Of proteins and processing Mechanisms of protein damage upon rapeseed processing and their effects on nutritional value

Abstract

Amino acids are crucial for livestock animals, primarily obtained from the protein fraction of plant ingredients in their diets. However, the hydrothermal processing of protein-rich co-products from the vegetable oil industry, such as defatted rapeseed meal and soybean meal, can lead to structural and chemical changes in proteins, reducing their nutritional value. This often results in reduced protein digestibility. Undigested proteins are fermented in the large intestine, producing bacterial biomass and fatty acids. The bacterial biomass is excreted in feces, contributing to nitrogen content. Chemically modified amino acids that are absorbed but not utilized for protein deposition are excreted in urine. Nitrogen excretion can increase nitrate content in water reservoirs and negatively impact intestinal mucosa and villus height, reducing protein digestion and absorption. High nitrogen levels in the large intestine can promote the growth of harmful bacteria and lead to diarrhea. Minimizing nitrogen reaching the large intestine would benefit gut health and prevent economic losses associated with unconverted nitrogen in animal feeds.