THE EFFECT OF SEED TEMPERING AND MICRONIZATION TEMPERATURE ON THE PHYSICOCHEMICAL PROPERTIES OF CHICKPEA FLOUR AND ITS PERFORMANCE AS A BINDER IN LOW-FAT PORK BOLOGNA

The overall goal of this research was to investigate the effect of seed tempering moisture and micronization temperature on the physicochemical properties of chickpea flour and its subsequent performance as a binder in a model low-fat pork bologna product. This work was divided into three studies. In the first study, the effect of seed tempering moisture (untempered (7% moisture) or tempered to 15 or 22% moisture) and surface micronization temperature (115, 130, 150 or 165oC) and on the physical, chemical and functional properties of chickpea flour were investigated. Chickpea flour became darker as seed moisture or micronization temperature increased. Increasing the micronization temperature at 22% seed moisture increased starch gelatinization from 8.2 to 34.0%. The lipoxygenase activity of chickpea flour also was reduced by micronization of seed. Lipoxygenase activity in flour from non-micronized seed and flour from seed micronized at 115oC without tempering was determined to be 1.98×105 and 1.12×105 units/g of protein, respectively, with no activity found in any other treatments. There was an increase in the water holding (WHC) and oil absorption capacity (OAC) of flour when chickpea seed was tempered to 22% moisture before micronization. Flour from untempered seed and from seed tempered to 15% moisture exhibited small increases in WHC as micronization temperature increased. Micronization had no effect on the OAC of untempered flours, whereas OAC decreased in flour from seed tempered to 15% moisture at higher micronization temperatures. Rapid visco-analysis (RVA) revealed that peak viscosity and final viscosity of all flours from tempered seed decreased with increasing micronization temperature, whereas the trend for both peak viscosity and final viscosity was in the opposite direction with untempered seed. The effect of seed tempering moisture and micronization temperature on the performance of chickpea flour as a binder in a low-fat, comminuted meat product (i.e., low-fat bologna) was investigated in study 2. Both the textural and sensory properties (trained sensory panel, n=12) of the bologna (10% fat) were explored. In study 3, a consumer panel was performed with 101 untrained participants evaluating selected formulations in order to better understand consumer purchasing behaviour as it relates to comminuted meat products containing a pulse-based binder. Bologna containing flour from micronized chickpea was more yellow in colour (CIE system, trained panel and consumer panel evaluation) compared to those with added wheat flour or no binder. There was no effect of tempering or micronization conditions on cook loss or expressible moisture of bologna containing chickpea flour, whereas bologna produced with wheat flour had the greatest WHC among all bologna treatments. Texture profile analysis (TPA) showed that the addition of chickpea flour from seed tempered to 15% or 22% seed moisture and micronized to 115, 130 or 150oC or flour from untempered seed micronized to 130 or 150oC led to an increase in hardness to a level similar to that of bologna containing wheat flour; sensory evaluation by the trained panel did not produce a similar result. A difference in flavour intensity was not found among all bolognas containing chickpea flour during sensory evaluation. Bologna produced with chickpea flour from seed micronized to 150oC and from seed tempered to 22% moisture and micronized to 115oC was comparable to bologna containing wheat flour with respect to overall texture, overall juiciness and flavour acceptability. These results demonstrated that selection of appropriate seed tempering conditions and micronization temperatures is important with respect to the utilization of chickpea flour as a binder in low-fat bologna