The effect of butter grains on physical properties of butter-like emulsions

Pasture feeding improves the nutritional, textural and techno-functional characteristics of butter

There is an increasing consumer desire for pasture-derived dairy products, as outdoor pasture-based feeding systems are perceived as a natural environment for animals. Despite this, the number of grazing animals globally has declined as a result of the higher milk yields achieved by indoor, total mixed ration feeding systems, in addition to the changing climatic conditions and lower grazing knowledge and infrastructure. This has led to the development of pasture-fed standards, stipulating the necessity of pasture and its minimum requirements as the primary feed source for products advertising such claims, with various requirements depending on region for which it was produced. This work investigates the differences in the composition and techno-functional properties of butters produced from high, medium and no pasture allowance diets during early, mid and late lactation. Butters were produced using milks collected from 3 feeding systems: outdoor pasture grazing (GRS; high pasture allowance); indoor total mixed ration (TMR; no pasture allowance); and a partial mixed ration (PMR; medium pasture allowance) system, which involved outdoor pasture grazing during the day and indoor TMR feeding at night. Butters were manufactured during early, mid and late lactation. Creams derived from TMR feeding systems exhibited the highest milk fat globule size. The fatty acid profiles of butters also differed significantly as a function of diet, and could be readily discriminated by partial least squares analysis. The most important fatty acids in such analysis, as indicated by their highest variable importance projection scores, were CLA C18:2 cis-9 trans-11 (rumenic acid), C16:1 n-7 trans (trans-palmitoleic acid), C18:1 trans (elaidic acid), C18:3 n-3 (α-linolenic acid) and C18:2 n-6 (linoleic acid). Increasing pasture allowances resulted in reduced crystallization temperatures and hardness of butters, while concurrently increasing the 'yellow' b* color. Yellow color was strongly correlated with Raman peaks commonly associated with carotenoids. The milk fat globule size of cream decreased with advancing stage of lactation and churning time of cream was lowest in early lactation. Differences in the fatty acid and triglyceride contents of butter as a result of lactation and dietary effects demonstrated significant correlations with the hardness, rheological, melting and crystallization profiles of the butters. This work highlighted the improved nutritional profile and functional properties of butter with increasing dietary pasture allowance, primarily as a result of increasing proportions of unsaturated fatty acids. Biomarkers of pasture feeding (response in milk proportionate to the pasture allowance) associated with the pasture-fed status of butters were also identified as a result of the significant changes in the fatty acid profile with increasing pasture allowance. This was achieved through the use of 3 authentic feeding systems with varying pasture allowances, commonly operated by farmers around the world and conducted across 3 stages of lactation.

Assessing Mechanical and Rheological Properties of Potato Puree: Effect of Different Ingredient Combinations and Cooking Methods on the Feasibility of 3D Printing

The effects of agar, alginate, butter, olive oil, and carrots on the mechanical and rheological properties of potato puree prepared by two different cooking methods (microwave heating (MP) and boiling (BP)) were investigated and interpreted in terms of starch microstructural changes. Microscopic observations revealed more aggregated and densely concentrated starch granules in MP samples. This consequently led to a significant increase (p < 0.05) in mechanical and rheological properties up to five times more than BP samples. All samples exhibited shear thinning non-Newtonian behavior. Butter proved its ability to maintain stiff network formation with starch molecules forming lipid-starch complexes characterized by high retention properties and increased stability due to high thixotropic and yield stress values. The pseudo-plasticity combined with high self-supporting ability (high yield stress and mechanical values) comprised by MP samples allows them to better behave during advanced technological processes such as extrusion 3D food printing.

Methodologies for the Characterization of the Quality of Dairy Products

The growing interest of consumers in food quality and safety issues has contributed to the increasing demand for sensitive and rapid analytical technologies. Physicochemical, textural, sensory, etc., methods have been used to evaluate the quality and authenticity of milk and dairy products. Despite the importance of these standard methods, they are expensive and time consuming. Recently, spectroscopic methods have shown great potential due to speed of analysis, minimal sample preparation, high repeatability, low cost, and, most of all, the fact that these techniques are noninvasive and nondestructive and, therefore, could be applied to any on-line monitoring system. This chapter gave examples of the application of the most commonly traditional methods for the determination of the quality of milk and dairy products. A special focus is devoted to the use of infrared and fluorescence spectroscopies for the evaluation of the quality of dairy products.