Gelatin, derived from animal tissues, is a widely used ingredient in the food industry. Fish gelatin has gained attention as a halal alternative due to its abundance, favorable functional properties, and versatility in food applications. However, tracing the origin of gelatin remains challenging, highlighting the need for reliable authentication methods. Conventional analytical techniques are often limited by long analysis times, low specificity, inability to detect source-specific markers, high costs, and the requirement for sophisticated instruments. This study investigated the volatile compound profiles of commercial gelatin from various fish species (pangasius, tilapia skin, tuna skin, and cod) and compared them with commercial pork gelatin by using Headspace Solid-Phase Microextraction coupled with Gas Chromatography-Mass Spectrometry (HS-SPME GC-MS) combined with multivariate data analysis. The HS-SPME GC-MS approach effectively classified gelatin samples based on their volatile profiles. Partial least squares-discriminant analysis (PLS-DA) identified five key discriminant volatiles for pork gelatin (decane, boronic acid, ethyl-, bis(2,2-dimethylpropyl) ester, m-anisoyl amide, N-(2-phenylethyl)-N-decyl, 1-pentadecene, and 2-tetradecanone) and four for fish gelatin (hexadecane, 1,2-oxathiane, 6-dodecyl, 2,2-dioxide, n-tridecan-1-ol, and 9-nonadecene), with decane and hexadecane identified as the most influential markers for pork and fish gelatin, respectively.
Coffee pulp waste, a by-product of the coffee industry, is often considered low-value and poses environmental concerns if not properly managed. However, its high pectin content presents potential for use in producing edible films. This study investigated the effect of citric acid concentration (0.1, 0.5, and 1 M) during extraction on the yield and characteristics of the pectin produced. The results showed that the higher the citric acid concentration, the higher the pectin yield, ranging from 7.7% at 0.1 M to 22.13% at 1 M. However, higher acid concentration resulted in decreases in equivalent weight (235.59±11.76 to 93.53±3.71 mg/eq), methoxyl content (5.43±0.22 to 1.86±0.00%), and degree of esterification (38.4±0.34 to 5.56±0.22%). In contrast, the galacturonic acid content increased (80.23±3.95 to 190.18±7.47%). FTIR analysis confirmed that higher citric acid concentrations significantly influenced the structural and chemical characteristics of the pectin. Overall, extraction using citric acid at concentrations of 0.1–1 M produced pectin classified as low-methoxyl and low-ester pectin, with potential applications in calcium-induced gel systems, low-sugar food products, thickeners, and biodegradable edible films. Future studies should optimize extraction conditions, including pH, temperature, time, and solvent-to-solid ratio, to enhance pectin yield and quality.
Fish processors usually discard fish bones as waste. The transformation of fish bones into carbon materials presents promising feasibility in view of sustainability. Acid-treated carbon is an inexpensive chemical adsorption material whose behavior is strongly related to its structural and compositional features. This work produced and characterized carbon materials from fish bone waste modified by H3PO4 and HCl. Snapper and red grouper (RG) fish bones were the raw materials. Heads of RG constituted 46.6% of the total weight, which is significantly higher than the 25.1% of snapper. While the bone and head of RG reached 18.11 and 17.38%, respectively, the snapper fish produced a higher percentage of 30% variability in nitrogen. The yield for acid treatment with H3PO4 was relatively higher (140%) than that of HCl (126.7%). The H3PO4-treated carbon showed FTIR peaks at 3646.58, 2989.79, 2348.43, and 1491.04 cm-1, while the HCl-treated carbon produced peaks around 3630.19, 2340.72, 1318.4, 1058, and 659.68 cm-1. The EDS analysis provided more carbon in HCl-treated samples (52.26%) than in H3PO4 (44.12%). The results provide initial compositional and structural analysis of acid-treated fish bone carbon. However, researchers should justify their practicability through additional experiments (e.g., BET surface area and adsorption performance tests) in the adsorption or water treatment fields.
This study explores the development of functional noodles made from modified beneng taro (Xanthosoma undipes K. Koch) flour, modified cassava flour (mocaf), and soy protein isolate (SPI) aiming to promote food diversification and offer a nutritious alternative for individuals with metabolic disorders. The research employed a completely randomized design (CRD) with three formulations as follows: F1 (50:40:10), F2 (50:35:15), and F3 (50:30:20) of modified beneng taro flour, mocaf flour, and SPI. The noodles was analyzed for dietary fiber, proximate composition, sensory evaluation, starch, and glycemic index. The modified beneng taro flour was produced through lactic acid fermentation using a commercially available mixed-culture starter (Bimo CF), followed by drying and milling. Dietary fiber analysis showed that formula F1 with 50% modified beneng taro flour, 40% mocaf flour, and 10% SPI had the highest fiber content (12.3 g/100 g). The sensory evaluation indicated that the formula F2 with 50% modified beneng taro flour, 35% mocaf flour, and 15% SPI was preferred for its color, texture, taste, and overall acceptance. Based on sensory preference, further nutritional, starch, and glycemic analyses were conducted on formula F2. The selected formula had a nutritional profile as follows: 13.2 g/100 g moisture, 2.6 g/100 g ash, 15.1 g/100 g protein, 1.2 g/100 g fat, 67.7 g/100 g carbohydrates, 64.1 g/100 g starch, 58.4 g/100 g in vitro starch digestibility, and 5.8 g/100 g resistant starch. The glycemic index was 43.6 (low) with a moderate glycemic load of 16.9. The postprandial glucose response showed better control than with pure glucose. The integration of modified beneng taro flour, mocaf flour, and SPI in formula F2 produced a nutritionally balanced noodle with good sensory qualities, high fiber and protein content, and a low glycemic index. This research highlights the potential of local ingredients for food diversification and the creation of healthier dietary options.
Obesity has become a reasonably high contributor to death in the world, with a prevalence showing a stable increase. The research aimed to determine total phenolic content (TPC), total flavonoid content (TFC), antioxidant capacity, and pancreatic lipase inhibitory activity of some extracts from basil (Ocimum basilicum) leaves, tamarind (Tamarindus indica) leaves, and gelugur (Garcinia atroviridis) fruits. They have been reported able to show anti-obesity effects by inhibiting the activity of pancreatic lipase. The extracts were prepared by ultrasonication with 70% ethanol and tested for TPC, TFC, DPPH, and FRAP antioxidant capacity, as well as pancreatic lipase inhibitory activity. The results showed that tamarind extracts showed the highest TPC, and this was in line with DPPH and FRAP antioxidant capacity, i.e., 38.84 µmol TE/g dried weight (dw) and 741.43 µmol TE/g dw, respectively. Meanwhile, the pancreatic lipase inhibition activity of the samples was still lower than that of the positive control (orlistat), with tamarind leaf extracts having the highest activity(IC50 154.63 µg/mL). Furthermore, phenolic compounds have a strong correlation to pancreatic lipase enzyme inhibition activity. Based on the results, tamarind had the highest TPC, antioxidant capacity, and pancreatic lipase inhibitory activity compared to basil leaves and gelugur fruit extracts.
Kencur (Kaempferia galanga L.) extract is rich in phenolic compounds that function as antioxidants, and it has also been reported to have anti-diabetic potential. To mask its undesirable aftertaste, the extract of kencur was microencapsulated using whey protein isolate (WPI), gum arabic (AGM), or maltodextrin (MDE). The antioxidant properties and essential oil content of spray-dried microencapsulated kencur extract were then compared with those of the pure extract. Microcapsules were prepared by dispersing kencur extract into each coating solution, homogenizing, and spray-drying the mixtures. The resulting microcapsules were evaluated for production yield, particle size distribution, morphology, antioxidant activity (percent radical scavenging activity, %RSA), total flavonoid content, and total phenolic content. Statistical analysis (ANOVA with Duncan’s post-hoc test at α= 0.05) identified significant differences among the coating materials. The microencapsulation yields were 67.21% with WPI, 58.64% with AGM, and 61.95% with MDE. The antioxidant activities (%RSA) of the microcapsules were 46.07% for WPI, 47.18% for AGM, and 44.89% for MDE. The flavonoid content was 18.19 mg QE/g for WPI, 19.29 mg QE/g for AGM, and 18.83 mg QE/g for MDE, while the total phenolic content was 5.76 mg GAE/g for WPI, 6.62 mg GAE/g for AGM, and 5.25 mg GAE/g for MDE. The coating materials significantly influenced microencapsulation yield, antioxidant activity, and total phenolic content (p<0.05), but the flavonoid content was unaffected. Overall, microcapsules with gum arabic (AGM) exhibited the highest antioxidant activity and phenolic content.
The research aimed to isolate and modify lysozyme from local chicken egg white to improve the antibacterial activity of lysozyme hydrolysates, and to characterize the isolated and modified lysozyme. Lysozyme was isolated from local chicken egg white using an ion-exchange resin. The lysozyme isolate was then modified with pepsin in a low-pH solution, and the pepsin-modified samples were neutralized to pH 7 before testing. The enzymatic activity of lysozyme was measured spectro-photometrically using Micrococcus lysodeikticus. The antibacterial activity of lysozyme was tested using the microdilution method. The lysozyme was characterized by SDS-PAGE and RP-HPLC. The yield of lysozyme isolate was 5.35±0.23% (n= 3) with a lysozyme concentration of 41.07±4.44 mg/g (n= 3). After dialysis, the lysozyme concentration was 143.24±8.32 mg/g (n= 3). The enzymatic activity of the lysozyme isolate was 4,778±1,835 unit/mg (n= 3). The modification of lysozyme improved its antibacterial activity by decreasing its MIC value from 6 mg/mL (or >6 mg/mL) to 3 mg/mL and increasing its antibacterial spectrum to include Bacillus cereus, Staphylococcus aureus, Salmonella Typhimurium, and Escherichia coli. However, all low-pH treatments against E. coli reduced the MIC value only from >6 mg/mL to 6 mg/mL. The SDS-PAGE and RP-HPLC profiles of the lysozyme isolate showed that it had the same molecular weight (MW) and retention time (RT) as the standard lysozyme, with values of approximately 14.70±0.43 kDa (n= 3) and 43.59±0.09 min (n= 3), respectively. The modification of lysozyme also affected its enzymatic activity and SDS-PAGE and RP-HPLC profiles, explaining why the antibacterial activity increased.
Chia seeds (Salvia hispanica) and basil (Ocimum basilicum) are known to have high fat content. The chemical components of chia and basil consist of protein (20.89 and 26.05%), fat (37.61 and 26.03%), carbohydrates (36.81 and 42.47%), ash (4.69 and 5.45%), and water (7.40 and 7.75%) respectively. The research aimed to determine the antioxidant activity of chia and basil seed oil and their fatty acid profiles. The high fat content was used to extract oil using the hexane solvent maceration method, carried out in two repetitions.. The yields of chia seed oil (21.39%) and basil seed oil (16.99%) based on the t-test showed they were significantly different. Seed oil quality was measured by testing water content, and results were obtained that met SNI 3741-2013 and SNI 01-3720-1995 standards. The total phenolic content of chia seed oil (1.69%) and basil seed oil (1.62%) showed that the results were not significantly different. The antioxidant activity of seed oil was tested using the DPPH and FRAP methods, which showed that chia seed oil had more excellent antioxidant activity than basil seed oil. The fatty acid composition was tested using gas chromatography with a flame ionization detector (FID). The fatty acid profile results from chia and basil seed oil showed that the highest fatty acid was linolenic acid in chia seed oil at 62.72% and basil seed oil at 54.73%, followed by linoleic fatty acids (19.71% in chia seed oil and 20.19% in basil seed oil) and oleic (6.66% chia seed oil and 12.04% basil seed oil). The research results show that chia and basil seed oil have antioxidant activity and contain high levels of PUFA, thus strengthening their nutritional value and health benefits to be used as functional food ingredients.
Cocoa butter characteristics vary between origin, therefore influencing its industrial quality and application. This study investigated physicochemical characteristics of cocoa butter from eight districts in Central Sulawesi, Indonesia. Cocoa butter was extracted with a hydraulic press and analyzed for free fatty acids (FFA), moisture content (MC), slip melting point (SMP), fatty acids profile using GC-FID, triacylglycerol profile using HPLC-RID and solid fat content (SFC) profile convert from DSC melting curve. Data were analyzed using one-way ANOVA (p<0.05), followed by Tukey’s HSD test for multiple comparisons. Principal component analysis (PCA) was performed to identify geographic clustering patterns. Significant differences were observed across districts. Samples FFA were complied with the Indonesian, CODEX, and industry standard, except cocoa butter from BG. Major fatty acids were detected, such as palmitic (24.08–27.42%), stearic (27.78–35.37%), oleic (32.48–40.45%), as well as major triacylglycerol such as POP (14.87–18.55%), POS (40.91–43.37%) and SOS (27.28–31.42%). Slip melting point range from 29.5–32.22 °C. Butter contain 60.8–74.3% solid fraction at 20 °C, then rapid melting to 30 °C. Strong positive correlation was found between FFA, UFA, and MUFA. Conversely, those variable correlate negatively with SFA, SFC 25 °C, and SMP. PCA revealed four geographic clusters which show that geographic origin influence variation in fatty acid composition, triacylglycerol profile, and melting behavior. These findings show distinct regional profiles and confirm Central Sulawesi’s potential as a source of high-quality cocoa butter for industrial applications.
Purple sweet potato (Ipomoea batatas var. Ayamurasaki), a crop widely cultivated in West Java, is notable for its high anthocyanin content and antioxidant potential. This study examined the effect of pre-gelatinization, via steaming or boiling, on the physicochemical, functional, and bioactive characteristics of purple sweet potato flour, as well as its application in analog rice. Flour samples were prepared in non-pre-gelatinized and pre-gelatinized (steamed or boiled) forms, then dried, milled, and analyzed for color, pasting profile, proximate composition, total phenolic, anthocyanin, and antioxidant activity. The flours were subsequently used to produce analog rice, which was evaluated for cooking and sensory qualities. Pre-gelatinization significantly increased color intensity, with a* values ranging from 13.76 (boiled) to 17.67 (steamed), while non-pre-gelatinized flour exhibited a higher L* value (49.19). Non-pre-gelatinized flour demonstrated a pasting onset temperature of 80.9 °C and the highest final viscosity (1,769 cP), whereas pre-gelatinized flours showed no detectable pasting onset and reduced setback viscosity, decreasing from 668 cP (non-pre-gelatinized) to 611 cP (boiled) and 350 cP (steamed). Total phenolic content increased from 73.41 to 92.73–114.20 mg GAE/100 g, as well as anthocyanin rising from 0.48 to 0.63–0.77 mg CyE/g. In addition, DPPH scavenging activities rose from 74.71% to 84.05–97.70%. Analog rice produced from pre-gelatinized flour exhibited a deeper purple color, shorter cooking time (3.3–3.4 min vs. 4.3 min), and more pronounced sticky, soft, and chewy textures. Steaming was identified as the most effective pre-gelatinization method for improving flour functionality and enhancing bioactive compound retention.
The rising demand for non-dairy probiotic beverages has driven interest in fruit-based carriers such as mango juice. However, acidic conditions in such products can reduce probiotic viability. To maintain their health-promoting effects, probiotics are required to survive gastrointestinal tract. This study investigated the effect of microencapsulation of local lactic acid bacteria (LAB) with probiotic potential, Lactiplantibacillus plantarum 4C161 and Lacticaseibacillus rhamnosus BD2, in alginate on their tolerance to pH 2.5 and 0.5% bile salt, and their viability in mango juice during 28 days of storage at 4°C. Emulsion-based microencapsulation was performed by dispersing a 4% alginate solution containing the LAB in soybean oil with Tween 80 as emulsifier, and solidifying using CaCl2. Microencapsulated of both LABs in alginate showed higher tolerance to acidic and bile conditions than their free cells, with encapsulated cells viability reductions in low pH was 0.42 and 0.33 log CFU/g and bile salt was 0.13 and 0.17 log CFU/g respectively, while those of free cells were 0.97 log CFU/mL and 0.72 log CFU/mL for low pH, and 1.0 and 0.8 log CFU/mL for bile salt respectively. During storage, viability of both free cells and microencapsulated LAB showed only slight decreased after 28 days. Microencapsulation resulted in a smaller decrease during storage of mango juice pH (0.37–0.45) and less increase in total titratable acidity (TTA) (0.007–0.008%) compared to free cells. This study suggested that microencapsulation in alginate improves the survival of the tested probiotic candidate toward harsh condition of gastrointestinal tract. Mango juice has been shown to be a suitable carrier for both LAB with probiotic potential.
The quality assessment of black tea infusion in Indonesia is currently relies on general and less specific sensory evaluations. This study aimed to develop a sensory lexicon specifically for Indonesian black tea infusion, which will include clear definitions and reference standards for each attribute. The lexicon was constructed through expert panelist interviews and focus group discussions (FGD) involving trained panelists who had passed a selection process based on basic taste and aroma identification and triangle test. A total of 30 black tea samples were evaluated in three FGD sessions, each involving at least six panelists. The study identified sensory attributes categorized into six main groups: appearance, aroma, flavor, taste, aftertaste, and mouthfeel. The lexicon includes both desirable quality attributes and defect indicators that reflect a decline in product quality. Each attribute was accompanied by a definition and a reference standard with intensity levels based on a 0–15 scale. This sensory lexicon provides a foundation for developing of a more objective, systematic, and measurable sensory quality standard for Indonesian black tea.
Flakes are ready-to-eat cereals generally made from wheat and commonly consumed as a crispy breakfast substitute. In this study, a blend of modified cassava flour (Mocaf) and moringa leaf powder is formulated to produce a gluten-free flake. Since the use of both ingredients may adversely affect the aroma and taste of the product, another ingredient, such as “kepok” banana flour, could be incorporated into the formulation. This study aimed to investigate the effects of “kepok” banana flour incorporation on the physicochemical and sensory characteristics of the flakes made from the composite of Mocaf and moringa leaf powder. A completely randomized design was applied with different levels of “kepok” banana flour (0, 15, 30, 45, and 60%), with each treatment replicated three times. The data were analyzed by using Analysis of Variance (ANOVA) and followed by Duncan’s Multiple Range Test to verify significant differences between means. The results demonstrated that the concentration of “kepok” banana flour significantly affected (p<0.05) the physical, chemical, and sensory properties of the flakes. The flake achieved the most satisfying physicochemical and sensory properties when banana flour was added at 45%, resulting in a composition of 6.7% moisture, 2.2% ash, 5.5% protein, 20.9% fat, 64.7% carbohydrate, and 25.9% total sugar. The crispness retention of the flakes in milk was recorded at 10.1 minutes before notable softening occurred, while its appearance was brownish-green in color. Sensory evaluation revealed a mildly distinctive banana aroma, a slightly crisp texture, and a subtly banana taste. Mocaf-moringa flakes with the addition of 45% “kepok” banana flour exhibited an antioxidant activity of 33.8%, total phenolic content of 9.1 mg GAE/100 g, dietary fiber content of 10.2%, and resistant starch content of 9.9%, indicating their potential for development as a functional food.
Coffee consumption in Indonesia has expanded significantly alongside the rapid growth of café culture, creating demand for diverse modern iced coffee offerings. This development highlights the importance of dynamic sensory methods in capturing evolving perceptions in realistic settings. This study characterized the temporal sensory profiles of five modern iced coffee variations-Arabica iced Americano, Arabica iced latte, and three Robusta-based flavored coffee-milks (iced salted caramel, iced Irish, and iced butterscotch)-using the temporal dominance of sensations (TDS) method in a coffeeshop environment. A sensory lexicon was established through a focus group discussion (FGD) with eight consumers and applied in consumer-based TDS evaluations. The results demonstrated distinct sensory dynamics between black coffee and milk-based beverages. Americano was dominated by bitterness and roasted notes, with intermittent acidity. In contrast, flavored coffee-milk samples were consistently characterized by sweetness and chocolate as dominant attributes, resulting in confectionery-like profiles. Multivariate analysis, including a principal component analysis (PCA) that explained 89.46% of the total variance, confirmed two distinct clusters: (1) Americano and latte, characterized by bitterness and roasted notes, and (2) flavored coffee-milks, dominated by sweetness and chocolate. These findings highlight the suitability of TDS for evaluating dynamic sensory changes in café-style beverages, providing practical insights for optimizing recipes optimization and differentiating products in the modern coffee industry.
Microfiltration (MF) is a non-thermal technique for microbial removal; however, it may also alter sensory and physicochemical properties, as compounds larger than the membrane surface or pore size are excluded. This study aimed to optimize the formulation of Java tea-based functional drink prepared with microfiltered extracts to achieve a balanced composition with optimum antioxidant and antihyperglycemic activities and sensory acceptability. The results showed that the 0.2 μm MF reduced microbial counts to below the detection limit (<1x100 CFU/mL). Filtration also altered the physicochemical properties, causing significant changes in color, pH, particle size, polydispersity index, and total dissolved solids. A D-optimal mixture design was employed using Design-Expert version 13, considering five factors: proportion of Java tea, sappan wood, ginger, lime, and kaffir lime extract. A total of 25 formulations were evaluated for antioxidant activity, antihyperglycemic potential, and sensory acceptability. The developed models exhibited strong predictive performance, except for aroma, which was excluded from optimization. The optimum formulation was chosen based on the highest desirability index (0.936). The verified optimized formulation resulted in an antioxidant activity of 588 ppm AEAC, an α-glucosidase inhibition of 59.9%, and a hedonic taste score of 6.7 on a 9-point scale. Compared with pasteurized or commercial counterparts, the optimized microfiltered formulation showed no detectable microbial colonies, higher bioactivity than the pasteurized sample, and superior color and overall sensory acceptability.
This study investigated the effect of particle size on the physical properties of red ginger (Zingiber officinale var. rubrum) powder. The parameters analyzed included flow characteristics (bulk density, tapped density, Hausner ratio, compressibility index, and angle of repose), water content, water solubility, color, and morphology. Red ginger powder (RGP) samples were prepared across the millimeter-to-nanometer particle-size range with D50 values of 2256, 2066, 636, 580, 47.38, 40.37, 39.98, 34.82, and 0.22 μm. As the results, the particle size of RGP decreased from coarse (D50 2256 μm) to fine (D50 40.37–34.82 μm). While the bulk density fluctuated (0.32–0.34 g/cm³), the tapped density increased consistently (0.36–0.56 g/cm³). This increase in density was accompanied by rises in the Hausner ratio (1.12–1.73), compressibility index (10.77–42.17%), and angle of repose (22.98–39.71°). However, when the particle was further reduced to the nanopowders (D50 0.22 μm), the Hausner ratio, compressibility index, and angle of repose slightly decreased to 1.54, 34.95%, and 37.07°, respectively, which were lower than the values at D50 34.82 μm. The reversal occurs because the agglomerates behave as larger particles, with cohesive van der Waals forces predominantly affecting them. Water solubility and color brightness (L*) increased significantly with decreasing powder particle size, from 19.64 to 31.65% and from 27.9 to 55.4. Increase in surface area is thought to enhance solvent and light interactions. Water content increased from 10.51 to 15.06% as particle sizes decreased from 2256 to 47.38 μm, but decreased to 10.81% in nanopowders (D50 0.22 μm), likely due to agglomeration that reduces the accessible surface area. Overall, this study revealed that particle size reduction improved the water solubility, brightness, and density of RGP, particularly on the nanoscale, highlighting particle size control as a critical factor in food product development.
Pulsed electric field (PEF) is a non-thermal food-processing technology that increases cell-membrane permeability, thereby facilitating mass transfer and the movement of biomolecules across the membrane. Although PEF has been widely applied to liquid foods, its use in solid food matrices remains limited because of challenges in designing treatment systems and controlling process parameters. This study aimed to develop and characterize a laboratory-scale PEF system for solid-food pretreatment and to evaluate its application for oxalate reduction in taro (Colocasia esculenta) tubers. The developed PEF system consists of five components: a high-voltage power supply based on a flyback converter, a capacitor bank for energy storage, a high-voltage SiC MOSFET switch, and an ESP32 microcontroller for pulsed control and a treatment chamber with stainless steel electrodes. Electrical characterization showed that the PEF system successfully generated monopolar rectangular pulses with a maximum output of 3 kV, pulse widths from 400 ns to 19.2 µs, and frequencies from 5.9 kHz to 1.98 MHz. The treatment chamber was designed with adjustable electrode spacing (0.5–3.5 cm), enabling a wide range of electric field strengths while maintaining the same pulse-generation system. Application of the PEF system at 1.08 kV/cm for 10 s reduced oxalate content in taro tubers by up to 39%. These results demonstrate the laboratory-scale PEF system's capability to generate controllable, high-voltage pulses suitable for solid-food pretreatment.
Glutamic acid is an additive compound widely added to food to enhance the savory taste (umami). Lactic acid bacteria (LAB) are included in Generally Recognized as Safe (GRAS) and have the potential to produce various metabolite compounds, including glutamic acid, through fermentation. LAB can be isolated from salted mustard greens and dangke cheese. This study aimed to analyze the effect of LAB isolate types and fermentation time on the production of glutamic acid, glutamic acid profiling, and molecularly identify the LAB genus that produces the highest glutamic acid based on the 16S rRNA gene. The fermentation process of LAB was carried out using four selected isolates: D16, D15, S4, and S15, which were isolated from salted mustard greens and dangke cheese. Each isolate was incubated for five different incubation times: 0, 12, 24, 48, and 72 h. The identification of glutamic acid was carried out using the Thin Layer Chromatography (TLC) method, its quantification by spectrophotometry, and profiling by High-Performance Liquid Chroma-tography (HPLC). In addition, molecular identification of the highest-producing LAB isolate was conducted based on the 16S rRNA gene. The results showed that isolate S4 from salted mustard greens produced the highest glutamic acid after 48 h, with 670.05 mg/L and a total glutamic acid of 0.23% (w/w) based on HPLC results. Isolate S4 is known to be molecularly similar to the Pediococcus pentosaceus species. Local LAB isolates from salted mustard greens and dangke cheese can produce glutamic acid that can be used to enhance the taste of fermented foods.
Bacillus cereus is a heat-resistant spore-forming bacterium that has been linked to outbreaks of foodborne illnesses. Rendang is a traditional Indonesian food made from beef heated in coconut milk and seasoning consisting of various kinds of spices (bumbu rendang) which is thought to inhibit germination of bacterial spores. This research aimed to determine the fate of B. cereus spores during heating and storage of rendang. Spores of B. cereus were inoculated into rendang mixture (beef, bumbu rendang, coconut milk) and control (beef and coconut milk) to achieve a spore concentration of 5 log CFU/g. Rendang mixture or control was heated for 6 h to produce rendang with water content of 35.77% (db) and aw of 0.90. For storage study, rendang after heating was inoculated with 5 log CFU/g spores and stored at room temperature for 4 days. The number of total bacteria and spores was enumerated using total plate count (TPC) method. The number of B. cereus spores decreased during heating in rendang and control, but the decrease rate was slightly faster in rendang than that in control. At the end of heating, spores were reduced by 5 log cycles to <1 log CFU/g in rendang and control. The number of B. cereus spores in rendang and control decreased insignificantly during storage at room temperature. However, the total number of B. cereus in control showed an increase, suggesting possible germination, which was not observed in rendang. This research suggests that spices in bumbu rendang may contribute to inactivation of B. cereus spores during heating and inhibition of their germination during storage.
The jack bean plant (Canavalia ensiformis L.) contains storage proteins composed of essential amino acids, and the biological activity of these components occurs after a hydrolysis process. The hydrolysis of peptide bonds that appear in the digestive tract can be identified using an in silico approach that utilises a bioinformatics web page. This study aims to predict bioactive peptides resulting from the hydrolysis of storage proteins in the jack beans using a web-based in silico method. Based on literature studies, the jack bean’s dominant storage proteins include canavalin, concanavalin A, and concanavalin B. The amino acid sequences of each type of protein were obtained from the Universal Protein Resource (UniProt) page. Simulations of hydrolysis or cleavage of peptide bonds in the body using Gastrointestinal System (GIS) enzymes, in the form of pepsin, trypsin, and chymotrypsin or a combination thereof, were carried out in the Expert Protein Analysis System (ExPASy) portal on the Peptide Cutter page. The bioactive peptides resulting from the cleavage were identified for their suitability based on the literature using the BIOPEP-UWM database. The simulation results indicate that all jack bean storage proteins possess biological properties, including antihypertensives, antidiabetics, and antioxidant effects. Concanavalin A produced the highest bioactive peptide yield of 82.89%, followed by concanavalin B at 64.23%, and canavalin at 48.95%. The estimation of bioactive peptides from jack bean storage proteins by hydrolysis of body proteases using an in silico approach proved helpful. It can be further applied to other protein sources using different enzyme combinations.
