is durian peel compost at a dose of 3 kg per plot. The main effect of real organic NPK on all observation parameters. The best treatment is Organic NPK with a dose of 15 grams per plant.

Modification of cellulosic adsorbent via iron-based metal phenolic networks coating for efficient removal of chromium ion

Surface modification of durian rind cellulose (DCell) was done by utilizing the strong coordination effect of polyphenol-based metal phenolic networks (MPNs). MPNs from Fe(III)-tannic acid (FTN) and Fe(III)-gallic acid (FGN) were coated on DCell via a self-assembly reaction at pH 8, resulting in adsorbent composites of FTN@DCell and FGN@DCell for removal of Cr(VI). Batch adsorption experiments revealed that FTN coating resulted in an adsorbent composite with higher adsorption capacity than FGN coating, owing to the greater number of additional adsorption sites from phenolic hydroxyl groups of tannic acid. FTN@DCell exhibits an equilibrium adsorption capacity at 30°C of 110.9 mg/g for Cr(VI), significantly higher than FGN@DCell (73.63 mg/g); the adsorption capacity was increased at higher temperature (i.e., 155.8 and 116.8 mg/g at 50°C for FTN@DCell and FGN@DCell, respectively). Effects of pH, adsorbent dose, initial concentration, and coexisting ions on Cr(VI) removal were investigated. The kinetics fractal-based model Brouers-Sotolongo indicates the 1st and 2nd order reaction for Cr(VI) adsorption on FTN@DCell and FGN@DCell, respectively. The isotherm data can be described with a fractal-based model, which implies the heterogeneous nature of the adsorbent surface sites. The Cr(VI) adsorption via surface complexation with phenolic hydroxyl groups was confirmed by evaluating the functional groups shifting. FGN@DCell and FTN@DCell were found to have good reusability, maintaining over 50 % of their adsorption efficiency after four adsorption-desorption cycles. Environmental assessment with Arabidopsis thaliana demonstrated their potential in eliminating the Cr(VI) phytotoxic effect. Thus, this study has shown the efficient and economical conversion of durian waste into environmentally benign adsorbent for heavy metal treatment.

Application of durian rind smoke powder to preserve chicken meatballs at room temperature

Smoke powder is a natural alternative to artificial preservatives for extending the shelf life of food products. This study assessed the use of smoke powder derived from durian rinds as a preservative for chicken meatballs. Durian rinds were pyrolyzed at 300 °C (T1), 340 °C (T2), and 380 °C (T3) to produce liquid smoke. After filtration to separate the remaining carbon, the resulting liquid smoke was purified by distillation at 190 °C and then converted into a smoke powder through the addition of maltodextrin and spray drying. The feasibility of smoke powder as a preservative for chicken meatballs was tested using total volatile base (TVB), total plate count (TPC), pH, and most probable number (MPN) tests for Escherichia coli. The findings demonstrated an upward trend in TVB, TPC, and MPN values over the storage duration. The TVB and TPC tests revealed that meatballs preserved with T3 smoke powder retained acceptable quality upon 64 h of storage. The MPN value of the T3 sample showed that E. coli bacterial contamination could still be tolerated up to 68 h of storage.

Development of Photosensitive Hydrogel-based 3-dimensional Bioprinting Using Locally Extracted Pectin From Durian Rind Waste and Cellulose for Pharmaceutical Application

Introduction: Hydrogels have gained prominence in a variety of fourth industrial revolution applications, including three-dimensional (3D) printing. However, there are limitations to 3D manufacturing, such as deformities in the final product. This is a significant obstacle to adopting this technology in the pharmaceutical industry, as printed products may have insufficient mechanical properties and a high brittleness, making further processing of these dosage forms problematic. The objective of this study is to produce a new 3D bioink from a mixture of locally produced pectin-based material from durian rind waste and cellulose-based material (pectin/cellulose hydrogel) and to partially characterize the bioink hydrogel. Methods: Four formulations of pectin/cellulose-based hydrogel (3:1, 3:2, 4:1, and 5:3 ratio of pectin/cellulose) from durian rind waste and carboxymethyl cellulose (CMC) powder, as well as cross-linking agents, were developed and evaluated using a rheometer to evaluate viscoelastic properties, FTIR Spectroscopy to identify compounds, and thermogravimetric analysis (TGA) to evaluate thermal stability. Results: All bioink formulations exhibit outstanding shear-thinning behavior suitable for 3D printing. The viscosity of edible ink increases as the pectin/cellulose concentration increases. The formulation of 3:1 pectin/cellulose has greater heat resistance than others (highest thermal stability with 21.69% of residual weight) and the lowest percentage of weight loss (76.18%). Conclusion: The study of a pectin/cellulose hydrogel mixture provides an attractive outcome for the creation of bioink due to the effective synthesis of 3D printing shapes that are both smooth and uniform.

Efek ekstrak etanol kulit dalam durian (durio zibethinus) terhadap Actinomyces sp. (Laporan Penelitian)

Background: Caries is a disease in the oral cavity that involves the hard tissue of the teeth, which is common in young and old people and causes pulpal necrosis. One of the treatments performed to treat pulpal necrosis is root canal treatment. Until now, research related to durian skin which is associated with antibacterial reactions against bacteria that cause root canal disease is still narrow. Objective: To assess the antibacterial effect of ethanol extract of skin durian on Actinomyces sp. as a root canal irrigant. Methods: True experimental design research was carried out using Actinomyces sp. bacteria were treated with concentrations of 35%, 30%, 25%, 20%, and 15% by microdilution method. Results: The ethanol extract of durian skin is the most effective in inhibiting the growth of Actinomyces sp. is 35% with an average colony yield of 0.2 x 106 CFU/ml. Conclusion: The ethanol extract of the durian rind which has the most effective antibacterial effect is at a concentration of 35%.

Analysis of The Effect of Durian Rind Texture on Sugar Content Using The Box-Counting Method

Durian is a popular fruit native to Southeast Asia, even labeled as the king of fruits. Currently, both fresh and processed durians have been very well received by the public in both local and export markets [1]. However, it is not uncommon for durians purchased in poor quality, such as bland taste, rotten, or immature [2]. Therefore, a method to identify the quality of durian is needed. One of the durian elements that can be used to identify its quality is the shape and texture of its outer skin. The object discussed in this paper is the relationship between the fractal dimensions of durian skin image and the sugar content of durian flesh. Its fractal dimensions are searched using the box-counting method. The box-counting method is used to calculate fractal dimensions with the fractal object placed in a box area. Then it is calculated by how many boxes are needed to cover all the fractal parts. The relationship was then analyzed using the coefficient of determination. The results of the analysis produce an R-Square value of 0,029333. The R-Square value obtained shows that the fractal dimension of the texture of the durian skin does not significantly affect the sugar content of the durian flesh.

Preparation of Porous Carbon Materials as Adsorbent Materials from Phosphorus-Doped Watermelon Rind

In this study, phosphorus-doped watermelon rind carbon material (WC-M) was prepared by a muffle furnace, and the adsorption performance of WC-M material to dyes was investigated. At the same time, the effects of dye concentration, pH, adsorption time, adsorption temperature, and other factors on the adsorption effect were investigated. In the experiment, a muffle furnace was used to carbonize the watermelon rind doped with phosphoric acid, which simplified the experimental operation. Regarding the results of SEM analysis, the surface structure of WC-M materials is diverse. Isothermal maps of nitrogen adsorption and desorption show that the material contains more microporous structures and exhibits more active sites. The experimental results show that WC-M materials show good adsorption properties against cationic dyes (malachite green, MG) and anionic dyes (active black, AB). The neutral condition is conducive to the adsorption of MG, and the alkaline condition is conducive to the adsorption of AB. The adsorption rate reaches a maximum in the initial stage of adsorption, the adsorption capacity reaches 50% of the total adsorption capacity within 10 minutes before the reaction, and then the adsorption capacity gradually decreases until the adsorption equilibrium. The adsorption mechanism was explored by the pseudo-first-order kinetic model, second-order kinetic model, and intraparticle diffusion model. At the same time, through the analysis of multiple isotherm models, the overall adsorption process followed the Langmuir isotherm model, the adsorption of MG was more inclined to monolayer electron adsorption, and the adsorption capacity reached 182.68 mg⋅g−1. The reusability of WC-M materials in MG and AB adsorption was discussed. At this time, the concentrations of AB and MG were 120 mg⋅L−1 and 150 mg⋅L−1, and after 10 h of desorption, the desorption rates of MG and AB reached 67.7% and 83.3%, respectively; after five adsorption–desorption cycles, the adsorption rate of MG was still 78.5%, indicating that WC-M materials have good recovery effect. At the same time, the use of watermelon rind as an adsorption material belongs to the high-value application of watermelon rind, which belongs to “turning waste into treasure” and will not pose a certain threat to the environment. This experiment is also suitable for durian rind, pineapple rind, and other “waste” biomass materials, and the experiment has certain generalizations.

FORMULATION A NATURAL COSMETIC SCRUB OF DURIAN HUSK (DURIO ZIBETHINUS MURR.) AND THE CHARACTERISTIC TESTS)

The high production of durian fruit gives an environmental problem if it is not used properly. Durian fruit skin contains flavonoids, phenolic compounds, saponins, and tannins which have antioxidant activity. Its antioxidant activity makes durian husk a candidate as a basic ingredient for natural cosmetics. Producing a formulation of scrub preparations as natural cosmetics based on the results of the characteristic test was the purpose in this research. Experimental research with a post-test design technique was carried out by making the changes of the concentration of durian husk as an active ingredient in the scrub preparations used in this study. The form of an oil-in-water cream scrub was used as the formulation in a change of concentration range of 1% (F1), 1.5% (F2), and 3% (F3) for each formula. Furthermore, the characteristic test was carried out which included organoleptic test, homogeneity test. pH test, viscosity test, spreadability test, and adhesion test. In this research also used statistica tests. The results showed that the best formulation is obtained from formulation 3 (F3) with a concentration of 3% durian rind. The characteristic test results include: stable organoleptic test for storage in terms of shape, color and odor; homogeneity test formed granules and there was no separation between the oil and water phases; Stable pH test according to skin pH at 5.05; spreadability test 7.3 cm; viscosity test 64 dPa.s; and 2.41 minutes of adhesion test. It pointed that all formulations fulfilled the requirements for topical scrubs in each characteristic test.

FORMULATION FOR MAKING HAND SANITIZER BASED ON DURIAN PEEL EXTRACT (DURIO ZIBETHINUS MURR) IN IMPROVING ANTIBACTERIAL ABILITY

Maceration using ethanol solvent was chosen in extracting durian rind which was then evaporated to obtain 50 grams of durian peel extract. The results of the phytochemical screening test showed that the durian rind contains tannin compounds as evidenced by the addition of Iron (III) chloride reagent to produce a black solution. In addition, durian peel also contains terpenoid compounds which have been proven using the Lieberman Burchard reagent so that a blackish brown ring is produced in the extract. The best hand sanitizer product formulation is 75 mL of 96% ethanol, 2 mL of glycerin, 3 mL of 3% hydrogen peroxide, 10 mL of distilled water and 10 mL of a 6% concentration of durian peel extract solution. The hand sanitizer product has a liquid form, has a clear brownish color, has a distinctive durian rind aroma with a pH around 6 indicating that the hand sanitizer is suitable for use. Concentration of 6% Durian fruit peel hand sanitizer has better antibacterial ability than other concentrations with a large inhibition zone of 12.4 mm which is categorized as a strong level as an antibacterial substance.

Effect of Durio zibethinus Murr. cv. Monthong Rind as a Dietary Ingredient in Feed on the Growth Performance and Disease Resistance Against Aeromonas hydrophila in Red Tilapia (Oreochromis niloticus x Oreochromis mossambicus)

Monthong durian is a durian species mainly cultivated in Thailand. The rind makes up about 60-75% of whole fruit and is often discarded. Here, we evaluated the effect of durian rind, specifically the inner white peel, as a supplement for a fish diet on the growth performance and disease resistance against Aeromonas hydrophila in Red Tilapia. Fish with an initial average weight of 42.68 ± 0.11 g were fed diets supplemented with durian rind at 0, 10, 15, and 20% for 140 days. Subsequent results showed that growth performance in terms of weight gain, average daily gain, length gain, and specific growth rates were not significant among treatments (P &gt; 0.05). In addition, the feed conversion ratio and survival rate of fish fed with diets supplemented with durian rind were also not significantly different from the control (P &gt; 0.05). After the 140-day feeding trial, fish were injected intraperitoneally with A. hydrophila, and the cumulative mortality was recorded for 14 days. The survival rate of fish-fed durian rind-supplemented diets at all levels was higher than that of the control. The highest survival rate and relative survival percentage were fish fed with 10% and 15% durian rind in the diet. Taken together, the white peel of the durian rind can be a potential fish feedstuff and can act as a natural antibiotic to improve fish resistance against A. hydrophila. Recommended level of durian rind supplementation is 10%-15% in the diet which will not affect growth but can enhance disease resistance to A. hydrophila.

Sustainable 3D printing of oral films with tunable characteristics using CMC-based inks from durian rind wastes

With the growing interest in environmentally friendly and personalized medicines, new concept for combining three-dimensional printing (3DP) with natural-based biomaterials derived from agro-food wastes has emerged. This approach provides sustainable solutions for agricultural waste management and potential for developing of novel pharmaceutical products with tunable characteristics. This work demonstrated the feasibility of fabricating personalized theophylline films with four different structures (Full, Grid, Star, and Hilbert) using syringe extrusion 3DP and carboxymethyl cellulose (CMC) derived from durian rind wastes. Our findings suggested that all the CMC-based inks with shear thinning properties capable of being extruded smoothly through a small nozzle could potentially be used to fabricate the films with various complex printing patterns and high structural fidelity. The results also demonstrated that the film characteristics and release profiles could be easily modified by simply changing the slicing parameters (e.g., infill density and printing pattern). Amongst all formulations, Grid film, which was 3D-printed with 40 % infill and a grid pattern, demonstrated a highly porous structure with high total pore volume. The voids between printing layers in Grid film increased theophylline release (up to 90 % in 45 min) through improved wetting and water penetration. All findings in this study provide significant insight into how to modify film characteristics simply by digitally changing the printing pattern in slicer software without creating a new CAD model. This approach could help to simplify the 3DP process so that non-specialist users can easily implement it in community pharmacies or hospital on demand.

Effect of acid type and concentration on the yield, purity, and esterification degree of pectin extracted from durian rinds

This current research aimed to investigate the effect of acid type and concentration on the yield, anhydrouronic acid content (AUA), and esterification degree (DE) of durian rind pectin by using three types of mineral acids (hydrochloric, sulphuric, and nitric acids) and three types of organic acids (citric, tartaric, and acetic acids) at five different concentration (0.0001, 0.001, 0.01, 0.1, and 1.0 M). The pectin yield (0.93–10.23%), AUA (41.64–80.58%), and DE (0.43–25.69%) were pronouncedly affected by the acid type and concentration during extraction. The results were affected by the strong-weak and protic nature of the acids. The pectin yield and DE decreased at higher acid concentrations (0.1, 1.0 M), with mineral acids giving a more significant effect. Additionally, mineral acids were more effective in extracting pectin with greater purity (AUA > 65%). In contrast, organic acids-extracted pectins had AUA < 65%, indicating poor purity. All pectins extracted were low-methoxyl pectin (LMP) with DE < 50%. Based on the results, mineral acids appeared to be more suitable for durian rind pectin extraction than organic acids due to their good yield and purity of LMP. The FTIR spectra showed that durian rind pectins were rich in homogalacturonan content. 0.001 M H2SO4 could be a promising extractant for commercial LMP production (DE = 20.11%) from durian rind, considering its satisfying yield (9.13%) and purity (AUA = 66.72%), in which the LMP could be a potential thickener and stabilizer for low-calorie foods and beverages.

Improving the non-destructive maturity classification model for durian fruit using near-infrared spectroscopy

The maturity state of durian fruit is a key indicator of quality before trading. This research aims to improve the near-infrared (NIR) model for classifying the maturity stage of durian fruit using a completely non-destructive measurement. Both NIR spectrometers were investigated: the short wavelength NIR (SWNIR) ranging from 450 to 1000 nm and long wavelength NIR (LWNIR) ranging from 860 to 1750 nm. The samples collected for experimentation consisted of four stages: immaturity, prematurity, maturity, and ripe. Each fruit was scanned at the rind position on the main fertile lobe (header, middle, and tail) and stem. The classification models were developed using three supervised machine learning algorithms: linear discriminant analysis (LDA), support vector machine (SVM), and K-Nearest neighbours (KNN). The analysis results revealed that the use of durian rind spectra only obtained between 83.15% and 88.04% accuracy for the LWNIR spectrometer, while the SWNIR spectrometer provided 64.73 to 93.77% accuracy. The performance of model increases when developing with combination between rind and stem spectra. The LDA model developed using a combination of rind and stem spectra provided the greatest efficiency, exhibiting 97.28% and 100% accuracy for LWNIR and SWNIR spectrometers, respectively. The LDA model is therefore recommended for obtaining spectra from smoothing moving average (MA) + baseline of rind position and when used in combination with the MA + standard normal variance (SNV) of stem spectra. The NIR spectroscopy indicated high potential for non-destructive estimation of the durian maturity stage. This process could be used for quality control in the durian export industry to solve the problem of unripe durian being mixed with ripe fruit.

Electrical Analysis of Fermented Durian Rinds

In this study, Durian rind wastes were fermented using Saccharomyces cerevisiae yeast to break the starch to be smaller sugar molecule. Then, the pH was analyzed using digital pH-meter. The voltage and electric current were analyzed using multimeter. The result showed that the lower the pH value the greater its voltage and its electric current. The pH value influenced by fermentation time. The longer the fermentation time the lower the pH value. The type of microorganism and the composition of durian rind wastes were also affected the pH value. In this study, the fermentation process was set for 24, 48, 72 hours, and the pH value was resulted in the basic range. The highest voltage is 0.094 volt and the highest electric current is 0.058 mA measured in pH 12.3.