Effect of Cold Storage on the Rheological Characteristics of Dry Beans Yogurt

摘要

Background and Objective: In addition to being rich sources of several macro and micronutrients, the dry bean is a rich source of dietary fiber and oligosaccharides which could serve as non-dairy based substrates to produce yogurt. The aim of this research was to determine the effects of storage (4EC) on color and the rheological properties of legume yogurts. Materials and Methods: Milk was prepared from Kidney Beans (KB), Garbanzo Beans (GB) and Soybeans (SB), which served as control was pasteurized and inoculated with a combination of Streptococcus thermophilus and Lactobacillus delbrueckii subspecies bulgaricus and incubated at 42EC for 4.5 hrs or until the pH reached 4.6. Following fermentation, the yogurt was stored at 4EC for up to 28 days. The pH/acidity, color, viscosity, oscillatory and flow frequency as well as thixotropic measurements were determined weekly during storage of the yogurts. Results: Results indicated no significant change in pH during storage. No significant changes in color were noted during storage for both GB and KB yogurts. Results indicated significant (p0.05) changes in the flow behavior index in the control compared to KB and GB yogurt. Even though apparent viscosity (Pa sG1 ) in all yogurts was increased with storage, viscosity was significantly (p0.05) increased in KB and GB yogurts compared to control (SB) yogurt. The study indicated that storage impacted the viscoelastic and apparent viscosity properties of the legume yogurt. Conclusion: Overall, these results indicate KB and GB yogurt demonstrate promise as a potential nondairy-based probiotic product. The utilization of legume crops for such products will offer opportunities for the food industry, in terms of value addition to the development of novel functional foods.