Portal absorption of ¹⁵N and amino nitrogen in the growing pig after ingestion of labelled milk, yogurt or heat-treated yogurt

Abstract

-The aim of this experiment was to study 15 N and amino-nitrogen (AN) portal absorption in the growing pig after ingestion of uniformly (0.2509 APE) labelled 15 N milk (M), yogurt ingested just after manufacturing (Y0), yogurt stored for 21 d at 4 °C (Y21) and heat-treated yogurt (HY). The highest porto-arterial differences (PAD) in 15 N and AN were found in the period between 30 min and 90 min after ingestion. The absorption of nitrogen from M and HY mainly occurred during the 0-120 min time period (about 70% for M and 67% for HY). For Y0 and Y21, a larger displayed absorption period over the 0-240 min time period was observed. Y0 and Y21 presented a quite similar portal absorption profile. The 15 N absorption rate was close to 80% for each studied milk product, suggesting that under our experimental conditions, dairy products (M, Y0, Y21 and HY) deliver nearly the same amounts of nitrogen to the organism. AN absorption rates were around 78% with a higher variability between the milk products. These results also indicate that most of the proteins were absorbed within the 240 min postprandial period.

Assessment of the Benefits of Live Yogurt: Methods and Markers forin vivoStudies of the Physiological Effects of Yogurt Cultures

“…/ The proteolytic activity of yogurt bacteria results in a breakdown of only 1 Á/2% of milk protein, leading to a higher content of peptides and free amino acids in yogurt than in milk / Consumption of yogurt is followed by a more regular release of nitrogen through the intestine, which could result in a more gradual distribution and then absorption of dietary nitrogen components in the body The nitrogen absorption from yogurt is higher and more evenly distributed in time than from milk or heattreated fermented milk (33,35) 0/ Global absorption is similar to yogurt, but there are differences in kinetics and size of peptides ¡/ Less nitrogen is absorbed from heat-treated fermented milk than from live yogurt (33,35) Bioactive (38) Presence Lactose is, depending on the geographic area, often maldigested by a great part of adult population, with the exception of lactasesufficient Caucasians Small intestinal transit is very quick in lactose malabsorbers 0/ Amount of lactose: during fermentation, yogurt lactic acid bacteria digest 20 Á/30% of initial lactose content. Because of addition of dry matter before fermentation, the final amount of lactose is about the same in yogurt as in milk.…”

“…Mpassi et al (35) completed the Rychen study. They included a study of the effects of a live yogurt stored for 21 days at 48C.…”