Author(s)

Dakalo Dashe¹, Egon Bech Hansen², Mohammed Yusuf Kurtu¹, Tesfemariam Berhe¹, Mitiku Eshetu¹, Yonas Hailu¹, Amsalu Waktola¹, Adane Shegaw¹

¹School of Animal and Range Sciences, Haramaya University, Dire Dawa, Ethiopia.
²Division for Diet, Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, Kgs. Lyngby, Den-mark.

This study was conducted to investigate the effect of lactic acid bacteria (LAB) activated lactoperoxidase system (LPs) on keeping quality of raw camel milk at room temperature. Camel milk samples were collected from Errer valley, Babile district of eastern Ethiopia. The level of hydrogen peroxide (H₂O₂) for activation of LPs was optimized using different levels of exogenous H₂O₂. Strains of LAB (Lactococcus lactis 22333, Weissella confusa 22308, W. confusa 22282, W. confusa 22296, S. Infatarius 22279 and S. lutetiensis 22319) with H₂O₂ producing properties were evaluated, and W. confusa 22282 was selected as the best strain to produce H₂O₂. Storage stability of the milk samples was evaluated through the acidification curves, titratable acidity (TA), total bacterial count (TBC) and coliform counts (CC) at storage times of 0, 6, 12, 18, 24 and 48 hours. The LP activity and the inhibitory effect of activated LPs were evaluated by growing E. coli in pasteurized and boiled camel milk samples as contaminating agent. Results indicated that the W. confusa 22282 activated LPs generally showed significantly (P < 0.05) slower rates of acidification, lactic acid production and lower TBC and CC during the storage time compared to the non-activated sample. The H₂O₂ producing LAB and exogenous H₂O₂ activated LPs in pasteurized camel milk significantly reduced the growth of E. coli population compared to non-activated pasteurized milk. Overall, the result of acid production and microbial analysis indicated that the activation of LPs by H₂O₂ producing LAB (i.e.  W. confusa 22282) maintained the storage stability of raw camel milk. Therefore, it can be concluded that the activation of LPs by biological method using H₂O₂ producing LAB can substitute the chemical activation method of LPs in camel milk.

Camel Milk, Lactoperoxidase System, Lactic Acid Bacteria, Preservation

Dashe, D. , Bech Hansen, E. , Yusuf Kurtu, M. , Berhe, T. , Eshetu, M. , Hailu, Y. , Waktola, A. and Shegaw, A. (2020) Preservation of Raw Camel Milk by Lactoperoxidase System Using Hydrogen Peroxide Producing Lactic Acid Bacteria. Open Journal of Animal Sciences, 10, 387-401. doi: 10.4236/ojas.2020.103024.