Gary A. Sullivan

Application of exogenous enzymes to beef muscle of high and low-connective tissue.

Exogenous enzymes tenderize meat through proteolysis. Triceps brachii and Supraspinatus were randomly assigned to the seven enzyme treatments, papain, ficin, bromelain, homogenized fresh ginger, Bacillus subtilis protease, and two Aspergillus oryzae proteases or control to determine the extent of tenderization (Warner-Bratzler shear and sensory evaluation) and mode of action (myofibrillar or collagen degradation). Sensory evaluation showed improvement (P<0.0009) for tenderness and connective tissue component and all except ginger had a lower shear force than the control (P<0.003). Ginger produced more off-flavor than all other treatments (P<0.0001). Only papain increased soluble collagen (P<0.0001). Control samples were only significantly less than ficin for water soluble (P=0.0002) and A. oryzae concentrate for salt soluble proteins (P=0.0148). All enzyme treatments can increase tenderness via myofibrillar and collagenous protein degradation with no difference among high and low-connective tissue muscles.

Effects of conventional and alternative curing methods on processed turkey quality traits

Deli-style turkey breast cured with pre-converted celery juice powder (CP) or sodium nitrite (SN) was manufactured with ingoing SN concentrations or equivalent of 0, 50, 100, 150, and 200 ppm. Cured and total meat pigment, salt, and water activity were measured on d 0; color, pH, and residual nitrite were measured on d 0, 7, 14, 21, 28, 35, and 42. Untrained panelists evaluated sensory traits of 50, 100, 150, and 200 ppm products. The interaction of nitrite concentration and source affected (P≤0.05) b*, pH, and residual nitrite values. Less ingoing nitrite and increased storage resulted in less (P≤0.05) residual nitrite in products. Sensory results suggested products made with 200 ppm nitrite from CP were less acceptable. Overall, CP and SN products were similar for several traits, but this study suggests that the inclusion of ingoing nitrite from CP may be limited to 100 ppm nitrite (0.46% addition) for acceptable deli-style turkey breast.

Influence of sodium chloride reduction and replacement with potassium chloride based salts on the sensory and physico-chemical characteristics of pork sausage patties

This study evaluated the effects of sodium chloride reduction and replacement with potassium chloride or modified potassium chloride based salts using a weight or molar equivalent basis on the sensory and physico-chemical properties of pork sausage patties. Three independent replications of pork sausage patties were manufactured to compare five treatments: full sodium, reduced sodium, modified potassium chloride weight based replacement, modified potassium chloride molar based replacement, and standard potassium chloride weight based replacement. Salt replacement did not affect (P>0.05) moisture, protein, fat, textural properties, lipid oxidation, or redness. Sausage patties with modified potassium chloride were more acceptable than those with standard potassium chloride (P<0.001). Using modified potassium chloride replaced on a molar equivalent basis resulted in samples with more similar sensory characteristics to the full sodium control than replacement on a weight equivalent basis. The use of modified potassium chloride reduced sodium and improved sodium:potassium ratios while other changes in composition or physico-chemical characteristics were minimal.

Effect of Differing Ingredients and Packaging Technologies on the Color of High-Pressure Processed Ground Beef

High-pressure processing (HPP) is a nonthermal pasteurization technique to control pathogens, like Escherichia coli. However, color changes in raw beef induced by HPP restrict its use within the beef industry. The objectives of this study were to investigate the effects of adding curing agents (nitrite) and packaging with or without reducing compounds (ascorbic acid/erythorbate) on color retention in high-pressure processed ground beef. Color was measured (CIE L a b ) before HPP and on days 3, 7, 12, 14, 19, and 21 after HPP. Statistical analysis (SAS GLIMMIX) was run to identify the main effects of adding curing agents, packaging, and reducing agents on color retention. HPP resulted in a detrimental effect on the color of the beef patties for all treatments. Lightness and yellowness increased ( ) and redness decreased ( ) after high-pressure processing. The effect remained the same throughout the course of the study. However, there were less color changes in samples treated with reducing compounds. Both synthetic and natural sources of nitrite and ascorbic acid/erythorbate performed similarly in terms of their ability to maintain redness. Treatments leading to formation of nitrosylmetmyoglobin (Fe3+) had less severe color change compared to the treatments leading to the generation of nitrosylmyoglobin (Fe2+).