Chiang Mai Journal of Science

     This study aims to obtain a combination of probiotic strains resistant to stress conditions, which good effect the qualitative properties of heat-treated sausage. Lactic acid bacteria (LAB) strains were identified by matrix-assisted laser desorption-ionization-time of flight mass spectrometry (MALDI-TOF MS) after phenotypic evaluation and evaluated for probiotic potential including acid and bile salt tolerance, antibiotic resistance, and antibacterial activity. All tested Lactiplantibacillus plantarum strains showed high antibacterial activity. L. plantarum (PeE2) and additionally two Enterococcus strains with the best probiotic properties were selected among the strains. Except for the control group, 6 different sucuk doughs were prepared using them as mixed cultures. The ripened sucuk doughs (18 h, 4 ºC) were subjected to fast-drying (30 min, 60 ºC), heat-treated (64 ºC of inner temperature) and rapid-drying (10 min, 75 ºC) stages. The quality characteristics of samples were determined during storage (days 7, 14, and 21). Coliform bacteria growth ≤1 log cfu/g determined on the final day of storage. The lowest TBARS value was determined in L. plantarum +E. faecium (1:1 ratio) mixed culture. Regarding L* and a* color values, lower results were observed in the control group during storage. Using probiotic culture significantly affected textural values, taste and general acceptability (p<0.05) and contributed to the quality parameters. The result of the study may support the development of a new approach for using new probiotics in meat products.

     In this study, five metabolites were successfully isolated from the culture medium of Tubeufia longihelicospora strain GZCC 23-0405, comprising two dimeric naphtha-γ-pyrones (1–2), two dimeric coumarins (3–4), and one alkaloid (5). The elucidation of their chemical structures relied on a combination of NMR, MS, and optical rotation methods. Interestingly, these compounds represent the first instances of such metabolites being isolated from helicosporous hyphomycetes. Additionally, compounds (1) and (2) exhibited significant antimicrobial potential, with MIC and MBC values of 62.0 μg mL-1 and 248 μg mL^-1, respectively, against Pseudomonas aeruginosa. This study provides a comprehensive account of the extraction, isolation, structural characterization, and antimicrobial properties of these compounds, shedding light on their potential significance in the field of natural product research.

     Bamboo shoots are a significant agricultural commodity in Thailand. Processing bamboo shoots generates considerable waste, which poses logistical and environmental challenges. This study explored the enhancement of physicochemical properties of dietary fiber (DF) extracted from bamboo shoot waste through various enzyme combinations and sequences. The shoot base and strip portions were treated with combinations of amylase, protease, glucoamylase, lipase, cellulase, and xylanase. The highest DF yields were obtained from the shoot base using amylase, protease, and lipase (APL; 15.37±0.22 g/100 g), and from the shoot strip using amylase, glucoamylase, and protease (AGP; 9.43±0.06 g/100 g). Lipase-containing treatments increased soluble DF (SDF) content. Color, water-holding capacity (WHC), swelling capacity (SC), and oil-binding capacity (OBC) were analyzed. WHC and SC were notably enhanced by lipase-containing treatments (bamboo shoot strip: WHC 14.06±1.80 g/g with APL-X and SC 11.89±2.11 mL/g with APL-G; bamboo shoot base: WHC 10.46±0.37 g/g with AGP-L and SC 8.71±0.30 mL/g with AGP-L). The findings demonstrate that specific enzyme combinations can significantly improve the functional properties of dietary fiber extracted from bamboo shoot waste. This valorization of waste material has the potential to create value-added food and supplement products.

     Pickled mustard green (Brassica juncea) is a traditional fermented vegetable product in Thailand, commonly used as a culinary ingredient due to its distinctive flavor. However, community-level pickled mustard production often faces challenges in terms of consistent physical and chemical characteristics. This research aims to improve the quality of pickled mustard greens (PMGs) at the community level. The study investigated the effects of different fermentation processes on the chemical, physical, and volatile organic compound profiles of pickled mustard greens. Five fermentation treatments were compared, varying in starter culture concentration (0% and 2%), salt content (0% and 5%), sugar content (5% and 10%), and vinegar addition (0% and 5%). The results investigated that the treatment with lactic acid bacteria, salt, sugar, and vinegar (at concentrations of 2%, 5%, 5%, and 5% respectively) has a positive correlation with the physical quality of the PMGs. Significant differences in pH, titratable acidity, and salt content were found between inoculated and uninoculated samples. Hydrocarbons were identified as the primary compounds contributing to the flavor across all fermentation methods. These findings offer valuable guidelines for improving pickled mustard production, benefiting communities and private sectors involved in this field.

     Hyperglycemia among hospitalized patients is associated with an increased risk of mortality and infectious complications. In critically ill patients, hyperglycemia often occurs as a physiological response to stress. For critically ill patients who require nutrition support but have severe malabsorption or intolerance to polymeric formulas, oligomeric formulas may be beneficial. However, hyperglycemia might be a concern with these oligomeric formulas. This study aimed to determine the glycemic index (GI) of a test food, TOP-OP13NPD, a high-protein peptide-based enteral formula. The GI value of TOP-OP13NPD was determined following the protocols outlined in the International Organization for Standardization 26642:2010, involving 10 healthy adults (with an equal proportion of males and females). Both the reference glucose and test food provided 50 g of carbohydrates, and participants’ blood glucose levels were monitored for two hours. After consuming TOP-OP13NPD at 15, 30, 45, and 60 minutes, subjects exhibited significantly lower blood glucose levels than those on the glucose reference diet (p < 0.001). The incremental area under the curve at 120 minutes was also significantly lower compared to the glucose reference diet (1,380.08 ± 276.48 and 3,082.59 ± 677.16 mg × min/dL; p < 0.01). The mean ± SEM GI value of the test food was 48.62 ± 5.86. TOP-OP13NPD is classified as a low glycemic index diet. This result suggests that this formula may be suitable for individuals requiring oligomeric enteral nutrition who need to control their blood glucose levels.

     This study aimed to synthesize a new chemosensor, namely 1,1’-(1,4-phenylene)bis(3-(4-nitrophenyl)thiourea), specifically designed for detection of H2PO4−. The compound was characterized using FTIR, LC-MS, 1H NMR, and 13C NMR, while the colorimetric sensing abilities were validated through various analyses. These include linearity, limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy using UV-Vis spectrophotometry, RGB, and HSV color components. Digital images of color changes were captured using a smartphone camera and Color Grab app was used to quantify color components. Subsequently, anions test (NO3−, Cl–, HSO4−, and H2PO4−) were conducted in acetonitrile, where the addition of H2PO4− induced a distinct color change from colorless to yellow. The results showed that detection of H2PO4− depended on pH of the solution, with no color change observed at pH 1-3 due to anions converting to acidic species. At pH 5, H2PO4− was detected as a yellow color change, and alkaline conditions led to different color responses. Furthermore, UV-Vis detection showed recovery values of 99.80% to 100.6%, indicating high accuracy. RGB and HSV color component-based sensors showed recovery values of 101.6% to 114.4% and 92.50% to 110.2%, respectively. The LOD of the UV-Vis, RGB, and HSV methods were 0.16 μM, 0.46 μM, and 0.18 μM, while LOQ values were 0.54 μM,1.52 μM, and 0.61 μM, respectively. In conclusion, the synthesized chemosensor showed potential for accurate and sensitive detection of H2PO4− using UV-Vis spectrophotometry and digital colorimetric-based image.