Effect of Cholesterol Reduction on Goat Milk Yoghurt Components by Cyclodextrin from Different Carbon Sources and Bacillus spp

Aims: To produce Cyclodextrin from three CGTase producing Bacillus species (BI, B2, B3) and different starch sources, cassava varieties (30572, 419, and umu 37), sweet potato root (x-igbariam), cocoyam (edeuhie and NXS003). To treat Goat milk yoghurt with two different level of cyclodextrine (0.3% and 0.5%). To determine its cholesterol reducing effect during 6days refrigerated storage and to ascertain the effect on other yoghurt components.

Study Design: Multifactor randomized complete block design (RCBD) was used for this study. Each experiment was repeated in duplicate. Data obtained were subjected to analysis of variance (ANOVA) at the significant level of 5% (p≤ .05) using SPSS 20.

Place and Duration of Study: Department of Food Science and Technology, Michael Okpara University of Agriculture, Umudike, between May 2015 and october 2016.

Methodology: A Total of 37 yoghurt samples were formulated from 6 samples of starch, 3 samples of CGTase source and two (2) levels of cyclodextrin. total cholesterol, Fat, Protein, reducing sugar and total soluble solid content of cyclodextrin treated goat milk yoghurt were determined,

Results: During 6 days refrigerated storage, the cholesterol content of goat milk yoghurt decreased (p≤ .05) as a result of cyclodextrin treatment from 3.9 mg/ml (control) to 1.67 ml/ml (NXS 205) in cocoyam, 1.10 mg/ml (419-205) in cassava starch source and 1.52 mg/ml (pot 105) for sweet potato starch. Cyclodextrin from B. licheniformis and cassava starch (419) at 0.3 level was best in terms of cholesterol reduction. Cyclodetrin treatment also led to significant (p≤ .05) decrease in fat, protein, reducing sugar and total soluble solid content of goat milk yoghurt. Cholesterol reductions were not significantly affected at p≤ .05 by percentage of cyclodextrin.

Conclusion: The results showed that all cyclodextrins was effective in reduction of cholesterol in goat milk yoghurt. Cyclodextrin from cassava starch 419 and B. licheniformis at 0.3% level (419-303 = 1.10 mg) resulted in a goat milk yoghurt with lowest level of cholesterol among all the samples analysed. As the storage period progressed, the cholesterol levels also reduced as a result of cyclodextrin treatment. There was a direct relationship between increase in cyclodextrin and decreasing level of fat, protein, reducing sugar and total soluble solid of cyclodextrin treated goat milk yoghurt.