The effect of alkaline extraction and drying techniques on the physicochemical, structural properties and functionality of rice bran protein concentrates.

Rice bran protein concentrates (RBPC) were extracted using mild alkaline solvents (pH: 8, 9, 10). The physicochemical, thermal, functional, and structural aspects of freeze-drying (FD) and spray-drying (SD) were compared. FD and SD of RBPC had porous and grooved surfaces, with FD having non-collapsed plates and SD being spherical. Alkaline extraction increases FD's protein concentration and browning, whereas SD inhibits browning. According to amino acid profiling, RBPC-FD9's extraction optimizes and preserves amino acids. A tremendous particle size difference was prominent in FD, thermally stable at a minimal maximum of 92 °C. Increased pH extraction gives FD greater exposal surface hydrophobicity and positively relates to denaturation enthalpy. Mild pH extraction and drying significantly impacted solubility, improved emulsion properties, and foaming properties of RBPC as observed in acidic, neutral, and alkaline environments. RBPC-FD9 and RBPC-SD10 extracts exhibit outstanding foaming and emulsion activity in all pH conditions, respectively. Appropriate drying selection, RBPC-FD or SD potentially employed as foaming/emulsifier agent or meat analog.

In Vitro Starch Hydrolysis and Estimated Glycaemic Index of Biscuits from Unripe Banana Peel Flour.

Banana peels are industrial waste that is normally being utilized for biogas production or disposed of without use. By converting banana peels into flour, the waste product can be reduced and the benefits that originate from its fibre and bioactive substances can enhance the nutritional value in other food products. Furthermore, the flour will increase the economical source of the industry as it is obtainable at a low-cost. The transformation of banana peels (waste) into flour (food ingredient) can improve the sustainability of the food chain and promote consumers' health. The unripe banana peel flour (UBPF) constitute of 41.4% total starch and 37.6% total dietary fibre with a higher percentage of insoluble dietary fibre than soluble dietary fibre. Various levels of UBPF from Berangan variety ranging from 0% to 40% were incorporated in the formulation of biscuits. The partial substitution of UBPF significantly increased the total dietary fibre content of biscuits from 1.83% to 4.70%. Starch hydrolysis and estimated glycemic index (eGI) of biscuits were analysed by enzymatic in-vitro digestion. The result showed that partial substitution of Berangan BPF significantly decreased (p<0.05) the starch digestion rate thus lowering the eGI of biscuits from high eGI food to intermediate GI food. UBPF has great potential as a functional ingredient to improve the nutritive value of foods as well as to reduce the glycemic index of food products.