Two studies were conducted to evaluate the effects of milk solids on restructured and emulsified turkey rolls. the milk solids used were nonfat dry milk (NFDM), whey protein concentrate (WPC), and calcium caseinate (CC). Turkey rolls consisted of 100% breast meat or 90:10 or 70:30 breast-to-thigh, salt (1%), water (10%), internal or cluster fat (10%), and 3% of various milk solids (WPC, NFDM, CC). The objectives of these studies were to 1) determine which ratio between light and dark meat is preferred; 2) determine which of milk solids evaluated will permit the highest level of dark meat incorporation into evaluated products; 3) determine if there is a mechanism by which milk proteins lighten poultry meat; and 4) determine which milk protein produces the best bind between meat pieces. Panelists were used in the first study to evaluate cooked meat attributes of color intensity, color uniformity, cohesiveness, tenderness, roasted turkey flavor, juiciness, and overall acceptability. The attributes were rated on a seven-point scale. Rolls made with WPC or NFDM scored significantly higher for color uniformity, cohesiveness, roasted turkey flavor, and overall acceptability than rolls made with CC. No differences were noted among treatments for juiciness or toughness with rolls of the same light-to-dark meat ratio. However, the 90:10 rolls were rated significantly more tender than the rolls made with the 70:30 ratio. Rolls containing milk solids had significantly higher yields than the controls. In the second study, rolls were made using the preferred meat ratio (90:10 breast:thigh meat). NFDM and WPC were used as binders, but not CC, since in the first study it was an ineffective binding agent. The second study showed that no whitening or lightening occurred in turkey rolls. This researcher also found that both NFDM and WPC increased bind strength between meat pieces. Controls made without added milk solids had less bind strength between the meat particles. Meat particle size also affected bind strength in finished products, with finely chopped rolls having higher bind strength than coarsely ground rolls. Moreover, the second study had unexpected results indicating that NFDM will prevent development of pink discoloration during refrigerated storage. The penetrometer used for bind measurements is described.

A pink color defect is commonly observed in freshly cut surfaces of cooked turkey rolls and fades rapidly upon exposure to air. The non uniform pink color makes the product appear undercooked, and the product must be discounted. The oxidation-reduction potential of the meat is important in development of pink defect. A pink color similar to that of commercial product was observed when the cooked meat was treated with either sodium nitrite or sodium dithionite. The pink color in nitrite treated meat was due to nitroso pigment formation, but in samples treated with dithionite the pink color was due to formation of a hemochrome complex. Pink color was also observed in turkey rolls formulated with nicotinic acid, nicotinamide or sodium nitrite. Reflectance and absorbance spectrophotometric studies on commercial or laboratory prepared samples having pink defect showed that the responsible pigment was a reduced hemochrome rather than a nitroso pigment. The hemochrome is probably a nicotinamide-denatured globin complex with ferrous iron of the heme molecule. Oxidation-reduction potential measurement of meat systems showed that hemochrome formation is promoted by reducing conditions and prevented by oxidizing conditions. All constituents necessary for formation of pink defect are present in turkey meat, the variable most affecting its appearance being the redox potential of the meat.

Processed turkey rolls were prepared with 1 or 3% whey protein concentrates WPC-50 (pH=5.80), WPC-60 (pH=4.53) and WPC-75 (pH=6.85} containing 50, 60 and 75% protein along with controls (phosphate and no phosphate). Control rolls made with 0.5% phosphate had the highest bind strength, and sensory evaluation scores. Only WPC-75 (1%) was acceptable as a binding agent and flavor enhancer. WPC-60 reduced pink discoloration of rolls, but flavor, bind and cohesiveness scores were unacceptably low. WPC-50 was not an effective binding agent. In general, rolls made with 3% WPC had lower scores for intensity of turkey flavor. Bind strength and sensory characteristics were compared for restructured beef rolls formulated with 1% salt, 0.375% sodium tripolyphosphate (STPP) or O. 07 % sodium hydroxide (NaOH), and 5, 10 or 20% added water. Controls also had 1% salt, but no STPP or NaOH. Relative bind strength of rolls was STPP > NaOH > controls. Addition of 20% water reduced bind strength. Cooked yield, moisture content, beef flavor and texture of NaOH rolls were similar to STPP rolls. Bind strength and cohesiveness of NaOH rolls were lower than STPP rolls, but still acceptable. For measuring bind strength of turkey and beef rolls, a sensitive and inexpensive penetrometer was developed. It was equipped with a top-loading balance, accessories, IBM-compatible personal computer and Quick-Basic program that allowed continuously collected penetration force data . at specific time intervals. Penetrometer bind strength and taste panel cohesiveness of turkey and beef rolls were highly correlated (r=0.89 and r=0.93, respectively).