Microbiological and physical properties of pennywort (Centella asiatica) leaves using pulsed light technology

Pennywort (Centella asiatica) is a herbaceous vegetable commonly consumed raw as ‘ulam’ or salad. Consumption of raw leafy green vegetables is one of the pathogenic mechanisms that could cause foodborne outbreaks. The aim of the present work was therefore to investigate the effect of pulsed light (PL) treatment at fluences of 1.5, 4.2, 6.9, 9.6, and 12.3 J/cm² on the microbiological and physical quality of pennywort stored at 4 ± 1°C. Escherichia coli (E. coli) were inoculated onto the pennywort leaves before being exposed to PL and viewed using scanning electron microscopy (SEM). PL fluences of 6.9, 9.6, and 12.3 J/cm² significantly reduced the microbial count; however, the highest inactivation was obtained by using fluences of 9.6 and 12.3 J/cm². The color of pennywort was not significantly affected by PL treatment applied at lower fluences of 1.5, 4.2, and 6.9 J/cm²; however, at higher fluence, 9.6 and 12.3 J/cm², the color was affected. PL at 1.5, 4.2, 6.9, and 9.6 J/cm² was able to retain the texture appearance of the leaves. To conclude, PL at 6.9 J/cm² showed the best fluence to reduce total aerobic mesophilic count while retaining the physical properties of pennywort leaves and extend the shelf life to about four days. The inactivation of E. coli population was significantly higher at PL fluence of 6.9 J/cm². It was observed that PL caused the destruction to the surface of E. coli’s cell membrane. The reductions of samples inoculated with E. coli were better than those achieved in native microbiota. Furthermore, the present work also demonstrated that PL treatment was able to reduce the microbial count on pennywort leaves

Effects of culture conditions of immobilized recombinant Escherichia coli on cyclodextrin glucanotransferase (CGTase) excretion and cell stability

The targeting of recombinant proteins for excretion into culture medium presents significant advan-tages over cytoplasmic expression. However, during the excretion of recombinant protein, caution must be taken in order to avoid cell lysis due to pressure build-up through overproduction of the expressed recombinant protein in the periplasmic space. In the present study, recombinant Escherichia coli express-ing cyclodextrin glucanotransferase (CGTase) was immobilized by adsorption and entrapment in a porous hollow fiber membrane. The effects of culture conditions (post induction time, agitation rate and pH) on CGTase excretion, cell lysis and plasmid stability of immobilized cells were studied. The optimum post induction time, agitation rate and pH were found to be 24 h, 200 rpm and pH 9, respectively. The immo-bilized cells exhibited a 2.8–4.6-fold increase in CGTase excretion, a 16–95% reduction of cell lysis and a 323–464% increase in plasmid stability compared with free cells. Hence, immobilizing E. coli using a porous hollow fiber membrane proved to be valuable for the excretion of a recombinant protein and increased cell viability

Enzymatic activity of alginate coated and pulsed light treated fresh-cut cantaloupes (Cucumis melo L. var. reticulatus cv. Glamour) during chilled storage

The objective of the present work was to investigate the effects of alginate coating combined with repetitive pulsed light (RPL) treatment on the enzymatic activity of fresh-cut cantaloupes during chilled storage. Fresh-cut cantaloupes were coated with alginate (1.86%, w/v) followed by RPL treatment (0.9 J/cm2 at every 48 h up to 26 d) during storage. Untreated samples and samples with alginate or RPL alone were used as controls. Enzymatic activities [polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL), peroxidase (POD), pectinesterase (PE), polygalacturonase (PG), pectate lyase (PEL), β-galactosidase (β-Gal), α-arabinofuranosidase (α-AF) and cellulase] of fresh-cut cantaloupes were evaluated every 4 d during storage. Neither alginate coating nor RPL treatment has any effect on the activities of PE and PEL of fresh-cut cantaloupes during storage. The individual treatment or in combination did not increase the PAL, PPO, PG and cellulase activities of fresh-cut cantaloupes throughout the storage. Alginate coating with or without RPL was effective in maintaining low POD activity of fresh-cut cantaloupes. In addition, treatments using alginate coating or alginate coating+RPL were effective in reducing the β-Gal and α-AF activities of fresh-cut cantaloupes during storage. Overall, alginate without or with RPL was effective in reducing changes of enzymatic activities in fresh-cut cantaloupes during storage

Adequacy of contract provision in managing construction failure

In managing construction failure, normally efforts are made to identify the possible cause of failure and seek for the possible solution of the problems faced. Currently, there is no clear guideline available either within existing contract documents or legislations that can be used as a guide to resolve construction failure cases. Hence, this study has been undertaken to identify the limitations of current contract provisions which related to construction failure. It is conducted to evaluate the adequacy of contractual provisions in contract documents. The methodology adopted for this study includes literature research, interviews and questionnaire surveys with selected professionals in construction industry and legal sector. The findings of the study show that the limitations in current contractual provisions are eminent. It is also found that there is a need for consideration of inclusion of new provisions to be implemented into contract document. Despite there may be a difference of ideas between the respondents from construction industry and legal sector regarding to limitations of law and contract to solve construction failure cases. This study also made some proposal of important items that should be considered for improving current contract provisions

Impact of juice extraction method on the physicochemical, functional, and sensory properties of Sabah snake grass (Clinacanthus nutans) juice mix

The present work investigated the impact of several juice extraction methods (blender, centrifugal juicer, and slow juicer) and thermal pasteurisation (72°C, 15 s) on the different properties [physicochemical, polyphenol oxidase (PPO) activity, and functional] of Clinacanthus nutans juice mix during storage (28 d, 4°C). Regardless of juicing technique, all juices had similar colour and antioxidants [tested using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) methods]. The juices also had similar PPO activity and sensory acceptance in terms of colour, aroma, flavour, mouthfeel, and overall acceptability. The blender yielded juice with higher pH, soluble solids, and relative viscosity than other methods. The slow juicer was the best at retaining ascorbic acid (39.33 ± 3.06 mg/100 mL), while the blender was best at retaining phenolic compounds (11.82 ± 0.12 mg gallic acid equivalents/100 mL) and chlorophyll (6.95 ± 0.31 μg/mL). Pasteurisation negatively affected the colour, functional properties, and sensory characteristics (colour, aroma, flavour, and mouthfeel) of the juice

Enzymatic hydrolysis of pretreated kenaf using a recombinant xylanase: effects of reaction conditions for optimum hemicellulose hydrolysis

An efficient hemicellulose hydrolysis has now become a crucial step for xylooligosaccharides production for food additives and nutraceuticals industries. In this study, xylanase hydrolysis of pretreated hemicellulosic kenaf (Hibiscus cannabinus) for substantial hemicellulose hydrolysis was demonstrated. Experiments were performed primarily to investigate the effect of several critical reaction conditions towards the enzymatic hydrolysis of the pre-treated kenaf. The effects of various ranges of reaction conditions (substrate loading, xylanase loading, pH, temperature and time) were systematically and thoroughly studied. The study of hemicellulosic kenaf conversion using single enzyme was proven to effectively yield up to 59% of conversion after 48 h incubation using 3% (w/v) of substrate loading and 400 U of xylanase loading at 50°C in pH 4.0 buffer systems. The use of a single xylanase on the pre-treated kenaf was a key parameter in understanding the action of the main hemicellulose degrading enzyme towards hydrolysing the hemicellulose backbone of the pre-treated kenaf. Enzyme feeding strategy was also conducted and the results revealed that a batch feeding strategy of 400 U xylanase loading yielded the highest hemicellulose hydrolysis compared to the other fed batch enzyme feeding strategy. It was concluded that each reaction conditions and enzyme feeding strategy gave a significant impact towards the enzymatic hydrolysis and the use of optimum reaction conditions resulted in a high product yield at the end of the reaction. With the discovery of the importance of each reaction conditions involved in a hydrolysis, this study highlights the need for a comprehensive investigation on the reaction conditions using a mixture of enzymes towards achieving a complete hydrolysis with a higher product yield

Delivery of bioencapsulated proteins

Proteins and peptides have been used in pharmaceutical, nutraceutical, and food applications for their therapeutic and nutritional properties. However, administration of these molecules to the human body is challenging due to their low stability, low bioavailability, high biodegradability, immunogenicity, and inefficient permeability. These molecules require a tailored delivery system to ensure bioavailability and efficient maintenance to target location. Nanotechnology has emerged as an ideal platform in drug delivery as it provides a versatile system with excellent biocompatibility. This chapter discusses various nanomaterials that have been explored, particularly organic, inorganic, protein, and hybrid nanomaterials which are biocompatible for administration to human body. Challenges for the development of protein in nanomaterials are outlined and strategies for the nanoencapsulation in these nano-vehicles are discussed that aim for preservation of bioactivity, high protein loading, structural stability, permeability, and control release besides being easy for synthesis and cost-effective

Optimization and characterization of immobilized E. coli for engineered thermostable xylanase excretion and cell viability

There are many parameters that may have influenced the properties of cell during immobilization process. Particularly, the immobilization methods, carrier materials, and enzyme loading amount that have been proved to be important for immobilization process. The physiological responses of microorganisms are depending on the immobilization technique used. Typical alterations to the micro-environment of the immobilized cell involved the altered water activity, presence of ionic charges, cell confinement and modified surface tension. In this study, the graphene oxide was selected as a suitable carrier for immobilization process of recombinant E.coli and adsorption was chosen as an appropriate method to improve the production of engineered thermostable xylanase. High level production of thermostable xylanase by immobilized recombinant cell in the 5 L bioreactor was studied by using optimum research surface methodology (RSM) conditions was studied. The immobilization of E. coli onto nanoparticle matrix manages to improve the cell performance by improving the protein expression, reduced the occurrences of cell lysis as well as improved the plasmid stability of the host cell. Thus, immobilization contributes a physical support for both whole cells as well as enzymes to develop a better operative achievement system for industrialized fields and give rise to the biological advancement existing enzyme for instance xylanase

20th International Medical, Pharmaceutical, Cosmeceutical and Health Science Symposium

The 20th International Medical, Pharmaceutical, Cosmeceutical & Health Science Symposium (iMPaCHS) is an annual symposium co-organized by Faculty of Life and Health Sciences, International Medical School, School of Pharmacy, Management & Science of the Management & Science University, Malaysia. With the theme 'Advancing Health Science Innovations through Interdisciplinary Collaboration', the 20th iMPaCHS aims to promote holistic research skills for future betterment. Advancing health science innovations requires a multidisciplinary approach, which involves the collaboration of experts from various fields. Interdisciplinary collaboration enables the integration of knowledge, perspectives, and methodologies from different disciplines, leading to the development of novel and effective solutions to complex health challenges. By fostering interdisciplinary collaboration, health science can leverage the strengths of each field and accelerate the translation of research findings into clinical practice, ultimately improving and advancing the overall state of health science. This is in line with the sustainable development goal and collaborative research activity in the university. The 20th International Medical, Pharmaceutical, Cosmeceutical & Health Science Symposium (iMPaCHS) is an annual symposium co-organized by Faculty of Life and Health Sciences, International Medical School, School of Pharmacy, Management & Science of the Management & Science University, Malaysia. With the theme 'Advancing Health Science Innovations through Interdisciplinary Collaboration', the 20th iMPaCHS aims to promote holistic research skills for future betterment. Advancing health science innovations requires a multidisciplinary approach, which involves the collaboration of experts from various fields. Interdisciplinary collaboration enables the integration of knowledge, perspectives, and methodologies from different disciplines, leading to the development of novel and effective solutions to complex health challenges. By fostering interdisciplinary collaboration, health science can leverage the strengths of each field and accelerate the translation of research findings into clinical practice, ultimately improving and advancing the overall state of health science. This is in line with the sustainable development goal and collaborative research activity in the university

Adsorption of fatty acid on beta-cyclodextrin functionalized cellulose nanofiber

Fatty acids in wastewater contribute to high chemical oxygen demand. The use of cellulose nanofiber (CNF) to adsorb the fatty acids is limited by its strong internal hydrogen bonding. This study aims to functionalize CNF with β-cyclodextrin (β-CD) and elucidate the adsorption behaviour which is yet to be explored. β-CD functionalized CNF (CNF/β-CD) was achieved by crosslinking of β-CD and citric acid. Functionalization using 7% (w/v) β-CD and 8% (w/v) citric acid enhanced mechanical properties by increasing its thermal decomposition. CNF/β-CD was more efficient in removing palmitic acid, showcased by double adsorption capacity of CNF/β-CD (33.14% removal) compared to CNF (15.62% removal). CNF/β-CD maintained its adsorption performance after five cycles compared to CNF, which reduced significantly after two cycles. At 25 °C, the adsorption reached equilibrium after 60 min, following a pseudo-second-order kinetic model. The intraparticle diffusion model suggested chemical adsorption and intraparticle interaction as the controlling steps in the adsorption process. The maximum adsorption capacity was 8349.23 mg g−1 and 10485.38 mg g−1 according to the Sips and Langmuir isotherm model, respectively. The adsorption was described as monolayer and endothermic, and it involved both a physisorption and chemisorption process. This is the first study to describe the adsorption behaviour of palmitic acid onto CNF/β-CD