Qualitative effects of fresh and dried plum ingredients on vacuum-packaged, sliced hams.

Boneless ham muscles (Semimembranosus+Adductor) were injected (20% w/w) with a curing brine containing no plum ingredient (control), fresh plum juice concentrate (FP), dried plum juice concentrate (DP), or spray dried plum powder (PP) at 2.5% or 5%. Hams were cooked, vacuum-packaged, stored at<4°C and evaluated at 2-week intervals over 10 week. Evaluations were performed on sliced product to determine cook loss, vacuum-package purge, Allo-Kramer shear force, 2-thiobarbituric acid-reactive substances (TBARS), proximate analysis, objective color, sensory panel color and sensory attributes. FP, DP and 2.5% PP increased (P<0.05) cook loss by 2% to 7% depending on treatment and level, but the highest cook loss (17.7%) was observed in hams with 5% PP. Shear force values increased as the level of plum ingredient increased (P<0.05) from 2.5% to 5%, and the highest shear values were observed in hams containing 5% FP. There were no differences (P>0.05) in lipid oxidation among treatments as determined by TBARS and sensory evaluation. FP and PP ham color was similar to the control, but DP had a more intense atypical color of cured ham. Minimal changes in physical, chemical and sensory properties were observed during storage of all treatments.

Biomechanical and microbiological changes in natural hog casings treated with ozone.

The objective of this study was to determine the biomechanical and microbiological effects of exposing natural hog casings to ozonated water ≈7mg/l for 0, 2 or 4h at 16°C. A total of 450 casing segments representing 10 hanks were used over five testing days and arranged in a randomized block split-plot design. For each treatment, pH, temperature, actual ozone concentration, bursting strength, maximum rupture force, and L(∗), a(∗) and b(∗) color space values were determined. The bursting strength and the maximum rupture force values suggested that casings can be treated by ozone up to 2h without deterioration. After ozone treatments, changes in L(∗), a(∗) and b(∗) color space values made the casings appear lighter than the control samples. Microbiological studies showed that 1 and 2h ozonation reduced counts of Escherichia coli biotype I, which expressed green fluorescent protein, by 0.4 and 0.6log(10)CFU/25.4cm casing, respectively.

Antioxidant properties of plum concentrates and powder in precooked roast beef to reduce lipid oxidation.

Boneless beef roasts (Semimembranosus+Adductor) were injected (20%) with a brine containing (1) no plum ingredient (control), (2) 2.5 or 5% fresh plum juice concentrate (FP), (3) 2.5 or 5% dried plum juice concentrate (DP), or (4) 2.5 or 5% spray dried plum powder (PP). Whole roasts were cooked, vacuum-packaged and stored at <4.0°C for 10wk. At 2wk intervals, evaluations were performed on sliced product to determine vacuum-packaged purge, Allo-Kramer shear force, lipid oxidation (TBARS), color space values, and sensory attributes. All plum ingredients reduced TBARS values and had minimal effects on tenderness, sensory characteristics, color and appearance. Small changes in purge, color values, TBARS and some sensory properties were found during storage. These results indicate that 2.5% FP or DP could be incorporated into precooked beef roasts to reduce lipid oxidation and potentially, warmed-over flavor (WOF).