Amylase is one of the most important enzymes in the world due to its wide application in various industries and biotechnological processes. In this study, amylase enzyme from Hylocereus polyrhizus was encapsulated for the first time in an Arabic gum-chitosan matrix using freeze drying. The encapsulated amylase retained complete biocatalytic activity and exhibited a shift in the optimum temperature and considerable increase in the pH and temperature stabilities compared to the free enzyme. Encapsulation of the enzyme protected the activity in the presence of ionic and non-ionic surfactants and oxidizing agents (H₂O₂) and enhanced the shelf life. The storage stability of amylase is found to markedly increase after immobilization and the freeze dried amylase exhibited maximum encapsulation efficiency value (96.2%) after the encapsulation process. Therefore, the present study demonstrated that the encapsulation of the enzyme in a coating agent using freeze drying is an efficient method to keep the enzyme active and stable until required in industry.
The aim of this work was to recover the cellulose fibers from EFB using low-transition-temperature-mixtures (LTTMs) as a green delignification approach. The hydrogen bonding of LTTMs observed in 1H NMR tends to disrupt the three-dimensional structure of lignin and further remove the lignin from EFB. Delignification process of EFB strands and EFB powder were performed using standard l-malic acid and cactus malic acid-LTTMs. The recovered cactus malic acid-LTTMs showed higher glucose concentration of 8.07 mg/mL than the recovered l-malic acid LTTMs (4.15 mg/mL). This implies that cactus malic acid-LTTMs had higher delignification efficiency which led to higher amount of cellulose hydrolyzed into glucose. The cactus malic acid-LTTMs-delignified EFB was the most feasible fibers for making paper due to its lowest kappa number of 69.84. The LTTMs-delignified EFB has great potential to be used for making specialty papers in pulp and paper industry.
The effect of solvent, substrate-to-solvent ratio and concentration of pectinase on the extraction of betacyanins from the pulp of red pitahaya (Hylocereus polyrhizus) was evaluated with respect to yield, betacyanin content (BC) and total sugar content. The application of betacyanins from red pitahaya in ice cream was then evaluated by comparison to a commercial colourant, E-162. Without the use of pectinase, the highest yields (9.11 ± 0.35%) of betacyanins were obtained using 95% ethanol at a substrate-to-solvent ratio of 1:1. With the use of pectinase at a concentration of 1.5%, the highest yield (17.11-17.45%) of betacyanins were obtained using water as a solvent at a substrate-to-solvent ratio of 1:1 and 1:2. Pectinase treatment (1.5-2.5%) using water as a solvent yielded betacyanins with the highest BC (126.47-130.83 g kg-1) and lowest total sugar content (57.85-59.74 g kg-1). The BC and total colour changes were similar in ice cream containing betacyanins from red pitahaya and E-162 throughout the 21-days of frozen storage at -18 °C. Betacyanins from red pitahaya or E-162 enhanced the antioxidant properties of ice cream. The sensory evaluation of ice cream containing betacyanins from red pitahaya showed a better colour acceptability than E-162.
This study was conducted to optimize the production of spray-dried white dragon fruit (Hylocereus undatus) powder using resistant maltodextrin as wall material. The inlet air temperature (140 °C, 150 °C and 160 °C), outlet temperature (75 °C, 80 °C and 85 °C) and resistant maltodextrin concentrations (20%, 25% and 30%) were tested as independent variables. Process yield, moisture content, water activity, solubility, hygroscopicity and bulk density of the powders were analysed as responses. Process yield significantly (p
This study was carried out to evaluate the total phenolic content and anti-oxidant activity of methanolic extract of red pitaya, and hypocholesterolemic effect of red pitaya (Hylocereus sp.) on lipid profiles status on hypercholesterolemia induced rats. From the analysis, total phenolic content in red pitaya is 46.06 ± 1.77 mg GAE/100 g fresh weight and antioxidant activity is 76.10% using FTC method. TBA analysis also showed red pitaya extract had high antioxidant effect (72.90%). An in-vivo study also showed red pitaya has hypocholesterolemic effect on induced hypercholesterolemia rats. After 11 weeks of study, total blood cholesterol significant decrease (p
The physico-chemical properties of spray-dried pitaya peel powders kept at accelerated (45 ± 2°C) and room temperature (28 ± 2°C) for 14 weeks and 6 months, respectively were evaluated. Changes in physico-chemical properties of the peel powder were used as indicators of stability, while changes of the betacyanin pigment retention was used to calculate the shelf-life of the powder. Storage temperatures significantly (p < 0.05) affected all the studied parameters and Hunter a value had the most significant change. The pigment retention of peel powder was approximately 87% at 45°C and 89% at room temperature storage. Degradation of betacyanin pigment in the powder followed the first order reaction kinetics with the half-life (t1/2) of approximately 76 weeks at 45°C and 38 months at 28°C. The spray-dried pitaya peel powder had a solubility of 87 to 92% and low in powder hygroscopicity. The final Aw of the powder did not exceed 0.6 for both storage temperatures.
Pitaya peel (Hylocereus polyrhizus), which consists approximately 22% of the whole fruit weight, is discarded during processing. Physico-chemical properties of the discarded pitaya peel were determined in
order to evaluate its potential for recovery of any value-added materials. The moisture content of the peel was approximately 92.7% and it was low in total soluble solids, protein, ash and fat content. Betacyanin pigment (150.46 ± 2.19 mg/100 g) and pectin (10.8%) were high in the peel. Glucose, maltose and fructose were detected in the peel but not sucrose and galactose. The peel also had very high insoluble and soluble dietary fibre which had exhibited a good ratio of insoluble dietary fibre to soluble dietary fibre (3.8: 1.0).
Hylocereus undatus foliage is believed to contain antioxidants similar to its peel. Numerous studies have been conducted to determine the total phenolic content (TPC) and antioxidant activity on the Hylocereus undatus pulps and peels; however, similar studies on its foliage have yet to be investigated. In this study, Hylocereus undatus foliage and peels were extracted using two different solvents namely; chloroform and methanol through Folin-Ciocalteu method and Diphenyl-1-Ipicrylhydrazyl (DPPH) free radical scavenging assay for TPC and antioxidant activity, respectively. As for TPC, results revealed that the peels gave higher TPC in both methanol (48.15 mg GAE/100g extract) and chloroform (18.89 mg GAE/100g extract) extractions than foliage (30.3 mg GAE/100g extract and 5.92 mg GAE/100g extract, respectively). However, when a comparison was made between foliage and peels in terms of its scavenging effects in DPPH assay, the peels contained more antioxidants (18.71%) than foliage (38.3%) in the chloroform solvent extracts. This study shows that Hylocereus undatus foliage has a similar antioxidant activity as its peels and is potentially a natural antioxidant in food applications.
Nine solvents, namely, n-hexane, ethanol, acetonitrile, chloroform, ethyl-ether, ethyl-acetate, petroleum ether, n-butyl alcohol, and methanol were used to extract natural dyes from Cordyline fruticosa, Pandannus amaryllifolius and Hylocereus polyrhizus. To improve the adsorption of dyes onto the TiO2 particles, betalain and chlorophyll dyes were mixed with methanol or ethanol and water at various ratios. The adsorption of the dyes mixed with titanium dioxide (TiO2) was also observed. The highest adsorption of the C.fruticosa dye mixed with TiO2 was achieved at ratio 3:1 of methanol: water. The highest adsorption of P.amaryllifolius dye mixed with TiO2 was observed at 2:1 of ethanol: water. H.polyrhizus dye extracted by water and mixed with TiO2 demonstrated the highest adsorption among the solvents. All extracted dye was adsorbed onto the surface of TiO2 based on Fourier Transform Infrared Spectroscopy (FTIR) analysis. The inhibition of crystallinity of TiO2 was likewise investigated by X-ray analysis. The morphological properties and composition of dyes were analyzed via SEM and EDX.
The purification of thermo-acidic amylase enzyme from red pitaya (Hylocereus polyrhizus) peel for the first time was investigated using a novel aqueous two-phase system (ATPS) consisting of a thermo-separating copolymer and an organic solvent. The effectiveness of different parameters such as molecular weight of the thermo-separating ethylene oxide-propylene oxide (EOPO) copolymer and type and concentration of organic solvent on the partitioning behavior of amylase was investigated. In addition, the effects of phase components, volume ratio (VR), pH and crude load of purification factor and yield of amylase were evaluated to achieve the optimum partition conditions of the enzyme. In the novel ATPS method, the enzyme was satisfactorily partitioned into the polymer-rich top phase in the system composed of 30% (w/w) EOPO 2500 and 15% (w/w) 2-propanol, at a volume ratio of 1.94 and with a crude load scale of 25% (w/w) at pH 5.0. Recovery and recycling of components was also measured in each successive step of the ATPS process. The enzyme was successfully recovered by the method with a high purification factor of 14.3 and yield of 96.6% and copolymer was also recovered and recycled at a rate above 97%, making the method was more economical than the traditional ATPS method.
Crystals isolated from Hylocereus polyrhizus were analyzed using four different approaches--X-ray Crystallography, High Performance Liquid Chromatography (HPLC), Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) and Nuclear Magnetic Resonance (NMR) and identified as myo-inositol. The X-ray crystallography analysis showed that the unit-cell parameters were: a = 6.6226 (3) Å, b = 12.0462 (5) Å, c = 18.8942 (8) Å, α = 90.00, β = 93.98, δ = 90.00. The purity of the crystals were checked using HPLC, whereupon a clean single peak was obtained at 4.8 min with a peak area of 41232 μV*s. The LC-MS/MS technique, which is highly sensitive and selective, was used to provide a comparison of the isolated crystals with a myo-inositol standard where the results gave an identical match for both precursor and product ions. NMR was employed to confirm the molecular structure and conformation of the crystals, and the results were in agreement with the earlier results in this study. The discovery of myo-inositol crystals in substantial amount in H. polyrhizus has thus far not been reported and this is an important finding which will increase the marketability and importance of H. polyrhizus as a crop with a wide array of health properties.
Multivariate analysis of thin-layer chromatography (TLC) images was modeled to predict antioxidant activity of Pereskia bleo leaves and to identify the contributing compounds of the activity. TLC was developed in optimized mobile phase using the 'PRISMA' optimization method and the image was then converted to wavelet signals and imported for multivariate analysis. An orthogonal partial least square (OPLS) model was developed consisting of a wavelet-converted TLC image and 2,2-diphynyl-picrylhydrazyl free radical scavenging activity of 24 different preparations of P. bleo as the x- and y-variables, respectively. The quality of the constructed OPLS model (1 + 1 + 0) with one predictive and one orthogonal component was evaluated by internal and external validity tests. The validated model was then used to identify the contributing spot from the TLC plate that was then analyzed by GC-MS after trimethylsilyl derivatization. Glycerol and amine compounds were mainly found to contribute to the antioxidant activity of the sample. An alternative method to predict the antioxidant activity of a new sample of P. bleo leaves has been developed.
In the present study, high-methoxyl pectin (HMP) was extracted from Hylocereus polyrhizus peel's using physico-chemical process. In addition, the hypolipidemic activity of HMP was investigated at different concentration and time corresponding to its adsorption ability. FTIR and contact angle analysis were used to determine the sorbent characterization. A high degree of esterification (63.8%) and the contact angle (95.5°) confirmed hydrophobic nature and resulting bad wetting of the HMP extract, respectively. The methoxyl content in the pectin acted as an affinity-precursor of the pectin towards cholesterol due to its increased hydrophobicity. The maximum equilibrium uptake capacity of cholesterol of 370.5mg/g (0.96mmol/g) was observed by HMP. The experimental data showed good fitting for Freundlich isotherm equation and followed pseudo-first-order kinetic model with a correlation coefficient (R2) of 0.89-0.97 due to physisorption mechanism. Intra-particle model confirmed that the cholesterol sorption rate by HMP was significantly influenced by external mass transfer (surface diffusion) and intra-particle diffusion (diffusion control). It was also revealed that the HMP extracted from Hylocereus polyrhizus peels possess a high affinity towards cholesterol, making it an ideal hypolipidemic agent.
Betacyanins are reddish to violet pigments that can be found in red pitahaya (Hylocereus polyrhizus) and red spinach (Amaranthus dubius). This study investigated the impact of sub-fractionation (solvent partitioning) on betacyanin content in both plants. Characterization of betacyanins and evaluation of their antimicrobial activities were also carried out. Betanin was found in both plants. In addition, isobetanin, phyllocactin and hylocerenin were found in red pitahaya whereas amaranthine and decarboxy-amaranthine were found in red spinach. Sub-fractionated red pitahaya and red spinach had 23.5 and 121.5 % more betacyanin content, respectively, than those without sub-fractionation. Sub-fractionation increased the betanin and decarboxy-amaranthine content in red pitahaya and red spinach, respectively. The betacyanin fraction from red spinach (minimum inhibitory concentration [MIC] values: 0.78-3.13 mg/mL) demonstrated a better antimicrobial activity profile than that of red pitahaya (MIC values: 3.13-6.25 mg/mL) against nine Gram-positive bacterial strains. Similarly, the red spinach fraction (MIC values: 1.56-3.13 mg/mL) was more active than the red pitahaya fraction (MIC values: 3.13-6.25 mg/mL) against five Gram-negative bacterial strains. This could be because of a higher amount of betacyanin, particularly amaranthine in the red spinach.
The peel of Hylocereus polyrhizus is often regarded as a waste hence this study was aimed at exploring the feasibility of using the peel as a natural colorant using simple water extraction method. Samples were subjected to a series of temperatures: Room temperature (RT), 50, 80 and 100 degrees C; varied length of heating time from 1, 2, 3, 4, 5 and 10 min and a varied range of pH using 1 M of citric acid solution. The best condition to obtain highest betacyanin content was heating samples at 100 degrees C for 5 min in a pH 5 citric acid solution. The next part of this study involved the stability test of the pigments obtained through the best method determined earlier. The pigments were dried and resuspended in distilled water. The samples were then exposed to light to monitor pigment changes. Initial resuspension of the dried pigments yielded a comparable high content of betacyanins to its juice counterpart. The results showed that resuspended pigments had high pigment retention and were stable up to 7 days. These initial findings must be further studied in more controlled conditions to understand the stability of betacyanin. Nevertheless, the results show that betacyanin obtained from the peel of dragon fruit has a high potential to be used as a natural dye.
Dihydroactinidiolide (1) and a mixture of sterols [campesterol (2), stigmasterol (3) and beta-sitosterol (4)], together with the previously isolated individual compounds beta-sitosterol (4), 2,4-di-tert-butylphenol (5), alpha-tocopherol (6), phytol (7) were isolated from the active ethyl acetate fraction of Pereskia bleo (Kunth) DC. (Cactaceae) leaves. Cytotoxic activities of the above mentioned compounds against five human carcinoma cell lines, namely the human nasopharyngeal epidermoid carcinoma cell line (KB), human cervical carcinoma cell line (CasKi), human colon carcinoma cell line (HCT 116), human hormone-dependent breast carcinoma cell line (MCF7) and human lung carcinoma cell line (A549); and non-cancer human fibroblast cell line (MRC-5) were investigated. Compound 5 possessed very remarkable cytotoxic activity against KB cells, with an IC(50 )value of 0.81microg/mL. This is the first report on the cytotoxic activities of the compounds isolated from Pereskia bleo.
Red-fleshed dragon fruit (Hylocereus polyrhizus) is rich in antioxidants. The aim of this study was to determine the effects of heat pasteurization, pH adjustment, ascorbic acid addition as well as storage under agitation and light or dark condition on betacyanin content in red-fleshed dragon fruit (Hylocereus polyrhizus) juice and concentrate. The concentrate was produced by concentrating clarified red-fleshed dragon fruit juice in a rotary evaporator at 40 °C. UV-Visible spectrophotometer was used for analyzing betacyanin content. Addition of 0.25 % ascorbic acid, pH 4.0, and pasteurization at 65 °C for 30 min were selected as the best processing conditions to retain betacyanin content in red-fleshed dragon fruit juice. Storage at the agitation speed of 220 rpm showed that the concentrated samples had higher betacyanin stability compared to juice, while both juice and concentrate had almost similar betacyanin stability when tested for storage in the presence of light. In summary, ascorbic acid stabilized betacyanin in both juice and concentrate at agitated or non-agitated conditions. In contrast, light degraded betacyanin in both juice and concentrate models.
Food-borne diseases have always been a major concern to the consumers, food safety authorities and food industries. Hylocereus spp or Pitaya peels are normally treated as wastes and will be discarded during processing. In this study, the antibacterial activity of ethanol, chloroform and hexane extracts from Hylocereus polyrhizus (red flesh pitaya) and Hylocereus undatus (white flesh pitaya) peels against nine pathogens was evaluated using disc diffusion method and broth micro-dilution method. Result from disc diffusion method showed that chloroform extracts from H. polyrhizus and H. undatus peel were found to exhibit good antibacterial activity where almost all the pathogens studied were successfully inhibited. Result of the minimum inhibitory concentration (MIC) showed that all extracts inhibit the growth of bacteria in the range of 1.25-10.00 mg/mL for all bacteria while their minimum bacteriacidal concentrations (MBC) indicated double of the MICs concentration except for B. cereus, L. monocytogenes and C. jejuni. Even though there is no clear trend indicating which bacteria were sensitive most to the extract, it can be concluded that chloroform extract of both H. polyrhizusand H. undatus peel showed the most potent antibacterial activity. Thus, these findings could be used further to understand the antibacterial property of the peel of pitaya fruits.
The present work sought to investigate the nutritional composition and phytochemical properties of red pitaya (Hylocereus polyrhizus) juices from Malaysia and Australia and to determine the optimum ethanol concentration (in the range of 0 – 100% ethanol) for the extraction of phenolic, flavonoid and betacyanin contents. The predominant macronutrient in red pitaya juice was carbohydrate while potassium and vitamin A were the major mineral and vitamin content. Red pitaya juice from Malaysia achieved optimal total phenolic content at 20% of ethanol (20 mL ethanol in 100 mL water, v/v); total flavonoid content at 60% (v/v); and betacyanin content at 0% (v/v). Red pitaya juice from Australia achieved the maximum total phenolic content at 60% (v/v); total flavonoid content at 20% (v/v); and betacyanin content at 80% (v/v). Nutritional composition and the phytochemical properties of red pitaya in Malaysia and Australia were significantly different suggested the role of environmental factors like soil and climate on the phytochemical properties of red pitaya.
Nowadays consumer is more demand on natural foodstuff instead of synthetic product due to their concern on health. The objective of this study is to investigate the effect of C. caudatus extract on the number of microflora in oyster mushroom at different concentration of C. caudatus extract and exposure time using dilution method. The results showed that the number of microorganisms (Log10 CFU/g) in oyster mushroom in term of Total Plate Count (TPC), Bacillus cereus, Escherichia coli and Staphylococcus aureus were 6.13 ± 0.04, 6.15 ± 0.09, 5.97 ± 0.04, and 6.46 ± 0.00, respectively. The effect of C. caudatus extract on microflora in oyster mushroom at concentrations of 0.00%, 0.05%, 0.5%, and 5.0% with exposure time of 0, 5, 10, and 15 min demonstrated that the reduction number of microflora in oyster mushroom was dependent on the concentration of C. caudatus extract and exposure times. The number of TPC (Log10 CFU/g) in oyster mushroom was significantly reduced after treated with C. caudatus extract at concentration of 0.05% for 15 min; 6.13 ± 0.04 reduced to 2.62 ± 0.07. Moreover, B. cereus (Log10 CFU/g) in oyster mushroom was significantly reduced by treatment of C. caudatus extract at concentration of 0.05% for 5 min; 6.15 ± 0.09 reduced to 3.77 ± 0.15. Meanwhile, the number of E. coli (Log10 CFU/g) in oyster mushroom was significantly reduced at concentration of 0.05% for 10 min; 5.97 ± 0.04 reduced to 3.21 ± 0.13. Lastly, the survival number of S. aureus in oyster mushroom was significantly reduced after treated with C. caudatus extract at concentration of 0.05% for 15 min; 6.46 ± 0.00 reduced to 4.83 ± 0.07. In conclusion, C. caudatus extract has potentiality to be developed as natural sanitizer for rinsing raw food materials such as oyster mushroom.