Masters Theses

Date of Award

8-1990

Degree Type

Thesis

Degree Name

Master of Science

Major

Food Science and Technology

Major Professor

H. Dwight Loveday

Committee Members

S.L. Melton, M.P. Penfield, M.J. Riemann

Abstract

The push for convenience in our society has forced the meat industry to develop precooked, ready-to-serve entrees. The impact of cooking method on the quality of such a product was the subject of this study. Impingement cookery was evaluated as a method to precook and reheat beef top loin steaks. Boneless beef strip loins were sliced into 2.5 cm steaks that were precooked to an internal temperature of approximately 60°C in an impingement oven or rotary oven. The steaks were cryogenically chilled to 1°-4°C, vacuum packaged and stored for 9 da in darkness at 1.5°C. The steaks were transferred to a retail display at 4°C under fluorescent light for 3 da. The steaks were reheated to approximately 45°C using one of four methods: impingement oven, microwave oven, convection oven or conventional oven broiler. Precooking and reheating yields and storage losses were calculated and surface Hunter color "L", "a" and "b" values were determined. A puncture probe attached to an Instron Universal Testing Machine was used to determine mechanical parameters of hardness, cohesiveness and chewiness. Warner-Bratzler shear force values were also determined. Chemical analyses on the reheated steaks included chemical moisture and lipid and TBA analysis. A 12- member oriented sensory panel evaluated the steaks on the basis of external surface color, internal doneness, softness to tooth pressure, chewiness, moisture release, warmed-over flavor and overall acceptability.

Impingement-precooked steaks had higher precooking and reheating yields and storage losses than the rotary-precooked steaks. They also had lower Instron hardness and higher cohesiveness values as weU as lower Warner-Bratzler shear force values. Sensory panelists found the impingement-precooked steaks to be lighter in surface color, less weU done in internal doneness, softer, moister and less chewy, with less warmed-over flavor than the rotary-precooked steaks. They also found the impingement-precooked steaks to be more acceptable.

Impingement reheating resulted in greater reheating yields than oven broiling as well as higher Hunter "L" values than convection, oven broiler and microwave reheating. Sensory panelists found the impingement-reheated steaks to be darker in external surface color than the oven broiler and microwave-reheated steaks.

Interactions were observed for sensory internal doneness, chewiness, moisture release, external color, warmed-over flavor and overall acceptability. An interaction was also detected for Instron hardness.

Download
Files over 3MB may be slow to open. For best results, right-click and select "save as..."

Share

COinS