Stabilization and Preservation of a Traditional Sorghum-based Fermented Beverage

Background and Objectives: Traditional fermented cereal beverages such as Obushera from sorghum and/or millet are commercialized owing to their popularity among consumers. However, Obushera separates into two phases after processing, which could be mistaken for spoilage. Additionally, Obushera has a limited shelf life of 4–7 days at room temperature. The objective of this study was to assess the potential of various stabilizers and preservatives for the production of acceptable shelf-stable Obushera. Materials and Methods: Effects of seven treatments of 1) 0.4% xanthan gum, 2) 0.4% carboxymethyl cellulose, 3) Lactobacillus rhamnosus yoba, 4) 0.4% xanthan gum and Lactobacillus rhamnosus yoba, 5) 0.4% carboxymethyl cellulose and Lactobacillus rhamnosus yoba, 6) 0.4% xanthan gum and 0.4% carboxymethyl cellulose and Lactobacillus rhamnosus yoba, and 7) a control (no stabilizers) on sedimentation rate were assessed within 120 h at room temperature. Effects of four treatments of 1) pasteurization (90 C for 10 min) and 0.25% xanthan gum, 2) pasteurization and 0.25% xanthan gum and 0.2% potassium sorbate and 3) pasteurization and 0.25% xanthan gum and 0.1% sodium-benzoate and 4) control (pasteurized with no additives) on shelf stability and consumer acceptability were investigated. Results: Treatments with xanthan (sedimentation index of 0–25%) for stabilizing Obushera were significantly (p 0.05) more effective than those with no xanthan (sedimentation index of 49–67%). Xanthan (0.25%) significantly (p 0.05) improved consumer acceptability of Obushera. All preservation treatments (p 0.05) prolonged the shelf life of the beverage up to four months. No microbial growth was detected in the products during storage while pH (3.7–4.0) and acidity (0.5–0.6%) did not change significantly (p 0.05). All products were acceptable during storage. Conclusions: Obushera and related products can be stabilized and preserved using xanthan (0.25%) and pasteurization (90 ˚C for 10 min) with no added preservatives.