30 research outputs found

    Biodesulfurization of the mixture of dibenzothiophene and its alkylated derivatives by Sphingomonas subarctica T7b

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    Organosulfur compounds classified as dibenzothiophenes (DBTs) and their derivatives are contained in petroleum. When used as fuel, these substances release SOx emissions, thus contributing to air pollution, acid rain, and climate change. Therefore, it is necessary to reduce the content of these organic sulfur compounds in fuels and one way to achieve this is through bacterial desulfurization. This study reports the biodesulfurization process of a mixture of DBT, 4-hexyl DBT, 4,6-dibutyl DBT, and various organosulfur compounds in light gas oil (LGO). The experiment was conducted by treating 1 mL of aromatic organosulfur compounds with 100 mg/L in \textit{n}-tetradecane or 1 mL LGO with 5 mL mineral salts in sulfur-free medium, incubated at 27 °C for 5 days with shaking at 273 rpm. Gas chromatography analyses revealed that the growing Sphingomonas subarctica T7b cells desulfurized and converted 88.29% of DBT to 2-hydroxybiphenyl as a metabolite while a mixture of DBT and 4,6-dibutyl DBT was desulfurized at 86.40\% and 7.00%, respectively. Furthermore, the mixture of DBT, 4-hexyl DBT, and 4,6-dibutyl DBT had a desulfurization percentage of 84.40%, 41.00%, and 6.66%, respectively, after five days of incubation. The compounds were observed to desulfurize slightly better as single compounds compared to when mixed with other aromatic sulfur compounds

    Pemanfaatan Tepung Rumput Laut Gracilaria sp. pada Tempe sebagai Alternatif Pangan Sumber Yodium

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    Tempe merupakan produk pangan bergizi tinggi yang digemari dan diterima oleh masyarakat luas tetapi umumnya memiliki kadar yodium yang rendah. Rumput laut yang kandungan yodiumnya cukup tinggi dapat digunakan sebagai bahan fortifikasi yodium pada makanan. Penambahan rumput laut pada tempe diharapkan dapat menjadi alternatif pangan sumber yodium untuk menanggulangi masalah GAKY (Gangguan Akibat Kekurangan Yodium). Tujuan penelitian ini adalah untuk mengetahui pengaruh penambahan tepung rumput laut Gracilaria sp. terhadap kadar yodium pada tempe serta mengetahui karakteristik yang dihasilkan. Perlakuan yang dilakukan adalah perbandingan kedelai dan tepung rumput laut 100:0; 97,5:2,5; 95:5; 92,5:7,5; dan 90:10. Perbandingan kedelai dan tepung rumput laut 92,5:7,5 merupakan komposisi terbaik yang menghasilkan tempe dengan kadar yodium 0,26 mg/g; nilai sensoris hedonik rata-rata 5 (agak suka), serta 100 gram tempe tersebut memenuhi 17,47% angka kecukupan gizi (AKG) yodium orang dewasa per hari. Studi ini menunjukkan bahwa tempe tersebut dapat digolongkan sebagai pangan sumber yodium karena telah memenuhi 15% AKG orang dewasa. ABSTRACT Tempeh is a highly nutritious food that is popular and accepted by diverse community groups but has low iodine levels. Seaweed, with a high iodine content can be used as a fortification ingredient to increase the iodine levels of the foods. The addition of seaweed in tempeh is expected to be used as an alternative food source of iodine contents to overcome the IDD (Iodine Deficiency Disorders) problem. This study aimed to determine the effect of the addition of Gracilaria sp. seaweed flour to iodine levels in tempeh and to determine the characteristic of the product. The treatments were 5 (five) compositions of soybean and seaweed flour, in the ratio of (100:0), (97.5:2.5), (95:5), (92.5:7.5), and (90:10). The composition of soybean and seaweed flour in the ratio of 92.5:7.5 was the best composition that produces tempeh with an iodine content of 0.26 mg/g; hedonic sensory test results on average 5 (somewhat like) and 100 g of tempeh met 17.47% of the daily iodine requirements for the adults. This study showed that tempeh can be considered as an alternative food source of iodine content as it contributed to 15% of adult’s daily nutritional adequacy

    Physicochemical Characteristics of Fresh-cut Tropical Fruit during Storage

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    Fresh-cut tropical fruit is increasingly popular currently, stimulated by public awareness of health and practical lifestylefresh-cut fruit presenting consumers' convenience, safety, and quality. Tropical fruit contains functional components that are quite varied and good for health. Mangosteen, Mango, and Rambutan are three exotic tropical fruits that have high economic value and are liked by foreign people. They have a nonedible relatively high and potentially processed into fresh-cut fruit—the process of stripping cutting and slicer, causing wounds that spur damage. During storage, fresh-cut fruits undergo physical-chemical changes—increased respiration rate, ethylene production, oxidation, and browning processes that can shorten shelf life. The damage will be faster if stored at an improper temperature. Fresh-cut fruit is preferably stored at cold temperatures, to extend the shelf life. The research aims to determine the physicochemical characteristics of fresh-cut tropical fruits during cold storage. The research uses a pattern of random group three replicate. The first factor is fruit type (Mango, Mangosteen, Rambutan); the second factor is storage time in cold temperatures (0, 5, 10 days). The variables observed in the study included physical characteristics color (L*a*b*), weight, and texture. Observations of chemical characteristics include moisture content, pH, total acids, vitamin C levels, and total dissolved solids. Freshcut tropical fruit has different physicochemical characteristics and experiences deterioration during cold temperatures. The characteristics of tropical fruit have changed significantly on day 5. Mango shows more significant changes than others, seen from variable moisture content, vitamin C, color, and texture. Meanwhile, based on the physicochemical analysis, rigidity of fresh-cut Mango higher than Mangosteen and Rambutan

    Microemulsion Characteristics of Oil-in-Water with Surfactants as α-tocopherol Carriers

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    Microemulsions are relatively stable carrier agents for bioactive components. This study aimed to determine the characteristics of oil-in-water (O/W) microemulsions as carriers of α-tocopherol compounds in variations of α-tocopherol concentration, pH, and dilution. The O/W microemulsion was made from a mixture of surfactants (Tween 80, Tween 20, and Span 80) with virgin coconut oil (VCO) in a ratio of 85:15 with a total volume of 5 mL added with 10 mL of distilled water. The research used a randomized block design (RBD). The data were analyzed using ANOVA and continued with Tukey's test and regression analysis. Treatments in microemulsion were the addition of α-tocopherol with concentrations of: 0.25, 1.50, 1.75 and 2.0%. Observations were made on the turbidity index values, appearance, droplet diameter, and microemulsion stability. In addition, observations were made on the stability of the microemulsion at variations of pH (4.5, 5.5, 6.5), and dilution (10, 50, and 100 times). The results showed that the microemulsion was able to carry α-tocopherol compounds up to a concentration of 2% with a turbidity value reaching 0.1036 ± 0.0033% with a transparent appearance. A mixture of three surfactants (Tween 80, Tween 20 and Span 80) has the ability to increase droplet stability. The α-tocopherol microemulsion had a droplet diameter below 30 nm and stayed stable against the effects of centrifugation at pH 4.5 with dilutions up to 50 times and remained stable upto pH 6.5 with dilutions between 50 – 100 times

    Ecogel incorporated with nano-additives to increase shelf-life of fresh-cut mango

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    Fresh-cut mango is a very popular product commonly consumed due to its health and safety benefits to the community. The rise in cutting results, which increases respiration, ethylene production, oxidation, and browning processes, tends to shorten its life. Edible coating of aloe gel (Ecogel) serves as an additive matrix to extend the life of fresh-cut mango with the incorporation of antioxidant, acidulant, and antimicrobial additives. The edible coating ability is strongly influenced by molecular structure, size, and chemical constituents, with the nanoparticle used to determine the edible coating capability. This study, therefore, aims to determine the influence of incorporation nano-additive material and its concentration to extend the shelf life of the mango. The complete random design was used to determine the factorial pattern of citric, ascorbic, and potassium sorbate acid using a concentration of 0.15, 0.3, and 0.45 %. The mixture of nano-additives consists of citric acid, ascorbic acid, and potassium sorbate at a concentration of 0.15 %, which is the best formulation for Ecogel. The characteristics of fresh-cut fruit coated with Ecogel are suitable at a temperature of 7 ± 1 C until day 6. Therefore, Ecogel prolongs the shelf-life of fresh-cut mango

    Identification of Contaminant Fungi on Pedetan, an Dry Fish Product of Lemuru (Sardinella lemuru)

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    Dry fish products of Lemuru (Sardinella lemuru) known in Bali under the name "pedetan" is one kind of dried seasoned processed products that is quite popular among the people of Bali, especially in Jembrana Regency.  In general the process is done through drying lemuru fish in the sun so it is possible for them to grow and develop the contaminant fungi that may affect the health of consummers.  This study aims to isolate and identify fungi that contaminate pedetan.  Pedetan samples were taken from 10 villages which are the pedetan production centers in Jembrana Regency. The identification was done macroscopically, microscopically, and molecularly through analysis of 18S rRNA gene. The results of this study indicate that there are four types of fungi that are found as contaminants of pedetan, namely Aspergillus flavus, Aspergillus aculeatus, Aspergillus niger, and Aspergillus tubingensis. Efforts are needed to improve the composition of spices in order to maximally reduce the population of contaminant fungi in pedetan. Keywords: Sardinella lemuru, pedetan, contaminant fung

    Selection and the Growth Condition Optimization of Ethanol‐Producing Microbes Isolated from Ragi Tapai

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    Ethanol is a biofuel produced from renewable resources, which potentially plays an important role in solving future fuel problems. This study aimed to select the highest ethanol-producing isolate from candidates obtained from previously isolated candidates from ragi and cassava tapai. The selection process was conducted in 2 stages, namely: 1) Selection of the highest ethanol-producing isolate from seven isolate candidates using PYG media containing peptone, yeast extract, and glucose at 0.75%, 0.75%, and 15%, respectively and was followed by: 2) Optimization of the growth conditions of the highest ethanol-producing isolate, which was conducted at various temperatures of 27, 30, 33, 35, 37, and 40°C with the combination of various pH of 3.5, 4.5, 5.5, and 6.5. The experimental results showed that the R5I3 isolate was the highest ethanol-producing performance isolate, which yielded approximately 4.69±0.25% (v/v). Following the temperature and pH optimization of the fermentation processes, the optimum growth conditions were at 35°C and pH 5.5, where the ethanol produced was increased to 8.63 ± 0.04% (v/v). With these results, this new strain has the potential to be used in bioethanol production processes and other industrial applications

    Exploring Microbial Diversity in Green Honey from Pulau Banggi Sabah: A Preliminary Study

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    The microbiological composition of honey can include microorganisms that are beneficial or harmful to human health. Therefore, it is essential to investigate the microbiological quality of different honey types available in the market. However, there is limited information available on the analysis, isolation, and characterization of honey-associated microbes, especially for green honey from Banggi Island. Green honey is sourced from underground areas within the island's forest. This study aimed to assess the microbiological quality of raw (freshly collected) and processed green honey by examining the presence of bacteria, yeast, molds, and pathogens. The results revealed that raw green honey had a slightly higher total plate count (770 ± 0.03 cfu/g) compared to processed green honey (640 ± 0.02 cfu/g). Both raw and processed green honey contained Lactobacillus spp. with counts of 350 ± 0.02 cfu/g and 160 ± 0.02 cfu/g, respectively. Bacillus count was higher in raw green honey (110 ± 0.01 cfu/g) compared to processed green honey (5 ± 0.01 cfu/g). Molds were only detected in raw green honey, while osmophilic yeast counts were higher in raw green honey (16000 ± 0.03 cfu/g) compared to processed green honey (120 ± 0.02 cfu/g). Mesophilic bacteria, thermophilic bacteria, coliforms, E. coli, and Staphylococcus aureus were not detected in either raw or processed green honey. Furthermore, green honey was free from pathogenic bacteria such as Salmonella spp., Listeria spp., and Shigella spp. Bacteria isolated from green honey included Lysinibacillus macrolides, Lysinibacillus boronitolerans, Paenibacillus cineris, Paenibacillus favisporus, and Bacillus oleronius, none of which were pathogenic. This study identified important microorganisms present in green honey, which have the potential to provide beneficial effects without posing any harm to human health

    Physicochemical and antioxidant properties of Apis cerana honey from Lombok and Bali Islands

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    Limited honey production worldwide leads to higher market prices, thus making it prone to adulteration. Therefore, regular physicochemical analysis is imperative for ensuring authenticity and safety. This study describes the physicochemical and antioxidant properties of Apis cerana honey sourced from the islands of Lombok and Bali, showing their unique regional traits. A comparative analysis was conducted on honey samples from Lombok and Bali as well as honey variety from Malaysia. Moisture content was found slightly above 20% in raw honey samples from Lombok and Bali, adhering to the national standard (SNI 8664:2018) of not exceeding 22%. Both honey types displayed pH values within the acceptable range (3.40–6.10), ensuring favorable conditions for long-term storage. However, Lombok honey exhibited higher free acidity (78.5±2.14 meq/kg) than Bali honey (76.0±1.14 meq/kg), surpassing Codex Alimentarius recommendations (50 meq/kg). The ash content, reflective of inorganic mineral composition, was notably lower in Lombok (0.21±0.02 g/100) and Bali honey (0.14±0.01 g/100) compared to Tualang honey (1.3±0.02 g/100). Electric conductivity, indicative of mineral content, revealed Lombok and Bali honey with lower but comparable values than Tualang honey. Hydroxymethylfurfural (HMF) concentrations in Lombok (14.4±0.11 mg/kg) and Bali (17.6±0.25 mg/kg) were slightly elevated compared to Tualang honey (6.4±0.11 mg/kg), suggesting potential processing-related changes. Sugar analysis revealed Lombok honey with the highest sucrose content (2.39±0.01g/100g) and Bali honey with the highest total sugar content (75.21±0.11 g/100g). Both honeys exhibited lower glucose than fructose content, aligning with Codex Alimentarius guidelines. The phenolic content, flavonoids, and antioxidant activity were significantly higher in Lombok and Bali honey compared to Tualang honey, suggesting potential health benefits. Further analysis by LC-MS/MS-QTOF targeted analysis identified various flavonoids/flavanols and polyphenolic/phenolic acid compounds in Lombok and Bali honey. The study marks th

    The first ITS1 profiling of honey samples from the Southeast Asian region Lombok, Bali and Banggi Island

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    Southern Asian fowers ofer honeybees a diversity of nectar. Based on its geographical origin, honey quality varies. Traditional methods are less authentic than DNA-based identifcation. The origin of honey is determined by pollen, polyphenolic, and macro-microorganisms. In this study, amplicon sequencing targets macro-microorganisms in eDNA using the ITS1 region to explore honey’s geographical location and authentication. The variety of honey samples was investigated using ITS1 with Illumina sequencing. For all four honey samples, raw sequence reads showed 979,380 raw ITS1 amplicon reads and 375 ASVs up to the phylum level. The highest total number of 202 ASVs up to phylum level identifed Bali honey with 211,189 reads, followed by Banggi honey with 309,207 a total number of 111 ASVs, and Lombok represents only 63 ASVs up to phylum level with several read 458,984. Based on Shannon and Chao1, honey samples from Bali (B2) and (B3) exhibited higher diversity than honey from Lombok (B1) and green honey from Sabah (B4), while the Simpson index showed that Banggi honey (B4) had higher diversity. Honey samples had signifcant variance in mycobiome taxonomic composition and abundance. Zygosaccharomyces and Aspergillus were the main genera found in Lombok honey, with percentages of 68.81% and 29.76% respectively. Bali honey samples (B2 and B3) were identifed as having a signifcant amount of the genus Aureobasidium, accounting for 40.81% and 25% of the readings, respectively. The microbiome composition of Banggi honey (B4) showed a high presence of Zygosaccharomyces 45.17% and Aureobasidium 35.24%. The ITS1 analysis efectively distinguishes between honey samples of diferent origins and its potential as a discriminatory tool for honey origin and authentication purposes
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