| Extrusion can have a significant effect on the flavor and aroma profiles of food products manufactured through this process. Novel research focuses on the use of reactive flavor precursors added to the extruder feed before processing to increase production of flavor volatiles or change the flavor profile. Potato flakes may be used to manufacture crispy, but bland, extruded snacks. Sulfur containing amino acids have been reported to enhance potato flavor. The objective of this study was to evaluate the effects of sulfur compounds on physical and flavor characteristics of extruded potato snack-like products.;DL-methionine (0.25, 0.50, 1.0%), thiamin-HCl (0.25, 0.50, 1.0%), L-cysteine (0.25, 0.50%) and benzyl disulfide (0.50, 1.0%) were dry blended with potato flakes prior to extrusion in a Werner-Pfleiderer corotating twin screw extruder Model ZSK-30 (Ramsey, NJ) under a specific set of conditions (screw speed, 200 rpm; mass flow rate, 10.5 kg/hr; feed moisture, 15%; barrel temperature profile, 38-38-116-116-138$spcirc$C; and circular die, 9.7 mm length x 4 mm ID).;Product moisture was significantly reduced by the 0.25 and 1.0% dl-methionine, and 0.50% benzyl disulfide treatments when compared to the control. Cysteine and dl-methionine significantly increased lightness of the products. Dl-methionine (0.25 and 1.0%) and cysteine (0.50%) treatments resulted in significant lower bulk density of the extrudates as compared with the control.;Two pyrazines and two thiazoles were identified from the extrusion of potato flakes with added methionine and thiamin respectively. The thiazoles may be formed due to thermal degradation of thiamin. The descriptive flavor profile developed by the trained panelists included 6 major sensory attributes (toasted, vinegary, sulfur, bitterness, ricey, starchy). Methionine and cysteine treatments had higher sulfur scores than other treatments. There was no significant difference in ricey and toasted notes among treatments. Overall, control and thiamin added potato snack type products had similar but stronger flavor profiles comparing to the other products.;This study confirms the utilization of extrusion cooking in combination with sulfurous flavor precursors in changing the sensory flavor profile of food systems. |
