Currently, there is increasing interest on low cost and commercially available materials for the adsorption of heavy metals. The vital benefits of adsorption technologies are its potential in reducing the concentration of heavy metal ions using low-cost adsorbent materials. Fruit peel wastes (FPW) are readily available in abundance. Furthermore, it has a high potential as a sustainable adsorbent due to its large quantity of lignocellulosic materials. Realizing this potential, there are many studies on various fruit peels waste adsorbents used in the removal of Pb (II), Cu (II) and Cd (II) ions from wastewater. However, there is no comprehensive review of these adsorbents, especially on the factors that influenced the adsorption capacity. Hence, this review aims to study on the various fruit peels waste adsorbents and the factors by comparing the metal binding capacities, metal removal performances, sorbent dosage, optimum pH, temperature, initial concentration and contact time. Finally, the adsorption mechanisms were also discussed.

Collagen was extracted from the body wall of sea cucumber (Holothuria scabra) using the pepsin-solubilized collagen method followed by isolation using dialysis and the ultrafiltration membrane. The yield and physicochemical properties of the collagen obtained from both isolation methods, denoted as D-PSC and UF-PSC, were compared. The ultrafiltration method affords a higher yield of collagen (11.39%) than that of the dialysis (5.15%). The isolated collagens have almost the same amino acid composition, while their functional groups, referred to as amide A, B, I, II, and III bands, were in accordance with commercial collagen, as verified by Fourier Transform Infrared (FT-IR) spectroscopy. The UV-Vis absorption peaks at 240 nm and 220 nm, respectively, indicated that the collagens produced are type-I collagen. The D-PSC showed interconnecting sheet-like fibrils, while the UF-PSC exhibited a flaky structure with flat-sheets arranged very close to each other. The higher yield and comparable physicochemical properties of the collagen obtained by ultrafiltration as compared with dialysis indicate that the membrane process has high potential to be used in large-scale collagen production for food and pharmaceutical applications.

Research background. Microbial contamination of food products is one of the significant causes of food spoilage and foodborne illnesses. The use of active packaging films incorporated with antimicrobial agents can be a measure to improve food quality and extend shelf life. Nevertheless, antimicrobial agents such as silver, copper, titanium and zinc in the packaging films have raised concerns among consumers due to toxicity issues. Experimental approach. The current study aims to develop biodegradable gelatine- based edible films incorporated with microcapsules of Clitoria ternatea-derived anthocyanins as a natural antimicrobial agent. The impact of incorporation of microcapsules with anthocyanins on the morphology, thermal, mechanical, water vapour barrier and physicochemical properties of the gelatine films was evaluated in this study. The effectiveness of the developed films against foodborne pathogens and their application for perishable food protection were also investigated. Results and conclusions. The results show that incorporating anthocyanin microcapsules enhances the gelatine film physical and mechanical properties by increasing the thickness, tensile strength, Young’s modulus and elongation at break of the films. Scanning electronic microscopy analysis revealed that the film surface morphology with anthocyanin microcapsules had a homogeneous and smooth surface texture compared to the control. The thermogravimetric analysis also showed a slight improvement in the thermal properties of the developed films. Agar well diffusion assay revealed that the developed films exhibit significant inhibition against a broad-spectrum of bacteria. Furthermore, the films composed of gelatine with anthocyanin microcapsules significantly reduced the total viable count of microorganisms in the bean curd during storage for 12 days compared with the control films. Novelty and scientific contribution. Increasing global awareness of healthy and safe food with minimal synthetic ingredients as preservatives has sparked the search for the use of antimicrobial agents of natural origins in active food packaging material. In this study, a safe and effective active packaging film was developed using an environmentally friendly biopolymer, gelatine film incorporated with microcapsules of Clitoria ternatea-derived anthocyanins as a natural antimicrobial agent. This study demonstrated that such a method is not only able to improve the film physical properties but can also significantly prolong the shelf life of food products by protecting them from microbial spoilage.

The main focus of this study was to produce the angiotensin-I converting enzyme (ACE) inhibitory peptides from collagen type I using new combination of Thermoase PC10F and tilapia skin as a protein collagen source. In silico evaluation of amino acids profile of collagen type I, ACE-inhibitory peptides and sensory profile of the hydrolyzate were performed using Protparam and BIOPEP, respectively, to initially predict the potential peptide produced. Hydrolysis conditions were studied based on the best preliminary design of degree hydrolysis (DH) using o-phthalaldehyde (OPA) method. The temperature of 60°C, pH of 5 and an enzyme to substrate ratio of 1:100 were observed as the best conditions to obtain the highest DH using Thermoase PC10F. Peptide chain length (PCL) showed a proportional decrease as DH increased. In silico study of alpha 1 and alpha 2 collagen type I indicated a significant amount of glycine and proline, which are known to stabilize the collagen structure. The profile of potential biological activity suggested that 247 ACE-inhibitory peptides could be obtained from the parent protein sequence of collagen type I alpha 1 and alpha 2. In silico hydrolysis by thermolysin is believed to release potent theoretical peptides with IC₅₀ less than 5 μM for both collagen type I subunits with a high number of occurrences. Further analysis on its potential sensory peptides had shown that both alpha 1 and alpha 2 contained mainly sweet amino acid, bitter peptides, and bitter amino acids.