Supercritical carbon dioxide (Sc-CO₂) is an alternative tool to extract lipid for the production of fish oil and enzyme from fish by-products (FBPs). In the application of Sc-CO₂, this review covers sample preparation, lipid extraction operation, and characterization of fish oil and enzyme as final products. Generally, the fish samples with moisture content less than 20% and particle size less than 5 mm are considered before lipid extraction with Sc-CO₂. Sc-CO₂ parameters, such as pressure (P), temperature (T), extraction time (t_ext), and flow rate (F), for simultaneous recovery of fish oil, protein, and enzyme were found to be less severe (P: 10.3–25 MPa; T: 25–45 °C, t_ext: 20–150 min; F: 3–50 g/min) than the extraction of fish oil alone (P: 10–40 Mpa; T: 35–80 °C; t_ext: 30–360 min; F: 1–3000 g/min). The enzyme from the Sc-CO₂ defatted sample showed higher activity up to 45 U/mg due to lower denaturation of protein as compared to the organic solvent treated sample albeit both samples having similar pH (6–10) and temperature stability (20–60 °C). Overall, mild extraction of lipid from FBPs using Sc-CO₂ is effective for the production of enzymes suitable in various industrial applications. Also, fish oil as a result of extraction can be produced as a health product with high polyunsaturated fatty acids (PUFAs) and low contamination of heavy metals.

Three novel peptide sequences identified from palm kernel cake (PKC) generated protein hydrolysate including YLLLK, WAFS and GVQEGAGHYALL were used for stability study against angiotensin-converting enzyme (ACE), ACE-inhibition kinetics and molecular docking studies. Results showed that the peptides were degraded at different cleavage degrees of 94%, 67% and 97% for YLLLK, WAFS and GVQEGAGHYALL, respectively, after 3 h of incubation with ACE. YLLLK was found to be the least stable (decreased ACE-inhibitory activity) compared to WAFS and GVQEGAGHYALL (increased ACE-inhibitory activity). YLLLK showed the lowest K_i (1.51 mM) in inhibition kinetics study when compared to WAFS and GVQEGAGHYALL with K_i of 2 mM and 3.18 mM, respectively. In addition, ACE revealed the lowest $K_{\mathrm{m}}^{\mathrm{app}}$ and $V_{\max }^{\mathrm{app}}$ and higher catalytic efficiency (CE) in the presence of YLLLK at different concentrations, implying that the enzyme catalysis decreased and hence the inhibition mode increased. Furthermore, YLLLK showed the lowest docking score of −8.224 and seven interactions with tACE, while peptide GVQEGAGHYALL showed the higher docking score of −7.006 and five interactions with tACE.

The study aimed to establish the detection method for bound 3-, 2-MCPD, and glycidol using accelerated solvent extraction (ASE) and gas chromatography mass spectrometry (GC-MS). The ASE was modified for reduced solvent volume and process time to extract lipid from the chocolate spread, infant formula, potato chips, and sweetened creamer. The solvent selected for ASE was a mixture of iso-hexane and acetone at 100°C with the lipid and analyte recovery ranging from 96.9% to 98.6% and 84.1% to 107.5%, respectively. The derivatisation of analytes was adopted from the AOCS method Cd29a-13 for GC-MS analysis. The results showed that the coefficient of determination (R²) of all analytes was >0.99. The limit of detection (LOD) was 0.1 mg kg⁻¹ expressed in lipid basis for both bound 3- and 2-MCPD and 0.2 mg kg⁻¹ expressed in lipid basis for bound glycidol. The limit of quantitation (LOQ) was 0.3 mg kg⁻¹ expressed in lipid basis for both bound 3- and 2-MCPD and 0.6 mg kg⁻¹ expressed in lipid basis for bound glycidol. A blank spiked with 3-monochloropropanediols fatty acid esters (MCPDE) and 2-MCPDE (0.3, 2.1, and 7.2 mg kg⁻¹) and glycidol esters (0.6, 4.7, and 16.6 mg kg⁻¹) were chosen for accuracy and precision tests. The recoveries were 91.7% to 105.9%. Both repeatability and within-laboratory reproducibility of the analysis were within the acceptable level of precision ranging from 1.7% to 16%. This is the first time that a full validation procedure extending to both accuracy and precision tests has been carried out for sweetened creamer and chocolate spread. Overall, the combined protocol of ASE and AOCS Cd29a-13 was successfully validated for both solid and liquid food samples with lipid content from 10% to 30%.

The fish consumption has increased tremendously due to the dramatic increase in world population. Catfish, the most cultivated species worldwide, showed an increasing trend in global production from year to year. Hence, loads of fish by-products (FBP) were generated especially viscera, materials rich in digestive enzyme notably protease. FBP is often thrown away without any attempt of recovery leading to serious environmental pollution and disposal problems. However, the application of certain protease in either food or non-food industry has become a controversial issue with regards to religious belief (porcine-related product or unslaughtered animals without religious compliance) and health concerns (Bovine Spongiform Encephalopathy (BSE) diseases). Therefore, in this study, protease was extracted and purified from the visceral waste of African catfish (Clarias gariepinus). This study aimed to identify the specific activity and molecular weight of the purified protease at different purification stages. The crude protease was extracted and purified using 60% ammonium sulfate precipitation and dialysis. The study showed that the fresh viscera contained 5.9% protein. The specific activity of the protease indicated a gradual increase as it was further purified up to the dialysis stage (608.70 U/ mg) from the crude extract (263.82 U/mg) by 2.3 folds with half of the visceral protease managed to be recovered (61.43%). In SDS PAGE analysis, purified protease from the dialysis process portrayed unique features such as dimer with an apparent low molecular weight of 15 kDa and 16 kDa. It was obvious that the utilization of the visceral waste from a halal source such as catfish for the extraction of a beneficial protease would be a winwin situation in both environment and industry players from all sectors.

The efficient production of mung bean protein isolate (MBPI) is essential for sustainable food processing, yet it is energy-intensive due to drying phase required to convert raw mung beans into a fine powder. This work was carried out to calculate the thermal conductivity constant (k) of protein (A), moisture (B) and residual carbohydrate (C) of spray-dried MBPI. The protein slurry was prepared by dissolving MBPI in water at the ratio of 1:3, 1:4, and 1:5 prior to spray drying. The protein slurry was then spray dried at three different inflow temperatures of 140, 160, and 180 °C. A Series and Parallel Combination "Block" Model in tandem with a Central Composite Design (CCD) were selected to calculate the thermal conductivity constant of A, B and C. Eight arrangement components on A, B, and C component, measurements were derived from the initial three data points by utilizing the CCD method, in the preliminary study. By utilizing the series-parallel approach and statistical combination, there are a total of forty study arrangements. The thermal conductivity of MBPI with arrangements of A, B, and C (pABC); and a series of combinations of A and C in parallel to B (sAC pB) ranged from 0.1964-0.224 Wm-1 ℃ -1, with R2 = 98.73%-99.42%. Therefore, the energy requirement of spray drying process for MBPI could be predicted by the thermal properties of each component selected in the protein isolate.