Microfiltration and ultra-high-pressure homogenization for extending the shelf-storage stability of UHT milk

Abstract

Fat separation, gelation or sedimentation of UHT milk during shelf-storage represent instability phenomena causing the product rejection by consumers. Stability of UHT milk is of increasing concern because access to emerging markets currently implies for this product to be stable during shipping and prolonged storage, up to 12 months. The role of microfiltration prior to UHT process in avoiding or retarding the gelation or sediment formation was studied by comparing microfiltered UHT milk to conventional UHT milk. A second trial was set up to study the effects of double ultra-high pressure homogenization in delaying the cream rising and UHT milk homogenized once at lower pressure was taken as control. All milk samples were produced at industrial plant level. Milk packages were stored at 22 °C, opened monthly for visually inspecting the presence of cream layer, gel or sediment and then analysed. Microfiltration markedly delayed the formation of both gel particles and sediment, with respect to the control, and slowed down the proteolysis in terms of accumulation of peptides although no correlation was observed between the two phenomena. The double homogenization, also evaluated at ultra-structural level, narrowed the fat globule distribution and the second one (400 MPa), performed downstream to the sterilization step, disrupted the fat-protein aggregates produced in the first one (250 MPa). The adopted conditions avoided the appearance of the cream layer in the UHT milk up to 18 months. This study contributes important knowledge for developing strategies to delay instability phenomena in UHT milk destined to extremely long shelf storage.

Microfiltration membrane processes: A review of research trends over the past decade

“…This is followed closely by the food industry where MF membranes are utilized on a large scale for effective removal of bacteria from food products. For example, an important industrial food application is milk filtration whereby many different kinds of milk have been reported to undergo MF for the removal of spores [21] , bacteria [22] and retarding of gelatin and sediment formation in ultra-high temperature milk [23]. Owing to MF membranes' capacity to reject a variety of large scale contaminants, the desalination industry has been utilizing MF process as a pretreatment step prior to NF or RO for a considerable period of time [2].…”

The free listing task for describing the sensory profiling of dairy foods: A case study with microfiltered goat whey orange juice beverage

“…Microfiltration has been applied to milk aiming the development of dairy products, such as whey beverages (Vieira et al, 2020), yogurts with high-protein content (Jørgensen, Abrahamsen, Rukke, Johansen, & Skeie, 2017), cheeses (Chamberland et al, 2019), and UHT milk (D'Incecco, Rosi, Cabassi, Hogenboom, & Pellegrino, 2018).…”

Effect of Homogenization Pressure on Plasmin Activity and Mechanical Stress-Induced Fat Aggregation of Commercially Sterilized Ultra High Temperature Milk during Storage

“…Consumer claims regarding fat aggregation amounted to about 12% (24 cases) of the total number of the milk-related consumer claims (214 cases) of one major company in 2019. Thus, protein proteolysis and subsequent gelation, and cream layer formation during storage are closely related to the quality of commercially sterilized UHT milk ( D’Incecco et al., 2018 ).…”