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Gallic acid content in taiwanese teas at different degrees of fermentation and its antioxidant activity by inhibiting PKCδ activation: in vitro and in silico studies
(2016) Teeradate Kongpichitchoke; Chiu, Ming-Tzu; Huang, Tzou-Chi; Hsu, Jue-Liang
Teas can be classified according to their degree of fermentation, which has been reported to affect both the bioactive components in the teas and their antioxidative activity. In this study, four kinds of commercial Taiwanese tea at different degrees of fermentation, which include green (non-fermented), oolong (semi-fermented), black (fully fermented), and Pu-erh (post-fermented) tea, were profiled for catechin levels by using high performance liquid chromatography (HPLC). The result indicated that the gallic acid content in tea was directly proportional to the degree of fermentation in which the lowest and highest gallic acid content were 1.67 and 21.98 mg/g from green and Pu-erh tea, respectively. The antioxidative mechanism of the gallic acid was further determined by in vitro and in silico analyses. In vitro assays included the use of phorbol ester-induced macrophage RAW264.7 cell model for determining the inhibition of reactive oxygen species (ROS) production, and PKCδ and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunit (p47) activations. The results showed that only at a concentration of 5.00 μM could gallic acid significantly (p < 0.05) reduce ROS levels in phorbol ester-activated macrophages. Moreover, protein immunoblotting expressed similar results in which activations of PKCδ and p47 were only significantly (p < 0.05) attenuated by 5.00 μM treatment. Lastly, in silico experiments further revealed that gallic acid could block PKCδ activation by occupying the phorbol ester binding sites of the protein.
Microencapsulation of Litsea cubeba Essential Oil in β-Cyclodextrin Using Paste and Co-Precipitation Methods
(2014) Elizei, Pooyan Shakouri; Wunwisa Krasaekoopt
Microencapsulation of Litsea cubeba essential oil (LCEO) with β-cyclodextrin (BCD) was carried out using the paste and co-precipitation methods at various oil concentrations and ratios of LCEO to BCD adapted from a central composite design to determine the effect of these factors on the microencapsulation efficiency, microencapsulation yield, surface oil and recovery of the finished product. In addition, the effect of different levels of water activity and temperature on the oxidative stability of the powder was investigated. Treatment 4 using the paste method with 90% LCEO and a ratio of LCEO to BCD of 15:85 was found to be more efficient compared to samples produced by the co-precipitation method. This condition provided an oil loading of 102 mg.g-1 of powder, 74.7% microencapsulation yield, 71.9% microencapsulation efficiency, 94.8% recovery of LCEO powder and surface oil with 4.08 mg.g-1 of powder. Statistical analysis indicated that the temperature and water activity had significant effects on the peroxide value. Moreover, there was an interaction between these two factors. The LCEO powder had higher oxidative stability with the lowest peroxide value of 4.9 meq.kg-1 when it was stored at 10 °C and a water activity of 0.53 whilst the accelerated conditions of 50 °C and a water activity of 0.64 resulted in the highest peroxide value (13.6 meq.kg-1) and lower oxidative stability. It was notable that except for the samples stored at a water activity of 0.64 and temperatures of 30 and 50 °C, the other samples did not exceed the limit for the peroxide value of 10 meq.kg-1 which is the acceptable limit for edible vegetable oils.
Microencapsulation of Saffron (Crocus sativus L.) Extract in Copolymer Complexes Using Extrusion Method
(2015) Shakoori, Pooria; Wunwisa Krasaekoopt
This study describes the preparation of alginate-chitosan and alginate-gelatin beads containing saffron components to be incorporated as additives in food products. This study evaluated the influence of incorporating hydrophilic natural polymers, alginate-chitosan and alginate-gelatin on preserving saffron components. The alginate beads were coated with chitosan and gelatin as copolymer by extrusion method with a polyelectrolyte complex reaction between two oppositely charged poly-ions. The beads were formulated, optimized and evaluated to obtain high encapsulation efficiency of crocin, safranal and picrocrocin as the main components of saffron. The encapsulation variables were selected in accordance with Central Composite Design and were further optimized via response surface methodology. Alginate concentration significantly influenced particle size and encapsulation efficiency of alginate-chitosan and alginate-gelatin beads (p ≤ 0.05). Both chitosan and gelatin positively affected encapsulation efficiency. The optimum condition for preparing alginate-chitosan beads was an alginate concentration of 1.97% and chitosan concentration of 0.925%; this yielded an encapsulation efficiency of 66.3 ± 1.5, 86.2 ± 0.7 and 52.9 ± 3% for picrocrocin, safranal and crocin, respectively. The optimum condition for preparing alginate-gelatin beads was an alginate concentration of 1.95% and gelatin concentration of 3.65%; this yielded encapsulation efficiency of 39.2 ± 2.9, 31.9 ± 1.7 and 18.3 ± 1% for picrocrocin, safranal and crocin, respectively. The results clearly indicated that, in combination with alginate, chitosan was a better copolymer than gelatin for encapsulating saffron components.
Investigating the Effect of Cold Soak Duration on Phenolic Extraction during Cabernet Sauvignon Fermentation
(2015) Siriwan Panprivech; Lerno, Larry A.; Brenneman, Charles A.; Block, David E.; Oberholster, Anita
The impact of increasing cold soak (CS) duration (0, 1, 4, 7, and 10 days at 10 °C) on the extraction of phenolic compounds during the CS period and primary fermentation as well as the final composition of Cabernet Sauvignon wine was investigated. The results showed that CS duration had no effect on hydroxycinnamate and flavonol extractions. Greater amounts of gallic acid, (+)-catechin, (−)-epicatechin, and total tannins were extracted with increasing CS duration, with differences maintained during bottle aging. Anthocyanin extraction and color density increased with longer periods of CS; however, by the end of primary fermentation, as well as three months’ bottle aging, there were no significant differences due to CS duration. The wines made with seven and 10 days of CS had higher seed tannin contributions and total tannin compared to the non-CS wine, which could potentially result in increased astringency.
Biofilm production by Zymomonas mobilis enhances ethanol production and tolerance to toxic inhibitors from rice bran hydrolysate
(2014) Tatsaporn Todhanakasem; Atit Sangsutthiseree; Kamonchanok Areerat; Young, Glenn M.; Pornthap Thanonkeo
Microorganisms play a significant role in bioethanol production from lignocellulosic material. A challenging problem in bioconversion of rice bran is the presence of toxic inhibitors in lignocellulosic acid hydrolysate. Various strains of Zymomonas mobilis (ZM4, TISTR 405, 548, 550 and 551) grown under biofilm or planktonic modes were used in this study to examine their potential for bioconversion of rice bran hydrolysate and ethanol production efficiencies. Z. mobilis readily formed bacterial attachment on plastic surfaces, but not on glass surfaces. Additionally, the biofilms formed on plastic surfaces steadily increased over time, while those formed on glass were speculated to cycle through accumulation and detachment phases. Microscopic analysis revealed that Z. mobilis ZM4 rapidly developed homogeneous biofilm structures within 24 hours, while other Z. mobilis strains developed heterogeneous biofilm structures. ZM4 biofilms were thicker and seemed to be more stable than other Z. mobilis strains. The percentage of live cells in biofilms was greater than that for planktonic cells (54.32 7.10% vs. 28.69 3.03%), suggesting that biofilms serve as a protective niche for growth of bacteria in the presence of toxic inhibitors in the rice bran hydrolysate. The metabolic activity of ZM4 grown as a biofilm was also higher than the same strain grown planktonically, as measured by ethanol production from rice bran hydrolysate (13.40 2.43 g/L vs. 0.432 0.29 g/L, with percent theoretical ethanol yields of 72.47 6.13% and 3.71 5.24% respectively). Strain TISTR 551 was also quite metabolically active, with ethanol production by biofilm and planktonically grown cells of 8.956 4.06 g/L and 0.0846 0.064 g/ L (percent theoretical yields were 48.37 16.64% and 2.046 1.58%, respectively). This study illustrates the potential for enhancing ethanol production by utilizing bacterial biofilms in the bioconversion of a readily available and normally unusable low value by-product of rice farming.
Fermentation of rice bran hydrolysate to ethanol using Zymomonas mobilis biofilm immobilization on DEAE-cellulose
(2015) Tatsaporn Todhanakasem; Tipong Narkmit; Kamonchanok Areerat; Pornthap Thanonkeo
Background: The major challenges associated with the fermentation of lignocellulosic hydrolysates are the reduction in the operating cost and minimizing the complexity of the process. Zymomonas mobilis biofilm has been emerged to resolve these complexities. Biofilm has been reported to tolerate to the toxic inhibitors and easily manipulated toward the cell recycle through the cell immobilization. Results: Z.mobilisZM4 and TISTR 551were able to develop biofilms onDEAE cellulose under the differences in the morphologies. Z. mobilis ZM4 developed homogeneous biofilm that brought DEAE fiber to be crosslinking, while Z. mobilis TISTR 551 developed heterogeneous biofilm in which crosslinking was not observed. Ethanol production under batch and repeated batch fermentation of rice bran hydrolysate containing toxic inhibitors were compared between these two biofilms. TISTR 551 biofilm produced the maximum yield (YP/S) of 0.43 ± 0.09 g ethanol/g glucose (83.89% theoretical yield). However the repeated batch could not be proceeded due to the bacterial detachment. Z. mobilis ZM4 biofilm produced the maximum yield (YP/S) of 0.177 ± 0.05 g ethanol/g glucose (34.74% theoretical yield) in the batch culture and the biofilm remained intact to proceed along the repeated batch. The highest ethanol yield (YP/S) in the repeated batch of Z. mobilis ZM4 was 0.354 ± 0.07 g ethanol/g glucose (69.51% theoretical yield). Conclusions: Homogeneous biofilm structure of Z. mobilis provided more recycle beneficial over the heterogeneous biofilm structure for the ethanol production from lignocellulosic hydrolysate.
Freeze–thaw stability of edible oil-in-water emulsions stabilized by sucrose esters and Tweens
(2015) Suwimon Ariyaprakai; Kanitha Tananuwong
This work aimed to investigate freeze thaw stability of 20 wt% coconut oil (CtO) and corn oil (CnO)- in-water emulsions stabilized by 1 wt% of various types of sucrose esters and Tweens. Sucrose esters composed mainly of sucrose monostearate (S1670), sucrose monopalmitate (P1670), sucrose monolaurate (L1695), Tween 20 (TW20), Tween 60 (TW60), and Tween 80 (TW80) were used. After all emulsions were frozen at 20 ± 2 C and thawed to room temperature, their stability was analyzed from visual appearance, optical micrographs, amounts of destabilized oil, and average particle sizes. The CtO emulsions stabilized by S1670 and P1670 were very stable, the CtO emulsions stabilized by L1695 partly destabilized, and the CtO emulsions stabilized by TW20, TW60, and TW80 mostly destabilized into oil layers separated on top. The excellent stability of CtO emulsions stabilized by S1670 and P1670 was also confirmed from similar thermograms obtained from differential scanning calorimeter after three cooling–heating cycles (40 C to 40 C to 40 C at 5 C/min). It was proposed here that S1670 and P1670 affected the interfacial fat crystallization and their interfacial layers protected CtO emulsions against partial coalescence. Differently for the case of CnO emulsions, the CnO droplets remained liquid during freezing. All CnO emulsions stabilized by any emulsifiers destabilized by coalescence since these small surfactants could not provide enough interfacial barriers.
Sensory characterization of instant tom yum soup
(2016) Kamolnate Kitsawad; Nasara Tuntisripreecha
Kamolnate Kitsawad 5.86Assumption University of Thailand Nasara Tuntisripreecha Abstract Instant tom yum soups are widely available in the market in various forms, powder, paste, and liquid. Despite the similarity in the use of key ingredients, each product is unique in flavor. The aim of this study was to characterize the sensory profile of instant tom yum soup. Descriptive analysis was performed to examine the sensory profiles of 12 instant tom yum soups. Sensory descriptors were generated; appearance (color, amount of oil, cloudiness), aroma (modified lime, pungent, lemon glass, chili paste, sugar-boiled banana puree), taste (bitterness, spiciness, saltiness, sourness, sweetness), flavor (rancid, herb, coconut milk, kaffir-lime, galangal, orange peel), texture (swallow ability, amount of particle, oily mouth feel).
Zymomonas mobilis biofilm formation on different types of carriers
(2016) Tatsaporn Todhanakasem; Rashmi Tiwari
Zymomonas mobilis biofilm have been proposed to enhance the bioethanol production from agricultural derived materials. Z. mobilis biofilm reactor has been prospected to be used for a large scale bioethanol production. The cost effective carrier for Z. mobilis biofilm reactor was searched. This study investigated the biofilm forming abilities of Z. mobilisstrain TISTR 551 and ZM4 on biotic (loofah and corn silk) or abiotic carriers (flatted sheet polyvinyl chloride, PVC). Biofilm formation was visualized for 3 consecutive days under the bright-field microscope. Only Z. mobilis TISTR551 represented the biofilm forming ability on corn silk under the microscopic observation, while no biofilm formation on loofah and PVC was observed. The mature biofilm was developed on day 3. The biofilm formation was also quantitatively analyzed based on the weight differentiation of the carrier and the carrier with the bacterial attachment. The net biomass weight of TISTR 551 and ZM4 on corn silk carrier was 0.6 ±0.1 g and 0.33± 0.1g respectively. Therefore, corn silk illustrates its potential to be used as a cost effective biocarrier for Z. mobilis biofilm.
Encapsulation of protease from Aspergillus oryzae and lipase from Thermomycess lanuginoseus using alginate and different copolymer type
(2016) Thu, Truong Thi Mong; Wunwisa Krasaekoopt
Although the application of enzymes in food as a food processing aid and enzyme supplement is ofinterest and widely used, the enzymes can be easily deactivated or lose their activity due to many causessuch as pH and moisture as well as through the introduction of incompatible ingredients during foodprocessing and storage. These problems can be solved by the encapsulation technique, especially in a gelmatrix. The inﬂuences were studied of the alginate concentration, types of copolymer and their con-centrations on the bead size, encapsulation yield (EY), encapsulation efﬁciency (EE), leakage and theretention of enzyme activity during storage period of encapsulated protease from Aspergillus oryzae andlipase from Thermomyces lanuginosus beads. A solution of puriﬁed protease or lipase was encapsulated incalcium alginate-chitosan beads (CACB), calcium alginate-xanthan gum beads (CAXB) and calciumalginate-maltodextrin beads (CAMB) using the extrusion method. Increasing the alginate and copolymerconcentrations in the solution increased the bead size, EY, EE and the retention of enzyme activity duringthe storage period and reduced leakage of both the encapsulated protease and lipase. In addition,different types of copolymer signiﬁcantly (p0.05) affected these properties of both encapsulatedenzymes. Furthermore, protease encapsulated using 2.0% alginate and 0.2% chitosan provided the highestEY (81.7%) and EE (77.2%) with a bead size of 1.85 mm and 8.1% leakage. The retention of encapsulatedprotease activity and the shelf-life of encapsulated enzyme which was expressed as half-life, the timerequired for the enzyme activity to decrease by half (thalf life) were 75.8% and 27.2 wk, respectively afterstorage at 4C for 10 wk. For lipase, encapsulation using 2.0% alginate and 0.4% xanthan gum providedthe highest EY (42.5%) and EE (43.9%) and the bead size and leakage were 1.81 mm and 6.2%, respectively.The retention of encapsulated lipase activity and the thalf lifewere 77.9% and 27.8 wk, respectively afterstorage at 4C for 10 wk. CACB was a suitable complex polymer for encapsulating protease while CAXBwas suitable for lipase. EY and EE values of CACB-protease were higher than those of CAXB-lipase.Therefore, the encapsulation method, gelling conditions and interactions between carriers and lipaseshould be further studied.
Development of corn silk as a biocarrier for Zymomonas mobilis biofilms in ethanol production from rice straw
(2016) Tatsaporn Todhanakasem; Rashmi Tiwari; Pornthap Thanonkeo
Z. mobilis cell immobilization has been proposed as an effective means of improving ethanol production. In this work, polystyrene and corn silk were used as biofilm developmental matrices for Z. mobilis ethanol production with rice straw hydrolysate as a substrate. Rice straw was hydrolyzed by dilute sulfuric acid (H2SO4) and enzymatic hydrolysis. The final hydrolysate contained furfural (271.95 ± 76.30 ppm), 5-hydroxymethyl furfural (0.07 ± 0.00 ppm), vanillin (1.81 ± 0.00 ppm), syringaldehyde (5.07 ± 0.83 ppm), 4- hydroxybenzaldehyde (4-HB) (2.39 ± 1.20 ppm) and acetic acid (0.26 ± 0.08%). Bacterial attachment or biofilm formation of Z. mobilis strain TISTR 551 on polystyrene and delignified corn silk carrier provided significant ethanol yields. Results showed up to 0.40 ± 0.15 g ethanol produced/g glucose consumed when Z. mobilis was immobilized on a polystyrene carrier and 0.51 ± 0.13 g ethanol produced/ g glucose consumed when immobilized on delignified corn silk carrier under batch fermentation by Z. mobilis TISTR 551 biofilm. The higher ethanol yield from immobilized, rather than free living, Z. mobilis could possibly be explained by a higher cell density, better control of anaerobic conditions and higher toxic tolerance of Z. mobilis biofilms over free cells.
Properties and applications of different probiotic delivery systems
(2012) Wunwisa Krasaekoopt
Probiotic products should contain and maintain viable cells during the product shelf life at least above therapeutic minimum level for the benefit of consumers. Due to their generally poor viability and stability in food products, especially in fermented dairy products, as well as in the host gastrointestinal tract, various microencapsulation techniques for probiotics have been developed in recent years to overcome these issues. This chapter describes the benefit of microencapsulation, various encapsulation techniques used to encapsulate probiotics and the application of encapsulated probiotics in selected food systems. The use of various supporting or encapsulating materials, such as alginate, chitosan and carrageenan is also discussed. Special treatments (such as complexation coating) of capsules for further improving the stability of the probiotics are also described.
Microbial Biofilm in the industry
(2013) Tatsaporn Todhanakasem
Biofilms represent negative and positive attributes in the industries. Biofilm is a functional consortium of microorganisms attached to either biotic or abiotic surfaces and embedded under the extracellular polymeric substances (EPS). Spoilage and pathogenic microorganisms can develop biofilms on food industrial surfaces that can lead to food spoilage and disease transmission when the inappropriate clean up and control have been applied in the food industies. However, single and mixed species of microbial biofilms also represent tremendous advantages in bioprocesses and waste treatments. Biofilm reactors have been employed in order to improve the productivities, stability of the processes and reduce the production cost. To understand biofilm, numerous direct and indirect experimental approaches have been used to study the biofilms. Molecular genetics approaches have led to study on the process of biofilm development in order to understand its genetic regulations.
Microencapsulation of Probiotics in Hydrocolloid Gel Matrices: A Review
(2013) Wunwisa Krasaekoopt
The use of hydrocolloid gel matrices to encapsulate probiotics is of interest due to their gentle and simplicity of gel formation as well as mild condition used. This technique enhances the viability of entrapped cells during the product shelf life at least above therapeutic minimum level as well as in the gastrointestinal tract to ensure the health benefits of consumers. This review describes the advantages of microencapsulation, hydrocolloid gel matrices such as alginate, carrageenan and whey protein, microencapsulation processes, special treatments for further improvement in encapsulation efficiency of gel matrices as well as food applications of microencapsulated probiotics.
Interfacial and emulsifying properties of sucrose ester in coconut milk emulsions in comparison with Tween
(2013) Suwimon Ariyaprakai; Tanachote Limpachoti; Pasawadee Pradipasena
In this study, sucrose esters were presented as a promising alternative to petrochemically synthesized Tweens for application in coconut milk emulsions. The interfacial and emulsiﬁer properties of sucrose ester (SE), mainly sucrose monostearate, had been investigated in comparison with Tween 60 (TW), an ethoxylate surfactant. The interfacial tension measurement showed that SE had a slightly better ability to lower the interfacial tension at coconut oilewater interface. These surfactants (0.25 wt%) were applied in coconut milk emulsions with 5 wt% fat content. The effects of changes in pH, salt concentration, and temperature on emulsion stability were analyzed from visual appearance, optical micrograph, droplet charges, particle size distributions, and creaming index. Oil droplets in both SE and TW coconut milk emulsions extensively ﬂocculated at pH 4, or around the pI of the coconut proteins. Salt addition induced ﬂocculation in both emulsions. The pH and salt dependence indicated polyelectrolyte nature of proteins, suggesting that the proteins on the surface of oil droplets were not completely displaced by either added nonionic SE or TW. TW coconut milk emulsions appeared to be thermally unstable with some coalesced oil drops after heating and some oil layers separated on top after freeze thawing. The change in temperature had much lesser inﬂuence on stability of SE coconut milk emulsions and, especially, it was found that SE emulsions were remarkably stable after the freeze thawing.
Stability of Orange Oil-in-Water Emulsions Prepared by Multilayer Membranes
(2013) Suwimon Ariyaprakai; Qi, Wu Jai
Due to the small molecular size of orange oil, primary orange oil–in-water emulsion can easily undergo Ostwald ripening destabilization. To improve the stability of orange oil emulsion, multilayer emul- sion was prepared using Citrem as emulsifier and gelatin as coated biopolymer. Firstly, primary emulsion containing 20 wt% orange oil and 0.4 wt% Citrem was produced. Since Citrem was an anionic emulsifier, the primary emulsion had a negative charge of ~ -57mV. Then, the primary emulsion was suspended in 0.5 wt% gelatin aqueous solution at pH 3 with the ratio of primary emulsion to gelatin aqueous solution of 1:1. The gelatin that was positively charged at this pH condition coated around the primary emulsion and double layer emulsion (secondary emulsion) with a ζ-potential value of ~ +20 mV was Produced. The particle sizes of primary and secondary emulsions at various time intervals were detected using a laser diffraction particle analyzer. The results showed that the average particle size (d3,2) of secondary emulsion on the first day was 1.5 (± 0.02) microns and that after storage at room temperature (~25 °C) for 14 days was 1.5 (± 0.02) microns, indicating good emulsion stability. The particle size of the primary emulsion (d3,2) increased from 1.3 (± 0.02) microns to 1.8 (± 0.02) micron, or increased by a factor of 1.4.
Use of Rice Hull Hydrolyzate in the Cultivation of Lactobacillus acidophilus
(2012) Tatsaporn T.; Nikapong Puanglamyai
This project aims to minimize the cost of production of live L. acidophilus by replacing the expensive carbon source in the fermentation medium with the rice hull hydrolyzate and compare the growth efficiency of the microbe in the rice hull formulated medium with the rich medium (de Man Rogosa Sharpe or MRS). Rice hull was hydrolyzed with diluted H2 SO4 and HCl at various concentrations 0.25, 0.5 and 1% v/v at 120 o C for 30 minutes. The hydrolyzate was further overliming with Ca(OH) 2 and filter through the diatomaceous earth. The treatment with 0.5% and 1% HCl provided the reducing sugar of 23.05 and 27.45 g/L which were close to MRS broth of 20.88 g/L. The hydrolyzate from the treatment with 1% HCl was further mixed with MRS in the ratio of MRS: hydrolyzate of 25: 75 and 10: 90 v/v. The MRS mixed with the hydrolyzate in the ratio of 25:75 v/v gave the maximum specific growth rate (µmax ) of 0.437 hour -1 which was comparable to the MRS broth of 0.424 hour -1 . The biomass yield (Yx/s ), dry weight and viable cell number on the formulated medium at 48 hours cultivation were 0.21 g/g, 2.61 mg/ml and 2.07 × 10 8 CFU/ml respectively in comparison to MRS at 48 hours cultivation which were 0.19 g/g, 3.07 mg/ml and 2.19 × 10 8 CFU/ml (viable cell number in MRS represented the maximum level at 9 hours) respectively. The total acidity produced by the culture in formulated medium and MRS were 1.461% and 1.761%. Although, the formulated medium from rice hull hydrolyzate reduced the production cost in term of medium requirement, the time required for obtaining the same amount of viable cells in the hydrolyzate was longer than using MRS as a sole medium.
Determination of suitable palate cleanser for spicy tom yum soup
(2014) Kamolnate Kitsawad
Palate cleansers are required in sensory tests as they help improve the accuracy for sensory responses especially for foods containing strong flavour. The objective of this study is to determine a suitable palate cleanser that can be used to relief spiciness in a Thai dish, tom yum soup. The untrained judges rated the spiciness of three levels of spicy tom yum soups before and after using five palate cleanser strategies, water, bread, unsweetened milk, 10 percent sucrose and nothing. One palate cleanser strategy was used per session, thus the judges performed a total of five sessions. All of the palate cleanser strategies have shown to exhibit the ability to relief spiciness of the tom yum soups where milk was most effective Thus, using milk as a palate cleanser strategy follow by a water rinse is considered to be one of the appropriate palate cleanser choices for spicy soup.
Review: the Bioavailability Activity of Centella asiatica
(2015) Patchanee Yasurin
Centella asiatica (Bao-bog, Tiger Herbal, Pennywort, Gotu kola) has been announced as one of five “Thailand Champion Herbal Products (TCHP)” by the Department for Development of Thai Transitional and Alternative Medicine, Ministry of Public Health. C. asiatica has been investigated for its bioavailability activity, antimicrobial activity, antioxidant activity, anti-inflammatory activity, wound healing activity and anticancer activity. C. asiatica contains many types of active compounds: terpenoids, terpenoids and phenols. Thus, C. asiatica has high potential to be applied in pharmaceutical, cosmetic and food industries.
Production, purification and characterization of an ionic liquid tolerant cellulase from Bacillus sp. isolated from rice paddy field soil
(2015) Patchanee Yasurin
Background: Lignocellulosic biomass is a renewable, abundant, and inexpensive resource for bioreﬁning process to produce biofuel and valuable chemicals. To make the process become feasible, it requires the use of both efﬁcient pretreatment and hydrolysis enzymes to generate fermentable sugars. Ionic liquid (IL) pretreatment has been demonstrated to be a promising method to enhance the sacchariﬁcation of biomass by cellulase enzyme; however, the remaining IL in the hydrolysis buffer strongly inhibits the function of cellulase. This study aimed to isolate a potential IL-tolerant cellulase producing bacterium to be applied in bioreﬁning process. Result: One Bacillus sp., MSL2 strain, obtained from rice paddy ﬁeld soil was isolated based on screening of cellulase assay. Its cellulase enzyme was puriﬁed and fractionated using a size exclusion chromatography. The molecular weight of puriﬁed cellulose was 48 kDa as revealed by SDS-PAGE and zymogram analysis. In the presence of the IL, 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) concentration of 1 M, the cellulase activity retained 77.7% of non-IL condition. In addition, the optimum temperature and pH of the enzyme is 50°C and pH 6.0, respectively. However, this cellulase retained its activity more than 90% at 55°C, and pH 4.0. Kinetic analysis of puriﬁed enzyme showed that the Km and Vmax were 0.8 mg/mL and 1000 μM/min, respectively. Conclusion: The characterization of cellulase produced from MSL2 strain was described here. These properties of cellulase made this bacterial strain become potential to be used in the bioreﬁning process.

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