Preparation of unidirectional polypropylene reinforced kenaf composite using mechanical impregnation method

Kenaf plant is one of the potential sources of natural fibre in Malaysia. Research in kenaf plastic composite is growing tremendously parallel to the high demand from the plastic industry which aiming to produce the natural fibre based materials. In this project, unidirectional kenaf fibres and polypropylene (PP) were used for manufacturing a composite. The composite was prepared by a new developed mechanical impregnation method. The mechanical impregnation technique involves transferring the PP into unidirectional kenaf fibre and controlling compression pressure given on the composite mould. The mechanical impregnation is composed by three parts; (1) compression moulding, which function to form the composite product by using identified mould, (2) a controlled speed barrel plunger, which is place to melt the polypropylene and transfer the melted polypropylene into unidirectional kenaf bundle, (3) a load cell, which is to determine the pressure given. Properties of PP were evaluated using melt flow index test (MFI) and viscosity determination. It was found that the MFI of polypropylene at optimum processing temperature 230°C is 36.7 g/10min. Besides that, PP also showed a zero viscosity behavior or η0 and a lower Newtonian region were observed at this temperature. PP/Kenaf composite was produced with the optimum processing parameters and mechanical properties were investigated according to tensile test and izod impact test. The thermal properties were determined by dynamic mechanical analysis (DMA) and the morphology of fracture surface was studied using scanning electron micrograph (SEM). The pressure is stable at 200 Kpa and the tensile strength of PP/Kenaf composite increased to 35.14 Mpa as compared to virgin PP with addition of 40% volume of kenaf fibre. However impact strength was decreased to 130.98 J/M. The dynamic mechanical properties of PP/Kenaf composites showed that the storage modulus (E’) and loss modulus (E”) decreases with increase in temperature. However, the storage modulus (E’) and loss modulus (E”) of PP/Kenaf composite was increased as compared to virgin PP. This finding showed that the addition of kenaf fibres in composite influenced the elasticity of PP. In addition, the tan δ properties were decreased because the relative damping peak height is affected by the concentration of the measured materials. It was also found that the glass transition temperature (Tg) of PP/Kenaf composite was shifted to the lower temperature at 14.7°C. From the scanning electron micrograph (SEM), it can be clearly seen that the PP is fully penetrated in the unidirectional kenaf fibre and this also illustrated the efficiency of mechanical impregnation process. However, the micrograph of impact test found that the fibre pull out and showed the fibre breakage behavior. These imply that, the preparation of unidirectional polypropylene reinforced kenaf composite using mechanical impregnation method will create opportunities to the small medium industry and fresh entrepreneur to increase the composite production by implementing a lower energy and lower cost for economic growth in Malaysia. Therefore, it will improve the smart materials production where only through this material the balance of the ecology can be maintained. Finally, the sources of resources can be diversifying according to the composite based industries, particularly in terms of natural fibre

Quality evaluation of mango using non-destructive approaches: A review

Mango (Mangifera indica L.) is one of the most popular and nutritionally rich fruits. It is also acknowledged as the king of fruits in India. Quality attributes of mango fruit depends on its appearances such as size, shape, skin colour, flesh colour, flavour, sweetness, and aroma. Over the recent years, non-destructive techniques have been garnering the interest of researchers as potential technologies that can be used for quality assessment of fruits in a part of postharvest processing. The present patterns of non-destructive techniques are more efficient, inexpensive, yield faster and accurate results. This mini review paper focuses on some of the previous applications of non-destructive techniques in quality evaluation of mango, focusing specifically on the non-destructive technique based on quality parameters. The future trend of using non-destructive techniques for quality evaluation is also discussed in this review paper

Optimisation of Stingless Bee Honey Nanoemulsions Using Response Surface Methodology

Nanoemulsions (NEs) have been used in a wide range of products, such as those producedby the food, cosmetics, and pharmaceutical industries, due to their stability and long shelf life. Inthe present study, stingless bee honey (SBH) NEs were formulated using SBH, oleic acid, tween 80,glycerol, and double-distilled water. SBH NEs were prepared using a high-pressure homogeniserand were characterised by observing their stability and droplet size. Fourier Transform-Infrared(FTIR) analysis was used to observe the functional groups of the SBH NEs after being subjected tohigh-pressure homogenisation. Transmission Electron Microscopy (TEM) images were then usedto confirm the particle size of the SBH NEs and to investigate their morphology. The effects ofthe independent variables (percentage of oleic acid, storage time, and storage temperature) on theresponse variables (particle size and polydispersity index) were investigated using the responsesurface methodology, along with a three-level factorial design. The results showed that the modelsdeveloped via the response surface methodology were reliable, with a coefficient of determination(R2) of more than 0.90. The experimental validation indicated an error of less than 10% in the actualresults compared to the predicted results. The FTIR analysis showed that SBH NEs have the samefunctional group as SBH. Observation through TEM indicated that the SBH NEs had a similar particlesize, which was between 10 and 100 nm. Thus, this study shows that SBH NEs can be developedusing a high-pressure homogeniser, which indicates a new direction for SBH by-products

Phytochemical content, antioxidant activity and mineral elements of honey produced by four different species of Malaysian stingless bees

This study investigated the phytochemical composition of honey from four species of Malaysian stingless bee i,e. Tetragonula laeviceps, Geniotrigona thoracica, Lepidotrigona terminata, as well as Heterotrigona itama. The measured phytochemical composition was total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity, pH, colour intensity, and mineral element analysis i.e. Magnesium (Mg), Calcium (Ca), Zinc (Zn), Potassium (K), and Sodium (Na). The production of honey by the L. terminata had the highest TPC value (6.74±0.57 mg GAE/100 g FW) while the T. laeviceps possesses the highest TFC value (14.85±3.71 mg QE/100 g FW). In the antioxidant activity measurement, honey from the H. itama obtained the highest percentage of 1,1-diphenyl-2- picrylhydrazyl (DPPH) inhibition (29.52±0.45%) and honey from T. laeviceps displayed the highest value in the Ferric reducing antioxidant power (FRAP) analysis (0.95±0.013 abs). The four distinct stingless bee species’ colour intensity demonstrated the variation of colour intensity in the range of 0.09-0.23 abs mAU. All honey obtained the pH values (4.75-5.03) within the acidic medium. Mg is the major mineral element in all honey samples which is followed by Na, Ca, K, and Zn

A review of non-destructive techniques applied for measuring quality of oil palm fresh fruit bunches

The quality of oil palm fruits is evaluated through several characteristics such as the ripeness level, oil content, and free fatty acid. Besides human visual assessment and destructive techniques, another alternative method that provides quality assessment on oil palm fresh fruits bunches (FFB) is through the application of non-destructive techniques. A few of the non-destructive techniques are covered in this review such as machine vision system, visible or near infrared spectroscopy, image processing using relative entropy, fluorescence technique, Kinect camera, and optical sensor system. The main quality parameter that is being evaluated is the ripeness level of the FFB because the maturity of FFB has a direct impact on the quality of the extracted oil that will eventually affect the economic value of palm oil

Optimization of Compression Moulding Temperature for Polypropylene Materials

In this work, the effect of processing temperature of polypropylene (PP) on the viscosity and the melt flow index (MFI) is studied towards the best fabrication of PP/kenaf composites. PP with MFI grade 41 and as density value of 0.95 g/cm3 is used as a raw material. The compression moulding machine is utilized to produce the moulded samples from PP pallets. The viscosity and the MFI tests have been selected as criteria to determine an optimum processing temperature. As optimum temperature 230°C has been found

Optimization of compression moulding temperature for polypropylene materials

In this work, the effect of processing temperature of polypropylene (PP) on the viscosity and the melt flow index (MFI) is studied towards the best fabrication of PP/kenaf composites. PP with MFI grade 41 and as density value of 0.95 g/cm3 is used as a raw material. The compression moulding machine is utilized to produce the moulded samples from PP pallets. The viscosity and the MFI tests have been selected as criteria to determine an optimum processing temperature. As optimum temperature 230°C has been found

Phytochemical compositions and antioxidant activities of Malaysian stingless bee honey

The current study investigates the phytochemical composition of Malaysian stingless bee honey (Kelulut honey-KH), which consists of total phenolic (TPC) and total flavonoid content (TFC), and antioxidant activity. The honey was collected from five different regions in Malaysia i.e. south, central, eastern, northern and east coast regions. TPC and TFC were quantified by using Folin-Ciocalteu and the aluminum chloride colorimetric techniques, respectively. The antioxidant activity was investigated using two methods: 1) 1,1-diphenyl- 2-picrylhydrazyl (DPPH) radical scavenging assay; 2) ferric reducing/antioxidant power assay (FRAP). The findings indicated that there were significant differences in phytochemical compositions and antioxidant activities of KH between different regions. This implies that geographical location, as well as cultivation and treatment processes, have significant effects on the KH quality

Effect of Kelulut Honey Nanoparticles Coating on the Changes of Respiration Rate, Ascorbic Acid, and Total Phenolic Content of Papaya (Carica papayaL.) during Cold Storage

This study evaluated the respiration rate of coated and uncoated (control) papayas(Carica papayaL.) with 15% ofKeluluthoney (KH) nanoparticles (Nps) coating solution during coldstorage at 12±1◦C for 21 days. The respiration rate of the papayas significantly changed duringstorage, with an increase in CO2and a decrease in O2and C2H4, while the ascorbic acid and totalphenolic content was maintained. The changes in respiration rate were rather slower for coatedpapayas when compared to control ones. A kinetic model was established from the experimentaldata to describe the changes of O2, CO2, and C2H4production in papayas throughout the storageperiod. All O2, CO2, and C2H4were experimentally retrieved from a closed system method and thenrepresented by the Peleg model. The outcomes indicated the Peleg constantK1andK2, which weregained from linear regression analysis and coefficients of determination (R2), seemed to fit well withthe experimental data, whereby theR2values exceeded 0.85 for both coated and control papayas. Themodel confirmed both the capability and predictability aspects of the respiration rate displayed bypapayas coated with KH Nps throughout the cold storage period. This is supported by the differencesin the stomatal aperture of coated and control papaya shown by microstructural images

The causal agent of anthracnose in papaya fruit and control by three different Malaysian stingless bee honeys, and the chemical profile

Anthracnose is a fungal disease that leads to a serious quality problem on a wide range of fresh produce. The current study attempted to investigate the potential of antifungal activity in Malaysian stingless bee or kelulut honey (KH) against anthracnose disease in papaya. KH was obtained from bee honey collectors from three different regions in Malaysia i.e Selangor, Kelantan and Sarawak. The screening for antifungal activity was performed via poison agar method using in vitro and in vivo assays against postharvest fungus Colletotrichum sp. The presence of the fungus was detected and confirmed by polymerase chain reaction (PCR) as well as a morphological technique. Results indicated 15% concentration of KH exhibited potent inhibitory effects and suppressed the mycelial growth of Colletotrichum sp. The scanning electron microscope (SEM) analysis revealed the rupture of the spores of fungus treated with 15% concentration of KH solution and degradation of hyphal growth.Further study was conducted on the KH solution for the detection of phenolic and flavonoid compounds by using high-performance liquid chromatography (HPLC) with a diode array detector. Results demonstrated that all of the samples contained gallic acid, coumaric acid, ferulic acid, and salicylic acid as phenolics compounds while naringenin and kaempferol as flavonoid compounds, which could contribute to the antifungal potential