14A-30

W. G. MCGLYNN¹, P. G. Crandall², and E. A. de Feliz². (1) Food and Agricultural Products Center, Oklahoma State University, 112 FAPC, Stillwater, OK 74078-6055, (2) Department of Food Science, University of Arkansas, 272 Young Avenue, Fayetteville, AR 72704

Large containers for thermal processing of food offer several advantages attractive to food service operations, including greater unit volume and more efficient storage and handling. To prove the feasibility of such containers, we constructed two prototypes of nickel-plated steel with volumes of about 11 liters. Container dimensions were specified to maximize surface area to volume. A Large Diameter Small Height (LDSH) container had internal dimensions of about 470mm x 140 mm while a Small Diameter Large Height (SDLH) container was about 140mm x 806mm. Previous research showed maximum calculated process times of 21 minutes for green beans to reach an Fo of 6.0 and 45 minutes for pinto beans to reach an Fo value of 8.0 at 121.1°C in a still retort. This study examined use of an agitating retort to reduce process times. The effect of reduced times and agitation on retention of nutritive and quality values was also examined. Heat penetration test results indicate that agitation reduces process times by about 30% for green beans and pinto beans. Protein denaturation analyses conducted using the Coomassie Blue G Dye Binding test showed that the average concentrations of soluble proteins for fresh, SDLH, and LDSH processed green beans were 0.684, 0.673, and 0.714 mg/ml respectively. This suggests that there is no appreciable denaturation of protein in the green beans when processed in the large containers. Puncture strengths and peak shear force readings were obtained for the green beans. Average puncture strengths were 0.980 newtons for beans processed in the SDLH container and 0.555 newtons for those in the LDSH container. Peak shear force readings were 110 and 102 pounds the SDLH and LDSH containers respectively. These results further validate the feasibility of the large containers and demonstrate that agitation during processing minimizes nutrient and quality losses as well as process times.