Effect of Technological Treatments on Human-Like Leptin Level in Bovine Milk for Human Consumption.

Damiano Magistrelli,Fabia Rosi

doi:10.3390/foods3030433

Abstract

In this experiment, raw milk and commercially available full-cream UHT milk, semi-skimmed UHT milk, skimmed UHT milk, full-cream pasteurized milk, semi-skimmed pasteurized milk and infant formulas for babies between 6 and 12 months of age were analyzed by RIA, with a method using an antibody directed against human leptin and human leptin as reference standard. Raw milk and full-cream UHT milk did not differ for human-like leptin. Leptin content of full-cream pasteurized milk was not different to that of full-cream UHT milk, but it was 14% lower (p < 0.05) than that observed in raw milk. Human-like leptin level of semi-skimmed UHT milk was not different to that of semi-skimmed pasteurized milk, but it was 30% lower (p < 0.0001) than those of full-cream UHT and full-cream pasteurized milks. In skimmed UHT milk, leptin was 40% lower (p < 0.0001) than in full-cream UHT milk. Leptin was correlated (p < 0.001) with lipid content. Leptin level of infant formulas was not different to that of skimmed milks. Results suggest that the heat treatment (pasteurization or UHT) is not a modifier of human-like leptin content of edible commercial bovine milks, whereas the skimming process significantly reduces milk leptin level.

Highlights

Leptin, the product of the ob gene, is a 167-amino acids hormone characterized by a high degree of homology among species
Raw milk and full-cream UHT milk did not differ for human-like leptin level
No difference was observed between full-cream UHT milk and full-cream pasteurized milk, but human-like leptin content of full-cream pasteurized milk was 14% lower (p < 0.05) than that observed in raw milk

Summary

Introduction

The product of the ob gene, is a 167-amino acids hormone characterized by a high degree of homology among species. It is mainly synthesized by adipose cells as an indicator of energy stores in the body [1]. Leptin enters the central nervous system by receptor-mediated transcytosis across the blood-brain barrier and targets the hypothalamus, the major effector organ for energy homeostasis, decreasing appetite and promoting basal metabolism, thereby reducing body fat mass [1]. Leptin directly promotes gonadotropin secretion by interaction with specific receptors on the pituitary gland [3]

Results

Discussion

Conclusion