Effect of storage temperature on the physiochemical properties of UHT milk

Abstract

The aim of the study was to assess the physicochemical changes occurred during storage of UHT milk for 90 days at three different temperatures i.e. 10 ˚C, 25 ˚C and 35 ˚C. pH, titrable acidity, total solids, lactose, moisture were the parameters used for physicochemical analysis. The results showed an increasing trend in titrable acidity, total solids with the passage of time. Temperature also affected the quality of UHT milk while lactose and moisture showed decreasing trend with the increase in temperature and storage period. The maximum titrable acidity (0.21%) and total solids (12.34%) were observed at 90 d of storage at 37 ˚C while lowest titrable acidity 0.11% and total solids were noticed at 0 day of storage at 10 ˚C. Significantly highest lactose (4.073 %) moisture (87.92%) and pH (6.79) was noticed at 10 ˚C during 0day storage while decline in lactose (3.53%), moisture (86.66%) and pH (6.42) was observed during 90 day of storage at 37 ˚C temperature.

Physico-Chemical Changes, Microbiological Properties, and Storage Shelf Life of Cow and Goat Milk from Industrial High-Pressure Processing

“…The pH for both HPP-treated and pasteurized cow and goat milk decreased significantly (p < 0.05) during a 22-day storage period (Figure 1). Similar results were obtained by Siddique et al [41] who reported pH declination at the end of 90 days storage of UHT milk. Brodziak et al [42] mentioned about statistically significant pH reduction of open drinking cow milk after 7 days of storage.…”

“…Brodziak et al [42] also reported increase of titratable acidity in open drinking cow milk after 7-day storage in pasteurized milk, followed by micro-filtered milk and UHT milk. The increase in titratable acidity is mainly due to increasing lactic acid concentration after degradation of lactose caused by predominant spoilage lactic acid bacteria (LAB) under low oxygen, temperature, and acidic condition [41,45]. The specific gravity of both cow and goat milk increased gradually when approaching day 22 of storage (Figure 3).…”

Effect of Milk Quality and Stabilizers on Some Physicochemical Properties of UHT-Milk

“…With increasing the storage period, there is a raise in acidity and viscosity with a decline in pH (Siddique et al, 2016). In this study, there was increasing of viscosity during storage in all samples (Fig.…”

The effects of packaging type and storage temperature on some of UHT milk quality indexes

“…The Scanning Electron Microscopy (SEM) microphotographs showed the reduction of superficial contamination on cardboard surfaces was due to the entrapping of the microbial cells within the fibers and the pores of this packaging material and their death overtime due to the absence of water and nutrients. Hence, the type of packaging material studied played a significant role in this respect (Siroli et al, 2017) which would explain the results obtained through the present study as the number of SFB was always higher when UHT milk has been filled into the pouch versus Tetra Brik packages.…”

“…milk) and presents significant advantages from an environmental and microbiological standpoint than plastic materials (e.g. pouch packages) (Hladíková et al, 2015; Siroli et al, 2017). The Scanning Electron Microscopy (SEM) microphotographs showed the reduction of superficial contamination on cardboard surfaces was due to the entrapping of the microbial cells within the fibers and the pores of this packaging material and their death overtime due to the absence of water and nutrients.…”