Screening of Yoghurt Produced by Local Strains of Lactic Acid Bacteria Isolated from Locally Fermented Yoghurt “Kindirmo” For Flavour Compounds

Abstract

Study’s Novelty/Excerpt

• This study presents comprehensive screening of local strains of lactic acid bacteria (LAB) isolated from "Kindirmo" for their potential to produce flavor-enhancing compounds in yoghurt.
• The research uniquely identifies specific LAB strains, such as Leuconostoc mesenteroides dextranicum and Lactobacillus acidophilus, and demonstrates their capacity to produce a variety of volatile flavor compounds using GC–MS analysis.
• The findings suggest the potential application of these isolates in improving the taste of "Kindirmo" and other food products, thereby contributing valuable insights to the field of food microbiology and fermentation.

Full Abstract

Yoghurt is known as cultured milk which is derived from the action of bacteria on lactose to produce lactic acid, carbon dioxide (CO₂₎, acetic acid, diacetyl, acetaldehyde, and other flavor compounds. The aim of this research was to screen yoghurt produced by local strains of lactic acid bacteria isolated from locally fermented yoghurt “Kindirmo” for the production of flavor-enhancing compounds. A total of five “Kindirmo” samples were collected from two farmhouses located in Daura local government of Katsina State, Nigeria. The samples were collected and transported in ice containers. Serial dilutions of the “Kindirmo” samples were made and plated using the pour-plate method on de Man, Rogosa, and Sharpe (MRS) agar and incubated anaerobically at 37°C for 72 hours, followed by bacterial identification using Vitek system. Thereafter, yoghurt was produced using the isolated lactic acid bacteria and volatile flavor compounds in the yoghurt were determined using GC–MS analysis. Out of all the five (5) samples analyzed, only two (2) were positive for Lactic acid bacteria. The lactic acid bacteria identified were leuconostoc mesenteroides dextranicum and Lactobacillus acidophilus. While Lactobacillus acidophilus produced 14 volatile flavor compounds, leuconostoc mesenteroides dextranicum produced only 12. Butanoic acid, Hexanoic acid, Acetaldehyde, Propane, Acetone, ethyl ester, Lactic acid, and Diacetone were some of the flavor compounds detected. The research shows the potentials of the isolated LAB to produce flavor compounds, which could be used to enhance the taste of Kindirmo. It is recommended that the isolates should be used for further study on how to produce Kindirmo with single and co-culture of the LAB, or rather on how to produce the flavor enhancers for application in other foods or food products.