Lee Yit Leng
No Thumbnail Available
Preferred name
Lee Yit Leng
Official Name
Yit Leng, Lee
Alternative Name
Leng, L. Y.
Leng, Lee Yit
Lee, Yit Leng
Main Affiliation
Scopus Author ID
36515068600
Researcher ID
AFJ-9629-2022

Research Output

conference proceeding conference... journal article journal ar... conference proceedings conference... journal journal journal-article journal-ar...

Filters

10
3
10
Reset filters

Settings
Now showing 1 - 10 of 10
No Thumbnail Available
Publication

Estimating shelf-life of fresh Brazilian spinach: Paper and plastic packaging

2023-04-24 , Norawanis Abdul Razak , Amran M.A.F. , Sharon S. , Wei L.T. , Abd Razak Shaari , Lee Yit Leng , Ras Izzati Ismail , Sriyana Abdullah

The selection of packing materials is an important factor to prolong the shelf life of food products, especially for perishable foods or produces. This research was conducted to determine the effect of packing materials (papers and plastics) on fresh Brazilian spinach leaves quality such as moisture content, water activity and total color difference (Δη). The samples were stored at ambient temperature (25 °C) for 16 days. The moisture content and water activity of the samples were measure by moisture analyzer and water activity meter, respectively. The total color difference (Δη) was calculated based on L∗, a∗ and b∗ parameters. Generally, based on overall results, the packing materials significantly affected the quality of fresh Brazilian spinach leaves throughout 16 days of storage period. The results asserted that the paper materials are not suitable to use to pack fresh Brazilian spinach leaves for long period. It is also not recommended to use any paper material to pack fresh produce, especially perishable vegetables and fruits, in protecting their quality. The use of HDPE and PP plastics is recommended to prolong the shelf life of the fresh Brazilian spinach leaves. However, it has a limitation in controlling the changes of leaves color.

View
No Thumbnail Available
Publication

Mechanical and physical properties of khaya senegalensis solid fuel pellet with different binder percentages

2021-10-25 , Ras Izzati Ismail , Shaari A.R. , Khor Chu Yee , Alina Rahayu Mohamed , Rahim M.S.b.A. , Lee Yit Leng , Wan Nur A'tiqah Wan Draman , Nur Lailina Makhtar , Norawanis Abdul Razak , Mohd Riduan Jamalludin

The characteristics of the solid fuel pellets, such as its strength, durability and density can be used to assess its quality. During the transport and storage, pellets with low strength and durability produces dusts and ultimately resulting in equipment blockage, high pollution emissions, and an increased risk of fire and explosion. Therefore, pellet manufacturing process should be given priority to improve pellet quality. The use of binder in the production of pellets will aid in improving pellet quality. Therefore, this study investigates the influence of different binder percentages on the mechanical properties of K. senegelensis fuel pellets. Durability, unit density, bulk density and diametral compressive strength testing were carried out in compliance with international standards. It was discovered that pellets containing 4% cassava starch binder produces better results, particularly in terms of durability and compressive ldiametral strength.

View
No Thumbnail Available
Publication

Antioxidant capacity and total phenolic content of fresh, oven-dried and stir-fried tamarind leaves

2017 , Lee Yit Leng , Mohd Nadzrin Mohammad Radzi , Abd Razak Shaari , Norawanis Abdul Razak , Khor Chu Yee

The aim of this study was to compare the antioxidant capacity and total phenolic content as well as the chemical groups of fresh, oven-dried and stir-fried tamarind (Tamarindus indica L.) leaves. Methanol was used for extraction of fresh, oven-dried and stir-fried tamarind leaves. The stir-fried leaves were prepared using medium heat for 10 minutes prior to extraction and chemical analysis while dried leaves were obtained by oven drying at 60°C for 3 hours. The stir-fried leaves had significantly highest total phenolic content (TPC) (139.87 mg/g) and percentage DPPH radical-scavenging inhibition (69.92%) while the fresh leaves had the lowest TPC (39.31 mg/g) and antioxidant capacity (16.46%). The FTIR spectral data suggest that the heat treatment increased the amine groups as well as the antioxidant capacity of the tamarind leaves. To increase the antioxidant capacity, the tamarind leaves should be prepared in a stir-frying process.

View
No Thumbnail Available
Publication

The effect of torrefaction reaction temperature on the Elaeis Guineensis Empty Fruit Bunch (EFB) pellet durability and calorific value

2020 , Ras Izzati Ismail , Lee Yit Leng , Nur Lailina Makhtar , A A A Rahman , J A A Dali , A R Shaari , Khor Chu Yee , A R Mohamed , Mohd Riduan Jamalludin , Norawanis Abdul Razak , Wan Nur A'tiqah Wan Draman

Empty Fruit Bunch (EFB) are not being fully utilized for energy production due to its high moisture content, low density, having bulky characteristics and low calorific value. In order to improve characteristic of Elaeis Guineensis empty fruit bunch as fuel, pre-treatment process is necessary to overcome these shortcomings. Therefore, the aim of this research is to examine the effect of torrefaction reaction temperature on the Elaeis Guineensis pellet energy characteristics. The observed pellet qualities include the pellet durability and calorific value of the pellet. The torrefaction of empty fruit bunch was conducted in a fixed-bed reactor at 200°C, 220°C, 240°C and 260°C. The torrefied sample was pelletized, analysed and tested to examine the characteristics of empty fruit bunch biomass as fuel. The pelletization process was carried out by using the cold single press pelletizer and using cassava starch as binder. At higher torrefaction temperature, the decomposition of cellulose and lignin become more prominent. At the torrefaction temperature 260°C, the gross calorific value is the highest due to the removal of moisture, release of volatile matter and the decomposition of biomass components such as hemicellulose, cellulose and lignin which resulted in energy densification. By comparing the torrefied empty fruit bunch at 260°C with the untorrefied empty fruit bunch, it was found that the torrefaction increased the energy densification and pellet qualities of empty fruit bunch that can be utilized as biomass energy sources in renewable energy.

View
No Thumbnail Available
Publication

Production of Solid Biofuels From Renewable Resources: A Review

2023-06-09 , Ras Izzati Ismail , Khor Chu Yee , Shaari A.R. , Alina Rahayu Mohamed , Abdul Halim M.H.B. , Rahman A.A.A. , Lee Yit Leng , Nur Lailina Makhtar , Norawanis Abdul Razak

Increasing concerns over greenhouse gas emissions, volatile fossil fuel prices, and political instability have led to biomass as a renewable energy source. Close cooperation from the government supported by independent bodies also helps produce this effective and sustainable energy source. As a result, the current growth of solid biofuels has increased tremendously. Agricultural, municipal, forest, commercial waste and dedicated energy crops are the main sources of biomass. Due to this biomass's nature, the methods to produce them into solid biofuels are also different. The energy potential of these biomass sources is quite dependent on the use of technology and public awareness. Therefore, this paper review feedstock biomass, processing processes, product types and properties of solid biofuels in terms of mechanical and combustion. The paper also reviews the solid biofuel production situation in Malaysia.

View
No Thumbnail Available
Publication

Soil Macrofauna abundance in the intercropping of Mangifera Indica with aromatic plants

2023-12 , Iqbal Usamah , Lee Yit Leng , Noor Hasyierah Mohd Salleh , Norawanis Abdul Razak , Zarina Zakaria , Ras Izzati Ismail , Nur Lailina Makhtar

Soil macrofauna such as earthworms, beetles, ants, and centipedes are an important aspect of soil health as they help in the breakdown of plant residue to provide natural resources such as carbon, nitrogen, and phosphorous into the soil. Monocropping practice uses heavy machinery, pesticides, and herbicides to maintain farm productivity, which negatively impacts soil macrofauna abundance. Thus, intercropping is a sustainable practice for farmers to maintain soil health with the minimal use of external input, which can do more harm to the soil ecosystem over a long period of time. The objective of the study is to evaluate the effect of intercropping mango with pandan and lemongrass on soil macrofauna density compared to mango monocrop. The field experiment consisted of mango, mango-pandan intercrops, and mango-lemongrass intercrops. Soil macrofauna was assessed using the tropical soil biology and fertility (TSBF) monolith method. The result showed that intercropping of mango-lemongrass and mango-pandan had higher soil macrofauna density compared with mango monocrop due to the presence of intercrops providing more natural resources and a better soil environment for soil macrofauna to grow and reproduce. However, further long-term research is needed to reinforce these findings.

View
No Thumbnail Available
Publication

Design and fabrication of automatic temperature control for chicken shade

2024-03 , M.H.H. Asaad , Nur Lailina Makhtar , R. I. Ismail , Lee Yit Leng , Norawanis Abdul Razak , Wan Nur Atiqah Wan Draman

One of the most crucial sectors to explore in Malaysia are agriculture and poultry. Indeed, there is a strong correlation between agricultural growth and economic growth. The inconsistent weather in Malaysia will cause the temperature to increase and decrease, and this problem will affect the health of the chicken. Small-sector farmers cannot afford the high cost of installing and maintaining the temperature control system. Therefore, new effective technological approaches were required to continuously improve the productivity, profitability, and sustainability of major farming systems. An automatic temperature control system was designed to control the temperature in the chicken shade. This system was controlled by Arduino UNO, which was programmed using Arduino IDE software. The system started to operate when the sensor detected the temperature in the chicken shade above 28oC. The exhaust fan, pump, and water sprinkler are the main components in this system that control the temperature in the chicken shade. The system reduced the temperature in the chicken shade by 1oC to 3oC. The system also affects the rate of chicken growth. By lowering the temperature in the chicken shade, the rate of the chicken growth increases. The chicken starts to grow faster in week 3 at 5 weeks. Starting in week 3, the chicken in controlled room temperature was 46g heavier than the average chicken weight in a normal room. In week four, the average chicken weight in a controlled room was 116.25g heavier than in a normal room. In week six, the average weight of chicken in the controlled room was 884.5, while in normal room conditions, it was 732g. The initial bar graph and week six bar graph for both conditions show significant differences in the chicken's growth rate.

View
No Thumbnail Available
Publication

The Effect of Different Waste Material Binders in Relation to Khaya Senegalensis Solid Fuel Pellet Quality

2023-11-01 , Ras Izzati Ismail , Khor Chu Yee , Alina Rahayu Mohamed , Mustafa N.M.K.N. , Lee Yit Leng , Nur Lailina Makhtar , Norawanis Abdul Razak

Fuel pellets are an attractive renewable energy source derived from biomass sources thanks to their uniformity and ease of handling. However, raw biomass and waste material binders have several drawbacks, which include poor physical properties, particularly low density and compositional heterogeneity, which restrict their wider use as a general source of energy. Besides, due to the low energy density, low bulk density, and uneven shape and size of raw biomass, it is very difficult to store and transport biomass in its original form, which decreases transport efficiency. This study investigated the effect of waste material binders (rice husk, corn cob, and sugarcane bagasse) on the mechanical and thermal properties of Khaya Senagalensis pellets. The mechanical and thermal properties were determined according to ASTM standards. Waste material binders have affected pellet quality such as density, bulk density, moisture content, durability, compressive strength, shatter index, water resistance, ash content, volatile matter, fixed carbon, and calorific value. From the analysis, sugarcane bagasse as a binder shows the highest quality pellet in terms of mechanical properties. Sugarcane bagasse produces the highest density (0.967g/cm3), bulk density (0.4094), durability (99.71%), shatter index (98.85%), water resistance (98.35%), and thermal properties, which are the highest volatile matter (94.71%) and the lowest ash content (1.71%). In a nutshell, sugarcane bagasse is a good binder that gives a positive impact to the K.senegalensis pellets in terms of storage and transportation compared to corn cob and rice husk binder.

View
No Thumbnail Available
Publication

Effect of initial moisture content on physical properties of Orthosiphon stamineus ground powder during storage

2020-12-18 , Norawanis Abdul Razak , Rahim N.A.S.A. , Abd Razak Shaari , Lee Yit Leng

Initial moisture content of ground powder is very important factor in maintaining the physical quality of the product during storage. This research was conducted to investigate the effect of initial moisture content of Orthosiphon stamineus ground powder on physical properties such as moisture content, water activity and colour properties during short term storage period. In this research, the experimental treatments were arranged in a completed randomized design (CRD) that consisted of two main factors which were initial moisture content (8, 13 and 20 %) and storage period (0, 2, 4, 6, 8 and 10 weeks). The changes of moisture content, water activity and colour properties were analyzed using moisture analyzer, water activity meter and chroma meter, respectively. From the results, it was revealed that the best initial moisture content to maintain the quality of O. stamineus ground powder was 13 %. At early of storage period, moisture content and water activity were slightly reduced and they started to stable at week 8 to 10. The consistency of moisture content and water activity is expected to last for the next 6 months under same storage condition. However, it could be observed that the colour of O. staminus ground powder was slightly affected during short term storage.

View
No Thumbnail Available
Publication

Hot air drying of Brazilian spinach leaves

2024-03 , Norawanis Abdul Razak , Lim Teik Wei , Lee Yit Leng , Sriyana Abdullah

Brazilian spinach is one of the best leafy vegetables with tons of nutrients and has a range of health benefits. Its quality also determines the acceptance of customers to buy and consume it. The common method to extend the shelf life of the spinach is through drying treatment and preserving the color and texture quality of the leaves. Therefore, this study aimed to determine the drying characteristics of Brazilian spinach and investigate the effect of drying temperature on the color and texture quality of Brazilian spinach. Brazilian spinach leaves were dried using a hot air dryer under different temperatures (30, 50, 70 and 90C). Results showed that the drying rate increased when temperature increased. It was found that the Midili model gave the best fitting to the experimental moisture ratio for a specific drying treatment. Drying the Brazilian spinach leaves at 50C was the best condition for preserving their color and texture properties.

View