Available at: https://digitalcommons.calpoly.edu/theses/2890
Date of Award
9-2024
Degree Name
MS in Agriculture - Food Science and Nutrition
Department/Program
Food Science and Nutrition
College
College of Agriculture, Food, and Environmental Sciences
Advisor
Samir Amin
Advisor Department
Food Science and Nutrition
Advisor College
College of Agriculture, Food, and Environmental Sciences
Abstract
Every year, the carrot industry worldwide wastes up to 50% of carrots as raw material due to processing (Šeregelj et al., 2020). When carrots are juiced, the remaining fibrous pulp is often discarded as carrot pomace. In order to redirect this food waste, the first objective of this research was to optimize formulations for an extruded puffed snack that is most similar to commercially available puffed snacks, utilizing baby lima bean flour and carrot pomace
Hardness (kg), cross-sectional expansion ratio, bulk density (g/cm3), moisture content (%), water activity, specific mechanical energy (kJ/kg), carotenoid concentration (ppm), and total dietary fiber (%) were observed in response to manipulating carrot pomace (5-10%), bean flour and rice starch (88.25-94.42%), monoglyceride (0.50-1.50%) and calcium carbonate (0-0.25%) levels. Blends were extruded under a 40/40/60/60/100/120/140/160°C barrel temperature, 350 rpm screw speed, 42 mL/h water flow rate, and 0.399 kg/h feed rate. Hardness, water activity, and moisture content measurements were also taken from two other commercially available puffed snacks – one corn-based and one potato-based – and compared with those measurements of the extruded samples.
The second objective of this research was to develop a lab involving the extrusion of potato starch under four different processing parameters. Two die temperature levels (110°C and 120°C) and two water flow rate levels (2.0 mL/min and 2.3 mL/min) would be combined in order to produce four unique treatments. Students would measure hardness (kg), cross-sectional expansion ratio, bulk density (g/cm3), moisture content (%), and specific mechanical energy (kJ/kg) of the extruded samples. Pre- and post-lab questions would assess any changes in knowledge of extrusion after participating in the lab activity, discussion questions relate the content back to IFT standards and essential learning outcomes for approval of undergraduate food science and food technology programs, and lab safety questions would ensure smooth and safe operations.
Within the range of this study, the optimum condition for a puffed snack with the greatest consumer acceptability potential was 91.17% bean flour and rice starch (1:1 ratio), 8.33% carrot pomace, 0.05% monoglyceride, and 0% calcium carbonate. It was concluded that this formulation composition resulted in an increased expansion ratio and decreased hardness, which are qualities linked to greater consumer acceptability. Based on the data collected from other commercially available puffed snacks, it was determined that several puffed snacks extruded within this study (88.88-94.42% bean flour and rice starch, 5-10% carrot pomace, 0-0.25% CaCO3, and 0.5-1.17% monoglyceride) did not demonstrate a statistically different texture. These findings demonstrate the potential for the valorization of carrot pomace byproduct in order to create an acceptable fiber-rich extruded snack.