FOOD SCIENCE 89
Measuring total fat content
otal fat is a crucial measurement in food analysis. Where fatty acids are bound to glycerides, sterol esters, glycol and phospholipids acid or alkaline hydrolysis is required. Hydrolysis disrupts cell walls, breaks up fat emulsions and lipid protein bonds. Multiple AOAC methods exist for various
T
matrices that incorporate acid or alkaline hydrolysis to accomplish total release of fat from various products followed by total fat extraction by mixed ethers. These AOAC methods are labour intensive with variations in reproducibility across matrices. Presented in a recent validation study,
Hydrotherm data is compared to AOAC 922.06 method data, which is a manual acid digestion utilising Mojonnier tube extraction for acid hydrolysis. Hydrotherm performed equivalent to the AOAC method. It was found to have higher hydrolysis efficiency in comparison to the AOAC method. The Hydrotherm is an automated, fully enclosed acid hydrolysis system according to ISO 8262-1, the Weibull-Berntrop gravimetric method. Paired with the Soxtherm (rapid soxhlet extraction), the fat analysis of food products is fully automated with minimal labour.
The Hydrotherm is an acid hydrolysis system for fat analysis of food products
In this study, NIST 1546 Meat Homogenate (n=36) was analysed using both methods, in which the Hydrotherm performed equivalent to the AOAC method. 21 products – including cheese, soups/sauces, meats (raw/cooked, deli, breaded), pet treats, tortillas, and taco shells – were analysed in which the Hydrotherm was found to have higher
hydrolysis efficiency in comparison to the AOAC method. Utilising the Hydrotherm for automated acid hydrolysis, good repeatability, high productivity, precise results and universal applicability are all achievable.
For more information visit
www.gerhardt.de
Determining sodium content O
ne commonly used method for quantifying sodium in foodstuffs is to determine the counterion chloride using argentometric titration, the concentration of which can be used to deduce the sodium concentration from the 1:1 stoichiometry of sodium chloride. This method involves errors because sodium is not only present with chloride as the counterion. A new method for direct titration of sodium with thermometric endpoint detection solves this problem. Thermometric titration shares with
potentiometric titration the use of a sensor to detect the endpoint of the titration reaction. In the case of thermometric titration, however, the sensor is a fast
solution. Because it relies merely on a change of solution temperature to find the endpoint, there is no need to calibrate the sensor. Sensor maintenance is minimal, and it can be stored dry between titrations. As for sample preparation, users only
responding thermometer. Hence, instead of measuring the electrochemical potential in the solution, this robust, highly sensitive thermometer tracks the reaction enthalpy, i.e. the temperature change in the solution. The endpoint of the titration is marked
precisely by the moment when the reaction stops and no significant temperature change is registered any longer in the
need to ensure that the matrix does not prevent the analyte from reacting with the titrant and that the sample is sufficiently mobile. Accurate results are
available in less than two minutes. Metrohm provides the 859 Titrotherm
with Tiamo software for thermometric titrations, a total solution that can easily be automated by integrating an autosampler.
For more information visit
www.metrohm.com
www.scientistlive.com
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92