Agriculture and Natural Resources

Spatial model of forest area utilization in integration of production forest functions, Central Sulawesi, Indonesia

Wed, 14 Feb 2024 00:00:00 +0700

Importance of the work: The determination of the function of limited and permanent production forests has different land- and climate-limiting factors. Therefore, environmental damage is feared when using integrated production forest areas as stipulated in a Government Regulation of the Republic of Indonesia.
Objectives: To identify models applicable to dryland ecosystems for the utilization of forest areas in the spatial integration of producing good functions.
Materials & Methods: A limited production forest study area covering 500.28 ha was investigated using a descriptive method with a spatial data simulation approach utilizing GIS technology.
Results: The spatial models of forest area utilization in the integration of forest functions were: Model 1 (local protected area); Model 2 (utilization of timber forest products in a natural forest with delayed selective logging); Model 3 (utilization of timber forest products in a natural forest with selective logging); Model 4 (reforestation/plantation forest pattern rehabilitation); and Model 5 (rehabilitation of agroforestry patterns), with areas of 374.48 ha, 74.59 ha, 0.35 ha, 50.11 ha, and 0.75 ha, respectively.
Main finding: The delineation of the five spatial models of forest area utilization in the integration of production forest functions needs to be followed up with testing at the site level.

Glycemic responses of special rice: Case study in Thai geographical indication rice cultivars

Chutima Lerdluksamee, Wararat Srikaeo, Khongsak Srikaeo — Wed, 14 Feb 2024 00:00:00 +0700

Importance of the work: Thai geographical indication (GI) rice cultivars which are special rice types, have not been evaluated for their glycemic responses.
Objectives: This study aimed to determine the glycemic indices and glycemic loads of 10 rice varieties registered as Thai GI rice.
Materials & Methods: The 10 Thai GI rice varieties; Kum Lanna, Rai Leum Pua Petchabun, Kalasin Kaowong, Hom Mali (Phayao, Thung Kula Rong-Hai and Surin), Leuang Patew Chumphon, Rai Dawk Kha Phangnga, Sangyod Muang Phatthalung, and Jek Chuey Sao Hai were analyzed for their glycemic responses using the standard in vivo method.
Results: It was found that Thai GI rice varieties exhibited medium to high glycemic indices and all samples showed high glycemic load values (>20). The glycemic indices ranged from 62.3 (Sangyod Muang Phatthalung) to 82.3 (Kalasin Kaowong). Glycemic indices were discovered to be primarily impacted by variety rather than geography.
Main finding: This study was the first to report the glycemic indices of 10 Thai GI rice cultivars and updated the glycemic index database of special rice types, allowing consumers to select healthier rice varieties, such as ones with medium glycemic indices.

Growth, total lipid content and fatty acid composition of Amphora sp. isolated from Gulf of Thailand as alternative lipid source in larviculture

Wed, 14 Feb 2024 00:00:00 +0700

Importance of the work: Amphora sp. strains contain a high lipid content that could be an excellent substitute ingredient in fish meal and fish oil.
Objectives: To evaluate the growth performance and lipid content of four Amphora sp. strains isolated from four different locations in the Gulf of Thailand.
Materials & Methods: Four Amphora sp. strains—Sichang Island (ASC), Samaesarn Island (ASS), Pran Buri (APB) and Laemyai (ALY)—isolated from four different locations in the Gulf of Thailand were cultured in F/2 medium for 13 d. Biomass and the specific growth rate (SGR) of the experimented Amphora sp. were determined. Two Amphora sp. strains with high biomass performance were further investigated for their lipid content and fatty acid composition.
Results: Among the Amphora sp. strains, ASC had the highest biomass production (1.01×106 cells/cm2), followed by ALY (3.75×105 cells/cm2), with the biomass performance of these two strains being significantly higher than for the other two strains. ALY had the fastest growth rate, while ASC grew more slowly, but was more stable. The mean (±SD) maximum lipid content of ALY was 74.35±2.46%, while that of ASC was 45.38±4.18%. The major UFAs detected in both strains included eicosapentaenoic acid, docosapentaenoic acid, docoxahexaenoic acid and stearidonic acid.
Main finding: ALY, with the fastest growth rate and the highest lipid content was the most efficient candidate for mass production, while ASC was more tolerant as an aged culture, which should be useful for long-term mass production.

Coupled Eulerian-Lagrangian simulation of spray-drying skimmed milk powder

Pornpen Nualnuk, Somboon Sukpancharoen, Thongchai Rohitatisha Srinophakun — Wed, 14 Feb 2024 00:00:00 +0700

Importance of the work: Drying skim milk powder is a complex process dependent on the drying temperature, airflow and residence time distribution in the spray dryer. Stickiness can impact production.
Objectives: To simulate the movement of particles within the spray dryer, and account for the observed stickiness of the skimmed milk powder.
Materials & Methods: 1) The model was validated using available published data to determine model accuracy. 2) The model was used for airflow pattern prediction. 3) The particle residence time was predicted. 4) The stickiness was predicted in the context of the spray drying process. 5) The final component simulated the spray drying process itself.
Results: A three-dimensional CFD simulation was performed for a co-current pilot plant spray dryer using a pressure nozzle for the purpose of spray drying skimmed milk powder. The simulated data agreed with published experimental findings, suggesting that the CFD simulations provided accurate predictions of the activity inside the spray dryer. The airflow comprised a core that flowed at high speed, with a slower zone of recirculation around the core. The particle trajectories depended upon the airflow patterns, resulting in the residence time of the smaller particles exceeding that of the larger particles. The deposits resulting from stickiness were typically on the walls of the conical section.
Main finding: Stickiness arises during the process of spray drying, and this is important because it is a quality that can be utilized in controlling the potential enlargement of the particles. This can lead to better-quality powder.

Carbon sequestration and surface energy balance measurement using eddy covariance technique for mangrove forest under influence of treated domestic wastewater, Phetchaburi province, Thailand

Wed, 14 Feb 2024 00:00:00 +0700

Importance of the work: There is a growing demand for the quantification of carbon sequestration.
Objectives: To quantify the flux movement of carbon dioxide within the King’s Royally Initiated Laem Phak Bia Environmental Research and Development (LERD) Project in Phetchaburi province, Thailand in a natural mangrove forest receiving treated domestic
wastewater.
Materials & Methods: The initial study used the eddy covariance technique to quantify the carbon dioxide fluxes within the study location.
Results: The mangrove forest served as a carbon sink, sequestering an estimated 19.94 tCO2/ha/yr. However, during the day, the forest’s role as a secondary treatment system led to the release of CO2 into the atmosphere due to the absence of photosynthetically active radiation at nighttime. However, this research also investigated the surface energy balance based on the calculation of the closure gap of the latent, sensible and ground heat fluxes, which equaled 0.62, indicating that the energy use in the mangrove canopy closely resembled that of a natural forest.
Main finding: Understanding the CO2 flux in the treated mangrove forest contributed to the expanding body of research on the “Blue Carbon” dynamics in mangrove forests.

Pathogenicity and molecular phylogenetic analysis reveal Colletotrichum siamense as causal agent of leaf fall disease in rubber trees (Hevea brasiliensis) in southern Thailand

Wed, 14 Feb 2024 00:00:00 +0700

Importance of the work: Leaf fall disease of rubber trees (Hevea brasiliensis) has devastated rubber production in southern Thailand.
Objectives: To identify and characterize the pathogen responsible for leaf fall disease in rubber trees and to test the pathogenicity of the isolated pathogens in accordance with Koch’s postulates.
Materials & Methods: Leaf sampling was carried out in all 13 districts of Narathiwat province, southern Thailand. Fungal isolation was performed using a tissue transplanting technique. The obtained isolates were tested for their pathogenicity that was determined using Kochs’ postulates through the detached leaf technique. The causal agent was identified based on morphological and molecular evidence.
Results: In total, 160 isolates were obtained from all sampling locations. The pathogenicity tests using detached leaves demonstrated that all isolates showed the leaf spot, with three isolates (2CHI12, 1SP12-1 and 4MU33-1) producing the most severe symptoms. These three causal agents were identified as Colletotichum siamense 2CHI12, 1SP12-1 and 4MU33-1, based on morphological and molecular evidence. The species of the causal agent was identified using the internal transcribed spacer (ITS) region, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), actin (ACT), chitin synthase (CHS-1), beta-tubulin 2 (TUB2) and the Apn2-Mat1-2 intergenic spacer region, as well as the partial mating type (Mat1-2) (ApMat) genes that were amplified based on polymerase chain reaction using the primer pairs ITS1/ITS4, GDF1/GDR1, ACT-512F/ACT-783R, CHS-79F/CHS-345R, Bt2a/Bt2b, and AM-F/AM-R, respectively.
Main finding: The morphological and phylogenetic analysis confirmed that the causal agent of leaf fall disease was Colletotichum siamense.

Tyrosinase inhibitors from fruits of Piper sarmentosum: Isolation, characterization and structure-activity relationship study

Wed, 14 Feb 2024 00:00:00 +0700

Importance of the work: Piper sarmentosum has long been used in Thai cuisine and traditional medicine. This was the first report on tyrosinase inhibition from the fruits of P. sarmentosum.
Objectives: To isolate and characterize the secondary compounds from the fruits of P. sarmentosum together with evaluation of their tyrosinase inhibitory activity.
Materials and Methods: The CH2Cl2 and acetone extracts were separated and purified using a variety of chromatographic techniques. The structures of isolated compounds were identified based on their spectroscopic data, particularly nuclear magnetic resonance. The tyrosinase inhibitory activity of the isolated compounds was evaluated using the colorimetric method with kojic acid as the positive control.
Results: In total, 21 compounds were isolated from the P. sarmentosum fruits, consisting of 6 phenylpropanoids, 9 phenylpropanamides, 5 alkyl amides and 1 lactone. Compounds 4, 9, and 18 had the most potent tyrosinase inhibitory activity with values for the concentration at 50% inhibition of 1.7 mM, 2.7 mM and 2.8 mM, respectively.
Main finding: Phenylpropanoids, phenylpropanamides and alkyl amides showed potent tyrosinase inhibition. This was the first report on tyrosinase inhibition in this plant. Therefore, the fruits of P. sarmentosum have potential for further research for their use in cosmetic and pharmaceutical applications.

Effect of bentonite and cassava tails and stalk on cassava planted in an upland Grossarenic Grossarenic Paleustult and soil property changes

Wed, 14 Feb 2024 00:00:00 +0700

Importance of the work: Cassava in Thailand is mainly planted in low fertility soils of the northeast with unsatisfactorily low yield in return. Treating the soils with soil amendments coupled with adequate fertilization can be a solution to sustainably improving the yield of cassava grown in these soils.
Objectives: To investigate the effects of bentonite (BTN) and cassava tails and stalk (CTS) on cassava yield and some soil properties.
Materials & Methods: A field experiment was conducted over 2 yr in a Grossarenic Paleustult. A split plot design was used, where the main plot consisted of BTN (1.25 t/ha and 2.5 t/ha), CTS (6.5 t/ha and 12.5 t/ha) and a mixture of BTN+CTS (1.25 t/ha + 6.25 t/ha and 2.5 t/ha + 12.5 t/ha), while subplots comprised ratios of N-to-P2 O5-to-K2O fertilization of 0:0:0 and 100:50:100 kg/ha.
Results: Almost all the amended plots with or without NPK chemical fertilizer addition interactively produced greater values for fresh tuber yield, starch yield and aboveground biomass than the non-amended plot, even with 100:50:100 kg/ha (N:P2O5:K2O) added in both growing seasons. Overall, the addition of BTN+CTS at the rate of 2.5 + 12.5 t/ha with NPK fertilization induced the significantly highest N uptake in the tuber and in the leaf plus branch, P uptake in the leaf plus branch and K uptake in the tuber, the stem base
and the leaf plus branch. In addition, soil amendments applied for two consecutive years increased the soil pH, total N and available P, K and Ca contents over the control that had no addition of these soil amendments.
Main finding: The BTN+CTS treatment, after application for two consecutive years clearly increased the yield of cassava and improved some major soil properties.

Carbonaized carbon aerogels derived from pomelo peels for sorption of some organic solvents

Thu, 29 Feb 2024 00:00:00 +0700

Importance of the work: Agricultural waste materials can be used to fabricate carbon aerogels that can absorb contaminated organic solvents.
Objectives: To investigate the potential of pomelo peel carbon aerogel (PCA) as a potential sorbent for organic solvents from the surface of water.
Materials & Methods: The peel was removed from pomelo fruits and cut into small pieces, before placing in a freezer at -20°C for 24 hr, followed by freeze-drying at -80 °C for 48 hr and then carbonizing in a muffle furnace at 300°C for 3 hr. Afterward, the carbonized product was characterized for morphology and tested for sorption capacity and reusability.
Results: The average density and porosity of the PCA were 0.0777 g/cm3 and 96.12%, respectively. PCA had an interconnected, porous morphology and contained hydrophobic functional groups. The PCA sorption capacities for n-hexane, benzene and toluene floating on the surface of water for 10 s, 20 s and 30 s were in the ranges 5.20–5.96 g/g, 5.34–6.06 g/g and 6.66–7.66 g/g, respectively. The maximum PCA sorption capacities for n-hexane and benzene were at 20 s, while for toluene the maximum sorption capacity was at 10 s. At 20 s, the PCA absorbed more toluene (7.48 ± 0.26 g/g; mean ± SD) than benzene (6.06 ± 0.24 g/g) and n-hexane (5.96 ± 0.16 g/g), respectively. After five cycles of reuse, the PCA sorption capacities for n-hexane, benzene and toluene remained similar to the high values of the initial uptake.
Main finding: The PCA, as characterized by water contact angle, the Brunauer-Emmett-Teller specific surface area, field-emission scanning electron microscopy and Fourier transform infrared spectroscopy, had an interconnected, porous morphology and hydrophobic functional groups. PCA expressed good sorption capacity for n-hexane, benzene and toluene floating on surface water and had sustained reusability for five cycles.

Enhancing enzyme digestibility of red tilapia (Oreochromis niloticus and O. mossambicus) and improving water quality in fish farming using Napier grass silage

Thu, 29 Feb 2024 00:00:00 +0700

Importance of the work: Utilizing locally available and more affordable plant-based raw materials could mitigate the increasing costs of raw fish feed ingredients. This study should enhance understanding regarding using Napier grass (Pennisetum purpureum ‘Pak Chong 1’) as a fish feed ingredient and its effect on fish, digestive enzyme activities and water quality in aquaculture.
Objectives: To assess the efficacy of different processed forms of Napier grass as a feed ingredient for red tilapia (hybrid between Oreochromis niloticus and O. mossambicus) and efficacy of extracted tannins in reducing the ammonia content in water.
Materials & Methods: The in vitro digestibility was analyzed of four Napier grass variants (dried, fresh, fermented and boiled). Proteolytic, amylase and cellulase enzyme activity levels were assessed.Tannin extraction was used to evaluate the efficiency of Napier grass extracts in reducing water ammonia levels based on the microwave method, which yielded a higher tannin content than the reflux method. Then, the extracted tannins were applied to water samples to examine their efficacy in reducing the ammonia content.
Results: The red tilapia fed fermented Napier grass (SN) had the highest enzymatic activity, with trypsin activity at 0.439 µmol DL-lanine/g feed, amylase activity at 0.828 µmol maltose/g feed, while the cellulase activity was 587.123 µmol maltose/g feed (p < 0.05). The application of Napier grass extracts successfully reduced the ammonia content in the water samples at 0.15 mg/l NH3-N/g dry
Napier grass. Evidence for the binding of tannic acid and ammonium ion was identified.
Main finding: Napier grass, particularly in its fermented form, can serve as an effective alternative feed for aquaculture. Tannin extracted from Napier grass efficiently reduced the ammonia content in water.

Somatic responses of injured Siamese fighting fish (Betta splendens) raised using various recipes of Thai herbal fermented water

Saowalak Malawa, Nutt Nuntapong, Karun Thongprajukaew — Thu, 29 Feb 2024 00:00:00 +0700

Importance of the work: Thai herbal remedies offer an alternative to chemicals to help in the recuperation of injured Siamese fighting fish (Betta splendens).
Objective: To evaluate fish survival and growth, feed utilization, skin coloration, digestive enzyme activity, muscle quality and whole-body composition at the end of herbal treatment for 5 wk.
Materials & Methods: Each male fighting fish had one-half of its caudal fin amputated and then was allocated to one of nine experimental groups. Each fish was reared separately for 5 wk in its own small tank. Treatments consisted of two controls, with one using non-fermented water (CT 1), while the other control consisted of fermented water (CT 2) and was mixed with various products—dried lemongrass leaves (1 g/L), dried clay (50 g/L) and salt (5 g/L). Subsequently, CT 2 was added to different combinations of dried Indian almond leaves (0.25 g/L), dried banana leaves (1.5 g/L) or dried papaya leaves to make seven other treatments.
Results: No mortality occurred and fish growth performance was not influenced by the herbal treatments. The feed conversion ratio significantly (p < 0.05) increased in association with decreasing amylase-specific activity, whereas protein- and lipid-digesting enzymes remained consistent. Skin coloration parameters were either reduced or preserved due to the herbal treatments. Muscle quality was unchanged, whereas the crude protein, crude lipid and ash contents in whole-body were similar across the nine treatments.
Main findings: Whereas entire fish can compensate for growth normally, these findings indicated minor effects of long-term herbal treatments on the somatic changes in the injured fish. The results endorsed the therapeutic approach of fermented water of Thai herbs in Siamese fighting fish.

Fractionated organic carbon in relation to soil aggregates and other soil properties in humid, tropical lowland, salt-affected soils

Thu, 29 Feb 2024 00:00:00 +0700

Importance of the work: The understanding of the relationships among soil properties, soil aggregates, and fractionated organic carbon (OC) in tropical, lowland, salt-affected soils (SASs) is unclear and requires further investigation.
Objectives: To investigate the proportion of OC fractions in relation to water stable aggregates (WSAs) and other soil properties in selected SASs.
Materials & Methods: Lalerng Phimarn and Non Thai transects were chosen with four soils along each toposequence (LP1–LP4 and NT1–NT4, respectively). Fractionated OC, WSAs and other soil properties were analyzed.
Results: All SASs were classified as Typic Natraqualfs with silt+clay and with sand particles dominating in the soils of the LP and NT transects, respectively. Only aggregates < 0.50 mm were detected in these SASs. Dissolved OC was almost undetectable. Particulate organic matter was positively and negatively correlated with the sand (r = 0.783, p < 0.01) and clay (r = -0.812, p < 0.01) contents, respectively. This fraction was adversely affected by electrical conductivity (r =-0.706, p < 0.01) and the sodium adsorption ratio (r = -0.741, p < 0.01). The OC bound to silt+clay increased with increasing WSA5 (0.1–<0.25 mm; r = 0.542, p < 0.015) and mean weight diameter (r = 0.525, p < 0.01) and was positively correlated with OM (0.650, p < 0.01), total N (r = 0.544, p < 0.05) and extractable Ca (r = 0.526, p < 0.05). The chemically resistant OC had a positive correlation with WSA7 (< 0.053 mm; r = 0.686, p < 0.01) and clay content
(r = 0.581, p < 0.05).
Main finding: Sodium overcame OM and induced WSA breakdown in these SASs. The s+c dominated, while the particulate OM was equally dominant in the sandier SASs. The chemically resistant carbon fraction was vital for C sequestration in the SAS subsoil.

Effect of beeswax edible film on preservation of Naem product quality during storage

Thu, 29 Feb 2024 00:00:00 +0700

Importance of the work: Beeswax (BW) could be a natural ingredient applied in edible packing film to effectively extend the shelf-life of Thai fermented sausage (‘Naem’).
Objective: To evaluate the capability of edible films made from beeswax in extending the shelf-life of Naem.
Materials & Methods: Naem samples were wrapped using one of four different film groups: polyvinyl chloride (PVC) or 0%, 1% or 3% BW. Changes were determined and compared in the pH, moisture content, color (L*, a* and b*), lipid oxidation and aerobic plate count (APC) and growth rates of lactic acid bacteria, Escherichia coli, Enterobacteriaceae, Staphylococcus spp. and Salmonella spp. in the Naem samples of the four groups during refrigerated storage.
Results: The 1% and 3% BW groups had significantly higher pH, L* and b* values after storage for 15 d than the PVC and 0% BW groups. The moisture content in the PVC group was significantly higher than in the other three groups. Naem in the 1% or 3% BW group had the lowest lipid oxidation level at 1.13 mg malondialdehyde/kg at an initial storage stage and still maintained a lower level after storage for 15 d. Additionally, their APC counts were significantly lower than for the PVC and 0% groups during storage. No Enterobacteriaceae were detected in the 3% BW group, while E. coli, Staphylococcus spp. and Salmonella spp. were not found in all groups after storage for 15 d.
Main finding: The edible film made from 3% BW significantly improved the shelf-life of Naem, with fewer changes in color, lipid oxidation, and microbial growth.

Implications of genotypic and phenotypic variation in Dura × Dura oil palm for maternal selection

Thu, 29 Feb 2024 00:00:00 +0700

Importance of the work: Selecting suitable maternal palms is essential for breeding high-yielding Tenera oil palms for commercial seed production.
Objective: To assess the genetic and physical characteristics of progenies from Deli Dura breeding population of oil palm for maternal selection.
Materials & Methods: The experiment applied using one-way analysis of variance to investigate 12 different traits in three Dura × Dura families: A (46 palms); B (40 palms); and C (41 palms). Genetic variation parameters, a phylogenetic tree and principal coordinate analysis were determined using 30 microsatellite markers, using the POPGENE program to cluster them among Dura and their offspring.
Results: The three investigated families of Dura × Dura showed clear separation into three genotype clusters. The observed heterozygosity value was higher than expected, indicating no inbreeding in this oil palm. Each family showed distinctive traits—family A exhibited sex ratio, fresh fruit bunch and oil yield, family B oil-to-bunch ratio and family C plant height and height increment. This information should help in the selection of Dura as the maternal palm for next-generation improvement or for producing new commercial Tenera.
Main finding: The variation observed in oil palms provided information on the immature phase of the new Dura as an elite line, with clustering of their SSR genotypes. The essential traits identified for genetic improvement were fresh fruit bunch, sex ratio, plant height and oil-to-bunch ratio.

In vitro gas production and fermentation of dairy cow diet contaminated with glyphosate herbicide

Thu, 29 Feb 2024 00:00:00 +0700

Importance of the work: Glyphosate is one of the most widely used herbicides in Thailand. However, its residue can interfere with microbial activity.
Objectives: To evaluate ruminal degradation and fermentation of microbiota measured using an in vitro gas production technique in different glyphosate-contaminated dairy cow diets.
Materials & Methods: A completely randomized design was utilized for the experiment, incorporating six treatments: glyphosate levels of 0.43 mg/kg dry matter (DM), 1.05 mg/kg DM, 2.33 mg/kg DM, 2.98 mg/kg DM, 4.77 mg/kg DM, and 5.54 mg/kg DM in the dairy cow diet. Each treatment comprised five replications. An in vitro gas production technique was used for data collection at various incubation times.
Results: None of the levels of glyphosate affected the accumulation of gas production at 8 hr, 12 hr, 24 hr and 48 hr incubation. However, glyphosate at over 2.33 mg/kg DM reduced the accumulated gas production at 72 hr incubation. The lower gas production was due to the insoluble fraction in those diet containing glyphosate at 2.98 mg/kg DM, 4.77 mg/kg DM and 5.54 mg/kg DM. There were no effects on DM degradability at all glyphosate levels at 24 hr, while at 1.05 mg/kg DM, there was a decrease at 48 hr. Values of pH, ammonia nitrogen and total volatile fatty acid decreased when more than 2.33 mg/kg DM glyphosate were added. The higher levels of glyphosate provided greater propionic acid and butyric acid proportions at 12 hr, which were greatest in the diet at 5.54 mg/kg DM.
Main finding: A dairy cow diet contaminated with glyphosate at higher than 2.33 mg/kg DM decreased the microbial activities of feed degradation, requiring more ammonia nitrogen to be used for microbial protein synthesis.

Use of different epoxide ring openers and volumes of epoxidized palm oil to modify palm oil into biopolyol

Neswati, Novizar Nazir, Syukri Arief, Yusniwati — Thu, 29 Feb 2024 00:00:00 +0700

Importance of the work: Epoxide ring openers and the volume of epoxidized palm oil are the most influential factors on the hydroxyl number.
Objectives: To investigate the effects of three types of epoxide ring opener and varying volumes of epoxidized palm oil on the production of biopolyol.
Materials & Methods: This study used 10 mL, 20 mL or 30 mL of epoxidized palm oil reacted with 30 mL of different epoxide ring openers (ethylene glycol, propylene glycol and distilled water) and added 1% sulfuric acid catalyst at 50°C for 1 hr. Biopolyol
was characterized based on the hydroxyl number and Fourier-transform infrared spectroscopy (FTIR).
Results: The optimum results for biopolyol as raw material for flexible polyurethane foam were a mixture of 10 mL of epoxidized palm oil with 30 mL of ethylene glycol, based on mean ± SD values for: hydroxyl number (99.37±7.27 mg KOH/g), acid number (1.19±0.1 mg KOH/g), viscosity at 30°C (46.10±6.45 cP) and density at 30°C (0.906±0.009 g/mL) and a clear yellow color. A wave number of 3332.05/cm in the FTIR represented the alcohol group (hydroxyl) in the polyol sample.
Main finding: Ethylene glycol successfully produced biopolyol according to the specified criteria as a suitable raw material for flexible polyurethane foam with a hydroxyl number of less than 100 mg KOH/g and an acid number of less than 2 mg KOH/g.

Somatic responses of injured Siamese fighting fish (Betta splendens) raised using various recipes of Thai herbal fermented water

Saowalak Malawa, Nutt Nuntapong, Karun Thongprajukaew — Thu, 29 Feb 2024 00:00:00 +0700

Importance of the work: Thai herbal remedies offer an alternative to chemicals to help in the recuperation of injured Siamese fighting fish (Betta splendens).
Objective: To evaluate fish survival and growth, feed utilization, skin coloration, digestive enzyme activity, muscle quality and whole-body composition at the end of herbal treatment for 5 wk.
Materials & Methods: Each male fighting fish had one-half of its caudal fin amputated and then was allocated to one of nine experimental groups. Each fish was reared separately for 5 wk in its own small tank. Treatments consisted of two controls, with one using non-fermented water (CT 1), while the other control consisted of fermented water (CT 2) and was mixed with various products—dried lemongrass leaves (1 g/L), dried clay (50 g/L) and salt (5 g/L). Subsequently, CT 2 was added to different combinations of dried Indian almond leaves (0.25 g/L), dried banana leaves (1.5 g/L) or dried papaya leaves (2.5 g/L) to make seven other treatments.
Results: No mortality occurred and fish growth performance was not influenced by the herbal treatments. The feed conversion ratio significantly (p < 0.05) increased in association with decreasing amylase-specific activity, whereas protein- and lipid-digesting enzymes remained consistent. Skin coloration parameters were either reduced or preserved due to the herbal treatments. Muscle quality was unchanged, whereas the crude protein, crude lipid and ash contents in whole-body were similar across the nine treatments.
Main findings: Whereas entire fish can compensate for growth normally, these findings indicated minor effects of long-term herbal treatments on the somatic changes in the injured fish. The results endorsed the therapeutic approach of fermented water of Thai herbs in Siamese fighting fish.