Effect of bovine feeding system (pasture or concentrate) on the oxidative and sensory shelf life of whole milk powder

peer-reviewedCorrelating volatile compounds with the sensory attributes of whole milk powder (WMP) is fundamental for appreciating the effect of lipid oxidation (LO) on sensory perception. LO compounds can adversely affect the sensory perception of WMP by imparting rancid, metallic, and painty notes. Whole milk powders derived from milk produced by cows maintained on a pasture diet (grass and grass-clover mix) versus a nonpasture diet [total mixed ration (TMR); concentrates and silage] were stored at room temperature 21°C (ambient storage) and 37°C (accelerated storage) and analyzed for volatile compounds and sensory attributes every 2 mo for a total of 6 mo. Thirteen volatile compounds originating from LO were chosen to track the volatile profile of the WMP during storage. Color, composition, total fatty acid, and free fatty acid profiling were also carried out. Significant variations in the concentrations of 14 fatty acids were observed in WMP based on diet. Concentrations of free fatty acids increased in all sample types during storage. Similar trends in sensory attributes were observed with an increase in painty attributes, corresponding to an increase in hexanal. Buttery/toffee attributes were found to be more closely correlated with TMR WMP. Those WMP derived from pasture diets were found to be more susceptible to LO from a volatile perspective, particularly in relation to aldehyde development, which is likely due to increased concentrations of conjugated linoleic acid and α-linolenic acid found in these samples

Impact of autolysis on amino acid catabolism and flavour development in Cheddar cheese by isogenic strains of Lactococcus lactis

The rapid release of intracellular enzymes due to autolysis into the cheese matrix is thought to have a positive influence on flavour development. The objective of this study was to investigate the impact of autolysis on amino acid catabolism and flavour development by using two isogenic starter strains having the same enzymatic potentials and differing only in their autolytic abilities: the highly autolytic Lactococcus lactis AM2 and its prophage cured derivative L. lactis AM2-C

Impact of autolysis on amino acid catabolism and flavour development in Cheddar cheese by isogenic strains of Lactococcus lactis

The rapid release of intracellular enzymes due to autolysis into the cheese matrix is thought to have a positive influence on flavour development. The objective of this study was to investigate the impact of autolysis on amino acid catabolism and flavour development by using two isogenic starter strains having the same enzymatic potentials and differing only in their autolytic abilities: the highly autolytic Lactococcus lactis AM2 and its prophage cured derivative L. lactis AM2-C