Cheese triangles texture measurement

PRINCIPLE OF THE TEST

Assessment of the firmness and stickiness of two different brands of triangle spreadable cheese by penetration using a 1 inch spherical probe.

CONTEXT

Cheese is made from curd by coagulating the casein in the milk. The type of curd that develops depends on handling techniques, moisture content and aging times. The texture of the cheese can vary depending on the fat content, humidity and protein matrix. An increase in the fat content results in a smoother cheese, as does an increase in the moisture content. It is largely the protein matrix that gives rise to the rigid forms of cheese. Changing the nature or amount of protein in the cheese will change its texture.

The analysis of the texture of cheese products is necessary to quantify the characteristics of the curd in order to predict the quality of the final product. Using the 1 inch ball probe, the firmness of the product can be determined. The spherical probe applies a gentle form of strain to the sample for a specified distance. The maximum applied force is a measure of the firmness of the sample.

With a growing market for low fat foods, texture analysis plays a critical role in developing low fat products where a developer may want to mimic the texture profile of the rich equivalent. in the fat of a product. The CT3 texture analyzer using a cylindrical probe can determine the consistency and firmness of soft cheese. Samples can also be tested directly from their containers on the production line.

METHOD

Equipment : CT3 with 4.5 kg load cell

Luminaire base table (TA-BT-KIT)

Spherical probe, 1 inch (TA-49)

TexturePro CT software

Settings :

Type of test: Compression

Pre-test speed: 1.5 mm / s

Test speed: 2.0 mm / s

Post-test speed: 2.0 mm / s

Target type: Distance

Target value: 8 mm

Trigger force: 4.5 grams

PROCEDURE

When alignment is complete, tighten the thumbscrews on the fixture base table to prevent further movement.

Start the penetration test.

Remarks :

When penetrating a sample in various places, the proximity of neighboring test holes should not be less than 20 mm. The penetration distance can be changed so that a greater depth will have decreased softness values and increased grip values. Therefore, all values obtained are relative to the specified distance and should always be reported for comparison.

For comparison purposes, penetration distances and container size should be kept constant throughout testing. The harder sample is best tested first in order to anticipate the maximum testing range required. This will ensure that the force capacity covers the range of other samples to be tested.

RESULTS

The graphs show the hardness of the whole and light cheese spread triangles using a spherical probe.

Figure I shows the force required to penetrate whole low fat cheese spreads stored at 6 ° C and tested at room temperature. Maximum force is a measure of the hardness of the sample. The area under the load versus time curve between the start of the test and the maximum force value is a measure of the hardness work performed. When the male probe withdraws from the sample, a negative force is generated. The maximum force required to separate the sample from the probe is the adhesive force. The area above the negative peak from the point where the probe reaches zero charge to the point where it separates completely from the sample surface is a measure of tackiness (energy required to remove the sample of its surfaces).

Figure II shows the force versus distance for the force required to penetrate the whole low fat cheese spread triangles tested at room temperature. The maximum force at the specified distance is a measure of the hardness of the sample. The area under the load / distance curve between the start of the test and the target distance (8 mm) is a measure of the hardness work performed. When the probe withdraws from the sample, a negative force is generated. The maximum force required to separate the sample from the probe is the adhesive force. The area under the negative portion of the load / distance curve is a measure of tackiness. Once the probe is completely separated from the sample (at zero load), it returns to the starting position above the sample surface.

OBSERVATIONS

When a trigger force of 4.5 g has been reached at the sample surface, the probe enters the sample a specified distance of 8 mm at a test speed of 2 mm / s. The maximum force over the specified distance is a measure of the sample's hardness (firmness) and the area under the positive curve a measure of the work done (energy required to deform the sample). The higher the force value, the firmer the sample. From Figure I, the low fat cheese spread triangle is firmer than the whole cheese spread triangle.

The negative portion of the graph is produced when the probe returns to the sample surface. The maximum negative value is a measure of the adhesion force (the force required to overcome the forces of attraction between the sample and the probe with which the sample comes in contact). The area below the negative portion of the graph is a measure of tack (the energy required for the probe to move away from the sample). From the table below, whole cheese spread triangles are more sticky than low fat cheese spread triangles.

The table below summarizes the average results of two samples of each type of product: