PSRU Journal of Science and Technology

DEVELOPMENT OF COMPOSITES PLYWOOD FROM AGRICULTURAL WASTES MIXED HIGH-DENSITY POLYETHYLENE PLASTIC WASTES

2023-11-27T09:43:32+07:00

This research aims to develop composites plywood using rice straw, sawdust, and mixed high-density polyethylene (HDPE) plastic waste. The composites plywood was conducted by blending 33.33 wt.% minced rice straw with 66.67 wt.% sawdust, with an additional 0-10 wt.% of HDPE plastic to replace rice straw and sawdust. The materials were mixed with resin and hardener as binders and then pressed using a hydraulic machine at room temperature for 3 days. It was found that all composite plywood samples exhibited smooth surface textures and consistent thickness. The physical properties of a density and a water absorption were shown as 0.88-0.98 g/cm³ and 8.96-18.64 %, respectively. Thermal conductivity was appeared in the range of 0.202-0.222 W/m·K. The mechanical property of specifically bending strength was presented at 5.52-12.49 N/mm². It was exhibited that the bending strength decrease with increasing plastic content. The properties of composites plywood were evaluated according to Japanese industrial standards (JIS A 5905-2003) and found the corresponding to the standards for medium density veneers. However, the optimal fabrication of composite plywood is including the removal of rice straw and replacing it with HDPE plastic of 5wt.%. This research is a guideline for the development of composites plywood and the enhancement of the value of waste in the future.

ANTIOXIDANT ACTIVITY TOTAL PHENOLIC AND TOTAL FLAVONOID CONTENTS OF MELIENTHA SUAVIS FRUIT

2023-12-08T09:02:13+07:00

This research is aimed to study the antioxidant activity of Melientha suavis fruit pulp extract. The dried fruit pulp was macerated with methanol. After solvent evaporation, the extract was tested for antioxidant activity by using DPPH and ABTS methods which determined using vitamin C and Trolox as standards. The result showed that the extract exhibited antioxidant activity against DPPH and ABTS with IC₅₀ values of 32.78 and 30.06 mg/mL, respectively, which calculated as Vitamin C Equivalent Antioxidant Capacity (VCEAC) values were 1.52 and 1.00 mg vitamin C/g extract, respectively. The antioxidant activity showed Trolox Equivalent Antioxidant Capacity (TEAC) values of 1.83 and 0.66 mg Trolox/g extract, respectively. Total phenolic and total flavonoid contents were 209.0±44.6 mg GAE/g extract and 109.5±49.5 mg QE/g extract, respectively. The fruit extract was found to contain antioxidant compounds phenolics and flavonoids with a high antioxidant activity value. Therefore, it should be developed and used as food products, beverages such as tea powder, or applied as an ingredient in other foods.

CHARACTERISTICS OF PROTOTYPE COCOA PRODUCTS FROM THE OVERPRODUCTION PROBLEM-SOLVING PROJECT THROUGH STEAM EDUCATION WITH A FOCUS ON THE BCG ECONOMIC MODEL

2023-11-30T09:18:25+07:00

This research aims to study the physical, chemical, and biological characteristics of prototype products derived from technology transfer through the "Overproduction Problem-Solving Project through STEAM Education with a Focus on the BCG Economic Model" project. The project focuses on transferring technology for processing fresh cocoa into various cocoa-based foods for communities of farmers in the learning group in the Ban Rai district, Uthai Thani province. After completing the project, two prototype products, namely craft cocoa and chocolate bars, underwent microbiological analysis to determine the total bacteria, yeast and mold and the presence of Bacillus cereus in the samples. Additionally, physical properties such as particle size and surface characteristics of the products were examined under a Scanning Electron Microscope (SEM). Chemical properties, including pH, moisture content, acid value, and free fatty acid, were also analyzed. Craft cocoa and chocolate bars exhibited good quality due to controlled processing temperatures (well-tempered), with moisture content values of 2.82% and 2.34%, and pH values of 5.95 and 5.76, respectively. The percentage of free fatty acid (palmitic acid) in craft cocoa and chocolate bars was found to be 1.54% and 1.31%. Microbiological examination of the products, particularly chocolate, met the safety standards set by the Ministry of Public Health. The results demonstrate the potential of these value-added and safe food products for production in agricultural communities in the area.

EVALUATION OF TEXTURE, COLOR, AND CHEMICAL COMPOSITION OF LOW-FAT CHICKEN NUGGETS FORTIFIED WITH QUINOA

2024-02-02T08:35:48+07:00

Superfood quinoa can be utilized to produce novel, healthful meat products that are crucial for lowering the risk of chronic illnesses. Four low-fat, konjac-based nuggets fortified with 10% to 40% quinoa, viz., the control (without quinoa), were assessed for their textural properties and color chromaticity. In comparison to the control nugget, incorporating 10% quinoa increased the nugget's textural characteristics, including hardness, cohesiveness, springiness, and chewiness but lower lightness. Increasing to 20% to 40% quinoa made the nuggets have more deteriorated textural characteristics and a darker color. The use of quinoa can increase the fiber content and reduce the protein content of the nuggets. The finding reveals that the optimal addition of 10% quinoa can improve the nugget’s texture and fiber content. This provides basic information that has the potential to be scaled up to the industrial level.

ISOLATION OF PHOSPHATE SOLUBILIZING BACTERIA CAPABLE OF PRODUCING ACC DEAMINASE FROM SOIL OF DROUGHT AREA IN THE NORTHEASTERN THAILAND

2024-02-20T09:36:13+07:00

This research was to study the isolation of phosphate solubilizing bacteria capable of producing ACC deaminase from the soil of drought areas in the northeastern Thailand. Soil samples were collected from sugarcane fields and public forest areas in Chaiyaphum, Khon Kaen, Nong Bua Lam Phu, Maha Sarakham, and Roi Et provinces. Phosphate solubilizing bacteria (PSB) were isolated using spread plate technique on Pikovskaya agar. Subsequently, PSB isolates were tested for growth in Tryptic soy broth (TSB) with polyethylene glycol-6000 (PEG6000) at a concentration of 260 g/L to simulate drought condition and for their ability to produce the ACC deaminase enzyme. From the experiments, a total of 34 isolates of phosphate solubilizing and ACC deaminase producing bacteria were obtained. All isolates were identified by 16S rRNA sequencing. Sequencing analysis revealed that belonged to the following genera: Klebsiella (11 isolates), Burkholderia (9 isolates), Pantoea (7 isolates), Enterobacter
(5 isolates) and Bacillus (2 isolates). The activity of ACC deaminase ranged from 3.78×10^-4to 3.52×10^-2 Unit/mL, and the specific activity of ACC deaminase ranged from 2.18×10^-6to 9.84×10^-5 Unit/µg-Protein. Among the PSB, isolate S15-U4 exhibited the highest enzyme activity and specific enzyme activity for ACC deaminase The strain S15-U4 is suitable for further development as a phosphate solubilizing biofertilizer that can be effectively used in crop production in drought prone areas.

DEVELOPMENT OF CRISPY VEGETABLE CHIP FROM KALE

2024-03-31T15:23:46+07:00

This research aimed to develop crispy vegetable chips from kale product and studied the physical, chemical, microbiological properties and sensory evaluation to obtain a good quality product. The product of crispy vegetable chip from kale for two recipes were evaluated with the color value (L*, a*, b*), water activity (a_w), moisture content, nutritional value, total plate count, yeast and mold and consumer preference test. From the experimental result, it was found that L*, a*, a_w, moisture content, nutritional value of recipe No.1 and recipe No.2 of crispy vegetable chip from kale were increased significantly different (P≤0.05). However, the b* value was not significantly different (P˃0.05). The analysis of the total plate count and yeast and mold of the product of recipe No.1 has been compliant according to Thai community product standard of dried seaweed (TISI 515/2547). The product of crispy vegetable chip from kale with recipe No.1 differentiates from recipe No.2 by using sesame oil and soy sauce as ingredients has the highest score from panelists for every sensory attribute with moderately from sensory evaluation test. Therefore, recipe No.1 of crispy vegetable chips from kale is a suitable solution for transferring knowledge to Ban Suan Ngok Ngam community enterprise, Nan province to make the product to be a commercial distribution in the future.

THE EFFECT OF DIFFERENT MICROBES ON THE CHEMICAL PROPERTIES AND THE MACRONUTRIENT CONTENTS IN LADY FINGER SHOOTS BIO-EXTRACT FERMENTATION

2024-03-17T12:26:20+07:00

This research studied the effect of microbial types on their chemical properties and macronutrient content including nitrogen, phosphorus and potassium in Lady Finger shoots biofertilizer fermentation. The inoculants used in the study were Super PD.2, EM and Lacticaseibacillus casei. Fermentation materials consisted of banana shoots, water, molasses and inoculum in the ratio of 3 : 10 : 1 : 0.025 (by weight) fermented at room temperature without oxygen. The results showed that the physical and chemical changes during the biofertilization process in all experimental batches occurred rapidly during 30 days of fermentation. At the fermentation period of 2 months, bio-fertilizer using microorganisms Super PD.2. EM and Lacticaseibacillus casei show changes in electrical conductivity and acidity were not difference. From the comparison the amount of macronutrients, it was found that the formula containing L. casei inoculum, bio-liquid fertilizer gave higher nutrients N-P-K than the formula without addition. The liquid organic fertilizer formula 3, fermented for 30 days had the highest nitrogen, phosphorus, and potassium contents of 1.045%, 0.547%, and 0.516%, respectively. The means of variance (ANOVA) analysis showed that was significantly different at a 95% confidence level (P<0.05). This biofertilizer fermentation can be used to replace the use of chemical fertilizers, which are expensive. The soil is loose and does not pose an environmental problem.

THE FORMULATION FOR THROAT SPRAY FROM STINGLESS BEE HONEY PICKLED HERB FOR ANTIBACTERIAL ACTIVITY

2024-04-09T09:20:29+07:00

Stingless bee honey is an important substance consisting of phenolic and flavonoid groups that have the effect of inhibiting the growth of bacteria, anti-aging and wound healing in the respiratory system. According to traditional Thai medical wisdom, honey is commonly used in pickling herbs. In this research, stingless bee honey was developed to pickle herbs such as limes, lemongrass, and kaffir lime were used. The objectives of this research were to study the physical characteristics; and test the antibacterial activity of stingless bee honey pickled herbs and to develop a throat spray from stingless bee honey pickled herbs and accelerated stability test conditions. Results of a study on the physical characteristics of stingless bee honey pickled herbs, found that it is a yellowish-brown, non-separated liquid, sweet and sour taste, specific fragrance, and pH=6.65. Minimum inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC) values of S. aureus, S. pyrogens and S. pneumonia were 1.56-3.13 %v/v. The F4 was the best formula which consisted of stingless honey pickled herbs 4.40 mL, 95% ethyl alcohol 0.40 mL, menthol 0.08 g, sodium benzoate 0.004 g, poloxamer 1 g and boiled water qs to 20 mL. For the results of the accelerated stability test, it was found that the pH and precipitation were not significantly slightly changed. There were no changes in color, and taste and foreign matter to be found. Therefore, throat sprays from stingless bee honey pickled herb will be further developed so that the formula and manufacturing processes can be transferred to entrepreneurs in the future.

บทบรรณาธิการ

2024-08-28T09:29:52+07:00

บทบรรณาธิการ

สารบัญ

2024-08-28T09:45:19+07:00

สารบัญ