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Molecularly imprinted polymers (MIPs) for benzylpiperazine (BZP, 1), an illicit designer drug, were developed by using both self-assembly and semi-covalent approaches. From an array of potential functional monomers (FMs) and using a combination of pre-synthetic interaction studies (by molecular modelling and NMR analysis) and binding assays, the highest performing self-assembly 1-MIPs were confirmed to result from methacrylic acid (7) as FM, ethylene glycol dimethacrylate (EGDMA) or trimethylolpropane trimethacrylate (TRIM) as crosslinkers and chloroform as the porogen and rebinding solvent at template (T): FM ratios of 1:1 and 1:2, giving imprinting factors (IF) 3 to 7. The semi-covalent 1-MIPs were designed using benzylpiperazine (4-vinylphenyl) carbamate (16) as the template–monomer adduct in combination with either EDGMA or TRIM. Our comparative analysis showed the semi-covalent polymers to have a stronger affinity for 1 (significantly lower Kd values and higher IFs) and faster uptake than the self-assembly systems. Both approaches have comparable cross-reactivity: marginal to low against cocaine (17) and morphine (18) and high against ephedrine (19) and phenylpiperazine (20). They also have comparable selectivity: highly selective towards 1 against 17, moderate against 18 and non-selective against 19. EGDMA-based self-assembly MIPs displayed a greater imprinting effect (higher IFs and NIP-to-MIP Kd ratios) than TRIM-based MIPs, while the TRIM-based semi-covalent MIP outperformed its EGDMA-based equivalent. By virtue of its modest selectivity against the test illicit drugs, 1-MIPs could potentially be used as a dummy MIP for the broad-based capture and enrichment of illicit drug blends for subsequent laboratory analysis.

Background: Tuckeroo (Cupaniopsis anacardioides) is one of eleven species that belongs to the Sapindaceae family, which is native to Australia. Objective: This study screened major phenolic groups from fresh or dried whole fruits, or just their skin. Methods: Using optimal ultrasound assisted extraction conditions with either acetone (50%) or methanol (50%) as extraction solvents. This study further tested their antioxidant capacity and cytotoxic activity against a panel of ten cancer cell lines for their potential health benefits. Results: The results showed that levels of major phenolic groups were significantly different with solvents used or types of materials (whole fruit or skin). The extract from dried skin fruit using acetone 50 % (SD-A50) had the highest level of total phenolic content(112.47 mg GAE/g) and total flavonoid content (101.89 mg CAE/g); however, the extract from fresh skin (SF-A50) had the greatest proanthocyanidin content (124.22 mg CAE/g). This SF-A50 extract also showed the strongest antioxidant activity and had the highest growth inhibition and the lower dose response (GI50 values of 20-145 μg/mL) against the HT29 (colon); U87, SJ-G2 (glioblastoma); MCF-7 (Breast); A2780 (ovarian); H460 (lung); A431 (skin); Du145 (prostate); BE2-C (neuroblastoma); and MIA PaCa-2 (pancreas) cancer cell line, revealing its therapeutic potential. Conclusions: Fourteen major compounds, including catechin were detected from the Tuckeroo fruit extract; future studies are recommended to further isolate, identify and test the health potentials from group and individual compounds of the Tuckeroo fruit extract.

This study aimed to determine the phytochemical, antioxidant, and anticancer activities of the crude extract and its fractions of Cupaniopsis anacardioides. The results showed that total phenolic content (TPC), their secondary metabolites (flavonoids—TFC; proanthocyanidins—TPro), and antioxidant activity were significantly different between the crude extract and its fractions. The butanol fraction (F3) had the highest levels of TPC, TFC, and TPro, followed by the crude extract, aqueous fraction (F4), dichloromethyl fraction (F2), and hexane fraction (F1). High-Pressure Liquid Chromatography (HPLC) analysis revealed 14 major bioactive compounds were identified in the C. anacardioides extract. Further analysis showed F3 fraction contained the highest levels of the major bioactive compounds, while F1 fraction had the lowest. A similar pattern was observed for antioxidant activities. The crude extract, F3 and F4 fractions were further tested for cytotoxicity against 10 cancer cell lines, including HT29 (colon); U87, SJG2 (glioblastoma); MCF-7 (Breast); A2780 (ovarian); H460 (lung); A431 (skin); Du145 (prostate); BE2-C (neuroblastoma); MIA PaCa-2 (pancreas); and one non-tumour-derived normal breast cell line (MCF10A). Except for Du145 (prostate), the crude extract, F3 and F4 fractions inhibited the cancer cell lines at 100 µg/mL, with F3 possessing greater activity against these cancer cell lines. Future studies are recommended to isolate and identify the major bioactive compounds of the F3 fraction, and further tested their impact against cancer cell lines. This could identify the potential of anticancer agents from C. anacardioides.

A short, pre-storage fumigation with hydrogen sulphide (H2S) gas at 0, 100, 250 and 500 µL L−1 affected development of a range of senescence characteristics of Navel and Valencia oranges and ‘Afour...

This study applied ultrasound-assisted extraction (UAE) to effectively extract phenolic compounds and antioxidant properties from the Tuckeroo fruits using Response Surface Methodology (RSM). The r...

Starch is the most popular plant polysaccharides, which has been widely used for the development of edible coating films because of its abundance, cost-effectiveness, and excellent film-forming abilities. Starch-based films have good optical, organoleptic and gas barrier properties, however, they have poor mechanical properties. Many attempts have been made to overcome these limitations, such as the addition of co-biopolymers or other secondary additives to improve the mechanical and tensile properties of the films. Properties of the starch-based films can be influenced by many factors, including types of starches, temperature and time during film formation, plasticizers, co-biopolymers, and storage conditions. Understanding the mechanisms of these factors is very important for future studies on the development of starch-based films. This review focuses on starch as a film/coating material and comprehensively discusses the effects of major factors on properties of starch-based films.

Scientific thinking is more than just critical thinking. Teaching the full range of ways to think like a scientist who practices high quality science is rare. A new core subject in the Bachelor of Science at the University of Newcastle was developed to allow students to explore six different ways to thinking scientifically through understanding what high-quality science is and contrasting it with poor science and non-science (pseudoscience). Our evaluation indicates that learning about how to think scientifically and be a scientist who practices high quality science is a skill that is valued by and relevant to first year undergraduate students. An evidence-based pedagogy including active learning, participatory learning, student-centred learning, constructive alignment and quality formative and summative feedback to students can support high learning outcomes.

Catharanthus roseus (C. roseus) is an important medicinal plant distributed in many countries. It has attracted increasing attention due to it being shown to possess a range of phytochemicals with various biological activities such as antioxidant, antibacterial, antifungal, antidiabetic and anticancer properties. Remarkably, vinblastine and vincristine isolated from this plant were the first plant-derived anticancer agents deployed for clinical use. Recently, new isolated indole alkaloids from this plant including catharoseumine, 14′,15′-didehydrocyclovinblastine, 17-deacetoxycyclovinblastine and 17-deacetoxyvinamidine effectively inhibited human cancer cell lines in vitro. Moreover, vindoline, vindolidine, vindolicine and vindolinine isolated from C. roseus leaf exhibited in vitro antidiabetic property. These findings strongly indicate that this plant is still a promising source of bioactive compounds, which should be further investigated. This paper provides an overview of the traditional use and phytochemical profiles of C. roseus, and summarises updated techniques of the preparation of dried material, extraction and isolation of bioactive compounds from this plant. In addition, purported health benefits of the extracts and bioactive compounds derived from this plant were also addressed to support their potential as therapeutic agents.

Helicteres hirsuta Lour. (H. hirsuta) has been used traditionally as a folk medicine for treating a range of common diseases such as furuncle treatment, pain relief, dysentery, measles, flu, anti-malaria and anti-obesity in some Asian countries, revealing that this plant material contains important bioactive compounds, which are linked with health benefits and/or can act as therapeutic agents. Hence, many attempts have been made to isolate and identify the key bioactive compounds present in H. hirsuta and conduct in vitro tests to investigate their biological activities. We recently revealed that H. hirsuta leaf contained high levels of total phenolic content [192.6 mg gallic acid equivalents (GAE)/g] and total flavonoid content [215.2 mg catechin equivalents (CE)/g]. The stem of H. hirsuta also had high contents of TPC and TFC (212.6 mg GAE/g and 280.1 mg CE/g, respectively). The results also revealed that phenolic compounds from this plant had a strong positive correlation with antioxidant capacity including DPPH, ABTS radical scavenging activity and ferric reducing antioxidant power (R2 range of 0.78 and 0.99), which are known to link with diverse bioactivities including antioxidant, antimicrobial, anticancer, antiobesity and antidiabetic effects. Additionally, H. hirsuta leaf and stem were found to contain high levels of saponins (808.0 and 347.5 mg escin equivalents/g, respectively), that were determined using colorimetric assay. Several individual compounds have been identified in the extracts of H. hirsuta, including rutin, methyl caffeate, 5,8-dihydroxy-7,4¢-dimethoxyflavone, isoscutellarein 4¢-methyl ether 8-O-b-D-glucopyranoside, 4,4¢-sulfinylbis(2(tert-butyl)-5-methylphenol), 7-O-methylisoscutellarein, 7,4¢-di-O-methylisoscutellarein, six lignans (pinoresinol, medioresinol, syringaresinol, boehmenan, boehmenan H, and trans-dihydrodiconiferyl alcohol), betulinic acid, 3-O-trans-caffeoylbetulinic acid, 3b-benzoylbetulinic acid, betulinic acid methyl ester, lupeol, 3β-O-acetylbetulinic acid, simiarenol, stigmasterol and β-sitosterol. The derived extracts and isolated compounds from this plant have been shown to inhibit the growth of various cancer cell lines in vitro as well as offering a promising source of active compounds for other health problems including obesity, diabetes and malaria. Further studies on the mechanisms of bioactive compounds from this plant are suggested to elucidate their mechanisms of action for health benefits. In addition, more in vivo tests associated with clinical trials are also needed to validate and confirm their effects for further development of nutraceutical and pharmaceutical products from this plant material.

Hydrogen sulphide (H2S) inhibits senescence in harvested fruit and vegetables but presents logistical, safety and regulatory issues to become a commercial treatment. D-cysteine and L-cysteine are s...

UV-C (180–280 nm) has been shown to extend the postharvest shelf-life of many horticulture crops. In this study, Tahitian limes (Citrus latifolia) were exposed to 0, 3.4, 7.2 and 10.5 kJ m(−2) UV-C then stored for 28 days in air at 10 °C and 80% RH. Weight loss, peel colour, calyx abscission, ethylene production, respiration rate, total soluble solids (TSS), titratable acidity (TA) and acceptability index were assessed. The results showed that UV-C treatment maintained lime peel green colour and retained calyx attachment after 28 days storage. UV-C treatment also affected endogenous ethylene production and respiration rate, where the highest UV-C treatment (10.5 kJ m(−2)) maintained low ethylene production and low respiration rates after 28 days storage with no differences between the different UV-C intensities. In terms of fruit acceptability, limes were exposed to 10.5 kJ m(−2) UV-C had a 60% acceptability index after 28 days storage, while untreated control fruit retained acceptability of 39%. In general, the pre-storage UV-C treatments did not affect fruit weight loss, TSS or TA contents during storage.

A rice starch edible coating blended with sucrose esters was developed for controlling the postharvest physiological activity of Cavendish banana to extend postharvest quality during ripening at 20 ± 2 °C. Coating effectiveness was assessed against changes in fruit physiochemical parameters such as weight loss, titratable acidity, total soluble solids, flesh fruit firmness, ion leakage, colour change, respiration, ethylene production, chlorophyll degradation and starch conversion were determined. The topography of coating material on the fruit surface was evaluated by scanning electron microscope (SEM). Surface morphology studies highlighted the binding compatibility of the coating matrix with the fruit peel character and formed a continuous uniform layer over the fruit surface. The results showed that the coating was effective in delaying ethylene biosynthesis and reducing respiration rate. Other factors impacting included delayed chlorophyll degradation, reduced weight loss and retention of fruit firmness for the first six days, all of which improved the commercial value of the fruit. The shelf life of coated fruit was prolonged for 12 days in comparison with the untreated control which ripened within seven days and lost marketability after Day 6. The pilot study demonstrates the effectiveness of a starch-based edible coating formulation for improving the ambient storage capacity of banana fruit.

The inhibition of the α-amylase and α-glucosidase activity facilitates the maintenance of circulating glucose levels by decreasing the rate of blood sugar absorption. Existing enzyme inhibitors such as acarbose, miglitol, and voglibose are used for inhibiting the activity of these enzymes, however, alternative solutions are required to avoid the side-effects of using these drugs. The current study aims to review recent evidence regarding the in vitro α-amylase and α-glucosidase inhibition activities of extracts derived from selected fruit, vegetables, and mushrooms. The mechanisms of action of the extracts involved in the inhibition of both enzymes are also presented and discussed. Compounds including flavonoids, phenolic acids, anthocyanins, saponins, carotenoids, terpenes, sugars, proteins, capsaicinoids, fatty acids, alkaloids have been shown to have α-amylase and α-glucosidase inhibition activities. Harvesting period, maturity stage, sample preparation, extraction technique, and solvent type are parameters that affect the α-amylase and α-glucosidase inhibition activities of the extracts.

Propargylglycine (PAG) is an inhibitor of hydrogen sulphide (H2S) production and has been used to explore the mode of action of H2S in prolonging storage of horticultural produce but little attention has been given to how PAG and H2S interact when both are applied to produce. This study examined the effect of sequential application of PAG and H2S on a range of postharvest senescence factors of the leafy vegetable pak choy (Brassica rapa subsp. Chinensis) stored at 10 °C. The results showed differential responses between factors when compared to application of PAG or H2S alone. As expected, fumigation with H2S reduced the rate of loss of leaf green colour, respiration rate, ethylene production, ion leakage and enhanced antioxidant activity and leaves sprayed with PAG showing converse effects. If PAG acted solely by inhibiting endogenous H2S production then subsequent treatment with H2S should fully negate any effect induced by PAG. However, for the combined PAG + H2S treatment, respiration was similar leaves fumigated with H2S, loss of green leaf colour was similar to the PAG single treatment and less than the untreated control, antioxidant activity was less than for PAG but greater than for control leaves, and ethylene production and ion leakage were similar to control leaves. Thus, the concept that PAG is exclusively an inhibitor of endogenous H2S production was not validated, with PAG having effects on metabolism that are not linked to the action of endogenous H2S. The additional actions of PAG could be through its inhibition of pyridoxyal-5′-phosphate (PHP) which is a coenzyme for numerous enzyme systems.

The aims of this study were to screen the phytochemical content, antioxidant, antimicrobial and cytotoxic properties of the extract and its fractions prepared from Catharanthus roseus (L.) G. Don (C. roseus) stem. C. roseus stem was powdered and extracted with methanol using ultrasound-assisted extraction to obtain the crude extract. The crude extract was further fractioned using liquid-liquid extraction technique to obtain extracts of increasing polarity including n-butanol and residual aqueous fractions. The crude extract and its derived fractions were then subjected to phytochemical screening and assayed for antioxidant, antimicrobial and cytotoxic activities. Results showed that the n-butanol fraction contained the highest levels of saponins and phenolics (3037.54 mg ESE/g and 77.87 mg GAE/g, respectively) and possessed the strongest antioxidant capacity amongst the tested extracts. HPLC analysis revealed that this n-butanol fraction had high levels of apigenin and kaempferol, whereas the aqueous fraction contained a high level of gallic acid. The n-butanol fraction was found to effectively inhibit the activity of Escherichia coli and Staphylococccus lugdunensis. The n-butanol fraction also possessed strong cytotoxic activity in vitro against a wide range of cancer cell lines including A2780 (ovarian), H460 (lung), A431 (skin), MIA PaCa-2 (pancreas), Du145 (prostate), HT29 (colon), MCF-7 (breast), BE2-C (neuroblastoma), SJ-G2, U87 and SMA (glioblastoma) at low doses (GI50 values of 5.2−21.0 µg/mL). These results indicate that the n-butanol fraction prepared from C. roseus stem is a rich source of bioactive compounds which can be isolated for further evaluation as potential antimicrobial drugs or antitumor therapeutic agents.

New therapeutic strategies such as the development of novel drugs and combinatorial therapies with existing chemotherapeutic agents are urgently needed to improve the clinical prognosis of pancreatic cancer. We have previously reported the antiproliferative properties of aqueous crude Eucalyptus microcorys extract against pancreatic cancer cell lines. In this study, bioassay-guided fractionation of the aqueous crude E. microcorys extract using RP-HPLC and subsequent assessment of the resultant fractions (F1-F5) for their antioxidant activity and cytotoxicity against pancreatic cancer cell lines were performed. The molecular mechanisms associated with the cytotoxicity was characterised by studying the effects of the most potent fraction-1 (F1) on apoptosis and cell cycle profiles as well as its phytochemical constituents by LC-ESI/MS/MS. F1 displayed significantly greater antioxidant activity in three different assays (p 0.05). Moreover, F1 exhibited significantly greater antiproliferative activity (IC

Phyllanthus amarus (P. amarus) has been used for herbal medicines, particularly for liver support in many countries. The preparation of dried sample is crucial for further extraction and isolation of phytochemicals. In this study, the effects of six different drying methods (hot-air, low temperature-air, infrared, microwave, sun and vacuum drying) on the phytochemical yield and antioxidant capacity were determined to identify the optimal drying method for P. amarus. The results showed that different drying methods, as well as different drying conditions within each method, significantly affected phytochemical yield and antioxidant capacity of P. amarus extracts. Infrared drying at 30°C was the best method for both retention of bioactive compound yield and antioxidant capacity of P. amarus extract, with twelve compounds were identified. Therefore, infrared drying at 30°C is suggested for drying P. amarus for subsequent assessment of bioactivity.

The study investigated the possibility of enhancing the shelf life of plum fruit coated with rice starch-ι-carrageenan (RS-ι-car) composite coating blended with sucrose fatty acid esters (FAEs). Film solution (starch 3%, carrageenan 1.5% and FAEs 2%) was prepared by mixing the ingredients and properties of stand-alone films (physical, mechanical, barrier and surface morphology) were studied before applying the coating on fruit surface. Fruit were stored at 20 °C for 3 weeks and analyzed for weight loss, ethylene production, respiration rate, color change, firmness, and titratable acidity (TA) and soluble solid content (SSC). Surface morphology of stand-alone film and fruit surface (after applying on the plum fruit) was studied using scanning electron microscopy (SEM). Phytochemical analysis was performed during the storage period and total phenolic content (TPC), total antioxidant capacity (TAC), flavonoid content (FC) and free radical scavenging activity were determined. The rice starch composite coating was shown to be effective in reducing both weight loss (WL) and respiration rate and inhibiting the endogenous ethylene production when compared to the uncoated control fruit stored at room temperature (p

Postharvest fumigation with hydrogen sulphide (H2S) can inhibit senescence of a range of fruit and vegetables. It has been suggested that the mode of action of hydrogen sulphide is through inhibiting either the endogenous production and/or the action of ethylene. This study compared the effect of fumigation with 250 μL L−1 hydrogen sulphide and 10 μL L−1 1-methylcyclopropene (1-MCP) on a range of factors associated with senesence of the leafy vegetable, pak choy stored at 10 °C and ventilated with ethylene-free air or air containing 0.1 μL L−1 ethylene. When pak choy was stored in an ethylene-free atmosphere, hydrogen sulphide and 1-MCP were equally effective in inhibiting the loss of green colour, respiration, ion leakage and endogenous ethylene production. However, for containers ventilated with ethylene, 1-MCP was more effective in inhibiting loss of green colour, respiration and ethylene production than hydrogen sulphide. Sequential fumigation with 1-MCP followed by hydrogen sulphide showed no difference in any quality factor to produce fumigated with 1-MCP. The study concluded that (i) the mode of action of hydrogen sulphide included inhibiting the action of ethylene and (ii) for pak choy, 1-MCP was a more effective fumigation treatment than hydrogen sulphide.

Response surface methodology (RSM) based on a three-factor and three-level Box–Behnken design was employed for optimizing the aqueous ultrasound-assisted extraction (AUAE) conditions, including extraction time (35–45 min), extraction temperature (45–55 °C) and ultrasonic power (150–250 W), for the recovery of total phenolic content (TPC) and rutin from lemon by-products. The independent variables and their values were selected on the basis of preliminary experiments, where the effects of five extraction parameters (particle size, extraction time and temperature, ultrasonic power and sample-to-solvent ratio) on TPC and rutin extraction yields were investigated. The yields of TPC and rutin were studied using a second-order polynomial equation. The optimum AUAE conditions for TPC were extraction time of 45 min, extraction temperature of 50 °C and ultrasonic power of 250 W with a predicted value of 18.10 ± 0.24 mg GAE/g dw, while the optimum AUAE conditions for rutin were extraction time of 35 min, extraction temperature of 48 °C and ultrasonic power of 150W with a predicted value of 3.20 ± 0.12 mg/g dw. The extracts obtained at the optimum AUAE conditions were compared with those obtained by a hot water and an organic solvent conventional extraction in terms of TPC, total flavonoid content (TF) and antioxidant capacity. The extracts obtained by AUAE had the same TPC, TF and ferric reducing antioxidant power as those achieved by organic solvent conventional extraction. However, hot water extraction led to extracts with the highest flavonoid content and antioxidant capacity. Scanning electron microscopy analysis showed that all the extraction methods led to cell damage to varying extents.

Polyphenols of citrus by-products, due to their antioxidant and antimicrobial activities, could be valorized by pharmaceutical and food industries, adding a value to the citrus processing companies. A number of studies have investigated the effect of ultrasound-assisted extraction (UAE) conditions on the recovery of phenolics derived from citrus waste using both organic solvents or mixed aqueous solvent systems. To maximize efficiency, UAE conditions should be tailored to the physical parameters of the solvent(s) employed. The aim of this study was to investigate the effect of four UAE parameters: particle size (1.40–2.80 mm), extraction time (10–60 min), extraction temperature (23–50 °C) and ultrasonic power (150–250 W) on the simultaneous recovery of p-coumaric acid, caffeic acid, chlorogenic acid, and hesperidin from citrus waste using pure water as a solvent. High-performance liquid chromatography (HPLC) was employed for the identification and quantification of the cited compounds. Particle size was determined to be an important parameter affecting compound recovery, with the exception of chlorogenic acid. A particle size of 1.40 mm resulted in the highest recovery of p-coumaric and caffeic acids (0.25 and 0.58 mg/g, respectively), while higher hesperidin yields were achieved from the particle sizes of 2.00 and 1.40 mm (6.44 and 6.27 mg/g, respectively). Extraction temperature significantly affected only the recovery of the flavanone glycoside (P

The effect of two lemon by‐product aqueous extracts at different concentrations (14, 7, 3.5 and 1 mg mL⁻¹) was tested against the in vitro growth of Alternaria alternata. Prior to extraction, one batch of by‐product was dehydrated by freeze‐drying (untreated by‐product), while the other batch was treated by microwave irradiation in conjunction with freeze‐drying (microwave‐treated by‐product). High‐performance liquid chromatography (HPLC) was employed for the identification of individual phenolic compounds with potent antifungal activities. Both lemon by‐product aqueous extracts inhibited the mycelial growth and suppressed the spore germination of the fungus in a concentration‐dependent manner. In general, the extracts obtained from the microwave‐treated lemon by‐product displayed enhanced antifungal activity than those obtained from the untreated one. Scanning electron microscopy (SEM) revealed that both lemon by‐product extracts affected the hyphal morphology of the fungus. The antifungal activity of the extracts was attributed to their phenolic acid and ascorbic acid contents.

This study aimed to optimise microwave-assisted extraction (MAE) conditions for total phenolic compounds (TPCs) and antioxidant activities of the alga Sargassum vestitum by using response surface m...

Green capsicums (Capsicum annum L.) were stored under low pressure (4 kPa) at 10°C for 5 and 11 days with 100% RH. The results showed that the incidence of stem decay under low-pressure storage for 5 and 11 days and storage at ambient atmosphere at 20°C for 3 days was lower compared to fruits that were stored at regular atmosphere at 10°C. Fruit that had been stored at low pressure at 10°C had no symptoms of flesh rots for up to 11 days, whilst fruit which had been stored at regular atmosphere at 10°C had 6% flesh rots after 11 days storage at 10°C.There was no difference in flesh firmness and colour retention between fruits stored at low pressure and regular pressure at 10°C. Capsicums stored at low pressure had higher overall acceptability compared to fruit that were stored at regular atmosphere at 10°C. These results demonstrate the potential of low pressure storage as an effective technique to manage capsicum fruit quality, however, there was no additional benefit when fruits were stored at lo...

Improvements in the hygroscopic properties of starch based films are important to strengthen their mechanical properties. The effects of different hydrophobic components-butyric acid (BA, C4:0), lauric acid (LA, C12:0), palmitic acid (PA, C16:0), oleic acid (OA, C18:1), stearic acid (SA, C18:0) and sucrose fatty acid ester (FAEs) on the rice starch (RS)-ι-carrageenan (ι-car) composite films were investigated. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) in combination with amylose-lipid complexing index (CI) were used to characterise the changes in structure and properties of edible films. The SEM results showed that the surface of films became smoother after the incorporation of fatty acids. Carbon-chain length was a major determinant of CI formation which further influenced the attributes of RS-ι-car films. The addition of FAEs to RS-ι-car improved film thickness, permeability, transparency, tensile properties (TS) and could be used to tailor biodegradable edible films with enhanced properties and future fruit coating applications.

Using response surface methodology, this study aimed to optimize five different ultrasound extraction parameters; including ultrasonic temperature, ultrasonic time, ultrasonic power, sample-to-solvent ratio and methanol concentration, for maximal extraction of bioactive compounds and antioxidant capacity from Helicteres hirsuta Lour. ( H. hirsuta ), which has been used as a traditional medicine for malaria and diabetes treatment. Results showed that either ultrasonic temperature or sample-to-solvent ratio had a greater influence on extraction efficiency of total phenolics, flavonoids and antioxidant capacity than that of methanol concentration. Optimal extraction conditions were determined to be ultrasonic temperature of 60 °C, ultrasonic time of 25 min, ultrasonic power of 150W, sample-to-solvent ratio of 3:100 g/mL, and a solvent composition of 40% (v/v) aqueous methanol. Under these conditions, 15.97 mg GAE/g of phenolics, 16.42 mg CE/g of flavonoids, and 13.34 g/100 g of extractable solids were obtained. The highest values for DPPH, ABTS and FRAP assays were also obtained under these conditions, with the exception of CUPRAC (88% maximum value). These optimal extraction conditions can be applied to prepare powdered crude extract for further isolation and purification of individual bioactive compounds for potential use in the pharmaceutical industry.