ex1 results

8/12/2019 Ex1 Results

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Results

In this exercise, the group used a cheese (Eden) and cultured milk (Yakult) as

samples for objective evaluation of foods. There were three samples for each type of food with

the same brand. Their weights are shown in table 1. The actual net weight was obtained through

the subtraction of the container weight with the gross weight (inclusive of the

wrapper/container). Thus net weight stands for the actual weight of the product that the

consumers get. There were only small deviations in the weight of the products.

Table1. Sample weights (Gross and Net)

Sample

Weight in grams

Mean Gross SDContainer

(Mean)SD

Mean

Actual Net

SD

Cheese a 36.16333 0.005774 1.606667 0.005774 34.55667 0.005774

Cheese b 36.77667 0.005774 1.55 0.01 35.22667 0.005774

Cheese c 36.15333 0.005774 1.5 0 34.65333 0.005774

Milk a 89.99333 0.015275 9.9933 0 80 0

Milk b 89.87333 0.005774 9.8733 0 80 0

Milk c 90.38333 0.005774 10.3833 0 80 0

Manufacturers label their own product with the net weight table 2 shows the deviation of

the actual net weight with the manufacturers declared net weight.

Table 2. % Deviation of the actual product

Declared Net Weight Actual Net Weight % Deviation (mean)

Cheese a 35 34.55667 1.266667

Cheese b 35 35.22667 0.647617

Cheese c 35 34.65333 0.990476

Milk a 80 80 0


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Milk b 80 80 0

Milk c 80 80 0

In the experiment in determining the colors of foods, the munsell book of colors and

HunterLab colorimeter were used. The results were as follows. The three cheeses served as

different trials. The milk was not included in the HunterLabs colorimeter since it is liquid and

slightly translucent

Table 3. Determination of Color of Foods

SampleMunsells book

of colors

HunterLabs Colorimeter

L a b

Cheese a 2.5y 8/6 76.17 1.66 29.49

Cheese b 2.5y 8/6 76.29 1.85 29.78

Cheese c 2.5y 8/6 76.34 2 29.97

Mean 76.26667 1.836667 29.74667

SD 0.087369 0.170392 0.24173

Milk a 10yr 8/4 - - -

Milk b 10yr 8/4 - - -

Milk c 10yr 8/4 - - -

The cheese was the only subject sample thus this was the only sample for the test of

firmness. The test was done using a needle and how much it could penetrate for 5 seconds. The

results are shown in table 4. It shows that the same brand of cheese may have different firmness

but this can also be attributed to human errors especially in handling the penetrometer.

Table 4. Test for firmness

SampleDepth of penetration in millimeters

Mean SDTrial 1 Trial 2 Trial 3

cheese a 20.7 22.6 23.1 22.1333 1.26622


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3 8

cheese b 24.6 24.8 24.924.7666

7

0.15275

3

cheese c 23.6 23.4 20.5 22.5

1.73493

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The pH of foods and its temperature are also necessary to determine whether it is

potentially hazardous or not. The experiment on pH and temperature subjected both milk and

cheese and the results are as follows. The milk has a pH within the PHF range while the cheese

was below 4.5. The milk was warmer than cheese and it can be attributed to its state which is

liquid.

Table 5.1.pH and temperature test for cheese

Trial

Mean SD1 2 3

pH 3.21 3.22 3.26 3.23 0.026458

Temp

(C) 20.6 25 23 22.86667 2.203028

Table 5.2.pH and temperature test for cultured milk

Trial

Mean SD1 2 3

pH 5.86 5.9 5.89 5.883333 0.020817

Temp

(C) 27.4 26 24.5 25.96667 1.450287


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To test the titratable acidity of liquid foods, a titrant (NaOH) was first standardized since

it was only prepared in the laboratory using NaOH pellets. It was standardized using a known

concentration and weight of analyte (KHP) and was titrated. The results are as follows:

Table 6.1Standardization of the Titrant

Standardization Trial

1 2 3 Mean SD

Weight of KHP (g) 0.2544 0.2601 0.2568 0.2571 0.002862

Volume of NaOH used (mL) 13.5 13.9 13.8 13.73333 0.208167

Normality of NaOH 0.092271 0.091624 0.092181 0.092025 0.000351

After the concentration of the titrant was identified, it was used in the diluted form of the

cultured milk. The milk was found to have 0.49% titratable acidity.

Table 6.2.Titratable Acidity of cultured milk

Trial 1 Trial 2 Mean SD

Weight of sample (g) 10 10 10 0

Volume of NaOH used (mL) 6 6.4 6.2 0.282843

%Titratable Acidity 0.49778 0.53006 0.51003 0.028327

The last experiment of this exercise was to determine the sucrose and salt levels which

are th soluble solids in food. The cheese was subjected to test using the salinometer to determine

the salt concentration while the cultured milk was subjected for sucrose concentration test. The

cheeses had different levels of salt concentration with nearly the same deviation each trial.


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Table 7.1.Total soluble solid test for cheese

Temp

(C)

Trial Mean

(Bx)SD

Corrected

Tss

Reading

%

TSS

1 2 3

cheese a 24 10.5 11.5 11 11 0.5 11.29 Bx 124.19

cheese b 26 17.5 17 17 17.16667 0.288675 17.62 Bx 193.82

cheese c 25 21 21 20 20.66667 0.57735 21.05 Bx 231.55

Table 7.2. Total soluble solid test for cultured milk

Temp

(C)

Trial Mean

(Bx)SD

Corrected

Tss

Reading

%

TSS

1 2 3

Milk a 28 14 14.5 14.5 14.33333 0.288675 14.93 Bx 14.93

ex1 results

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