Ash Content Research Articles

Physicochemical Characteristics and Antioxidant Activity of Murici Pulps (Byrsonima spp., Malpighiaceae) Sold in the Municipality of Santarém-PA, Brazil

Introduction: Murici is valued by the local population for its healing, anti-inflammatory, and antioxidant properties, which are attributed to its phenolic compounds and ca-rotenoids, although its quality and properties are not well-known. Objective: This research aimed to evaluate the quality of murici pulp (Byrsonima spp.) commercialized in some places of Santarém, Pará, Brazil. Methods: Murici pulp samples were collected in Santarém and Curuá, PA, between October 2022 and January 2023. The samples were packed in plastic containers and stored in a refriger-ated laboratory. Physicochemical analyses included pH, titratable acidity, total soluble solids, ash content, moisture, phenolic compounds, proteins, and sugars, following standard methods. Antioxidant activity was measured using DPPH, ABTS, and FRAP assays. Results: Murici pulp pH ranged from 3.2 to 3.6, all within legal limits, indicating higher acidity suitable for consumption. Titratable acidity ranged from 15.89 to 63.57 meq kg⁻¹, meeting regu-latory standards. Ash content varied from 0.15% to 0.86%, moisture from 75.11% to 83.58%, and phenolic compounds from 2.73 to 3.64 mg GA g⁻¹. Significant statistical differences were observed in all analyses, highlighting the nutritional and antioxidant potential of the pulp. Conclusion: Murici pulp samples showed low sugar and starch concentrations but high total acidity and antioxidant capacity (DPPH, ABTS, and FRAP). pH levels met legal standards, with significant variations due to ripeness and environmental factors. The study underscores murici's health benefits and quality variations influenced by environmental conditions and processing factors. conclusion: There were high values for antioxidant activity, all samples presented a pH value above the minimum value established by the equivalent legislation. In relation to soluble solids, only four samples obtained relatively low results, sugar analyzes demonstrated reduced values.

Carbonization of Refuse-Derived Fuel Pellets with Biomass Incorporation to Solid Fuel Production

In this work, dry carbonization (DC) and hydrothermal carbonization (HTC) of refuse-derived fuel (RDF) pellets were conducted to evaluate the physical, chemical, and fuel properties of the produced chars. In the dry carbonization tests, biomass sawdust was incorporated in different proportions on the samples to minimize agglomeration caused by the melting of the plastic fraction. The experiments were carried out in a temperature of 400 °C (DC) and 250–300 °C (HTC), in a residence time of 30 min. The respective chars and hydrochars were characterized according to their mass yield, apparent density, proximate, elemental, and mineral composition, chlorine content, high heating value, thermogravimetric profile, and surface functional groups. The results showed that the dry carbonization of RDF pellets with biomass incorporation, followed by a washing step, resulted in the production of chars with improved properties such as higher fixed carbon and higher heating value (HHV) (25–26 MJ/kg) and lower ash and chlorine content. Additionally, the HTC experiments demonstrated that hydrochars showed improved properties without the need for biomass addition and washing, however, with no significant difference in the HHV (20–21 MJ/kg). Therefore, DC of RDF pellets with 10% biomass incorporation seems to be a promising option to overcome the constraints of RDF utilization as an alternative fuel.

Antioxidant Properties of Freeze Dried Mix Fruits and Vegetables Product ‘Miss Freezy’ Using Lyophilization Method

Background: The proper processing of fruits and vegetable-based food products will improve appearance, taste, bioactivities, and preservation. Freeze-dried (FD) or lyophilization of foods extends shelf life and preserves food's nutritional value and bioactivities. The objective of this study is to compare the antioxidant properties, nutritional value, and vitamins of fresh fruit-vegetables and the combined FD product. Methods: A combination of fruits (mango, papaya, star-fruit, guava, banana, bengkuang), and vegetables (cucumber), called “Miss Freezy” were cleaned with an ozonizer and processed using the lyophilization method. The antioxidant activities measured included 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), 2,2-Diphenyl-1-picrylhydrazyl (DPPH), and Hydrogen Peroxide (H2O2) assay. While the proximate analysis measured was the determination of water content, ash content, fat content, protein and carbohydrate content, and vitamin C. Results: The value of antioxidant activity in fruit-vegetable combination FD products was higher than in fresh fruit. The median inhibition concentration (IC50) of DPPH, ABTS, and H2O2 scavenging activities were guava 48.74 µg/ml, guava 128.39 µg/ml, and banana 155.55 µg/ml, respectively. The results showed that the water content of fresh fruits, and vegetables was greater than FD products and inversely proportional to the level of ash, fat, protein, carbohydrates, and vitamin C lower than FD products. Conclusions: Based on the results of antioxidant activities, proximate analysis and vitamin C of the FD product was higher than fresh fruits and vegetables. The FD fruit-vegetable combination product can be used as an alternative snack product that is practical and healthy.

Characteristics of Buffalo Milk Curd on Variations in Fermentation Time

Curd is a processed product from buffalo milk through a fermentation process. The clumping of fresh buffalo milk into curd occurs due to the presence of Lactic Acid Bacteria (LAB) in buffalo milk. Curd contains lactic acid bacteria (LAB), which are beneficial for health. These bacteria not only extend the shelf life of food by inhibiting the growth of spoilage and pathogenic bacteria but also produce bioactive compounds that are good for the body. LAB contained in curd even has probiotic properties. This research used a starter of 10% buffalo milk curd. In one production, 4500 ml of fresh buffalo milk and 500 ml of starter are used, yielding 3.8 kg of buffalo milk curd. The results of observations during 7 days of fermentation were water content (81.25-72.53%), ash content (0.93-0.89%), protein content (8.97-7.94%), fat content (7 .72-7.10%), carbohydrate content (1.13-11.54%), pH value (5.72-4.27), temperature (26.87-28.43oC), Total Lactic Acid Bacteria (1.6x109- 8.1x109 cfu/ml).

Experiences with Green Charcoal: A Gender Consideration of Rural and Urban Households in Gulu District

The study focused on the use of green charcoal, a sustainable cooking fuel made from agricultural residues, in Gulu District, to highlight the experiences households have encountered, from a gender perspective. The study followed a cross-sectional design using qualitative approach which included the use of one-on-one interviews, focus group discussions, key informant interviews, and ethnographic observations for data collection. The findings show that households in Gulu District use a combination of cooking fuels such as firewood, wood charcoal, green charcoal, or gas. Furthermore, the study established that there were cases where both men and women had shared experiences in cooking, for example, knowledge of the faster cooking rate, cleanliness, and much ash content involved while using green charcoal. However, to a larger extent, there were gendered differences in cooking activities: while women predominantly handle cooking, men often influence decisions about what and how to cook, revealing underlying gender and power dynamics within households. Key findings indicate that green charcoal is favored for its affordability relative to traditional black charcoal, prolonged burn time, and higher heat output, though it is also harder to light and produces more ash. It is particularly popular in rural Owoo Sub-County, where residents are more involved in its production compared to their urban counterparts in Gulu City. The study concluded that positive experiences with green charcoal have facilitated its adoption and recommends further actions to promote its use. These include increasing awareness of its environmental, health, and financial benefits, improving product quality, and involving women and girls as advocates to expand its utilization

Improvement of Gluten-Free Sponge Cake with A Combination of Chia Seed Flour and Millet Flour

Background: Celiac disease is an autoimmune disorder in which the patient is permanently intolerant to proteins containing gluten, and the only treatment is to use a gluten-free diet. The present study is designed to investigate physicochemical, antioxidant activity, textural, and sensory properties attributes of developed gluten-free sponge cake containing chia seed (Salvia hispanica L.) flour (CHF) along with millet (Panicum miliaceum) and corn flour. Methods: The cake was produced using CHF (4, 8, 12, 16%; w/w) with the replacement of millet flour (MF), and 50% corn flour (CF) was used equally in all the samples. Results: Applied CHF significantly increased moisture, ash, protein, and fat content of gluten-free cakes (P<0.05). Replacement of CHF with MF reduced specific volume (using colza grains) and porosity (using image processing method) by 64% and 76%, respectively. Texture analysis showed an increase in hardness in all the three-storage times with the addition of CHF. Color measurement indicated that CHF significantly reduced the amount of a*, and L* values of the crusts. Radical scavenging activity by DPPH was improved in a dose-dependent manner (P<0.05). The lowest amount of CHF in cake formula had the highest score in sensory evaluation with verbal hedonic scale. Conclusion: Based on the results, the samples containing 4% CHF, 46% MF, and 50% CF had the most desirable texture and palatability with reasonable radical scavenging activity among developed gluten-free sponge cakes.

Effect of roasting on physicochemical, functional, thermal, pasting, and structural properties of tamarind seed powder

The impact of different roasting conditions on the nutritional profile, physical, functional, thermal, pasting properties, morphology, crystallinity, and functional groups of tamarind seed powder (TSP) was investigated. Roasting treatment enhanced ash, carbohydrate, fat, and flavonoid content (2.21 to 11.93 mg QE/g) while significantly reduced protein, fiber, phenol content, tannin (2.72 to 1.36 mg TAE/g), antioxidant activity, and physical characteristics like bulk density, tap density. The concentrations of minerals like Mg, K, Ca, and P (3006.00, 8313.85, 482.44, 2723.78 mg/kg) and essential and non-essential amino acids were significantly enhanced by roasting. The roasted TSP exhibited a significant difference in pasting and functional properties compared to the control powder. The proportion of crystallinity in the roasted powder decreased according to the XRD patterns. The SEM micrographs revealed slight modifications in the morphology of TSP after roasting. According to our outcomes, the enhanced nutritional content of roasted TSP has excellent potential for usage as a food ingredient with added value.

Honeycombed pomegranate-like sludge ceramsite particles: Preparation with fly ash floating beads as the pore-forming template and performance optimization

Ceramsite used in construction and building are typically limited by high water absorption rates, the contradiction between lightweight and high strength, and severe performance fluctuations. This can be attributed to the fact that ceramsites are currently prepared by high-temperature sintering expansion, wherein viscosity and surface tension of the liquid phases shall perfectly match with the gas generation rate. On the other hand, sand washing sludge and fly ash are common solid wastes in construction and building and their environmentally friendly disposal are of great significance. In this study, honeycombed pomegranate-like sludge ceramsites with low density (packing density = 733.2–968.3 kg/m3), high strength (cylinder compressive strength = 11.2–18.8 MPa), and low water absorption rate (one-hour water absorption rate = 1.2–2.8 %) were prepared with sand washing sludge and fly ash floating beads as the raw material and the pore-forming template, respectively. Also, the effects of particle size and content of fly ash floating beads on the structure and performance of the as-prepared ceramsite were investigated. The results indicated that the pore structure of the as-prepared ceramsite was directly dependent on size and content of the fly ash floating beads, suggesting that the performance of the as-prepared ceramsite can be customized by tuning size and content of the beads. Additionally, lightweight aggregate concrete prepared by using the as-prepared ceramsites exhibited improved 7-day and 28-day compressive strengths and reduced thermal conductivity compared with concrete prepared by using commercially available ceramsites. Overall, this study presents the preparation of ceramsite particles with both high strength and low density by using fly ash and sand washing sludge, both of which are abundant solid wastes in constructions, thus contributing to solid waste recycling in construction.

Influence of the moisture and ash content in flue gases on the performance of adsorption processes using activated carbons to capture the CO2 for reuse in greenhouses

Influence of the moisture and ash content in flue gases on the performance of adsorption processes using activated carbons to capture the CO2 for reuse in greenhouses

Chemical characterization of activated carbon derived from Napier grass, rubber wood, bamboo, and hemp

This study examines the process and analysis of activated carbons that use H2SO4, H2O2, and NaOH as activating agents. The distinct chemical methods employed by each activator impacted the ash and carbon content, surface properties, and functional groups of the activated carbons, exhibiting notable disparities. The ash level varied from 6.86% to 37.08%. H2SO4-activated carbons had the lowest ash content, suggesting better elimination of inorganic contaminants. The iodine number, which serves as a measure of adsorption capacity, was consistent among all samples, with values ranging from 800 to 950 mg g-1. This indicates that the three activating agents effectively increased the surface area and porosity. The BET surface areas varied between 9.14 and 167.42 m2 g-1, whereas the BJH adsorption surface areas ranged from 9.68 to 28.89 m2 g-1. The pore volumes ranged from 0.0071 to 0.0595 cm2 g-1, while the sizes ranged from 0.51 to 8.2 nm. These measurements suggest the presence of both micropores and mesopores. The FTIR spectra exhibited comparable functional groups among all samples, such as OH, CH, C=C, and C-O. The SEM-EDX and XPS tests showed that there was a lot of carbon. The carbon content was highest in H2O2-activated carbons because they were exposed to less severe oxidative conditions. These activated carbons comply with the requirements set by IUPAC and ASTM. They are suitable for catalytic processes and liquid adsorption, such as water and wastewater treatment. Subsequent research should aim to improve activation conditions to get the highest possible carbon content and optimise surface characteristics.

Araçaúna (Psidium myrtoides) Flour: Sequential Extraction with Supercritical Carbon Dioxide and Pressurized Fluids

Araçaúna (Psidium myrtoides) is a native fruit from the Brazilian Atlantic Forest. It was studied for the proximate composition of its flour and sequential extraction using supercritical fluid extraction (SFE) in the first stage with CO2 and pressurized liquid extraction (PLE) with ethanol and water in the second and third stages, respectively, at 50°C and 60°C. The proximate analysis revealed essential information about the flour regarding the content of protein, carbohydrates, lipid, ash and moisture. The sequential extraction at 60°C resulted in high yields (42.22%). The first stage using SFE captured the volatile fraction, notably 1,4-diethylbenzene, which corresponds to 53.70% of the total volatile compounds identified in the araçaúna. Comparing the second and third stages, the third stage with water at 50°C produced the highest levels of phenolic compounds (33.06±2.26mg GAE/g extract), total monomeric anthocyanins (3.91±2.10mg C3G/g extract), antioxidant activity by ORAC (415.13±13.66 µmol TE/g extract) and FRAP (747.16±18.49 µmol TE/g extract), and cyanidin-3-glucoside as the predominant compound (4.83% w/w).

Nutritional Composition of Forage Available to the Northern Hairy-Nosed Wombat.

Access to adequate nutrition supports an animal's chance of survival and reproduction; thus, it is particularly important for threatened species. The nutritional quality of forage available to the critically endangered northern hairy-nosed wombat (Lasiorhinus krefftii; NHW) has not been assessed for two decades. The NHW Recovery Action Plan 2022 highlighted a need to investigate the effects of invasive buffel grass (Cenchrus ciliaris) on the species' diet - reassessing the relative nutritional quality of highly abundant buffel grass will assist this investigation. This study assessed the nutritional composition of NHW food items, including buffel grass. Comparisons of the nutritional composition were made between two geographically distanced sites (both eucalyptus woodland and savannah with highly abundant buffel grass), seasons and plant genera. The nitrogen, gross energy, acid detergent fibre, neutral detergent fibre, ash and mineral content of plants and their relationship to scats, as faecal nitrogen is a good predictor of palatability of grass and nutritional status, were assessed. The nutritional content of plants varied significantly between sites, seasons and genera. Total forage nutritional quality was greatest during spring 2020 at Epping Forest National Park, during summer 2020/21 and autumn 2021 at Richard Underwood Nature Refuge and poorest during winter at both sites. Buffel grass may be a nutritionally valuable food item of the NHW during winter at both sites. There was no significant relationship between the N and gross energy in forage and scats. The findings of this study will inform management if there is a need to reduce invasive buffel grass, based on enhanced knowledge of the NHW nutritional requirements, by determining whether the species has access to suitable dietary items and meeting their nutritional requirements, particularly when forage quality is poorest or promotion of nutritionally valuable forage items is required. The study will also inform management of nutritional requirements at future translocation sites for the NHW.

Analyzing the impact of age on waste properties at an open dumpsite in Khulna

The rapid growth of the population has led to a significant increase in the amount of municipal solid waste (MSW), posing a burden and concern for our environment. Landfill mining as well as waste to energy could be a solution to this issue, but they require waste composition, particle size, and physiochemical and ultimate analysis are prerequisite requirements. Particle size was assessed through sieve analysis, categorizing MSW into ten different types followed by physiochemical and ultimate analyses. This study aimed to examine how the properties of MSW change with age. Findings showed that fine particles increased with age while larger particles decreased. With aging, certain physical components decreased, while others either increased or stayed constant. Organic content showed a significant decrease of 70.548% for fresh MSW and 0.35% for fifteen-year-old waste whereas plastic content remained almost constant after an increase from fresh MSW. Moisture content and volatile content of MSW reduced with age while fixed carbon and ash content increased with age. Ultimate analysis shows a drop of carbon, hydrogen, and nitrogen while oxygen shows a rise. Calorific value was found a decrease in trend with age indicating that the energy content of MSW reduced with age. A drastic reduction of unit weight was found in this study, dropping from 9.31 KN/m3 to 4.668 KN/m3. This study highlights the overall composition of MSW, the fluctuation in physiochemical analysis with age, and the sieve analysis and particle size distribution. It also displays the unit weight and the age-wise variation of the ultimate analysis. The findings of this study will aid landfill mining and waste to energy by providing comprehensive properties of MSW.

Understanding the time-dependent rheological behavior of seawater mixed cement paste with fly ash

Due to the relative scarcity of freshwater resources in coastal regions, the use of seawater in concrete construction has great potential due to its benefits in cost and resource. To further advance the application of seawater concrete, a deeper understanding of its rheological properties is essential. This study investigates the effects of fly ash on the time-dependent rheological behavior of seawater cementitious paste, such as yield stress, plastic viscosity, and structural build-up rate. The underlying mechanisms are analyzed using the theories of water film thickness (WFT), ion concentration, and hydration heat. The research findings confirm that the rheological parameters of seawater paste are generally higher than those of deionized water paste, regardless of the cementitious compositions. As fly ash content increases, the plastic viscosity of seawater paste increase, while the fluidity and dynamic yield stress decreases. Further analysis reveals that the decrease in the yield stress with fly ash content is well related to the increase in the WFT, but it cannot sufficiently explain the change of yield stress over time. Instead, the amount of hydration products in seawater paste shows a linear increasing relationship with the dynamic yield stress at 65 min. By contrast, the plastic viscosity can be related to the ion concentration in the interstitial solution, wherein an increase in the concentration of Ca2+ corresponds to an increase in the plastic viscosity. Moreover, the rheological parameters increase over time, with the growth rates between 5 and 35 minutes being higher than those between 35 and 65 minutes, possibly due to the rapid early hydration of the binder materials. This study offers a fundamental theoretical support for the use of seawater in various concrete applications.

Make it a standard? The creation and variability assessment of a consensus standard protocol for Tenebrio molitor larvae feeding trials

Abstract Interest in the nutrition of the yellow mealworm (Tenebrio molitor L.) larvae is on the rise, leading to an increase in publications on this topic. The absence of a standard protocol and resulting differences in experimental designs reduces comparability among studies and impedes research on mealworm nutrition. To address this, a consensus standardised protocol was developed specifically for the evaluation of mealworm larval growth and performance in feeding trials. The efficacy of this protocol was evaluated through an international ring test involving seven partners using two wheat brans as dry feed (a standard bran and a local bran) at 27 °C and 60% relative humidity. As experimental units, plastic crates filled with 2.1 kg of bran and 10,000 4-week-old larvae were used with six replicates. Agar gel was provided as wet feed ad libitum. The mean individual larval weight and the number of larvae per crate were determined weekly until either three or more replicates ran out of feed or pupation exceeded 10%. At harvest, the total larval fresh biomass and amount of frass was determined. Larval samples were taken for chemical analysis. To assess the protocol, the within (repeatability) and between (reproducibility) laboratory variability was calculated for each parameter. The repeatability was good (limit at 12% (standard) and 14% (local)). The reproducibility was poorer with a limit 2.7 times higher for the standard feed (36%) and 3.8 times higher for the local feed (55%). For both feeds, the total larval fresh harvest, amount of frass and the larval protein concentration were the most consistent both within and among laboratories. The highest variability was observed at the early life stages and for the larvae ash content. The detailed consensus standard protocol and repeatability/reproducibility estimates can be used as basis for future mealworm feeding trials, comparing results and future improvements.

Effect of sludge-based additive on particulate matter emission during the combustion of agricultural biomass pellet

In this study, the effects of a sludge-based additive on particulate matter emission during the cornstalk pellet combustion were investigated using a vertical fixed bed reactor combined with a Dekati low pressure impactor (DLPI). It was found that the PM1 and total PM10 yields from the cornstalk pellet combustion were much higher than those from the individual combustion of sludge-based additive. With the addition of sludge-based additive, the alkali and alkaline earth metals (AAEMs) in biomass would react with the Al/Si-containing and P-containing inorganic minerals in sludge-based additive to form various aluminosilicates, silicates, and K-Ca-P compounds, which could enhance the potassium fixation and retain it in the coarse particles, such as fly ash and residual ash. The PM1 and total PM10 yields from the composite pellet combustion could be effectively reduced by 62%, with the mixing ratio of sludge-based additive increasing to 75%. The mixing ratio of sludge-based additive showed a positive synergistic effect in reducing the emission of PM and a mixing ratio of <30% was recommended based on comprehensive considerations to produce relatively high-quality pellet fuel with respect to good heating value and low ash content and PM emission in later combustion application.

Aerated Concrete Made of MSW Incineration Ash: Effect of Blending Materials and CO2 Curing Condition

Municipal solid waste (MSW) incineration ash is used to produce aerated concrete blocks (ACB). To reduce cement usage and improve ACB quality, steel slag and blast-furnace slag were tested as cement substitutes, and CO2 mineralization technology was applied to cure ACB. The effect of steel blending ratios (MSW incineration ash, cement substitutes, water, aluminum powder) and CO2 curing conditions (temperature, pressure) on ACB properties was investigated. Under different conditions, the compressive strength, CO2 uptake and microstructure of ACB were determined. Higher fly ash content in ACB increases CO2 uptake but reduces compressive strength; ACB shows better mechanical properties when the cement is completely replaced by blast-furnace slag, but steel slag will cause ACB to fail to form; the optimal water-to-solid ratio enhances carbonation rate and compressive strength, and reducing aluminum powder content improves compressive strength. As the CO2 curing temperature increases from 25 to 105ºC, the carbonation rate and compressive strength of the ACB initially increase and then decrease, with the maximum CO2 uptake ratio of 20.0% and peak compressive strength occurring at 65ºC. When CO2 pressure increases from 0.2MPa to 1MPa, the carbonation rate rises to 23.4%, and the compressive strength first increases and then decreases, reaching 1.86MPa at a curing pressure of 0.6MPa, meeting the GB/T 11968-2020 B03 A1.5 grade standard. Approximately 0.58 tons of CO2 emissions can be reduced for every ton of ACB produced. This study established an innovative method to produce an environmentally friendly, low-carbon building material.

Effects of germination and gamma irradiation on physico-chemical and cooking qualities of pigmented red rice landrace: Ahu

The rice quality is influenced by various post-harvest treatments, including germination and gamma irradiation. The study investigates the combined effects of germination and gamma irradiation on the physico-chemical and cooking qualities of Ahu, a red rice landrace. The samples were subjected to germination for 0, 24, 48 and 72 hours and subsequently irradiated with gamma rays at doses of 0, 1, 2, 5 and 10 kGy. Post-treatment, samples were analyzed for proximate and mineral composition. Cooking quality parameters including cooking time, water absorption, and texture were also assessed. At a radiation dose of 2 kGy, both protein and carbohydrate content increased; however, they declined at higher doses. The ash content depicted a reduction with increased doses of radiation. Micronutrient composition remained largely unaffected by the irradiation process. Gamma irradiation also influenced cooking quality: water uptake ratio increased, while the optimum cooking time decreased at higher doses. Additionally, an upsurge of amylose content was demonstrated with increasing radiation levels, resulting in softer cooked rice. Thus, it can be attributed that dual processing of rice can effectively modify starch properties, rendering it a viable method for enhancing the textural and functional qualities.

Assessment of proximate composition, mineral element profile and antioxidant properties of the edible oyster mushroom grown in Bangladesh

Mushrooms have been considered as a therapeutic and nutrient-rich foods in numerous countries for years due to their significant levels of nutritional components, vitamins and antioxidants. This study aimed to assess the nutrient content, mineral profile and antioxidant properties of eight different kinds of oyster mushrooms (Pleurotus sp.) cultivated in Bangladesh. The mushrooms were analyzed for their moisture content, carbohydrates, proteins, fats, fibers, ash, vitamin A, and vitamin C. The mineral profile included sodium, potassium, calcium, and iron, as well as heavy metals. Antioxidant activities were evaluated through various methods, including phenolic, flavonoid and tannin content, total antioxidant activity, and DPPH (2,2-diphenyl-1-picryl-hydrazyl) scavenging capacity. The findings revealed that the mushrooms under investigation were high in carbohydrate (ranges between 45.25 and 63.22 g/100 g), protein (23.48–33.16 g/100 g) and dietary fiber (42.87–52.31 g/100 g). The total ash content was ranged from 7.28 to 9.41 g/100 g and vitamin C content was 0.020–0.416 mg/100 g. Interestingly, all of the mushrooms had a lower fat content (0.91–2.6%). The mineral profile indicated the presence of varying concentrations of essential elements. Hazardous heavy metals, such as Cd and Cr were not detected in the mushroom sample, while As and Pb were detected but lower than the tolerance levels. The oyster mushrooms exhibited high levels of phenolic, flavonoid, and tannin contents, as well as significant antioxidant capacity. A methanol extract of the oyster mushrooms exhibited scavenging activity against DPPH in a dose dependent manner with the highest capacity (75.4%) obtained at a concentration of 0.2 mg/ml. Our result suggests that these studied oyster mushrooms could be a good source of nutrition and antioxidants, which could be used as functional foods.

Karakteristik Fisikokimia dan Sensori Fruit Leather dari Campuran Buah Sirsak dan Buah Nangka

Fruit leather is a processed food derived from dried pulp, so it is a thin sheet that can be rolled up and has a distinctive flavor depending on the fruit as the raw material. This study aimed to obtain the best ratio of soursop and jackfruit on fruit leather's physicochemical and sensory characteristics. The fruit leather treatment in this study was the ratio of soursop pulp and jackfruit pulp, namely SN₁ (80:20), SN₂ (70:30), SN (60:40), and SN₄ (50:50). The data obtained were statistically analyzed using ANOVA test. If the calculated F value is greater than or equal to the F table, proceed with Duncan's Multiple Range Test (DMRT) at the 5% level. The results of variance analysis showed that the ratio of soursop pulp and jackfruit pulp had a significant effect on moisture content, ash content, acidity (pH), fiber content, total sugar content, color test, and sensory assessment consisting of descriptive test and hedonic test. This study's selected fruit leather treatment was SN₂ treatment of soursop pulp and jackfruit pulp (70:30). 11,47% moisture content, 0,49% ash content, 3,68 pH value, 0,38% crude fiber content, 51,73% total sugar content, color test L* value 58,68, a* value 10,94, and b* value 22,94. The descriptive test obtained yellow color, a slight jackfruit scent, a slight jackfruit taste, and a chewy texture. Assessment of color, taste, chewiness, and overall assessment was liked, and the panelists slightly liked the scent.