The ultrafiltration membrane process is widely used for fruit juice clarification, yet the occurring of fouling promotes a decline in process efficiency. To reduce the fouling potential in the membrane application in food processing, the use of natural phenolic compounds extracted from cocoa pod husk is investigated. The cocoa pod husk extract (CPHE) was prepared in phenolic nanoparticles form and added into the polymer solution at varying concentrations of 0.5 wt%, 0.75 wt%, and 1.0 wt%, respectively. The composite membrane was made of a cellulose acetate polymer using DMF (dimethylformamide) and DMAc (dimethylacetamide) solvents. The highest permeability of 2.34 L m−2 h−1 bar−1 was achieved by 1.0 wt% CPHE/CA prepared with the DMAc solvent. CPHE was found to reduce the amount of Escherichia coli attached to the membranes by 90.5% and 70.8% for membranes prepared with DMF and DMAc, respectively. It is concluded that CPHE can be used to control biofouling in the membrane for food applications.

The crab (Portunus pelagicus) shell is a marine biowaste produced by seafood industries. Traditionally, crab shells were collected to be converted into animal feed, however many of them are disposed of as industrial waste. A conversion of crab shells into hydroxyapatite is a better option for producing high-value biomaterial. Hydroxyapatite materials can be used as slow-release fertilizer while combining them with traditional fertilizer or as a stand-alone green fertilizer with high phosphatic content. Prior to hydroxyapatite conversion, the size reduction of crab shells is required. In this study, crab shell powder is derived from dried crab shell with the water content is approximately 10% wb. The size reduction is processed by using a customized batch type ball mill. This study is aiming at determining the kinetic model of milling parameters for crab shell milling by using the ball mills. An amount of 1.5 kg of dried crabs shell was milled by using 3-size mixed metal balls. The powder was then analyzed its particle size, and the particle size is used as an input in the mathematical model. The computational study focused on the calculation of optimal rotational velocity and kinetic model during the milling process. The kinetic model was based on Population Balance Equation of the mass balance principle, and the results are compared with experimented data characterized by particle size analyzer. It is observed that there are discrepancies between the model and experimental data due to the characteristic of raw materials; however the kinetic model can be used as a prediction of particle size reduction using the ball mill without conducting the real experiment.

<p>Teknologi membran merupakan teknologi yang dapat memisahkan dua fasa (permeat dan umpan). Kendala dalam teknologi membran yaitu bahan yang terkandung dalam umpan dan mengakibatkan terjadinya <em>fouling</em> (penutupan pori). Salah satu alternatif untuk mengurangi <em>fouling</em> yaitu menambahkan zat <em>antibiofouling </em>pada membran. Bahan yang dapat digunakan sebagai antibiofoulan alami adalah ekstrak bawang putih yang memiliki sifat antibakteri. Penelitian ini bertujuan untuk menganalisis pengaruh penambahan ekstrak bawang putih terhadap perbaikan karakteristik membran (ketebalan, kuat tarik, elastisitas), fluks air bersih, dan sifat <em>antibiofouling</em> pada bakteri <em>Bacillus subtilis</em>. Membran selulosa asetat dibuat dengan menggunakan metode inversi fasa dan pelarut dimetilformamida. Penambahan ekstrak bawang putih pada pembuatan membran selulosa asetat memiliki konsentrasi masing-masing sebesar 0,25% b/v (0,01 g), 0,5% b/v (0,02 g), 0,75% b/v (0,03 g), dan 0% b/v (kontrol) dengan ketebalan 0,3 mm. Hasil yang optimum diperoleh untuk membran dengan konsentrasi 0,5 % b/v yang menghasilkan pengujian kuat tarik sebesar 0,977 N/mm²dan untuk membrane dengan konsentrasi 0,25% b/v yang memberikan elastistas pertambahan panjang sebesar 12,22%. Sifat antibakteri membran dengan penambahan ekstrak bawang putih ditunjukkan dengan berkurangnya penempelan bakteri <em>Bacillus subtilis </em>pada permukaan membran sebesar 41,5% – 87,7% area.</p><p><strong>Synthesis and Characterization of Cellulose Acetate Membrane with The Addition of Natural Antibiofouling Garlic Extract<em>.</em></strong><em> </em>Membrane technology is a technology that can separate two phases (permeate and feed). The main problem in membrane technology is the material contained in the feed, which causes fouling (pore closure). An alternative to reducing fouling is by adding anti-biofouling substances into the membrane. The material that can be used as a natural anti-biofoulant is garlic extract which has antibacterial properties. This study aimed to analyze the effect of adding garlic extract on the improvement of membrane characteristics (thickness, tensile strength, elasticity), clean water flux, and anti-biofouling properties of Bacillus subtilis bacteria. The cellulose acetate membrane was synthesized using dimethylformamide as solvent through the phase inversion method. The addition of garlic extract in the manufacture of cellulose acetate membranes had concentrations of 0.25% w/v (0.01 g), 0.5% w/v (0.02 g), 0.75% w/v (0.03 g), and 0% w/v (control) with a thickness of 0.3 mm. The optimum results were obtained for the membrane with a concentration of 0.5% w/v, which resulted in the tensile strength test of 0.977 N/mm², and the membrane with a concentration of 0.25% w/v, which resulted in an elongation elasticity of 12.22%. The antibacterial properties of membranes with the addition of garlic extract were indicated by the adhesion reduction of <em>Bacillus subtilis</em> bacteria on the membrane surface by 41.5% – 87.7% area.</p>

Membrane technology provides advantages for separating and purifying food materials, including juice clarification. Ultrafiltration processes for fruit juices aim to remove haze components and maintain the stabilization of the juices. However, the membrane process during the clarification of fruit juices suffers from fouling, which deteriorates the process performance and products. Biofouling usually is found in the applications of the membrane in food processing. In this study, phenolic substances extracted from garlic bulbs are incorporated into a matrix of polymeric membranes to prevent fouling during juice clarification. Hydrophilic cellulose acetate was used as the polymer matrix of the membrane, and dimethylformamide was used as the solvent. The phenolic substances from garlic bulbs were incorporated into polymer solutions with different concentrations of 0%, 1%, 1.25%, and 1.5% w/v. The composite membrane was prepared using the phase inversion method, and the resulting membranes were later characterized. The results show that incorporating those phenolic compounds as the dope solution additive resulted in membranes with higher hydrophilic properties. They also modeled antibacterial properties, as shown by the reduced attachment of Bacillus subtilis of up to 91.5 ± 11.7% and Escherichia coli of up to 94.0 ± 11.9%.

The purification and concentration of orange juice are crucial to remove undesirable materials, such as pectin, which is responsible for juice clouds; or limonene, which is responsible for bitter taste. Membrane-based juice clarification is preferred due to its capability to separate specific targeted molecules, while still maintaining the clarified juice’s nutritional content. In this study, a novel designed bench-scale plate-and-frame membrane module composed of low fouling cellulose acetate membrane sheets was manufactured to facilitate orange juice clarification. The experimental results demonstrated the effectiveness of the developed module to be used for juice clarification. After incorporating the functional and structural design parameters, the final module had the following specifications: dimensions of 125 × 168 mm, an effective volume of 0.9–9.4 L, a total active membrane area of 1088 cm2, and a transmembrane pressure of 0.3–0.55 MPa. The results of the juice clarification show no difference in the value of pH, viscosity, total acid, water content, color L* (brightness), and color a* (reddish) of the feed, the permeate, and the retentate streams. The clarified juice had slightly higher total dissolved solids (°Brix), ash content, vitamin C, and color (b* yellowish). Overall, our findings demonstrated that the developed plate-and-frame module could effectively be used to clarify orange juice without altering the quality, i.e., reducing the nutritional contents.