Final answer:
Pasteurization, developed by Louis Pasteur in the 1860s, is a process to reduce microorganisms and hormones like BST in milk, with HTST and UHT being the most common methods used today. HTST pasteurizes milk at 72 °C for 15 seconds, and UHT at 138 °C for 2 seconds or more, allowing storage without refrigeration.
Step-by-step explanation:
The statement Pasteurization destroys 90 percent of BST found in milk relates to the process in which milk is treated to reduce the presence of bovine somatotropin (BST), a hormone naturally found in cattle, as well as various microorganisms that can cause disease. The content loaded Pasteurization techniques mentioned, namely high-temperature short-time (HTST) and ultra-high-temperature (UHT), aim to reduce these pathogens and hormones like BST effectively while retaining the milk's quality.
HTST involves heating the milk to 72 °C for 15 seconds, whereas UHT exposes the milk to 138 °C for at least 2 seconds. Both methods intend to extend the milk's shelf life and reduce health risks, with UHT allowing long storage without refrigeration. The process of pasteurization was first developed by Louis Pasteur in the 1860s and has evolved to include HTST and UHT methods we widely use today.