Abstract
Worldwide, tremendous amounts of food, including milk and dairy products, are lost or wasted. Although refrigeration permits longer storage of raw milk, low temperatures still do not prevent the action of other abiotic and biotic factors that promote biochemical, chemical, microbial, sensorial and nutritional changes in raw milk, which also affect milk-derived dairy products. Treatment by N2 gas flushing showed great potential in preserving the microbiological quality of raw milk during storage at low and milder temperatures. Here, we examined the impact of cold storage (at 6°C up to 7 days), on the ascorbic acid content, extent of auto-oxidation, and on levels of lipolysis and proteolysis along with bacterial growth, in three raw milk samples in the presence or absence of N2. When N2 gas was applied, lower levels of lipolysis and proteolysis were found to coincide with the detection of lower numbers of bacterial lipase and protease producers in raw milk. Furthermore, lower auto-oxidation was detected in N2-treated samples than in only cold stored controls. By demonstrating that key components of milk were better preserved during cold storage, the present study further highlights the advantages of the N2 flushing treatment in terms of preserving the quality and safety of raw milk and its derived dairy products.
Highlights
The Food and Agriculture Organization (FAO) estimates that globally one third of the food produced annually for human consumption is lost or wasted
During cold-storage, “total bacterial counts” and psychrotrophs increased in the controls (C3 and C7) for all samples (M1–M3)
After 7 days, practically all bacterial colonies were protease-positive in C7
Summary
The Food and Agriculture Organization (FAO) estimates that globally one third of the food produced annually for human consumption is lost or wasted. In Europe, the annual dairy product wastage and loss amounts to 29 × 106 t (FAO, 2012). These enormous losses contribute to major resource squandering with a proportionately negative impact on the environment. Despite the implementation of specific processing steps in existing high-tech food systems, spoilage due to microbial growth and concomitant biochemical activities remains significant as not all risks can be eradicated. This is due to the fact that microbes, especially bacteria, have remarkable adaptation properties (Angelidis et al, 2002; Jay et al, 2005; Burgess et al, 2016). Bovine milk, which comprises 4.6% carbohydrates, 4.1% lipids, 3.3% proteins, vitamins and minerals, is an
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
