Hydration properties and novel processing to produce whole pea snack food

Hydration and nutritional properties of peas, as well as different processing methods to produce a whole pea snack food were investigated in this study. Different varieties of peas from different locations grown in 2005 and 2006 were evaluated for hydration properties including hydration capacities and imbibing rates. Those varieties which absorbed water continuously to an acceptable level and contained lower levels of phytic acid and higher levels of total phenolics and antioxidant activities were subjected to two different processes: micronization and superheated steam system (SHS). The processed peas were assessed for the texture, phytic acid, phenolic acid and antioxidant levels. Results showed water absorption ability of peas was directly related to the initial moisture content and inversely related to the percent of stone seeds. The climatic, especially temperature differences, in the two years of the study influenced pea quality including hydration, antinutritional factors and antioxidant activities. Different processing conditions were explored for both micronization and superheated steam processes. Results showed the effects of tempering level and processing conditions on maximum force to break the processed seed were significantly different (P< 0.05) for all types of pea products. Pea products from SHS had significantly higher maximum force (up to 95.0 N) than the commercial peas (32.8 N) (P<0.0001) which is a pea snack fried in oil. However, the micronized peas had significant lower maximum forces at break (as low as 18.4 N) than the commercial peas (P<0.05). Micronization also decreased the phytic acid level and increased the total phenolics level. From the antioxidant activity results, micronization significantly increased the antioxidant level based on 2,2-Diphenyl-1-Picrylhydrazyl (DPPH•) analysis (P0.05). Therefore, micronization is a more effective technique than SHS to produce whole pea snacks, and adequate initial seed hydration is necessary for micronization to be effective.