Public health awareness is driving the increased demand for natural, low-calorie food products. This study aimed to evaluate the effect of stevia and cinnamon ratios on the physical, sensory, and microbiological characteristics of liquid sugar, as well as to identify the optimum formulation. Stevia extraction was conducted using a water-based heating method, while cinnamon was extracted using sonication. Results showed that increasing the proportion of cinnamon significantly elevated pH values (5.84 to 6.61), total dissolved solids (2.96 to 5.96 °Brix), viscosity (0.87 to 2.33 cP), and colour lightness (L*) of the formulated liquid sugar. All formulations were microbiologically safe, with Total Plate Count (TPC) <1 CFU/mL and negative results for E. coli. The F1 formulation (2 grams of stevia : 1 gram of cinnamon) was identified as the best treatment, providing an optimal balance between physical stability and sensory acceptance, particularly for the aroma attribute (score 5.25). This combination produces a stable functional sweetener, although cinnamon usage must be controlled to prevent bitterness from polyphenol compounds.
Scabies is an infectious skin disease caused by Sarcoptes scabiei and frequently complicated by secondary bacterial infections involving Streptococcus sp. and Staphylococcus sp. Lemongrass (Cymbopogon citratus) contains citral compounds effective as acaricides, ovicides, and antibacterial agents. Clove (Syzygium aromaticum) contains eugenol, which exhibits acaricidal, ovicidal, and antibacterial properties. This study aimed to evaluate the therapeutic potential of an herbal spray formulated from lemongrass and clove essential oil extracts against scabies under in vivo conditions. The experimental study employed five treatment groups with five replicates each. Twenty-five rabbits confirmed with S. scabiei infestation were allocated into: a positive control group (P+) treated with 5% permethrin cream, a negative control group (P–) receiving no treatment, and herbal spray treatment groups at concentrations of 2.5% (P1), 5% (P2), and 7.5% (P3), with essential oils combined at a 1:1 ratio. The herbal spray was applied twice daily for 14 days by uniform coverage of scabies lesions. Observations were conducted daily from day 0 to day 14, with data recorded on days 0, 7, and 14 using scab area reduction as the primary efficacy parameter. The results demonstrated that herbal sprays at 5% and 7.5% concentrations, which showed no statistically significant difference between them, achieved the greatest therapeutic outcomes with scab area reductions of 95.170% and 99.556%, respectively. These findings indicate that the lemongrass and clove herbal spray represents a promising, safer, and more effective alternative for scabies management.
The increasing demand for practical, nutritious, and locally sourced food products highlights the need to explore mangrove-based ingredients as functional alternatives in snack formulations. This study investigated the effect of Bruguiera gymnorrhiza fruit flour substitution on the sensory, physical, and chemical characteristics of snack bars to determine the most acceptable formulation based on the overall balance of product quality attributes. Four substitution levels (0%, 5%, 10%, 15%) were tested under a Completely Randomized Design (CRD). Sensory evaluation (n = 50), hardness testing, color measurement (L*, a*, b*, Hue°), proximate composition, caloric value, and carbohydrate content using the Luff–Schoorl method were conducted. The 5% substitution showed the most acceptable overall sensory performance, with the highest scores for color (3.28), aroma (3.24), and texture (3.31), although the control treatment showed the highest taste score. Increasing mangrove flour concentration decreased brightness and yellowness, while increasing redness due to enzymatic and Maillard browning. Hardness rose significantly, reaching 797.60 gf at 15%. The selected 5% formulation, identified as the most acceptable overall treatment, contained 23.79% moisture, 1.57% ash, 9.35% fat, 10.01% protein, 53.55% carbohydrate, and 342.46 kcal. Carbohydrate levels increased progressively across treatments. Overall, Bruguiera gymnorrhiza flour increased energy density while maintaining acceptable product quality, suggesting its potential as a sustainable local ingredient for snack-bar development.
Lactobacillus plantarum is one of the lactic acid bacteria that dominates during the natural fermentation of cassava. It can also be used as a single starter culture for cassava fermentation, producing modified cassava flour with improved physical and functional properties. As the main component of cassava flour, starch is expected to contribute to the changes that occur during fermentation. However, limited information is available regarding the effect of L. plantarum fermentation on cassava starch. This study aimed to determine the effects of inoculum concentration and fermentation time on the physical and functional properties of cassava starch fermented using L. plantarum. The experiment was arranged in a randomized complete factorial design with two factors: inoculum concentration (1, 2, and 3% v/v) and fermentation time (24, 48, and 64 hours). Scanning electron microscopy (SEM) images of the starch samples showed no changes in granule morphology. Statistical analysis demonstrated that neither inoculum concentration nor fermentation time significantly affected bulk density, water absorption capacity (WAC), oil absorption capacity (OAC), swelling power, or solubility at 65, 70, 75, 80, 90, and 95 °C. However, fermentation time significantly affected starch solubility at 85 °C (p < 0.05). These results indicate that starch may not be the only component influencing the physical and functional properties of fermented cassava starch.
Sweet corn based fermented beverages represent a promising innovation in cereal based products with potential as functional foods. However, the low lactose content in corn extract limits the growth of Lactic Acid Bacteria (LAB), thereby necessitating the addition of lactose sources from animal milk. This study aimed to evaluate the effect of buffalo milk addition on the physicochemical, microbiological, and sensory characteristics of a sweet corn based fermented beverage and to determine the optimal formulation. The study employed a completely randomized design with five levels of buffalo milk addition: 0%, 10%, 20%, 30%, and 40%. The parameters analyzed included ash content, protein content, fat content, titratable acidity, total LAB, and sensory properties. The results showed that buffalo milk addition significantly affected all measured parameters. Increasing buffalo milk concentration led to higher ash, protein, fat, titratable acidity, and LAB counts. However, none of the formulations met the minimum protein requirement specified by SNI 2981:2009. The formulation containing 30% buffalo milk was selected as the optimal treatment, as it provided the best balance among physicochemical properties, microbial quality, and sensory acceptability, although it did not yield the highest values for all parameters. The resulting product is more appropriately classified as a corn-based fermented beverage with buffalo milk addition and can be considered to partially meet the requirements of SNI 2981:2009.
The production of renewable energy from microalgal biomass offers a promising pathway to mitigate greenhouse gas emissions. This study compares the technical performance, economic feasibility, and carbon emissions of bioethanol and biogas production from Spirogyra sp. using SuperPro Designer 10.7. The results show that the technical performance is highly dependent on process configurations. The best-performing bioethanol scenario (E3-2: flotation–continuous fermentation) produced 537.37 kg/batch with an energy consumption of 41.81 MJ/kg . In comparison, the optimal biogas scenario (B1-1: mesophilic digestion–water scrubbing) yielded 1,026.56 kg/batch with a lower energy consumption of 7,614 MJ/kg . Techno-economic analysis revealed that all scenarios are currently economically unviable at the simulated scale due to negative Net Present Values (NPV < 0), despite some scenarios exhibiting positive Return on Investment (ROI). Biogas production demonstrated higher energy efficiency, while bioethanol offered a cleaner emission profile. An integrated biorefinery approach is recommended to improve overall economic viability and biomass conversion efficiency.
Fruit supply chains, especially for extremely perishable goods like snakefruit (Salacca zalacca), are intrinsically vulnerable to challenges that might compromise the quality, safety, and economic value of these products after harvest. Prior research has identified various risks and associated mitigation strategies; however, these studies are often fragmented, focusing on risk identification, efficiency assessment, or qualitative recommendations, and fail to offer a cohesive framework that quantitatively assesses risks under uncertainty while systematically ranking mitigation strategies among supply chain participants. This study employs a Fuzzy logic to assess risk levels amid uncertainty via likelihood-severity evaluation and utilize the Analytical Hierarchy Process (AHP) to methodically prioritize mitigation strategies and essential stakeholders within a multi-actor supply chain context. Data was gathered via interviews with 196 participants engaged in the supply chain, comprising farmers, suppliers, distributors, agro-industrial enterprises, and retailers. The data were subsequently validated by experts to ensure accuracy. The findings indicate that the primary issues are pests and diseases, insufficient inventory, fluctuating pricing, declining quality, and uncertainty regarding demand levels. The processes occurring post-harvest, during transportation, and in response to market fluctuations are the most vulnerable as a result of this. A comprehensive analysis revealed that distributors are the primary actors, succeeded by suppliers. This underscores the significance of maintaining the supply chain and ensuring the product quality is maintained. To ensure safety, it is advantageous to adhere to good handling practices (GHP), enhance transportation efficiency, and refine quality control techniques.
Natural cocoa powder needs to be processed with alkalizing technology to reduce acidity and darken the color to make it more suitable for industrial use. Two important factors that influence the alkalization process are temperature and duration time of the alkalization process. This research aimed to analyze the effect of temperature and duration time of alkalization process on changes in pH and color of alkalized cocoa powder. The research was designed using a completely randomized design, factorial 3x3, with 3 replications, where the first factor was the alkalization temperature (60, 80, and 100°C), and the second factor was the duration time of alkalization (15, 30, and 45 minutes). The results showed that alkalization was able to increase the pH and create a much darker color of cocoa powder, making it more suitable for industrial needs. The temperature and duration time, as well as the interaction of these two factors had a significant effect on the pH, L, a*, and b* values (p < 0.05). It was also obtained that the reaction rate constant (k) for pH was positive, while for the color components L, a*, and b* was negative, which meant that there was an increase in the pH value and a darkening of the color of cocoa powder during the alkalization process. Within the range of temperature and alkalization durations studied, the pH of the alkalized cocoa powder increased by 39.82-48.21%, compared with the natural cocoa powder. While L, a*, and b* decreased by 30.27-46.48%, 20.05-79.41%, and 22.23-71.21% compared to the natural cocoa powder, respectively. The k values for the analyzed parameters varied between -0.0342 - 0.0112 minute-1. Meanwhile, the A and Ea values were in the range of 0.03519 - 201.5220 minute-1 and 3.553 - 27.043 kJ.mol-1, respectively. The prediction equations for changes in pH and color components as a function of temperature and duration time obtained would be very useful for estimating the values of pH and color components of L, a*, and b* during the alkalization process.
Rice flour is a common ingredient in traditional food processing in Indonesia. Rice flour is commercially found in the market as white rice flour, and colorants are often added during processing. Traditionally, natural colorants are derived from plant sources, such as red pitaya (dragon fruit). Red pitaya is usually extracted and added separately to the dough. However, this practice is considered inefficient. Therefore, this study aimed to explore the impregnation of red pitaya’s pigments into rice flour and develop red-colored rice flour. Impregnation was carried out during the processing of rice grain into rice flour, specifically during soaking and milling, with varying soaking times (4, 8, and 12 hours). The results showed that pigment impregnation during soaking produced the best red-colored rice flour after soaking in the extract for 8 hours, with a moisture content of 10.9%; starch content of 68.5%; water-binding capacity of 232.14%; oil-binding capacity of 202.27%; and a particle size of 55.18 mm. Pigment impregnation during milling produced the best red-colored rice flour after 4 hours of soaking, with a moisture content of 12.3%, starch content of 76.6%, water-binding capacity of 206.45%, oil-binding capacity of 213.98%, and a particle size of 55.51 mm. The application of red-colored rice flour to rice paper shows that impregnation during soaking has a higher level of consumers’ acceptability, with a pink color and chewy texture, while impregnation during milling has a whiter color and a stiff texture of rice paper.
Robusta coffee (Coffea canephora) dominates coffee production in Indonesia. High caffeine content results in a bitter and less varied taste of robusta coffee, leading to its being economically inferior. To increase the value and quality of coffee, post-harvest processing can be modified, such as through honey processing, which involves fermentation. This study evaluated the physicochemical and microbial changes during fermentation, also comparing the honey-processed robusta green beans obtained from 24 and 48 hours of fermentation duration. Observations were conducted at each stage of the process, from pulping until the green bean coffee was obtained. Research parameters during fermentation included chemical tests (moisture, Aw, pH, total sugars, total phenolics) and total microbes count. Color testing (CIE lab) and additional chemical analysis, including total caffeine, were performed on the green coffee beans. Statistical tests were carried out using ANOVA (p<0.05) and Fisher’s test. The findings reveal that fermentation duration affects the microbial population, leads to changes in Aw, and results in a decrease in caffeine content in the resulting green beans.
Buah kecombrang (Etlingera elatior) merupakan salah satu tanaman yang dikenal memiliki manfaat sebagai pengawet dan penyedap makanan alami. Buah kecombrang memiliki kadar air sebesar 72% yang dapat menurunkan kualitas buah kecombrang. Fungsi buah kecombrang dapat dimaksimalkan melalui isotermal sorpsi air yang dapat digunakan untuk desain dan optimasi pengeringan, stabilitas masa simpan, penyimpanan, pengolahan, dan pengemasan. Pada penelitian ini, isotermal sorpsi air menggunakan metode gravimetri statis yang ditentukan pada rentang aktivitas air (aw) dari 0,063–0,843 pada tiga suhu yang berbeda (25, 35, dan 45 °C). Buah kecombrang menunjukkan kurva tipe Sigmoidal II dengan model Oswin sebagai model terbaik untuk adsorpsi dan desorpsi buah kecombrang pada tiga suhu yang berbeda. Batas fraksi air terikat primer, sekunder, dan tersier yang ditemukan pada buah kecombrang masing-masing sebesar 0,049; 0,127; 0,227 g/g (≃ 4,9% (aw < 0,201); 12,7% (aw 0,201 – 0,681); dan 0,227% (aw > 0,681)). Panas isosterik dan entropi menurun seiring dengan peningkatan kadar air kesetimbangan.
Salah satu komoditas pisang lokal yang menjadi ciri khas dari daerah Maluku adalah pisang tongka langit atau Musa troglodytarum L. Keunikan pisang tongka langit adalah memiliki tandan buah yang mengarah ke atas dan warna daging buah yang kuning sampai orange dengan kandungan beta karoten yang tinggi. Dalam upaya untuk memperpanjang umur simpan dan mempermudah penggunaannya maka buah pisang tongka langit dapat diolah menjadi tepung dengan menggunakan buah yang telah diperam sebagai bahan baku. Penelitian ini bertujuan untuk mengetahui karakteristik kimia, fisik dan fungsional dari tepung pisang tongka langit. Metode penelitian deskriptif dan ditampilkan dalam nilai rataan. Tepung pisang yang dihasilkan memiliki kadar air sebesar 7,30%, kadar pati sebesar 71,12%, kadar karotenoid kasar sebesar 0,44% dan nilai pH 5,4. Tepung pisang tongka langit yang dihasilkan memiliki nilai L* sebesar 81,25; a* sebesar 8,10 dan nilai b* sebesar 23,19, densitas Kamba tepung sebesar 0,58 g/mL, water holding capacity sebesar 2,29 g/g, oil holding capacity sebesar 1,23 g/g dan higroskopisitas sebesar 8,18%. Kandungan beta karoten tepung pisang tongka langit yang dihasilkan adalah sebesar 0,28 ppm. Kecernaan pati antara lain untuk pati tercerna cepat sebesar 7,85%, tercerna lambat sebesar 4,23%, total pati tercerna sebesar 18,82% dan kandungan pati resisten sebesar 81,18%. Tepung yang diperoleh memiliki karakteristik fungsional berupa kandungan pati resisten tinggi yang sesuai untuk produk dengan nilai Indeks Glisemik rendah dan produk gluten free yang tidak membutuhkan tepung dengan fungsi emulsifier seperti kue kering, biskuit dan roti kering.
This study aims to optimize the sustainable supply chain management (SSCM) model for tuna trash fish in the coastal area of Pasuruan by involving three leading actors in the supply chain: fishermen, collectors, and processing businesses. The approach method used is the Rapid Appraisal for Fisheries (RAPFISH), based on Multidimensional Scaling (MDS), to evaluate the level of sustainability across environmental, social, and economic dimensions. The results show that collectors are in the fairly sustainable category (73.50%), while fishermen (55.62%) and Micro enterprise of trash fish type tuna (55.27%) are at the lower limit of the same category. The main levers for each actor include occupational safety, labor cost efficiency, and working environment conditions. The main conclusion states that the sustainability of the tuna supply chain still requires cross-dimensional improvements. The implications of these results underscore the importance of targeted actor capacity-building strategies, such as occupational safety training for fishermen, digitizing collector administration, and enhancing consumer services in micro enterprises of trash fish type Tuna, as well as opening up opportunities for further research based on an integrative approach to support long-term sustainability.
Fenomena pengeringan dengan berbagai varietas irisan buah mangga (Manalagi, Gadung, dan Harum manis) menggunakan metode pengering vakum. Sampel dikeringkan dengan variasi suhu (40, 50, dan 60 °C) pada tekanan 300 mbar. Pra-pengeringan menggunakan dehidrasi osmosis (larutan sukrosa 20% selama 20 jam), blansing (titik didih 98±2 °C selama 10 menit), dan perendaman zat anti-browning (asam sitrat 1% dan kalsium laktat 1% selama 60 menit). Penelitian ini bertujuan untuk mengevaluasi pemodelan menggunakan tujuh model (Newton, Page, Modified Page II, Handerson & Pabis, Logarithmic, Midilli, dan Two-Term) serta menganalisa perubahan fisikokimia selama pengeringan. Hasil yang didapat adalah kadar air akhir terbaik terdapat pada mangga Manalagi hingga 12,89-20,07% (bb) dengan rata-rata laju pengeringan 2,33-2,60%bb/jam. Model prediksi kinetika pengeringan terbaik adalah model Page dan Two-Term. Uji ANOVA dua arah menunjukkan bahwa variasi mangga dan variasi suhu memberikan pengaruh nyata terhadap fisikokimia (TPT, rendemen, kekerasan, dan warna). Nilai perubahan fisikokimia didapatkan TPT terbaik mangga Manalagi (37,31-48,77%°Brix), rendemen terbaik mangga Manalagi (15,48-19,57%), kekerasan terbaik mangga Harum manis (2,58-16,07 kgf), warna L* terbaik mangga Manalagi (47,45-60,95), warna a* terbaik mangga Manalagi (5,77-9,59), mangga warna b* terbaik mangga Gadung (33,61-39,22).
Efisiensi proses dehidrasi dalam produksi furfural, sangat dipengaruhi oleh akurasi suhu. Penelitian ini bertujuan merancang reaktor tipe batch berpengaduk, menggunakan sistem “induction heating” tipe kumparan pancake coil dan kontrol suhu PID guna meningkatkan efisiensi proses dehidrasi. Penelitian terdiri dari dua tahap yaitu perancangan dan pembuatan prototype, serta pengujian. Bahan reaktor menggunakan stainless steel 304 dengan kapasitas 250 mL. Hasil penelitian menunjukkan bahwa sistem pemanas induksi mampu bekerja dengan baik untuk proses dehidrasi xilosa menjadi furfural pada reaktor batch pada suhu 100 °C dicapai selama 25 menit 4 detik. Suhu terbaik untuk proses dehidrasi xilosa menjadi furfural diperoleh pada suhu 150 °C, konsentrasi furfural yang dihasilkan pada suhu tersebut cenderung stabil berkisar 480–490 mg/L. Implementasi kontrol PID menghasilkan stabilitas suhu dengan deviasi ± 1 °C dari setpoint, yang berkontribusi pada peningkatan efisiensi reaksi.
In the weeding process, farmers still use the conventional method of swinging the sickle horizontally over the weed-covered soil repeatedly until the weed stems are cut and flush with the ground. This process can lead to rapid fatigue, especially in the musculoskeletal system or skeletal muscles. When weeding, the average farmer's back bends at a 90-degree angle while repeatedly pulling out weeds. In designing this machine, an anthropometric approach is used to determine the ergonomic design of the weed mower that provides worker comfort. Anthropometry is the study of human body dimensions and their application in design, including physical geometry, mass, strength, and body characteristics such as shape and size. Humans vary in shape, size, height, and weight. The sample size is 23 workers. Based on the research conducted on the weed, the researchers proposed an ergonomic weed-weeding machine design based on an anthropometric approach. The anthropometric measurements obtained are the height of the weed-weeding machine is 120.7 cm, the width range of the weed-weeding machine is 46.8 cm, and the depth range of the weed-weeding machine is 42.0 cm, using the results of the 50th percentile. The design of this weed-weeding machine is expected to have practical implications, including increased comfort and work efficiency for farmers, which in turn can speed up the weeding process and increase rice productivity. This design is also expected to encourage innovation in the field of work system design and ergonomics.
Jelly candy is a type of soft candy made with the addition of hydrocolloids. Currently, jelly candies are widely made with ingredients that can enhance their nutritional and functional value. Red beet, a material rich in bioactive compounds, can be used as a raw material for making jelly candy. Processing red beet into jelly candy may increase its acceptance due to reduced off-flavors. This study aimed to determine the effect of different types of hydrocolloids and the addition of ginger extract on the physicochemical and organoleptic properties of red beet jelly candy. The research method used was a nested design with three replications. The red beet jelly candy was made with different types of hydrocolloid (agar and carrageenan) and different concentrations of ginger extract (0%, 1%, and 2%). The results showed that the difference in the type of hydrocolloid significantly affected the ash content, nitrate and nitrite content, total phenol, and total betalain content of the product. While the addition of ginger extract nested in the type of hydrocolloid had a significant effect on the a* value, antioxidant activity, total phenol, and total betalain content of the product. The best treatment was determined using the Zeleny method. Data processing results showed that the best treatment obtained was agar jelly candy with the addition of 0% ginger extract, with an antioxidant activity value of 530.15 ppm.
Tanaman jahe merah (Zingiber officinale), termasuk dalam famili Zingiberaceae, mengandung senyawa bioaktif yang bersifat antioksidan, seperti flavonoid, zingiberen, dan polyphenol. Selain itu, tanaman ini juga mengandung komponen volatile (minyak atsiri) sekitar 2,58–3,50% dan non-volatile (oleoresin) sekitar 5,8–6,3%, di mana semakin tinggi kadar oleoresin maka rasa pedas pada jahe semakin meningkat. Tujuan dari penelitian ini adalah untuk mengetahui waktu ekstraksi dan perbandingan rasio bahan-pelarut yang optimal terhadap variabel respon rendemen, total fenol, dan aktivitas antioksidan pada ekstrak jahe merah dengan metode MAE. Penelitian ini menggunakan rancangan dua faktor, yaitu waktu ekstraksi (4, 8, dan 12 menit) dan rasio bahan-pelarut (1:15, 1:20, dan 1:25 g/mL). Metode respon permukaan (Response Surface Methodology/ RSM) digunakan untuk menganalisis pengaruh variabel serta menemukan kondisi optimum. Kondisi optimum yang terpilih adalah rasio bahan-pelarut 1:25 dan lama waktu ekstraksi 4,25 menit. Hasil verifikasi pada kondisi tersebut diperoleh rendemen 24,47%, total fenol 60,74 mg GAE/g, dan aktivitas antioksidan 36,56 ppm. Model yang didapatkan sudah dapat diterima dan mampu memprediksi secara efektif respon optimal dari parameter yang diteliti.
A cookie is a biscuit made from wheat flour as its main ingredient. Cookies have a crunchy and less dense texture. Wheat flour can be substituted with peanut tempeh flour and Cilembu cultivar sweet potato flour to increase the nutritional value. This study aims to determine the effect of substituting peanut tempeh flour and Cilembu cultivar sweet potato flour on the nutritional quality of the cookie. Four treatments were employed in this study. The ratio of wheat flour, peanut tempeh flour, and Cilembu cultivar sweet potato flour is the basis of the treatment. The treatments are K (100:0:0), A (60:35:5), B (60:25:15), and C (60:15:25). The results of this study prove that the substitution increases the nutritional quality. The cookie with treatment A has the best nutritional quality. It has water content 3.61% - 4.22%, ash content 0.93% - 1.43%, protein content of 8.15% - 14.11%, fat content of 21.17% - 32.70 %, carbohydrate content 48.33 % - 66.13 %, insoluble fiber content 1.23 %-2.73 %, soluble fiber content 4.90-8.44 %, white-orange color, texture 20.76-43.89 N, total plate count 1 x 101 CFU/g - 3 x 102 CFU/g, and the negative content of yeasts and molds. The cookies with treatment A meet the requirements of Indonesian National Standard (INS) 2973:2018 and INS 01-2973-2011. Cookies with treatment A is the best product based on chemical, physical, microbiological, and organoleptic values.
Penelitian ini dilatarbelakangi oleh limbah cair yang mengandung fosfat dan amonium, yang dapat mencemari perairan. Kristalisasi struvite dalam reaktor lapisan terfluidisasi (fluidized bed reactor) merupakan solusi karena dapat mengurangi polutan dan menghasilkan pupuk, namun masih perlu peningkatan efisiensi dan produktivitas. Struvite sendiri merupakan pupuk pelepas lambat yang ramah lingkungan. Penelitian ini bertujuan mengkaji pengaruh penambahan pasir silika terhadap efisiensi dan produktivitas pembentukan struvite. Ukuran partikel pasir silika distandarisasi menggunakan ball mill yang dioperasikan selama 30 menit dengan kecepatan 80 rpm, diikuti dengan pengayakan melalui saringan berukuran 50 mesh. Na₂HPO₄ digunakan sebagai sumber fosfat, NH₄Cl sebagai sumber amonium, dan MgCl₂ sebagai sumber magnesium. NaOH atau HCl digunakan sebagai larutan asam-basa. Terdapat dua faktor yang diteliti, yaitu penambahan pasir silika dan kecepatan aliran fluida. Analisis yang dilakukan meliputi produktivitas dan efisiensi pembentukan kristal struvite. Perlakuan terbaik menggunakan metode metode multiple attribute Zeleny. Kecepatan maksimum dan minimum aliran fluida dengan penambahan pasir silika adalah 0,0034 m/s (0,4 L/menit) dan 0,0102 m/s (1,2 L/menit). Produktivitas dan efisiensi tertinggi masing-masing sebesar 44,87 g/L dan 88,15%. Perlakuan terbaik yaitu kombinasi penambahan pasir silika dengan kecepatan aliran 0,0034 m/s (0,4 L/menit). Penambahan pasir silika dan penggunaan kecepatan minimum dalam proses pembentukan kristal struvite dapat meningkatkan produktivitas dan efisiensi kristal struvite. Kecepatan aliran menentukan transportasi ion ke permukaan kristal, di mana kecepatan maksimum dapat menyebabkan inti kristal yang baru terbentuk pecah.
