Quality attributes and rheological properties of novel high milk protein‐based extrudates made by supercritical fluid extrusion

Abstract

Supercritical fluid extrusion (SCFX) process has opened up a new way of extruding heat-sensitive materials such as milk protein concentrate (MPC) into novel nutritional porous extrudates. Three formulations (30%:66.5%, 60%:36.5% and 90%:6.5% of MPC: rice flour, w/w) with 1% Dimodan, 1% lecithin and 1.5% salt were extruded by using SCFX. The physical, rheological and thermal properties of the extrudates were evaluated. The results showed that the increased MPC contents decreased gelatinisation enthalpy and increased the viscosity of the extrudates, which contributed to develop stable porous extrudates; and the increased MPC contents also helped to form a stronger gel network existed in dispersion of the extrudate samples, which resulted in a higher stress to break the gel and flow. The radial and overall expansions, crispness, porosity, rehydration ratio, moisture content and water activity increased while the axial expansion, hardness, piece density, apparent density, bulk density, decreased with higher amounts of MPC contents in extrudates. The overall results indicated that 90% MPC-containing extrudate was very suitable for developing highly nutritional and healthy cereals/snacks.

Effect of extrusion processing conditions on the techno-functional, antioxidant, textural properties and storage stability of wholegrain-based breakfast cereal incorporated with Indian horse chestnut flour

“…A similar observation is shown in Figure 2B, where the variation of a w with respect to the feed moisture content (14%) also presents a straight line along the axis of screw speed (350 rpm). Generally, water activity above 0.7 promotes microbial load (Zhou et al, 2021). Thus, from our study, all the extruded samples prepared under different treatment conditions fell in the safe category of shelf-stable products.…”

Supercritical carbon dioxide extrusion of milk protein concentrate and rice flour blend: A new dairy nutrition delivery platform

“…Three replications of each sample were performed to determine an average piece density. The porosity (%) of extrudates was calculated by dividing the difference between true density and piece density by the true density of the extrudates (Dogan & Kokini, 2007; Mitra et al, 2021; Zhou et al, 2021). In order to determine the water solubility index (WSI) of the extrudates 2 grams of the ground extrudates were placed into a 50 ml centrifuge tube.…”

“…Conventional steam‐based extrusion cooking is a high‐temperature (120–200°C) short‐time (HTST) process that provides thermal and shear energy to the raw materials undergoing significant physical and chemical changes for producing foods (Harper, 1981). The extrusion cooking process is a versatile and efficient operation to manufacture a wide array of food products such as breakfast cereals, snacks, ready‐to‐eat foods, and the like (Mitra et al, 2021; Mitra & Ramaswamy, 2021; Zhou et al, 2021). The combination of thermal and mechanical energy in this process improves digestibility by gelatinizing starch, denaturing protein, and enhancing the polymerizing capacity for producing versatile good quality food products (Guy, 2001; Harper, 1981; Singh et al, 2007).…”

“…This improved extrusion process has potential for milk protein‐rich value‐added products to incorporate food industrial by‐products such as broken rice flour and pomaces. Recently, milk protein concentrate blending with apple pomace extrudates (Paraman et al, 2015), and milk protein concentrate blending with different carbohydrates extrudates (Liu et al, 2017; Zhou et al, 2021) were developed using the supercritical carbon dioxide extrusion process. These studies did not indicate how the extrudates can be used and did not compare the extrudates with the commercial samples to justify the commercial potential of the milk protein extrudates.…”

Protein fortification in oat flour gel using various dairy protein ingredients: An evaluation of textural and pasting properties

“…Similarly, the addition of calcium caseinate (CaCn) in oat starch led to a rise in breakdown, final, and setback viscosities, and an elevated gelatinisation temperature (Kumar et al 2022a). However, there are limited studies on the interaction between oat flour and milk proteins, where flour is replaced with milk protein constituents, thus affecting the properties of the native flour (Zhou et al 2021).…”