Evaluation of konjac blends, soy protein isolate and lean muscle as fat replacements in low-fat meat batters

The objective of this study was to evaluate low-fat bologna (LFB) treatments formulated with konjac blend (KB) types and levels, soy protein isolate (SPI) levels and moisture:protein (M:P) ratios of meat batter to determine the best combination with characteristics similar to control bologna (30% fat). Low-fat bologna model systems (LFBMS) were formulated with dry form of 0.5% or 1.0% KBs and a M:P ratio of 6.0 had textural characteristics similar to the control. The chemical composition of LFBMS with a 6.0 M:P ratio was approximately 78% moisture, 14% protein and Actual bologna manufactured in a pilot plant had similar trends with the model system except for cooking yield. Overall, no differences in sensory properties and Instron TPA values were observed when 2% SPI was added to LFB formulations except for a few cases. Sensory evaluation indicated that 1.0% KBs reduced pepper, spice (aftertaste) and salt taste resulting in sensory flavor scores similar to the control, whereas KSS had textural characteristics similar to the control, regardless of KB level and addition of SPI. The 1.0% KB level in combination with 2% SPI had characteristics similar to the control, based on TPA values and sensory flavor tests. The addition of KBs and replacement of meat protein with 2% SPI reduced the formulation cost by only 10 to 15% above that of the regular bologna and also resulted in a lower cost than the low-fat control.Sodium dodecyl gel electrophoresis (SDS-PAGE) showed the general profile of salt soluble protein fractions in LFB as affected by cooking, level and type of KBs, and SPI level, as compared to the control. Scanning electron microscopy (SEM) revealed the three dimensional relationship of various components such as protein, fat and polysaccharides in low-fat bologna.