The relationships among extruder responses, texture, and protein solubility of soy protein meat analogs were studied. Soy protein isolate and wheat starch at 9:1 ratio were extruded at 60%, 65%, and 70% moisture contents and 137.8, 148.9, and 160 °C cooking temperatures. The results showed that moisture content was a more

The effect of processing variables, including screw speed (200, 300, and 400 rpm), moisture content (18, 19.5, and 21%), and four different percentages (55, 70, 85, and 100%) of oat flour, on the extrudate physical properties (expansion, bulk density, and texture profiles) and sensory properties were studied. Increasing the percentage of oat flour resulted in extrudates with a lower specific length, higher bulk density, lower lightness, higher redness, lower yellowness, higher hardness, and lower springiness, gumminess, and chewiness. Higher moisture content reduced expansion, except for the 100% oat flour puffs. Screw speed had no significant effect on the bulk density, specific length, and expansion ratio. Principal Component Analysis showed that decreasing moisture content and increasing screw speed resulted in increased product temperature, which was highly correlated with attributes of a more expanded product such as lightness, crispness, shininess, and an open cell structure. With a higher screw speed and a higher product temperature, corn-related flavors were more likely to develop. High correlations between physical and sensory properties were observed.

Soy protein isolate and wheat starch at 9:1 ratio were extruded at 60%, 65%, and 70% moisture contents and 138, 149 and 160 °C cooking temperatures. The results indicated that moisture content was a more important factor than cooking temperature for both extrusion process parameters and product sensory characteristics. Extrusion at a lower moisture content resulted in a higher product temperature and higher die pressure. The resultant products were tougher, chewier, and more cohesive and had a more layered and fibrous structure. Water absorption capacity increased with both higher extrusion moisture and higher cooking temperature. Food Engineering and Physical PropertiesExtrusion Process Parameters . . . perature profile in the extruder from the first zone to the fourth zone before reaching the cooking temperature was 27, 60, 107, and 129 ЊC, respectively. The last 2 zones (fifth and sixth) were set at the desired cooking temperature (CT). The extruder responses, including die pressure, percent torque, and product temperature before the cooling die, were recorded. About half of the extruded samples were dried in a convection oven at 40 ЊC for about 24 h until the moisture content was 10 ± 0.5% (wet basis). The rest were stored in an airtight plastic container without dehydration in a walk-in freezer at -18 ЊC.

No abstract

No abstract