IN VITRO INOCULATION OF ASPARAGUS OFFICINALIS TISSUE CULTURE SHOOTS WITH FUSARIUM PROLIFERA TUM

ABSTRACT Artificially inoculated asparagus tissue culture plantlets with a virulent fungus,  Fusarium proliferatum showed signs of infection as early as 4 days after inoculation. Macroscopic observations revealed presence of early symptoms such as necrotic lesions at the affected area and light microscopic examinations clearly revealed the post-penetration events that took place including the destruction of surrounding cells. However, little is known of the hyphal activity or advancement on the host's surface at the initial stage after inoculation. Scanning electron microscopic examination clearly revealed the hyphal advancement on the surface and the mode of entrance into the host tissues beneath. Four days after inoculation, the fungi proceeded to spread out from the inoculation point onto the host surface which eventually developed into a sparse network of both aerial and non-aerial hyphae. Non-aerial hyphae form a network of mycelium that adheres to the surface and it's movement appeared to be oriented towards the stomata. Hyphal penetration occurs more often through the stomata, natural openings or wounds. In some cases, the hyphae crossed over the stomatal opening without entering the host tissues. At places where the cuticle layer is absent or not well developed the hyphae successfully grew in between the epidermal cells into the tissues beneath. Key words: Tissue culture/Asparagus officinalis/shoots/Artificial inoculstion/Fusarium proliferatum

Establishment of Wolbachia strain wAlbB in Malaysian populations of Aedes aegypti for dengue control

Dengue has enormous health impacts globally. A novel approach to decrease dengue incidence involves the introduction of Wolbachia endosymbionts that block dengue virus transmission into populations of the primary vector mosquito, Aedes aegypti. The wMel Wolbachia strain has previously been trialed in open releases of Ae. aegypti; however, the wAlbB strain has been shown to maintain higher density than wMel at high larval rearing temperatures. Releases of Ae. aegypti mosquitoes carrying wAlbB were carried out in 6 diverse sites in greater Kuala Lumpur, Malaysia, with high endemic dengue transmission. The strain was successfully established and maintained at very high population frequency at some sites or persisted with additional releases following fluctuations at other sites. Based on passive case monitoring, reduced human dengue incidence was observed in the release sites when compared to control sites. The wAlbB strain of Wolbachia provides a promising option as a tool for dengue control, particularly in very hot climates

Optimization of supercritical CO2 extraction of Anastatica hierochuntica.

Response surface methodology (RSM) was applied to optimize the variables affecting the supercritical carbon dioxide (SC-CO2) extraction of non-polar compounds from Anastatica hierochuntica using the Central Composite Design technique (CCD). Independent variables were temperature (32–46 °C) and pressure (22–46 MPa). Dependent variables were the percentage of the content of hexadecanoic acid, 9,12-octadecadienoic acid, heneicosane and heptacosane. Pressure was the most significant parameter that affected the content of the compounds. The hexadecanoic and 9,12-octadecadienoic content decreased while heneicosane and heptacosane increased with pressure. A number of choices can be run either at low pressure and low temperature or at low pressure and high temperature in order to optimize extraction of the selected compounds. Extraction either at low temperature (33 °C) and low pressure (25.6 MPa), or at high temperature (42 °C) and low pressure (22.0 MPa) maximized the yield of hexadecanoic, 9,12-octedecanoic, heneicosane and heptacosane

Storage stability and quality of polyunsaturated fatty acid rich oil fraction from longtail tuna (thunnus tonggol) head using supercritical extraction

The polyunsaturated fatty acids (PUFA)-rich fish oil fractionated from tuna head using supercritical carbon dioxide (SC-CO2) were stored at 4°C and –18°C for 60 days to study the storage stability. The changes in fatty acids, iodine value (IV), peroxide value (PV), acid value (AV), and saponification value (SV) up to 30 days were found to be negligible, then started to decrease from 45 and the significant changes were observed at 60 days. At 4°C, the PV, AV, and SV were increased from 1.74 to 6.72 meq O2/kg oil, 1.36 to 5.56 mg KOH/g oil, and 182.73 to 190.74 mg KOH/g oil, respectively, while IV and PUFA were decreased from 185.43 to 175.35 g I/100 g oil and 43.07 to 33.94% at 60 days. It is concluded that SC-CO2 extracted PUFA-rich fraction could be maintained in good quality for consumption at both temperature up to 60 days

Thermal properties, triglycerides and crystal morphology of bambangan (Mangifera pajang) kernel fat and palm stearin blends as cocoa butter alternatives

The aim of this study was to investigate the thermal properties of bambangan kernel fat (BKF) and palm stearin (PS) blends and their possibility as cocoa butter alternatives. The triglycerides, thermal behaviors, and crystal morphology of the BKF and PS blends were determined using high performance liquid chromatography (HPLC), differential scanning calorimetry (DSC), and polarized light microscope (PLM). All the blends had three main triglycerides; namely, 1,3-dipalmitoyl-2-oleoyl-glycerol, 1-palmitoyl-2-oleoyl-3-stearoyl-glycerol, and 1,3-distearoyl-2-oleoyl-glycerol. The melting onset temperatures decreased for both non-stabilized (−8.81 to −16.80 °C) and stabilized fat blends (−14.04 to −22.16 °C), whereas the melting offset temperatures shifted toward high temperatures for both non-stabilized (35.94–50.21 °C) and stabilized fat blends (48.35–53.16 °C) with PS. The crystallization onset temperatures increased for both non-stabilized (14.66–23.78 °C) and stabilized fat blends (15.46–26.89 °C), whereas the offset temperatures decreased with the addition of PS for non-stabilized (−15.68 to −22.02 °C) and stabilized fat blends (−15.73 to −22.38 °C). The stabilized fat blends showed higher melting and crystallization peak temperatures than non-stabilized fat blends. In the study of crystal morphology, the fat blends showed small spherulites with the diameter of 10–100 μm

Optimization of supercritical carbon dioxide extraction parameters of cocoa butter analogy fat from mango seed kernel oil using response surface methodology

Mango seed kernels (MSK) are discarded as agricultural wastes of industrial processing’s by-product as well as direct consumption of the mango fruits. The extraction parameters of SC-CO2 were optimized using central composite design (CCD) of response surface methodology (RSM) yielding cocoa butter analogy fats from MSK. The pressure, temperature, and CO2 flow rate were considered as variables, where the linear and quadratic effect of the flow rate of CO2, quadratic effect of pressure, and interaction between pressure and temperature was positive and most significant on the MSK oil yield. On the other hand, linear effect of pressure and temperature, quadratic effect of temperature, and interaction between temperature and CO2 flow rate had a less impact. The optimized oil yield was predicted to be 11.29 % at 44.2 MPa, 72.2 °C and CO2 flow rate of 3.4 ml/min which was close to the oil yield (11.7 %) of Soxhlet extraction method. However, the stearic (41.99 to 42.21 %) and oleic (43.78 to 43.89 %) the predominant fatty acids in terms of triglycerides constituents were found in MSK oils extracted by SC-CO2 and Soxhlet methods. The MSK oil extracted using SC-CO2 method could be regarded as premium quality cocoa butter analogy fats in this study