Ram R Panthi

Understanding the molecular properties and interactions of components within high‐protein dairy powders is important in predicting rehydration performance. Raman spectroscopy was used to generate molecular information which provided insights into interactions between caseins in micellar casein concentrate (MCC) powder formulated with varying proportions of glycomacropeptide (GMP). The Raman bands showed intense peaks at 1446 to 1476 cm⁻¹ (due to CH₂ vibration) and 1653 to 1668 cm⁻¹ (due to C=O of Amide I and C=C bond) in MCC powder samples blended with GMP. Enhanced rehydration characteristics of MCC powder containing GMP matched with these differences in Raman peak intensity.

Spray‐dried whey protein isolate (WPI) powders were prepared at pilot‐scale from solutions without heat (WPI_UH), heated (WPI_H) or heated with calcium (WPI_HCa), which were analysed and compared with a control sample (WPI_C). WPI_C, WPI_UH, WPI_H and WPI_HCa solutions had whey protein denaturation levels of 0.0, 3.2, 64.4 and 74.4%, respectively. Computerised tomography scanning showed that 52.6_, 84.0, 74.5 and 41.9% of WPI_C, WPI_UH, WPI_H and WPI_HCa powder particles had diameters of ≤30 µm. WPI_HCa and WPI_H powders were cohesive, while WPI_C and WPI_UH powders were easy flowing. Marked differences in microstructure were observed between WPI_H and WPI_HCa. There were no measured differences in wall friction, bulk density or colour.

Maasdam cheese was manufactured from standardized milk derived from each of three feeding systems: grass (GRA), grass and clover pasture (CLO), and indoor feeding of total mixed ration (TMR). Pasture‐derived cheeses had significantly lower L* (whiteness) and higher b* values (yellowness) compared to TMR‐derived cheeses. Acetate levels were significantly lower in CLO and butyrate levels significantly higher in TMR compared to the other cheeses. Grass‐fed cheese had significantly higher scores for smooth texture, ivory colour and shiny appearance compared to TMR. The influence of feed type was minimal on cheese yield, composition and on glycolysis, lipolysis and proteolysis during ripening.

This study compared the in‐vat moisture loss kinetics under fixed cheesemaking conditions during 75 min of stirring of curds prepared from protein‐standardised milks produced from indoor cows fed total mixed ration (TMR), or outdoor cows fed grass only (GRA) or grass mixed with clover (CLO). Relative curd moisture as a function of time was fitted to different empirical equations, of which a logarithmic function gave the best fit to the experimental data. The moisture loss rate constant (k/min) was found to be similar for curds from protein‐standardisedTMR,CLOandGRAmilks, showing minimal feed‐induced variations in syneresis.