Application of Density Measurements for Discrimination and Evaluation of Chemical Composition of Different Types of Mechanically Separated Meat (MSM).

At present, the problem of identifying and controlling different types of Mechanically Separated Meat (MSM) is a very important practical issue in the meat industry. To address this challenge, the authors propose a new, analytical method for the discrimination and characterization of MSM that uses density measurements. The method proposed by the authors, in contrast to the analytical methods existing so far, is rapid, non-destructive, relatively simple and can be computerized. The density measurements of meat samples were conducted with a modified pycnometric method. Statistically significant (p<0.01) differences were found in the evaluated mean values of density for all investigated types of meat. Subsequently, the density measurements were correlated with the physicochemical properties of meat samples. A high correlation coefficient was found between the density of meat samples and the content of protein, sodium and fat. The authors have proven that density measurements allow for rapid discrimination of various types of MSM, and can also be effectively used to determine the chemical composition of MSM samples, e.g., the content of protein, fat and sodium.

The first stage of refining of post-fermentation corn oil with a high content of free fatty acids and phytosterols - Comparison of neutralisation by an ion-exchange resin without solvent and base neutralisation.

Post-fermentation crude corn oil obtained as a by-product in the production of bioethanol from maize grains is characterized by a very high content of free fatty acids. Refining of post-fermentation corn oil will give a product that will be different from the refined oil obtained by extracting oil from corn germs. From the point of view of refining vegetable oils, the neutralisation of this oil is the most important process. Anionic ion-exchange resin was used in the research in a way to avoid the use of harmful organic solvents and a comparatively standard method of neutralising free fatty acids based on the use of a sodium hydroxide solution. Ion-exchange resin can be used in the processes of neutralising vegetable oil with an average content of free fatty acids, then the oil is neutralised in miscela. In the research, no organic solvent was used, but to reduce the flow resistance, a system based on an adjustable reduced pressure in the range of 300-50 mbar was used, to maintain a constant contact time of the oil with the resin in each cycle. The aim of the research was to obtain neutral oil with a high content of biologically active substances such as phytosterols and carotenoids. Both methods showed a reduction of free fatty acids up to 93-96 % and a similar refining loss of 18-19 %. The use of an ion-exchange resin allowed to obtain an oil in which the phytosterol content increased by 5 % for ß-sitosterol, by 6.3 % for Ï­5-avenasterol, and the carotenoid content was reduced by 35 %. An increase in the number of fatty acids, such as 18:1 cis-oleic acid and 18:2 cis-linoleic, was observed.

Effects of Concentration and Type of Lipids on the Droplet Size, Encapsulation, Colour and Viscosity in the Oil-in-Water Emulsions Stabilised by Rapeseed Protein.

The objective of this study was to extract the rapeseed protein from by-products and further examine the effect of lab-made rapeseed protein on the droplet size, microstructure, colour, encapsulation and apparent viscosity of emulsions. Rapeseed protein-stabilised emulsions with an increasing gradient of milk fat or rapeseed oil (10, 20, 30, 40 and 50%, v/v) were fabricated using a high shear rate homogenisation. All emulsions showed 100% oil encapsulation for 30 days of storage, irrespective of lipid type and the concentration used. Rapeseed oil emulsions were stable against coalescence, whereas the milk fat emulsion showed a partial micro-coalescence. The apparent viscosity of emulsions raised with increased lipid concentrations. Each of the emulsions showed a shear thinning behaviour, a typical behaviour of non-Newtonian fluids. The average droplet size was raised in milk fat and rapeseed oil emulsions when the concentration of lipids increased. A simple approach to manufacturing stable emulsions offers a feasible hint to convert protein-rich by-products into a valuable carrier of saturated or unsaturated lipids for the design of foods with a targeted lipid profile.

Replacement of milk fat by rapeseed oil stabilised emulsion in commercial yogurt.

The incorporation of lipid droplets and further characterization of matrices within dairy products may be possible using such adjacent particles as protein complexes/lipids. Among the range of varied emulsions and their functionalities, great attention has recently focused on the fabrication of high internal phase types. Feasibly, stable alternatives structured with health-beneficial lipids like those derived from plants could replace saturated fatty acids. As a fat replacement strategy, the fate of incorporated HIPE would require some adjustments either with storage stability and/or structural feat for the food matrix. Therefore, the replacement of milk fat by rapeseed oil stabilised emulsion in commercial yogurt was investigated. This involved 25%, 50% and 75% rapeseed oil respectively assigned as low (LIPE), medium (MIPE), and high internal phase emulsion (HIPE). Specifically, emulsions were examined by droplet size, encapsulation, pH, zeta potential, phase separation, and rheology. The fat free yogurt supplemented by HIPE were examined by droplet size, zeta potential, pH, color, sensory, texture and microbiological aspects against positive (regular milk fat) and negative (fat free) yogurt controls. Results showed increasing rapeseed oil contents would form smaller droplet-like emulsions. Within the yogurt matrix however, incorporating HIPE would seemingly reduce oil droplet size without much compromise to bacterial viability, sensory, or texture. Overall, this simple method of lipid alternation shows promise in dairy products.