Protein Rich Extruded Snack Food from Finger Millet Flour, Oat Flour, Potato Starch and Whey Protein Isolate Blends
Author | : Siddhesh Salunke |
Publisher | : |
Total Pages | : |
Release | : 2016 |
ISBN-10 | : OCLC:973734447 |
ISBN-13 | : |
Rating | : 4/5 (47 Downloads) |
Book excerpt: "Extrusion cooking is a high temperature short time shear process used to transform raw ingredients into modified intermediate and finished products. It has been widely used in food industry as it offers continuous processing while maintaining significantly higher nutrient levels. Recent studies suggested that most snack foods available in the market are categorized under the "unhealthy or junk food" category due to their higher fat, sugar and salt contents, and lower protein content. Hence, the overall objective of this research was to prepare high-value protein-rich products through the use of extrusion processing. To achieve this broad objective, specific blends of finger millet flour, oat flour, potato starch and whey protein isolate (W) were subjected to twin screw extrusion process with the specific objective of enriching the protein content of extruded snack product. Different blends of finger millet flour (F), oat flour (O), potato starch (P) and whey protein isolate (W) were prepared based on a D-optimal mixture design, with constrains: F (50-70%), O (10-30%), P (20-40%), and W (0-10%), followed by extrusion at screw speed of 100 rpm while temperatures in a extruder barrel were set to 80°C, 100°C, 120°C and 140°C from feeding zone towards the die. The resulting extruded products under the above conditions were found to have too high moisture content and water activity. Hence, the extruded products were dried at 55°C and 0.1 m/s air flow rate to reduce the final moisture content to 18% (dry basis) and water activity below 0.75 for shelf stability. Models were developed to predict drying times to reduce the product moisture to stable levels (water activity below 0.75). The results revealed that extrusion processing variables, viz. quantity of finger millet flour (F), oat flour (O), potato starch (P) and whey protein isolate (W) were found to have a significant (p