Siswo Sumardiono

This study aimed to enhance the physicochemical and functional properties of sago starch for noodle production using sequential ozonation and acetylation. Native sago starch was first ozonated to disrupt its crystalline structure, followed by acetylation with varying acetic anhydride ratios (4–8 g per 100 g starch) and reaction times (5–25 min). The acetyl content (%) and degree of substitution (DS) increased with higher acetylation agent ratios and longer reaction times, peaking at 6.644% acetyl content and 0.268 DS for the highest ratio (A-OS 8) at 25 min. Functional properties were significantly altered, with acetylated-ozonated starches showing increased moisture content (up to 15.168%), a higher water solubility index (WSI: 16.835%), and a reduced water absorption index (WAI: 30.419–33.692%) compared to native starch. Rheological analysis revealed that ozonation reduced the peak viscosity of native starch (5344 cP) to 4474 cP, while acetylation partially restored the viscosity (up to 5214 cP for A-OS 4). Structural characterization via SEM confirmed surface roughness and fissures in modified starches, whereas XRD and FTIR demonstrated retained A-type crystallinity with reduced order and successful acetyl group incorporation (evidenced by C=O peaks at 1740 cm⁻¹). In noodle applications, dual-modified starch improved texture, with reduced hardness (302.37 g for A-OS 8 vs. 593.46 g for native starch) and lower cooking loss (12.85% vs. 19.39%), alongside enhanced brightness (L* = 73.3) and shorter cooking times (5 min for A-OS 8). These results demonstrate that ozonation-acetylation synergistically modifies sago starch, optimizing its properties for noodle production by balancing its solubility, viscosity, and structural stability.

Artificial rice is one of the food diversification efforts that can be made from non-rice foodstuffs to reduce dependence on rice. In this study, artificial rice was made from a composite flour as raw material composed of modified cassava flour (mocaf) (Manihot esculenta), sago flour (Metroxylon sago Rottb), yellow pumpkin flour (Cucurbita moschata L.), and soybean flour (Glycine max) in different formula ratios. Artificial rice was produced using the extrusion method at temperatures of 70, 80, and 90°C. In this study, the artificial rice was analyzed for chemical and physical properties (water absorption, cooking losses, and cooking time). The best artificial rice formulation was obtained from a composite flour with a mocaf:sago:pumpkin:soybean flour ratio of 50:15:15:20, producing artificial rice with a moisture content of 9.83%, ash 2.32%, protein 10.89%, fat 8.18%, and carbohydrates 68.79%. Extrusion temperature had no significant effect on the chemical properties of artificial rice, with an optimum extrusion temperature of 80°C. All the participants showed acceptance of the artificial rice. This suggests that artificial rice could be used as a substitute for rice as a staple food.

Avocado seed, as a by-product resulting from avocado fruit processing, is still not widely utilized even though it contains high nutritional and bioactive values. Its processing into flour has the potential to be used as a raw material in food processing, even animal feed. However, its use is limited due to the presence of antinutrient compounds in it, such as tannin which is a polyphenolic compound that causes a decrease in protein digestibility and has a negative impact on the sensory quality of food. This review discusses the nutrients and antinutrients of avocado seed flour, especially the tannin compound and how to reduce it to be applicable, especially in the food industry. For tannin removal, various methods were examined and assessed according to effectiveness, advantages, disadvantages, and environmental impact. In phrases of sustainable processing requirements, this review also discusses the strategies to limit useful resource use, keep away from dangerous chemical compounds, and make contribution to developing the value of agricultural by-products. Instead of suggesting a specific method, this review seeks to offer a comparative summary to help in choosing the proper processing technique depending on product targets, useful resource, or specific processing conditions.

Studies on the kinetics of starch ozonation under basic conditions remain limited, particularly the effect of the level of alkalinity during ozonation on the suitability of ozonated sago starch for noodle production. This study aims to investigate the kinetics of ozonation reactions at various basic pH levels and the impact of ozonation on the viscosity, structural, and morphological properties of sago starch and its potential use in noodle production. The presence of carbonyls and carboxyls are key parameters for starch ozonation. The reaction kinetics were successfully conducted by observing the formation of carboxyl in the ozonation time range of 5-20 min at a sago starch suspension pH of 7.5-9.5. Prolonged ozonation was found to cause significant increases in carbonyl and carboxyl content. In contrast, high alkalinity of sago starch suspension (9.0 and 9.5) caused significant increases in carbonyl and carboxyl content compared to low alkalinity suspension (7.5 and 8.0). Kinetic modeling of Sago starch ozonation showed that the reaction followed pseudo-first-order kinetics concerning starch concentration, with the reaction rate increasing with increasing pH. The reaction rate increased with increasing pH, with the highest k value at pH 9.0 of 3.3538 × 10^-4 min^-1 (R² 0.976). When applied as a raw noodle material, rapid visco analyzer (RVA) analysis was used to study the viscosity profile of ozonated starch, enhancing its suitability for noodle production. Peak viscosity decreases after ozonation, reaching 4474 cP at pH 8.5 but partially recovers at pH 9.5 (5139 cP), reflecting structural changes. Trough and setback viscosities peak at pH 9.5, indicating improved stability, gel strength, and retrogradation, essential for texture. Breakdown viscosity decreases, demonstrating enhanced granule resilience, while peak time and pasting temperature remain consistent. Scanning electron microscopic (SEM), Fourier transform infrared (FTIR), and X-ray diffraction (XRD) analyses confirmed structural changes in Sago starch after ozonation. Ozonation improved Sago starch noodles by increasing cooking stability, reducing cooking loss, and slightly enhancing water absorption compared to native starch. However, wheat flour noodles exhibited superior water absorption and minimal cooking loss, attributed to gluten’s strong water-binding and cohesive properties. Ozonated Sago starch shows promise as a partial wheat substitute in noodles, but further sensory and molecular studies are required.

The potential of silver tetratungstate-doped bentonite intercalated with zwitterionic surfactant for removing Rhodamine B (RhB) was evaluated by comparing three composites, namely, AB (acid-activated bentonite), AB impregnated with Ag8W4O16 photocatalyst (Ag@AB), and Ag@AB intercalated with dodecyl dimethyl betaine (BS12) surfactant (Ag@OAB) with respect to their photocatalytic adsorption performance. The AB composite was prepared by treating natural bentonite with hydrochloric acid (HCl). Next, Ag@AB was synthesized by wet impregnation of Ag₈W₄O₁₆ onto AB. Lastly, the Ag@OAB was formed by intercalating the BS12 surfactant onto the Ag@AB composite. The morphology of the composite structures was characterized using Scanning Electron Microscopy (SEM). The addition of 4% Ag (w/w) tetratungstate W4O16 and 50% CEC BS12 to AB produced RhB removal percentages of 66% and 59%, respectively, compared to 65% for AB. The maximum removal percentage was achieved at pH 4 for the AB, Ag@AB, and Ag@OAB composites with RhB removal percentages of 67%, 71%, and 44%, respectively. The AB composite showed the highest regenerative ability compared to Ag@AB and Ag@OAB, with AB maintaining RhB removal at 70% after five regeneration cycles, while Ag@AB and Ag@OAB only reached four and three regeneration cycles. The total production cost of AB is fourteen to sixteen times lower than that of Ag@AB and Ag@OAB composites. In summary, the impregnation of the Ag₈W₄O₁₆ photocatalyst onto AB, resulting in the Ag@AB composite, increases the RhB removal efficiency compared to pristine AB. In contrast, the intercalation of the BS12 surfactant in Ag@OAB composite led to a decrease in RhB removal efficiency, resulting in the lowest performance among the three composites.

Edible coatings and films have gained significant interest due to their ability to extend the shelf life of fresh products. This research aimed to develop a novel indicator film using crosslinked–stearic acid acylation‐modified cassava starch and anthocyanin extracts, both of which can be utilized to create solid matrices that are safe for consumption. The physical properties of the films improved with the use of modified starch, exhibiting a stronger tensile strength (from 0.96 to 1.02 MPa). Additionally, flexibility increased from 121% to 129%, and the water vapor transmission rate was significantly reduced from 5.86 to 1.79 g/m²/h. Anthocyanin extracts also contributed to improvements in flexibility and reductions in water vapor transmission rate. Differential scanning calorimetry analysis indicated an increase in the film's thermal stability, with a transition temperature shifting from 276°C to 299°C, attributing to changes in the starch characteristics following modification. Fourier transform infrared spectroscopy revealed alterations in the molecular interactions between the CH and CC groups. The application of these edible films for storing and monitoring Indian mackerel fish meat demonstrated consistent results, particularly in terms of color change due to an increase in pH levels (from 7 to 8.5 over 2 days). Furthermore, TVB‐N levels in fish meat covered with the edible film were successfully reduced from 71 to 46 mg/100 g over the same period. These findings indicate that the films can function as intelligent food packaging, possessing antioxidant properties beneficial for human health while being biodegradable, thus reducing their environmental impact.

Conventional organic waste management methods often lead to environmental degradation and underutilization of valuable resources. In rural areas, such as Polaman Village, limited awareness and inefficient disposal systems exacerbate these issues, thus necessitating innovative and sustainable solutions. This study explores black soldier fly larvae (BSFL) bioconversion as a community-based solution for organic waste management, addresses environmental challenges, and promotes economic empowerment by converting waste into valuable by-products. The study employed a mixed-methods approach, beginning with baseline assessments of waste generation and existing management practices to identify community needs. Educational workshops and hands-on training sessions introduced BSFL bioconversion techniques to local stakeholders. Focus group discussions (FGDs) were conducted to facilitate dialog and collaboration between Polaman residents, the Polaman Resik Sejahtera Waste Bank, and Universitas Diponegoro. Continuous mentoring and pilot trials were conducted to ensure proper adoption and to demonstrate the feasibility of the proposed system. The results reveal that BSFL bioconversion significantly reduces organic waste while producing valuable by-products such as compost and larvae. These findings demonstrate the potential of BSFL bioconversion to align with circular economy principles, contributing to environmental sustainability and economic resilience. The project serves as a scalable model for addressing organic waste challenges in rural communities while advancing the green economy agenda.

Research background. With the increasing consumption of food commodities, particularly rice, and the substantial volume of food imports in Indonesia, there is an increasing need to explore alternative food sources. Rice analogues emerge as a potential substitute for traditional rice, serving as a viable staple food option. The aim of this study is to investigate the effect of the composition of raw material, namely sago and corn flour, on the physicochemical properties and consumer acceptance of rice analogues. Experimental approach. The rice analogues were produced using the hot extrusion method. The nutritional content (protein, carbohydrate, fat, moisture, fibre and ash) of the product was then analysed. Thermal stability and morphological properties were determined using differential scanning calorimetry (DSC) and scanning electron microscopy (SEM), respectively. A consumer acceptance test including taste, texture, aroma and colour was also carried out to evaluate the quality of cooked rice analogues. Results and conclusion. The results showed that the rice analogue produced by hot extrusion at 70 °C with black-eyed beans (15 % m/m) and skimmed milk powder (0.5 % m/m) had the most significant nutritional improvements such as increased content of protein, fat, carbohydrate, moisture content, ash and fibre. However, it should be noted that increasing the extrusion temperature above 70 °C meant that both density and hardness could no longer be controlled due to gelatinisation. Furthermore, 30 participants in the consumer acceptance test rated the texture, aroma, taste and colour positively, underlining the potential of rice analogue as a nutritious and attractive alternative to natural rice. The rice analogue made from modified sago with additional ingredients of corn and blackeyed beans has similar properties to natural rice. Novelty and scientific contribution. The combination of sago, corn and black-eyed bean flour as the main ingredients of the rice analogue is a novelty of this study. Furthermore, its nutritional profile exceeds that of natural rice, making it a viable and acceptable alternative in times of rice scarcity.

Dual-step starch modification is an effort to eliminate weaknesses in single-step modification. This research aims to study the effect of single-step or dual-step modification methods on the physicochemical properties of sago starch. The single step consists of ozonation (Oz) and acetylation (As), while the dual step (sequentially), namely ozonation-acetylation (Oz-As) and acetylation-ozonation (As-Oz). The physiochemical responses measured were water content, carbonyl content, carboxyl content, acetyl content, water solubility index (WSI), water absorption index (WAI), and color. Ozonation causes the formation of carbonyl and carboxyl groups, and the modification process certainly causes the addition of carbonyl and carboxyl groups both in single step and dual-step. Acetylation causes higher acetyl group values in either single-step (As) or dual step (Oz-As and As-Oz) compared to original sago starch. There was a significant difference between the single and dual steps in the WSI and WAI values. The characteristics of Ozonated-acetylated (Oz-As) modified sago showed starch the highest WSI and WAI results. The water content in single-step modified sago starch compared to native sago starch has no significant difference in water content, whereas the dual-step modified sago starch has a higher water content than the native one.