Liew Phing Pui

Bio: Liew Phing Pui is an academic researcher from University of Kuala Lumpur. The author has contributed to research in topics: Food science & Probiotic. The author has an hindex of 5, co-authored 17 publications receiving 78 citations.

Clinacanthus Nutans Hexane Extracts Induce Apoptosis Through a Caspase-Dependent Pathway in Human Cancer Cell Lines

Abstract: Background: Clinacanthus nutans (Cnutans) is a plant consumed as a cancer treatment in tropical Asia Despite the availability of numerous anecdotal reports, evaluation of active anticancer effects has remained elusive Therefore we here examined antiproliferative, reactive oxygen species (ROS)-inducing and apoptosis mechanisms of whole plant extracts in different cancer cell lines Methods: Antiproliferative actions of five solvent extracts (hexane, chloroform, ethyl acetate, methanol and water) of Cnutans were tested on non-small cell lung cancer (A549), nasopharygeal cancer (CNE1) and liver cancer (HepG2) cells using MTT assay The most potent anticancer extract was then assessed by flow cytometry to study cell cycle changes Intracellular levels of ROS were quantified by DCFH-DA assay Involvement of the caspase pathway in induction of apoptosis was assessed using caspase assay kits GC-MS analysis was performed to identify phytoconstituents in the extracts Results: Hexane and chloroform extracts were antiproliferative against all three cell lines, while the ethyl acetate extract, at 300 μg/mL, was antiproliferative in the CNE1 but not A549 and HepG2 cases Methanol and water extracts did not inhibit cancer cell proliferation The most potent anticancer hexane extract was selected for further testing It induced apoptosis in all three cell lines as shown by an increase in the percentage of cell in sub-G1 phase Dose-dependent increase in ROS levels in all three cell lines indicated apoptosis to be possibly modulated by oxidative stress At high concentrations (>100 μg/mL), hexane extracts upregulated caspases 8, 9 and 3/7 across all three cell lines GC-MS analysis of the hexane extract revealed abundance of 31 compounds Conclusion : Among the five extracts of Cnutans, that with hexane extract demonstrated the highest antiproliferative activity against all three cancer cell lines tested Action appeared to be via ion of intracellular ROS, and induction of apoptosis via intrinsic and extrinsic caspase pathways

Polysaccharide-Based Edible Films Incorporated with Essential Oil Nanoemulsions: Physico-Chemical, Mechanical Properties and Its Application in Food Preservation—A Review

Abstract: Edible films with essential oils (EOs) are becoming increasingly popular as an alternative to synthetic packaging due to their environmentally friendly properties and ability as carriers of active compounds. However, the required amounts of EOs to impart effective antimicrobial properties generally exceed the organoleptic acceptance levels. However, by nanoemulsifying EOs, it is possible to increase their antimicrobial activity while reducing the amount required. This review provides an overview of the physico-chemical and mechanical properties of polysaccharide-based edible films incorporated with EOs nanoemulsions and of their application to the preservation of different food types. By incorporating EOs nanoemulsions into the packaging matrix, these edible films can help to extend the shelf-life of food products while also improving the quality and safety of the food product during storage. It can be concluded that these edible films have the potential to be used in the food industry as a green, sustainable, and biodegradable method for perishable foods preservation.

Production of spray-dried Sarawak pineapple (Ananas comosus) powder from enzyme liquefied puree.

Abstract: Spray drying is used widely for converting liquid food products into powder form as the dried powder is known to have a longer shelf life at ambient temperature, convenience to use and low transportation expenditure. In this study, the Sarawak pineapple puree was spray-dried and the characterization of the resulting powder was performed. The process of enzyme liquefaction was optimized with Pectinex® Ultra SP-L and Celluclast® 1.5 L (single and combined treatment) at different concentrations (0–2.5 %) and incubation time (0-2.5 hours). The combined treatment with both enzymes (1.5% v/w Pectinex® Ultra SP-L + 0.5% v/w Celluclast® 1.5 L, 1.5 hour) was found to be the best parameter, which produced purees with the lowest viscosity of 67.98 ± 4.27 cp. Optimization of spray drying process was carried out using different inlet temperatures (150-180°C) and maltodextrin concentrations (15-30 % w/w). Results indicated that the spraydried powder produced at 160°C with 15% w/w of maltodextrin has the highest yield (31.63 %). The spray-dried powder was further characterized for the moisture content (6.00 ± 0.63%), water activity (0.36 ± 0.01 Aw), hygroscopicity (17.35 ± 0.64%), bulk density (0.46 ± 0.04 g/ cm3) and solubility (87.33 ± 2.08 seconds). The fruit powder of this study can be incorporated into different fruit added –value products, such as fruit juice, yogurt, jelly and other beverages.

Production of spray-dried enzyme-liquefied papaya (Carica papaya L.) powder

Abstract: Water removal during drying process consumes energy and lead to high production cost. Hence, enzymatic mash treatment was proposed to reduce the usage of water to produce feed concentration that is suitable for drying. In this study, papaya powder was prepared from papaya puree treated with 1.0% v/w of Pectinex® Ultra SP-L, a pectinase enzyme, with incubation under 50 °C up to 2 hours. The liquefied papaya puree was spray-dried at selected maltodextrin concentrations (10% to 50% w/w of papaya puree) and inlet temperatures (140 °C to 180 °C). The physico-chemical properties of papaya puree, spray-dried powder, and reconstituted powder were assessed. Results showed that an increase in maltodextrin concentration led to lower process yield, lower moisture content and hygroscopicity, and better solubility. The powder produced was brighter in colour (L*) and less yellowish (b*). The papaya puree added with 20% maltodextrin achieved the highest process yield (74.91% ± 9.15%) and better solubility (69.60 ± 0.48 s/g) with optimal moisture content (5.21% ± 0.15% dry basis) and hygroscopicity (24.79% ± 0.58%) which was selected as optimal concentration. Meanwhile, increasing spray drying inlet temperatures led to a reduction in moisture content (26%) but did not significantly affect (p > 0.05) water activity, hygroscopicity, bulk density and colour of spray-dried papaya powders. The inlet temperature of 150 °C achieved the highest solubility (48.17 ± 4.51 s/g) with moderate process yield (74.01% ± 7.69%) and moisture content (5.91% ± 0.70% dry basis) which was considered as optimal drying temperature. The reconstituted powder showed no significant effect in viscosity, pH, and colour regardless of the different maltodextrin concentrations and inlet temperatures used. The optimized spray powder showed no significant difference with initial spray drying feed in total soluble solids, pH, and b* value.

Microencapsulation of Lactobacillus plantarum 299v incorporated with oligofructose in chitosan coated-alginate beads and its storage stability in ambarella juice

Abstract: Aims: Microencapsulation has been used to protect the viability of probiotics in harsh environments such as gastrointestinal conditions and food composition. The present study aimed to optimize the microencapsulation of Lactobacillus plantarum 299v (Lp299v) using co-extrusion by varying two parameters (calcium chloride (CaCl2) and oligofructose (FOS) concentrations) and storage stability of the beads produced in ambarella juice at refrigerated and room temperature. Methodology and results: Chitosan coated-alginate microcapsule prepared with 4.0% (w/v) FOS and 2.5% (w/v) CaCl2 showed highest microencapsulation efficiency (93%). The microcapsules were subjected to gastrointestinal treatment and storage test in ambarella juice. Both encapsulated Lp299v with and without FOS showed higher viabilities compared with free cells after incubated in simulated gastric juice (SGJ) and simulated intestinal juice (SIJ). After 5 h of incubation in SIJ, the viabilities of both encapsulated probiotic with and without FOS were more than 10 CFU/mL. The Lp299v were stored in ambarella juice under refrigerated (4 °C) and room temperature (25 °C) for 4 weeks. At 25 °C, all forms of Lp299v lost their viabilities after one week. On the other hand, at 4 °C, viable cells count of both encapsulated Lp299v with and without FOS were reported to be more than 10 CFU/mL after 4 weeks of storage. Conclusion, significance and impact of study: Microencapsulation with FOS was able to improve Lp299v’s viability during storage in low pH fruit juices compared to those without FOS. The microencapsulated probiotics could be applied in ambarella juice for the development of functional food.

Phytochemistry, pharmacological activities, nanoparticle fabrication, commercial products and waste utilization of Carica papaya L.: A comprehensive review

Abstract: Fruits and vegetables are an important part of a healthy diet. In this regard, Carica papaya (papaya) is one of them, a native to Mexico and northern South America, now naturalized in many parts of the world including tropical and subtropical regions. The papaya fruit pulp is rich in minerals and many vitamins, while seed contains glucosinolates, tocopherols, carotenoids, and benzyl isothiocyanate. Papaya is known for numerous activities such as antioxidant, antibacterial, anticancer activity, anti-fertility agent, anti-inflammatory, antiulcer, antidiabetic, hepatoprotective, and many more due to the presence of phenolics, flavonoids, and alkaloids as the key phytochemicals. Many commercial products obtained from different plant parts are available in the market and are being utilized for various purposes. More specifically, papaya fruit is used to produce a large number of processed foods such as jam, jelly, pickle, candied fruit, puree, concentrate, and canned slices/chunks. Fruit peels find its application in cosmetics, in wastewater treatment, as animal feed, and as a binder in ceramics. Papaya leaf, bark, root, and seeds have also shown the insecticidal and repellent activities. More interestingly, in the recent past, papaya and different parts are used for nanoparticle synthesis which has shown numerous applications. This review mainly focuses on the various phytochemicals present in different parts of plant C. papaya, their pharmacological activities, and several other applications. For writing this review paper, a literature survey was carried out via classic books of medicinal and fruit plants. Online scientific databases, for instance, PubMed, Scopus, Sci Finder, Science Direct, the Web of Science, Wiley Online, Google Scholar, ResearchGate, and other search engines were explored up to October 2020 to detect valid reports, studies, and investigations. All literature on the proposed topics were analyzed and summarized in this review paper.

Recent Advances in Reducing Food Losses in the Supply Chain of Fresh Agricultural Produce

Abstract: Fruits and vegetables are highly nutritious agricultural produce with tremendous human health benefits. They are also highly perishable and as such are easily susceptible to spoilage, leading to a reduction in quality attributes and induced food loss. Cold chain technologies have over the years been employed to reduce the quality loss of fruits and vegetables from farm to fork. However, a high amount of losses (≈50%) still occur during the packaging, pre-cooling, transportation, and storage of these fresh agricultural produce. This study highlights the current state-of-the-art of various advanced tools employed to reducing the quality loss of fruits and vegetables during the packaging, storage, and transportation cold chain operations, including the application of imaging technology, spectroscopy, multi-sensors, electronic nose, radio frequency identification, printed sensors, acoustic impulse response, and mathematical models. It is shown that computer vision, hyperspectral imaging, multispectral imaging, spectroscopy, X-ray imaging, and mathematical models are well established in monitoring and optimizing process parameters that affect food quality attributes during cold chain operations. We also identified the Internet of Things (IoT) and virtual representation models of a particular fresh produce (digital twins) as emerging technologies that can help monitor and control the uncharted quality evolution during its postharvest life. These advances can help diagnose and take measures against potential problems affecting the quality of fresh produce in the supply chains. Plausible future pathways to further develop these emerging technologies and help in the significant reduction of food losses in the supply chain of fresh produce are discussed. Future research should be directed towards integrating IoT and digital twins for multiple shipments in order to intensify real-time monitoring of the cold chain environmental conditions, and the eventual optimization of the postharvest supply chains. This study gives promising insight towards the use of advanced technologies in reducing losses in the postharvest supply chain of fruits and vegetables.