Key Engineering Materials Vol. 840

Abstract: Crude laccase was produced by using the fermentation method of solid state fermentation and employed fungus Marasmius sp and rice straw as support media. The kinetics of laccase was investigated by using the substrate of 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). Laccase exhibits the maximum activity (V_m) of 1.45 mM/min and Michaelis-Menten (K_m) constant value of 4.11 mM. The effect of pH and temperature has also been evaluated. The results showed that this enzyme had an optimum pH of 4.6 and temperature of 60 °C. Decreased stability of laccases is found to be faster when stored at room temperature than cold temperatures.

Abstract: The aim of this research was to determine the host status of various species of plants and wild plants against Ditylenchus dipsaci. The research was carried out by conducting a survey and collecting sample at Central Java garlic centers situated in Magelang, Temanggung, Brebes, and Tegal. The host range of this nematode was diagnosed using a root painting method called the Byrd method. Nematodes in the root tissue were observed and calculated using compound microscope at 100x magnification and their images were captured using an optilab. The results showed that Allium sativum, A. cepa, A. porrum, Brassica oleracea var. botrytis, B. oleracea var. italica, B. chinensis var. parachinensis, Lactuca sativa, Zea mays, Capsicum frutescens, Apium graveolens, Cucumis sativus, Solanum tuberosum, Daucus carota are positively the hosts of D. dipsaci. Whereas B.oleracea var. capitata, Ipomea batatas, Colocasia esculenta are not the host of D. dipsaci. D. dipsaci also attacked to weed of Ageratum conyzoides. Grangea maderaspatana, Eleusine indica, Synedrella nodiflora are not the host of D. dipsaci. Lumbu Putih, Sangga Sembalun, and Lumbu Kuning varieties are good hosts for D. dipsaci. Tawangmangu Baru is a variety that is not suited for D.dipsaci.

Abstract: Chitosan is a long linear chain polymer that has biodegradable properties. Chitosan can be found naturally in marine and terrestrial environments. However, chitosan as an edible film has brittle and weak properties. Therefore, addition of plasticizers such as polyethylene glycol and also emulsifiers such as carboxymethylcellulose (CMC) could improve the chitosan properties. In this study, the potency of modified chitosan as an edible film will be tested as an Insect Ovipositing Repellent (IOR) against B. carambolae fruit fly, which is known as one of the main pests on fruits in Southern East Asia. Chitosan-based films plasticized with polyethylene glycol, emulsified with carboxymethylcellulose and lemongrass oils as essential oils were prepared. Then the films was characterized; intermolecular interactions were determined by Fourier-transform infrared spectroscopy (FT-IR), surface morphology was observed by scanning electron microscopy (SEM), and the mechanical properties such as elongation, tensile strength, the thickness was tested using universal testing machine (UTM). Guava (Psidium guajava L), as a sample was used for testing the potential of chitosan film as IOR against the B. carambolae fruit fly. The addition of CMC and lemongrass oils to the chitosan/PEG films increased tensile strength and reduced elongation at break of the blended films. The best film resulted from composite of Chitosan/PEG/CMC/Lemongrass oil with a ratio of 1%/0.5%/0.1%/2%, and it is active as fruit fly repellent with IOA and ER of -0.745 and 85.412%, respectively.

Abstract: A hybrid greenhouse effect dryer was examined for small-medium cracker industries. The system consists of a main drying chamber, biomass stove, heat exchanger, and shelf. This work aims to construct heat and mass transfer model which can describe well the drying process, as well as can be used to predict the greenhouse air temperature, product temperature, and moisture evaporation during drying. Drying is conducted in the room dryer for 9 samples of crackers where each sample is ± 150 grams and is divided into 3 samples placed on the bottom shelf, 3 samples on middle shelf, and 3 samples on the top shelf. Drying is carried out from the initial moisture content of crackers ± 63‒64% to 12‒14% for the standard fries. Mathematics model was simulated in MATLAB software and was validated by comparing the analytical and experimental result. The heat transfer model could describe well the heat transfer process during drying. It was shown that the analytical and experimental results are in good agreement, with mean error range values 5.38‒20.4%.

Abstract: Bioplastic composites of carboxymethyl cellulose (CMC) and N-P-K fertilizer have been prepared at various amount of N-P-K. The bioplastics were prepared by solvent casting the sol precursors containing 10 to 50% (wt.%) commercial N-P-K fertilizer powder in petri dishes. Characterization was done by using infrared spectrophotometer to access the functional groups, XRD to evaluate the crystalline phase, and universal testing machine to determine the mechanical properties. The nitrogen and phosphorus contents were determined by UV-Vis spectrophotometer, while the potassium content was determined by using atomic absorption spectrometer. The results show that the bioplastic composites of CMC/N-P-K fertilizer can be prepared up to 40% (wt.%) of N-P-K powder without losing its plasticity. The mechanical properties of the resulted bioplastic composites decrease at high content of N-P-K powder, with the highest at 25 wt.%. The uptake of nitrogen and phosphorous was not affected by the amount of the N-P-K powders precursor, but the potassium was. Various possible interactions between N-P-K powder and CMC matrix allow the resulting composite to function as a controlled release of N-P-K fertilizer.

Abstract: Sugarcane (Saccharum officinarum L.) is an agricultural commodities with a great extent of diversity and high economic value. In Indonesia, the great extent of diversity of sugarcane is evidenced by a large number of cultivars cultivated. Sugarcane diversities at the molecular level can be seen using DNA barcodes, one of which is the matK. The purpose of the study was to identify and characterize matK and reconstruct the phylogenetic tree to determine the phylogeny of 24 sugarcane cultivars Indonesia. matK was amplified using the PCR method with matK F-5’ATGATTAATTAAGAGTAAGAGGAT-3’ and matK R-5’AATGCAAAAATTCGAAGGGT-3. Results showed that the matK gene was successfully amplified as many as 1531 bp. The sequencing process was done to determine the nucleotide sequence and compared with those of the GenBank database. It showed that the samples used had a similarity of 98.87%-99.44% to that of matK in Saccharum officinarum, Saccharum hybrid cultivar and Saccharum spontaneum. Reconstruction of the phylogenetic tree showed that the samples used were located in the same clade with a zero genetic distance, while all the references from NCBI were also located in the same clade. The analysis of genetic variation indicated that it had no haplotype value.

Abstract: The hydrothermal extraction was carried out in a semi-batch extractor at a temperature of 160°C, a pressure of 7 MPa, and a water flowrate of 1 mL/min. Electrospraying was conducted at various voltages of 12, 14, and 16 kV, various distances between tip and collector of 6, 8 and 10 cm, precursor solution flow rate of 0.05 mL/h, and PVP concentrations of 6 and 8%, Particles obtained from electrospraying process were analyzed by SEM, FTIR, and spectrophotometer. The antioxidant efficiency (AE) of the particles was also examined. Based on the results, the morphology of particles was spherical with diameter less than 3 µm. The highest value of AE was 0.1058 min^-1 that indicated that Gracilaria sp extract in the particles produced by electrospraying has good antioxidant activity. In the FTIR analysis, carrageenan and flavonoids were contained in the particles. The result indicated that hydrothermal extraction followed by electrospraying process could be one alternative process for obtaining the best phytochemical particles.

Abstract: This article is about extracting the oil from Calophyllum inophyllum L using microwave hydrodiffusion gravity method (MHG). It mainly studies the effect of material size, microwave time, and microwave power on the extraction yield. The experiment shows that the factors which influence the extraction rate are microwave time, microwave power, and material size. The maximum condition for extraction oil using MHG method is 800 W in 20 minutes and the material size is 2 cm to give oil in 0.575% yield.

Abstract: Extraction of Allium sativum L. using Solvent-Free Microwave Extraction (SFME) without the addition of solvents in the process has been carried out. SFME is an alternative technique and method to produce essential oil and it has several advantages in terms of product quality. In this study, the essential oil was extracted from Allium sativum used extraction time from 10 to 90 min and microwave power in the range of 300-600 W. The result showed that SFME could produce the highest yield of 0.2636 g oil/100 g fresh garlic at 450 W and 90 min. In addition, the kinetic study of SFME model appears to be the best fit to explain with second-order than first-order model. It was proved by a good correlation between the experimental data and model achieved (R2>0.99) and (RMSE=0.0021). Based on the results obtained, second-order kinetic models could actually describe the kinetics model of extraction process from Allium sativum L. using SFME.

Abstract: Fucoidan is a sulfated polysaccharide which is mainly found in brown seaweed like Sargassum sp. In this study, fucoidan was extracted with two distinct methods, one was using 0.1 N HCl (Fucoidan A) and the other 0.1 N H₃PO₄ (Fucoidan B). The yield of HCl extraction was respectively 7.50% and H₃PO₄ extraction 7.02%. Characterization of crude fucoidan was carried out through fourier-transform infrared spectroscopy (FTIR), followed by total carbohydrate and total sulfate level measurement. Crude fucoidan was then used to determine its binding activity against Trichothecenes T-2 toxin. Quantitative analysis of 50 ug/ml T-2 toxin binding capacity shows an efficiency of 59.52% at pH 3.0 and 58.37% at pH 6.8 for crude fucoidan A. As for crude fucoidan B, efficiency of T-2 toxin binding capacity has value of 58.12% at pH 3.0 and 57.33% at pH 6.8. Meanwhile, Commercial crude fucoidan extract from Fucus vesiculosus sp. was used as control for T-2 toxin binding capacity analysis with efficiency of 57.31% at pH 3.0 and 56.64% at pH 6.8. Therefore, fucoidan from Sargassum sp. can be utilized better as mycotoxin especially T-2 toxin binder than from Fucus vesiculosus sp. through efficiency result of fucoidan binding capacity.