Conversion of agricultural residues into valuable products has become an important study in the industry. Generally, they are made up of lignocellulose biomass which requires a particular method such as pretreatment to enhance the desired yield to produce the end product. However, pumpkin is commercialized in very little way in Malaysia, and their processing generates tons of seeds and peels as byproducts. Not to mention the fact that pumpkin wastes have many beneficial nutrients and dry matter that can be utilized in many ways. Pumpkin peel is particularly rich in glucose content and can be converted through several main steps in bioethanol production; pretreatment, enzymatic saccharification, and fermentation which usually uses fungi to obtain fermentable sugar and followed by distillation. Furthermore, bioactive compounds such as carbohydrate, protein, minerals, fatty acid and a significant value on antioxidant compounds like tocopherol, phenols and carotenes are also found in pumpkin seed. On top of that, pumpkin seeds and peels contain quite an amount of pectin that can be extracted through acid hydrolysis and have great potential as gelling agents and thickeners in the food industry as an alternative source from the commercial pectin. These have proven that the usage of pumpkin residuals not only it can provide good benefits to human, in fact, various valuable products can be produced in a cheaper and sustainable way.

Lactase is a very important enzyme to cure lactose intolerance problem. However, it is naturally existing in soluble form and cannot be reused. The current study was performed to compare the productivity and stability of lactase immobilized on calcium alginate and magnetic chitosan. The reusability of immobilized enzyme was measured for 28 days. Thermal stability was measured at 27, 37, 50 and 70 ºC. Lactase immobilized on calcium alginate showed a better stability after 21 days where it retained up to 62% of enzyme activity. However, lactase on magnetic chitosan expresses a better thermal stability as it produced 6% more sugar than lactase on calcium alginate at the optimum temperature 50 ºC. Lactase immobilized on calcium alginate and magnetic chitosan showed significantly different enzymatic activity, stability, and reusability.

Lignocellulosic biomass has been used as an alternative source to food crops that serve as feedstock for bioenergy production. The conversion of biomass to bioenergy required pretreatment process. Ionic liquids (ILs) have been recognized as promising solvents that are capable of solubilizing and separating components of lignocellulosic biomass. This research focuses on understanding how ILs affects the activity of cellulases in the enzymatic saccharification process. Sigmacell cellulose was used in the enzymatic saccharification process inste. Two different ILs were added in the enzymatic saccharification mixtures and the activity of a mixture of commercially available cellulases was measured using high-performance liquid chromatography (HPLC) to measure glucose release. Sulphate based ILs were more harmful for cellulase action than [EMIM][OAc]. [HBIM][HSO4] inactivated commercial cellulases (Celluclast®) and cellobiase (Novozyme188) in the enzymatic saccharification process. In this research, it was observed that the main factor that affects the activity of cellulase is pH.

Sustainability of energy has always become an issue globally as current energy supplies are depleting gradually. Humans were too dependent on natural gasses as a source of energy before, which brought us to this crisis as they are non-renewable energy and take up to a million years to recover. Not only that, prolonged utilization of this type of energy brought deterioration to our environment. Biofuels are one of the renewable energy sources that are favoured in the industry nowadays. They have the potential to replace non-renewable energy while simultaneously decrease the environmental damage. Sourced from various agricultural residues and other plant substances, lignocellulosic materials are capable of being converted to non-renewable energy due to their lavish availability through three basic steps, pre-treatments, enzymatic hydrolysis and fermentation. This review seeks to observe the prospect of cassava peels as a source for biofuels production and other value-added products such as formic acid, levulinic acid, glycolic acid and vanillin.

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