Ultrasonication as a novel processing alternative to pasteurization for camel milk: Effects on microbial load, protein profile, and bioactive properties

Abstract

Ultrasonic technology presents a promising novel tool in the food industry for the processing of milk and dairy products. In this study, we investigated the effects of ultrasonication (US) as an alternative to thermal pasteurization for stabilization of the bioactive properties of camel milk. Camel and bovine milk samples were subjected to US at 6 different power levels (US1-US6), and 1 set of each type of milk was concurrently subjected to flash heat pasteurization (FHP) for comparative analysis (100 mL; n = 4). The microbiological and bioactive parameters of the samples were analyzed during 7 d of storage at 4°C. In both milk types subjected to US ≥ 140 W (US3), the bacterial load was reduced by almost 4 log cycles and complete reduction of microbial load was achieved with US = 170 W and US = 210 W (US5 and US6 treatments, respectively). No significant changes in protein patterns were observed with either FHP or US treatment. In addition, bioactive properties (cholesteryl esterase and pancreatic lipase inhibition) were either enhanced or retained at US3 or higher. 2,2′-Azino-bis-3-ethylbenzthiazoline-6-sulfonic acid and ferric reducing antioxidant power activities in camel milk were decreased after FHP treatment but increased or retained upon US, particularly at US3 and US4 (160 W). Overall, under our experimental conditions, US4 was effective in completely reducing the microbial count, while concomitantly retaining different bioactive properties of both camel and bovine milk. These outcomes highlight the potential of US at 160 W as an efficient nonthermal alternative processing method for milk.

Current progress of emerging technologies in human and animals’ milk processing: Retention of immune‐active components and microbial safety

“…In addition, Dhahir et al (2020a) investigated the effects of US on the milk-borne microorganisms (E. coli O157: H7 and S. Typhimurium) and several components in camel milk and found that US treatment for 15 min significantly reduced the microbial load of these two bacteria, and US did not show detrimental effects on the composition of fatty acids, lipid peroxides, and protein fractions. Recently, Mudgil et al (2022) investigated the influences of US treatments on microbial load, protein compositions, and bioactive properties of camel milk and reported that US at >160 W for 10 min could realize a microbial safety for public consumption without affecting its bioactive properties, such as antioxidative capacity and cholesterol esterase inhibition.…”

“…Recently, Mudgil et al. (2022) investigated the influences of US treatments on microbial load, protein compositions, and bioactive properties of camel milk and reported that US at >160 W for 10 min could realize a microbial safety for public consumption without affecting its bioactive properties, such as antioxidative capacity and cholesterol esterase inhibition.…”