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ItemThe study of natural antibiotics effect of Thai curry paste in Thai coconut milk based curry on salmonella enterica( 2012) Patchanee YasurinThe salmonellosis, disease cause by Salmonella sp., is a food safety issue that was concerned widely at this present. In the 2011, there were a lot of reports about the outbreaks of Salmonella sp. Thai curry paste is a very important ingredient in Thai kitchen which composed of variety type of herbs which are Capsicum annuum (chili), Citrus hystrix (Kaffir lime), Cuminum cyminum L. (Cumin), Allium ascalonicum L. (Shallot), Allium sativum (Garlic), Cymbopogon citratus (Lemongrass), Alpinia galangal (Galangal). All of the mentioned herbs have been investigated for their antibacterial activity in different independent laboratories, so that, they have a good chance to be a candidate as a food natural antibiotics. Therefore the aim of this project was to investigate the antibiotics effect of Thai curry paste in Thai coconut milk based curry model on S. enterica 4,5,12:i:-(human). The curry was prepared according to Thai traditional home cooking, and inoculated with 1% of culture. In addition, the control was performed in the same manner into the NB medium. To evaluate the antibiotics effect, the serial dilutions and viable cell counts methods were used on the Salmonella- Shigella agar every hour for 6 hrs at room temperature. The statistical analysis was done by SAS program. It was found that S. enterica 4,5,12:i:-(human) level was significantly reduced (P < 0.05) in curry comparing with control at 4th hr; 5.72±0.06 and 5.84±0.01, at 5th hr; 5.80±0.04 and 5.91±0.03, and at 6th hr; 5.85±0.04 and 5.96±0.01 log CFU/ml, respectively. It revealed that Thai curry paste have inhibitory effect against the growth of S. enterica 4,5,12:i:-(human) since the 4th to the 6th hour. This indicates that Thai curry paste showed the promising as food natural antibiotics.
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ItemThai consumer behavior and attitude: effect of gender and degree of Food Neophobia on product liking and food related life style( 2012-01) Aussama SoontrunnarudrungsriFood Neophobia Scale (FNS) is important for product development since it might indicate consumer’s purchasing decision of novel food products. This study was aimed to investigate whether FNS can identify product preference and consumer behaviors (Food Related Life Style (FRL)). Thai consumers were screened using FNS in order to have balanced number of consumer who has food neophilic, neutral, and neophobic. Each consumer responded to the questionnaire consisted of demographic, preference test, and FRL scale. According to the preference test, Flavored Brownie, Meangkam rice bar, Core pineapple and cream cheese pie, and Fang herbal juice, were significantly different by the highest liking means of all four product ideas obtained from neophobic consumer. Thus, it might be the evidence to show that food neophobia cannot predict whether consumer will like the new product. The finding from the FRL showed that there were 2 categories significantly different (Novelty and Looking for new ways). On the other hand, the preference score of male and female was not significantly different in all ten product ideas. However, there are 5 out of 23 lifestyle dimensions in FRL found significantly different by female had higher average Likert scores in Importance of product information[5.4, 4.8], Attitudes to advertising[5.1, 4.4], Specialty shops[4.8, 4.2], and Social relationships [5.5, 4.9]. Male was only more positive towards Snacks versus meals [4.3, 3.7]. And the finding from this study suggests that FNS may not be an effective way to predict product preference but it might help us understand consumer behavior and attitude
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Itemผลการเปรียบเทียบฤทธิ์ในการต้านแบคทีเรียของส่วนประกอบในพริกแกงแดงในสูตรจําลองแกง ป่าและแกงกะทิต่อเชื้อ Salmonella Enterica 4,5,12:i:- (human) US cloneจากการศึกษาฤทธิ์ต้านเชื้อแบคทีเรียของส่วนประกอบหลักของพริกแกงซึ่งประกอบด้วยสมุนไพรเจ็ดชนิด คือ พริก (Capsicum annuum), มะกรูด (Citrus hystrix), ยี่หร่า (Cuminum cyminum L.), หอมแดง (Allium ascalonicum L.), กระเทียม (Allium sativum), ตะไคร้ (Cymbopogon citrates), และ ข่า (Alpinia galangal) ในสูตรจําลองแกงป่า และ แกงกะทิกับเชื้อ Salmonella Enterica 4,5,12:i:- (human) US clone โดยใช้วิธี agar diffusion method ลงบนอาหาร เลี้ยงเชื้อ Sallmonella Shigella ภายใต้การสกัด 3 สภาวะ โดยใช้การปรุงแบบอาหารในครัวเรือน คือ แกงป่าใช้น้ําในการ สกัด แกงกะทิใช้กะทิยูเอชที และ กะทิสดในการสกัด ผลจากสารสกัดทั้งสามชนิด แสดงให้เห็นว่าแกงกะทิที่ใช้กะทิสดใน การสกัดมีศักยภาพสูงสุดในการยับยั้งเชื้อ S. Enterica 4,5,12:i:- (human) US clone โดยในกระเทียม และ เม็ดยี่หร่าพบ ฤทธิ์ต้านแบคทีเรีย 0.90 ± 0.14cm ในแกงกะทิที่ใช้กะทิยูเอชที พริกแห้งให้ฤทธิ์ต้านแบคทีเรียที่สูงที่สุดคือ 0.93±0.12cm และในแกงป่าในพริกแห้ง และ หอมแดงให้ฤทธิ์ต้านแบคทีเรียคือ 0.80 ± 0.00cm ในการหาค่าความเข้มข้นต่ําสุดที่ สามารถยับยั้งเชื้อ (MICs) โดยใช้วิธี broth dilution method, กระเทียมและผงยี่หร่าพบ160 µl/mlใน แกงกะทิโดยใช้กะทิ สด พริกแห้งในแกงกะทิโดยใช้กะทิยูเอชทีพบ80µl/ml ส่วนในแกงป่าพริกแห้งพบ80 µl/mlและหอมแดงพบ 160µl/ml ส่วนประกอบพริกแกงแสดงให้เห็นฤทธิ์ต้านแบคทีเรียที่มีแนวโน้มอย่างมีนัยสําคัญต่อ S. Enterica 4,5,12:i:- (human) US clone ชี้ให้เห็นว่าพริกแกงเป็นอาหารที่มีสารออกฤทธิ์ในการป้องกัน
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ItemA study of feasibility to utilize lignocellulosic biomass as materials for biodiesel productionLignocellulosic biomass is a renewable, inexpensive, and abundant resource with high potential for biofuel production to implement the sustainable energy energy worldwide. The bottleneck of biofuel production is the recalcitration of ligoncellulosic biomass to fermentable sugars. Searching for a novel cellulase, a biocatalyst is one of major challenges to promote biofuel production with economic and environmental friendly. Natural microorganism is the great source of cellulase production. Therefore the objective of this research is to identify thermophilic, rapid, efficient cellulose-degrading bacteria from organic fertilizer, rice field, activated sludge, and rain forest in Thailand. More than 300 isolates were screened at 45°C on carboxy-methyl-cellulose (CMC)-containing media to observe the cellulase activity. Using standard filter paper assay, only 9 isolates (S3-10, S3-20, L2-S1, L2-S2, S3-7, L3-S1, L11-S2, L11-S3, and L11-S4) showed high total cellulase activity among other isolates. All isolates then were cultured in media containing 4 different carbon sources; CMC, filter paper, untreated rice straw, nutrient broth (NB), to see effect of substrates on cellulase production. It showed that L2-S2 in Dubois salts media with rice straw could induce high total cellulase activity to 25.57 umole/mg-protein while L11-S3 in NB could induce the highest total cellulase activity to 27.92 umole/mg- protein. Therefore untreat rice straw and NB represented as an effective inducer for cellulase production. A portion of the 16srDNA genes of cellulase positive isolates were amplified and sequenced, then BLASTed to determine species. The results showed that most of isolates are Bacillus sp.
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ItemA study of feasibility of pretreatment process to utilize lignocellulosic biomass as materials for biodiesel productionBiomass is the most abundant renewable resource in the world and has potential to use as alternative materials to fossil resources for production of chemicals and fuels. For the effective conversion from biomass to biofuels or other chemicals, it requires high efficient hydrolysis of cellulose to glucose or fermentable sugars. In this study, lignocellulosic biomass, rice straw, rice husk, and water hyacinth were pretreated with different chemicals, or pretreated with microwave heating, or with combination of chemicals and microwave heating. Pretreated biomass was saccharified by using commercial cellulase enzymes and released sugar contents were measured. The combination of two pretreatment methods exhibited a synergy effect with 71.77% of the enzymatic sugar conversion. To study the possibility to utilize sugars from saccharified biomass, the de novo biosynthesis of fatty acid ethyl esters (FAEEs) in Acinetobacter spp were observed. The key biochemical reaction is the esterification between fatty acyl Co-A and ethanol using diacylglycerol acyltransferase (DGAT). The highest FAEE production up to 1,040±51 mg/l was found in A.baylyi culture that use biomass hydrolysate as a sole carbon source.
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ItemEffect of color and flavor on the perceived intensity of Stevia (Stevia rebaudiana) in sweetened beverage products( 2013) Aussama SoontrunnarudrungsriOne of the main health concerns today is diabetes and it causes by many reasons, one of 10 them is sweeten beverage consumption. Stevia is a great candidate of natural sweetener that 11 can be used in beverage products. It is 250 times sweeter than sugar, contains zero calories, 12 can decrease blood sugars and etc. This study was aimed to investigate percieved intensity of 13 sweetness (product still in the mouth), aftertaste as well as overall liking in beverage 14 preparing with Stevia extract powder (Stevioside) and sucrose in four different flavored 15 beverages (strawberry, green tea, orange, and lime/lemon). There were 120 consumers 16 participated in the study, most of them were 18-25 years old students with monthly income 17 about 10,000-20,000 Baht. Food Neophobia Scale (FNS), Food Involvement Scale (FIS), and 18 Health and Taste Attitude scale (HTAS) were used in order to obtained the consumer attitude 19 and behavior towards food products. It was found that Thai consumers in the study were 20 considered as food neophobic. Both finding from FIS and HTAS indicated that Thai 21 consumers were neutral in term of food involevement activites and attitude toward health 22 perspectives and taste of food products. When comparing between male and female in all 23 three psychographic scales, there was a significanlty different found in “Preparation and 24 Eating” subscale in FIS. According to the product testing, there were main effects of flavor 25 and sweetener on perceived sweet intensity and overall liking, but not with the aftertaste 26 intensity. There is no interaction effect between flavor and sweetener. When comparing 27 within the same sweetener, strawberry flavored beverage was perceived as the sweetest 28 product for both sucrose and stevia sample. Consumer percieved sweet intensity of sample 29 containing sucrose with orange, lime/lemon, and strawberry flavor the same. All stevioside 30 samples were percieved as having the same sweet intensity. Consumer percieved stawberry 31 flavor with stevioside sample as having the same sweet intensity as green tea sample 32 preparing with sucrose. The samples contained stevioside were less preferred than samples 33 prepared with sucrose. However, the green tea sample with sucrose was not significanlty 34 different from lime, orange, and strawberry sample containing stevioside in overall liking
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ItemAntibacterial Activity of Thai Red Curry Paste in Kang-Kati (Thai Red Curry) Model on Salmonella enterica Typhimurium DT104b( 2013-06) Patchanee YasurinNowadays food safety becomes an international concern. Natural antibacterial is now become very interesting food safety trend. The investigation on the food itself having antibacterial activity becomes more dynamic. Salmonella sp. has been reported its outbreaks recently in different variety of food. Kang-Kati (Thai red curry) is a Thai cultural dish and also worldwide well-known menu. The Thai red curry paste, Thai red curry’s main ingredients, compose of many herbs including Capsicum annuum (Red chili), Cymbopogon citrates (Lemongrass), Alpinia galangal (Galangal), Allium ascalonicum L (Shallot), Allium sativum (Garlic), Citrus hystrix (kaffir lime), Cuminum cyminum (Cumin). Therefore, this study aimed to investigate the potential of Thai red curry paste in Kang-Kati using fresh coconut milk model as natural antibacterial agent against S. enterica Typhimurium DT104b. Kang-Kati was prepared according to Thai homemade authentic cooking method as it has been served in Thai cuisine and was inoculated with 1% culture. Thai curry paste in-vitro antibacterial activity was evaluated by cell count serial dilution method on SS media every hour for 6 hrs at room temperature. The result showed that the level of S. enterica Typhimurium DT104b in Kang-Kati was significant lower than of positive control (NB) (P<0.05) in 6th hour; 8.32±0.04, 8.02±0.08 log CFU/ml, respectively. The t-test has been done by using SPSS on log CFU/ml with P < 0.05. It is indicated that Thai red curry paste in Kang-Kati model showed promising combinated antibacterial activity against food-borne pathogenic bacteria, S. enterica Typhimurium DT104b.
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ItemNatural Antibacterial Activity of Thai Curry Paste in Thai Red Curry (Kang-Kati) Model against Salmonella enterica 4,5,12:i:-(human)( 2013-06) Patchanee YasurinThe salmonellosis is a food safety issue that is concerned widely at this present moment. In 2012, there were more than 10 Salmonella outbreaks reported by Centers for Disease Control and Prevention (CDC). Foods as natural antibiotics itself might be considered as an alternative for food safety. Thai red curry is a Thai cultural dish which has become a well-known dish worldwide having fresh coconut milk and red curry paste as a main ingredient. The red curry paste main ingredients include various types of herbs; Capsicum annuum (chili), Citrus hystrix (Kaffir lime), Cuminum cyminum L. (Cumin), Allium ascalonicum L. (Shallot), Allium sativum (Garlic), Cymbopogon citratus (Lemongrass), Alpinia galangal (Galangal). All of the mentioned herbs have been investigated for their antibacterial activity. Therefore, the objective of this research is to investigate the antibacterial activity of red curry paste in fresh-coconut-milk-based Thai red curry (Kang-Kati) model on Salmonella enterica 4,5,12:i:-(human). Thai curry paste in-vitro antibacterial activity was evaluated by cell count serial dilution method on SS media every hour for 6 hrs at room temperature. Thai red curry was prepared by Thai homemade authentic cooking method as it has been served in Thai cuisine. The result showed that the S. enterica 4,5,12:i:-(human) log CFU/ml level in Thai red curry (Kang-Kati) was significantly lower than in nutrient broth, as positive control, (P < 0.05) since 3rd - 6th hr; 3rdhr; 6.14±0.04 and 6.29±0.01, 4th; 6.27±0.01 and 6.43±0.02, 5th hr; 6.36±0.05 and 7.20±0.03 and 6th hr; 7.13±0.01 and 7.40±0.02 log CFU/ml, respectively. The t-test has been done by using SAS on log CFU/ml with P < 0.05. The Thai red curry paste in fresh-coconut-milk-based Thai red curry (Kang-Kati) model showed promising antibacterial activity against food-borne pathogenic bacteria, S. enterica 4,5,12:i:-(human)
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ItemThe study of the biodiversity in local bio-fermented solution and the treatment of community wastewater at laboratory scale: wastewater from restaurantsBio-fermented solution is a solution composed of a diverse variety of microbes coexisting together, aiding the metabolism of each other. Nowadays,bio-fermented solution is widely used for many purposes and is one of the popular usages for wastewater treatment. In this experiment, the biodiversity of the bio-fermented solution was determined by selective and non-selective enrichment media. For the treatment of restaurant wastewater (collected from local department store food court and steak restaurant), 0 (control), 0.25, 0.5 and 1 mL of bio-fermented solution were inoculated per liter of wastewater. In the treatment procedure, light (with light and without light), time (24 hours and 48 hours) and oxygen (with oxygen and without oxygen) were varied. After treatment, the wastewater sample’s chemical and microbiological properties were tested. The chemical properties include total solid (TS), Biochemical oxygen demand (BOD), total suspended solid (TSS), total dissolved solid (TDS), pH and grease and oilcontent. The microbiological properties were measured by MPN method and total plate count method. The bio- fermented solution biodiversitieswere contained with Bacillus spp. 3.48×104 CFU.mL-1, mold 3.63×103 CFU.mL-1, lactic acid bacteria 4.35×104 CFU.mL-1, actinomycetes 1.27×105 CFU.mL-1 and yeast 1.35×105 CFU.mL-1. When using bio- fermented solution to treat restaurant wastewater, there were significant reduction of TS and grease and oil at 53.07% and 69.89% respectively. The best condition for restaurant wastewater treatment was 0.25 mL of bio-fermented solution per liter of wastewater without oxygen and light for 48 hours. However, the quality of treated wastewater was still above the standard required. Therefore, further experiment will be needed to improve the quality of water before discarding.
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ItemScreening and primary identification of lipid degradation microorganism from local bioextracts( 2014) Viyada KunathiganBioextract is a solution of fermented organic matters which mainly are agricultural leftover containing living microorganisms. Studies have shown that bioextract may be applied to agriculture, livestock, gardening and landscaping, composting, and bioremediation. Latterly, bioextract was introduced for wastewater treatment, due to bioextract characteristic and environmentally friendly. From previous studies (Nitsuwat et al., 2013), addition of bioextract was capable to reduce total solid, grease and oil in domestic wastewater. The grease and oil component in wastewater can create problem in sewage system and hard to lose from the wastewater. The aim of this research is to find and identify microorganism contained inside the bioextract that can degrade grease and oil. In the future increasing of these microorganisms in bioextract may improve the ability of bioextract for pretreating domestic wastewater containing grease and oil. In this research, lipid degradation microorganisms were isolated from the local bioextract sample. The bioextract biodivesity was found contained total aerobic bacteria 1.07x104 CFU.ml-1, actinomycetes 4.53x104 CFU.ml-1, yeast 2.67x104 CFU.ml-1, lactic acid bacteria 3.04 x 103 CFU.ml-1, and mold 1.98x103 CFU.ml-1. The screening methods used media added with tributyrin. Colonies that created clear zone were isolated and tested using tributyrin and vegetable oil. Total of 55 microorganisms were screened for their ability to degrade tributyrin. Ten strains were further selected from the second screening using vegetable oil. Then these ten isolates were primarily identified using morphological and biochemical characteristics. Majority of the selected isolates were in family Bacillaceae.
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ItemDetection of Orcinol-O-methyl transferase enzyme encoding gene in East Asian rose Rosa multiflora( 2014) Viyada Kunathigan3,5-dimethoxytoluene (DMT) is a key component of “tea scent” in Chinese rose (Rosa chinesis) and a hybrid of Chinese rose (Rosa X hybrida). DMT biosynthesis is catalysed by enzymes Orcinol O-methyltransferase (OOMT) 1 and 2 (Rosa chinesis and Rosa X hybrida) and OOMT like (Rosa chinesis Xing-xing-hei). The East Asian rose Rosa multiflora may also contain OOMT gene. The presence of OOMT gene in this rose could be a potential useful resource for Asian fragrance industry. This project aimed to detect the OOMT encoding gene in this rose variety. Rosa multiflora var. carnea and Rosa multiflora platyphylla were chosen as plant materials as they are abundant in South East Asian area. DNA extraction and primer design were achieved to amplify OOMT gene. The designed primers were expected to amplify all OOMT1, OOMT2, and OOMT like genes. With DNA templates and a pair of primers, PCR was conducted and showed the presence of OOMT gene in Rosa multiflora var. carnea (product size around 1200bp) but not in Rosa multiflora platyphylla. The 1200bp product size was close to the expected size of OOMT like gene’s PCR product (1211bp). A restriction enzyme digestion analysis was done and the results supported that the OOMT gene in Rosa multiflora var. carnea was OOMT like gene.
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ItemEffect of solvent extraction of Centella asiatica on antioxidant activity and antibacterial activity against Salmonella enterica EnteritidisNowadays, there are increasing trends of using natural products. Interestingly herbs are considered to be one of the alternatives consumers choose to use. In Thailand, Centella asiatica can be found in local market and locally called Buabok. C. asiatica is famous in Ayurvedic medicine for the treatment of leprosy, insanity, asthma, ulcers, eczema, skin tuberculosis, wounds, stomach aches, arthritis, varicose veins and high blood pressure (Ariffin et al, 2011 and Hakono et al, 1999). Due to the benefits of C. asiatica and its easily accessible, this studied had been done to evaluate the effect of solvent extraction of C. asiatica on antibacterial activity against Salmonella enterica Enteritidis and found out that ethanol and chloroform showed highest antibacterial activity against S. Enteritidis (9.33 ± 0.5774 and 9.50 ± 0.5000 mm., respectively) while hexane extract showed lowest activity (6.67 ± 0.1443 mm.) The minimum inhibitory concentrations (MICs), using a broth dilution method, were found to be 8 mg/ml for ethanol and chloroform. While hexane extract was found to be 32 mg/ml. The minimum bactericidal concentrations (MBCs) were greater than 32 mg/ml. Similar results were found in the antioxidant activity of C. asiatica referring to the amount of phenolic content. Total phenolic contents using Folin-Ciocalteu method, found out that ethanol extract contains highest phenolic content followed by chloroform with slightly lower in phenolic content and the lowest phenolic content was hexane extract (23.8020 ± 0.5241, 22.1718 ± 0.1403 and 7.9612 ± 1.6350 µg GAE/mg, respectively). Ferric reducing antioxidant potential value of ethanolic extract was greater than those of chloroform and hexane extract (6.4008 ± 0.0393, 3.4779 ± 0.6744 and 1.7693 ± 0.1279 mmol Fe2+/mg, respectively). According to the results, different extraction solvents affected the amount of total phenolic compounds and FRAP value. The difference in the antibacterial activity was found when using different extraction solvents.
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ItemThe Overview: the antimicrobial, antioxidant activities and chemical profile of Centella asiaticaAccording to the draft of Thai herbals development strategic plan; Thailand Champion Herbal Products: TCHP by the department for development of Thai transitional and alternative medicine, Ministry of Public Health, Centella asiatica (Bao-bog, Gotu Kola) is one of the five herbs in champion herbal products. To be able to produce quality herbal products, scientific proven data is needed to increase the confidence and acceptance of consumers, not only local wisdom. The variation in herbal form (fresh and dried), solvent types, and extraction ratio and extraction times could affect the antimicrobial activities, antioxidant activities and chemical profile. Thus that biological active compound compositions, antimicrobial activity, and antioxidant activity profiles would be the important stepping stone for development of medicine industry, food industry, cosmetics industry.
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ItemEffect of extraction and shaking time on antibacterial activity of dry centella asiatica againts food pathogenic microorganismsThe outbreaks caused by pathogenic bacteria still being a major human health and food industry problem. Since time immemorial, people used plant material as medicine and nowadays, it widely used as tea preparation. Centella asiatica is a potential herbs related to its antibacterial activity. Therefore, this study aimed to investigate the antibacterial activity of dry C. asiatica crude 95% ethanolic extract under different extraction time (1, 3, 5, and 7 days) and shaking action (120 rpm) against three human pathogenic bacteria; Salmonella enterica typhimurium U302 (DT104b), S. enterica enteritidis (human), S. enteric 4, 5, 12:i:- (human) US clone, and Bacillus cereus by using agar disc diffusion method. The results showed that the all extracts showed antibacterial activity against B. cereus with inhibition zone range of 0.214 ± 0.053 to 0.557 ± 0.559 mm but has not significantly effect on Salmonella sp. The highest antibacterial activity of dry C. asiatica achieved on the three days extraction time. The shaking action could increase antibacterial activity. The MIC (minimum inhibitory concentration) was between 40-80 µl/ml and MBC (minimum bactericidal concentration) was 80-160 µl/ml. This showed that C. asiatica dry extract could inhibit gram-positive bacteria rather than gram-negative and shaking effect gives promising factor to increase effectiveness of plant ethanol extraction.
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ItemThe fresh Thai local herbs in vitro antibacterial activity against Listeria monocytogenes 10403SThai local herbs are one important ingredient of Thai food. Six fresh herbs extracted by five different ethanol concentrations (0%, 25%, 50%, 75%, and 95%) were investigated for their individual antibacterial activity; Chilli (Capsicum annuum), kaffir lime (Citrus hystrix), cumin (Cuminum cyminum L.), shallot (Allium ascalonicum L.), garlic (Allium sativum), lemongrass (Cymbopogon citratus), and galangal (Alpinia galanga) against Listeria monocytogenes 10403S by using the agar disk diffusion method on Brain Heart Infusion media (BHI), five different ethanol concentrations (0%, 25%, 50%, 75%, and 95%). The results showed that 95 % ethanolic crude extracts gave the highest antibacterial activity against L. monocytogenes 10403S. Of all herbs, lemongrass extracted by 95% ethanol showed the highest antibacterial activity; 9.79 ± 1.68 mm. The minimum inhibitory concentrations (MICs), using a broth dilution method, were found to be between 16-128 µl/ml. The minimum bactericidal concentrations (MBCs), using a broth dilution method, were greater than 32-128 µl/ml. This indicated that all Thai local herbs showed the promising antibacterial activity against L. monocytogenes 10403S.
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ItemThe individual antibacterial activity of Thai red curry paste’s dry ingredients against Listeria monocytogenes using different ethanolic extractionThai red curry paste is a main ingredient of Thai Red curry. The paste contains herbs which have the potential to be natural antibiotics. Six herbs contained in Thai red curry paste were tested for their individual antibacterial activity against Listeria monocytogenes 10403S. Six herbs tested were Chilli (Capsicum annuum), Kaffir lime (Citrus hystrixShallot (Allium ascalonicum L.), Garlic (Allium sativum), Lemongrass (Cymbopogon citratus), and Galangal (Alpinia galanga). The agar disk diffusion method was used for in-vitro screening antibacterial activity of each crude extract against L. monocytogenes 10403S on Beef Heart Infusion media (BHI) with five different ethanol concentrations; 0, 25, 50, 75, and 95%. The 95 % ethanol crude extracts gave the highest antibacterial activity against L. monocytogenes 10403S in all herbs. The dry galangal 95% crude ethanolic extract showed the highest antibacterial activity; 10.50 ± 1.16 mm. The minimum inhibitory concentrations (MICs), using a broth dilution method, were found to be between 4-128 µl/ml. The minimum bactericidal concentrations (MBCs), using a broth dilution method, were greater than 32-128 µl/ml. The results showed that the six dry herbs have significant antibacterial activity against the food-borne pathogen, L. monocytogenes 10403S.
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ItemPurification and identification of bacterial cellulase activity of Bacillus subtilis W48 for biofuel productionLignocellulosic biomass is a renewable, inexpensive, and abundant resource with high potential for biofuel production to implement the sustainable energy worldwide. An important key of biofuel production is the hydrolysis of lignocellulosic biomass to fermentable sugars. Screening for a novel cellulase, as a biocatalyst, is challenge for development of biofuel production to be the economic and environmental friendly process. Natural environment is an important source to find an efficient cellulase producing bacteria. Previously, Bacillus subtilis strain W48 was screened and isolated from rainforest park at Assumption University, Bangkok, Thailand. In this study, we focused on the purification and characterization of cellulase enzyme produced by B. subtilis strain W48. The crude cellulase enzyme was collected by culture grown at 45°C in carboxy-methyl-cellulose (CMC) media. Then, it is concentrated by ammonium sulfate precipitation and fractionated by using size exclusion chromatography using sephacryl S- 100 HR column. In this study, the fractions that has highest CMCase activity (0.017 mg/ml), as endoglucanase, and FPase activity (0.013 mg/ml), exoglucanase, are fraction no. 13 and 11, respectively.
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ItemIsolation and purification of cellulase from alkaline-tolerant Bacillus subtilis(Universitas Katolik Soegijapranata, 2014-09) Passanee Thongthawee ; Malinee Sriariyanun ; Kraipat Cheenkachorn ; Jirapa Phetsom ; Patchanee YasurinLignocellulosic biomass is one of the most abundant renewable resource in the world. It has high potential to be used as material for biorefinery process because it yields fermentable sugar that can be converted to various bioproducts via microorganism functions. To make the biorefinery process success, the efficient hydrolysis process is needed to be improved to release the maximum amounts of sugars from lignocellulosic biomass. Natural environment is an important source to find an efficient cellulase producing bacteria. Previously, an alkaline-tolerant cellulase-producing bacterium, Bacillus subtilis strain MSB9, was screened and isolated from Botanic garden in Mahasarakham province, Thailand. In this study, we focused on the purification and characterization of cellulase enzyme produced by B. subtilis strain MSB9. The crude cellulase enzyme was partially purified and concentrated by ammonium sulfate precipitation and fractionated by using size exclusion chromatography using sephacryl S-100 HR column. Two of purified cellulase have relative molecular mass of 35 and 45 kDa, as determined by SDS-PAGE combined with CMC-zymogram.
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ItemDevelopment of Natural vegetable sanitizer from Thai local herbsNowadays, food safety becomes public concern, especially in fresh produce; fresh vegetables and fruits. The CDC has been reported at least 7 outbreaks from fresh produce in the past 3 years; for example, Escherichia coli O121 in raw clover sprouts (2014), E. coli O157:H7 in ready-to-eat salads (2013), Salmonella Saintpaul in cucumbers (2013), Salmonella Typhimurium and Newport in cantaloupe (2012), and E. coli O157:H7 in spinach and spring mix salad (2012). Washing, before consuming, is the most important step in order to prevent foodborne outbreak in fresh produces. Therefore, this research was aimed to develop vegetable sanitizer from crude extracts of Acacia concinna (Willd.) D.C (Som-poi), Capsicum annuum (Chili), Cymbopogon citratus (Lemongrass), Citrus hystrix (Kaffir lime) and Chrysanthemum indicum L. (Chrysanthemum) in order to reduce foodborne bacteria in fresh vegetable. These herbs have been reported for their antibacterial activity (Pitinidhipat and Yasurin, 2012; Utami et al., 2012; Saenghiruna and Yasurin, Lazuardi et al., 2013; 2013; Piya-isarakul and Yasurin, 2013; Saenghiruna et al., 2014; Dung et al., 2014). The 18 treatments with 3 different crude extracts percentage (0.5, 1 and 1.5%), 3 different volumes (3, 5, and 10 ml.) and 2 different soaking times (10 and 20 min) were investigated for their antibacterial synergistic activity using Lactuca sataiva (Lettuce) as vegetable model. The MPN, total place count on PCA, BHI agar for Listeria monocytogenes count, and SS agar for Salmonella sp. count were used to evaluate the antibacterial efficiency of vegetable sanitizer. The results showed that treatment 18 (using 10 ml of 1.5% crude extracts with 20 min soaking time) gave the highest bacterial efficiency statistically by vegetable sanitizer comparing with the commercial brand. The MPN number, the total plate count, and the L. monocytogenes count were 1.34 ±0.19 MPN/ml, 1.62 ± 1.02 log CFU/ml, and 1.31 ± 0.40 log CFU/ml, respectively. The Salmonella sp. was not found. The t-test has been done by using SAS on log CFU/ml with P0.05. It was found that crude extract percentage, used volume, and soaking time affected the antibacterial efficiency of this vegetable sanitizer.
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ItemFocus group discussion and sorting technique for jasmine tea( 2015) Kamolphan Ruengdej ; Kamolnate KitsawadJasmine tea is one of the most commonly consumed drinks in Thailand. Tea leaves are scented with jasmine flowers of which fragrance is absorbed. Jasmine tea currently available in Thai market is mostly in the form of dried leaf and tea bags, and a few are in the form of commercial PET bottle. The objectives of this present study were to examine consumer‟s concept of jasmine tea and to identify the attributes which consumers used to differentiate the jasmine tea. Fourteen commercial jasmine tea samples were included in this study. The samples were varied according to country of origin, tea base, and processing method of how jasmine was infused into the tea. A total of 24 tea drinkers were divided into 3 groups to discuss about their perceptions of jasmine tea. Then, jasmine tea samples were served, in random order, to each participant who was instructed to sort the jasmine tea samples according to similarities and differences in sensory characteristics using sorting technique. According to focus group discussion, it was found that the jasmine tea should be light yellow to brown color with sweet scent of jasmine flower, fresh aroma and flavor that led to relax and calm sensation with slightly sweet taste. Results from the sorting technique suggested that the important characteristics that consumers differentiate various jasmine teas were taste and aroma. The findings from this study would be beneficial for development of jasmine tea drinks for various consumer preferences