Assessing Impact of Cooking Methods on the Physicochemical and Sensory Properties of Instant Fortified Rice Congee for the Elderly.

Instant rice congee (IRC) fortified with functional ingredients is designed for supplementation in nourishing the elderly. In this study, collagen peptide and curcumin were fortified in IRC to improve antioxidant and protein content. Different cooking methods were used to prepare rice congee in order to retain the nutritional content of instant fortified rice congee (IFRC). The effect of cooking methods on IFRC were investigated in this study using field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). As for cooking methods, the steaming method (IFRC-S) exhibited the highest total phenolic content (TPC) at 36.13 ± 5.63 mg GAE/g sample; a ferric reducing antioxidant power (FRAP) value of 6.39 ± 0.24 mg TE/g sample and protein content at 52.20 ± 6.48%. There were no significant differences (p > 0.05) in the texture analysis of hardness, cohesiveness and viscosity between the different cooking methods. However, the boiling method (IFRC-B) showed the highest adhesiveness, at -58.78 ± 11.55 g/s. IFRC with different cooking methods also had no significant differences (p > 0.05) in bulk density, volume expansion and the water absorption index. In sensory analysis, it was found that there were no significant differences (p > 0.05) detected in attribute colour, odour, taste, texture and overall acceptability between each cooking method. This study is particularly useful for gaining a preliminary understanding of the development of IRC focused on the elderly.

Sc-CO2 extraction of fish and fish by-products in the production of fish oil and enzyme.

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 (text), 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, text: 20-150 min; F: 3-50 g/min) than the extraction of fish oil alone (P: 10-40 Mpa; T: 35-80 °C; text: 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.