Discussion: For this week, we did the experiment under family of cereal which was about to investigate the effect of different alkaline solution on the quality of yellow wet noodles. There were four different formulations that we used. According to the table A in the procedure, it stated that for formulation 1, we were using Sodium Carbonate with sodium chloride as the alkaline salt solution while formulation 2 with Soda Ash with sodium chloride and formulation 3 with Potassium Carbonate with sodium chloride .
However for formulation 4, we were not using any alkaline solution to make it become as the control product and only used sodium chloride. According to the result in table 1, we found that the highest moisture content of yellow noodles was from formulation 4 (62. 73 ± 8. 389) (control product) while the least was formulation 3 (57. 96 ± 0. 208). In cereals grains, there are protein and starch contain in it. The storage protein can be found in spherical membrane bound protein bodies.
The protein bodies are located in the seed endosperm in separate layers called aleurone and starchy endosperm. However, starch (amylose + amylopectin) can be found in spherical or polyhedral, membrane bound starch granules which are located in the starchy endosperm layers of the grain endosperm. Protein-starch interactions can be depending on temperature. At low temperature, such as room temperature, interactions between protein and starch are charge-charge (ionic) phenomena. In unheated dough, the degree of interaction depends largely on the isoelectric point of the protein.
Therefore the interaction is pH dependent. Salts influence the solubility of the noodles protein and play important role in water holding capacity. The effect of sodium chloride (NaCl) on water holding capacity of yellow wet noodles is dependent on pH. According to the researched found by Dahle who investigated the effect of pH and heat on the ability of protein to interact with starch, he found that at more alkaline pH, the protein becomes less positively charged and less to complex with negatively charged starch.
When the protein becomes less positively charged below the isoelectric point, the (NaCl) decreases the water holding capacity, while at the pH above the isoelectric point, water holding capacity is greatly enhanced. These results are related to the understanding of the effect of anions and cations on water and protein. Anions have the ability to bind to the protein molecule itself as it has the greater effect on the structure of water. Hamm reported that the isoelectric point of the protein was lowered in the presence of salts.
This effect would be due to the greater ability of the chloride ion to bind to the protein. As the net positive charge was neutralized by the chloride ion (Cl-), the protein should shrink and water holding capacity would be reduced. Back to the results in table 1, the formulation 3 has the lowest moisture content (57. 96 ± 0. 208) due to the higher pH (9. 22 ± 0. 006) and lowest ash content 0. 25 ± 0. 135). As discussed above, when the protein is less positive below the isoelectric point or more alkaline, there is present of higher alkaline salts.
The chloride ion (Cl-) in alkaline salts had neutralized the net positive of protein and it makes the protein shrink and the water holding capacity would be reduced. When the water holding capacity would be reduced, the amount of water to be absorbed will be in low amount. Thus, the moisture content in the yellow wet noodles in formulation 3 will be the least moisture content. Cations and anions have the different effect on the orientation of water molecules which surrounded them. Both cations and anions tend to arrange themselves in series.
In general for anions, the extent of structure breaking effect on water follows the order of F- < CH3CHOO- < SO4- < Cl- < Br- < I- < NO3- < ClO4- < SCN- < Cl3CCOO- . While for cations series is as follows Li+ < Na+ < K+ < Rb+ < Cs+ . In the alkaline salts solutions, there are interactions between anions and cations. Ions may also affect the protein binding. From the research of Bull and Breese, they reported the size of cation had little effect on the binding of the ion to the protein.
In contrast to the cations, the anions bound to the protein according to the size of the ionic radii. From the series of ions, we can say that potassium carbonate (K2CO3) add with (NaCl) in formulation 3, had higher ability to bind to the protein compared to sodium carbonate (NaCO3) add with (NaCl) in formulation 1. We do not compare with formulation 4 because of it do not add with any alkaline solution and definitely the results will be different far from others. Base on the table 2, texture profile analysis of yellow noodles shows that the formulations 3 give the hardest texture to the yellow wet noodles (3114. 00 ± 3161. 824) while the formulation 4 give the least hard to the yellow wet noodles (2657. 418 ± 2784. 080). The texture of protein-starch found in cereal products is always related to the water holding capacity. As mentioned above, the least water holding capacity was in formulation 3, thus the moisture content of it was lowest. The lower the moisture content, the yellow wet noodles will become harder. Go to the table 3, sensory evaluation of yellow noodles shows that the formulation 1 gives the best result in each of the sensory evaluation in term of the color, firmness, elasticity, and taste.
But only the aroma/flavor is the best for formulation 2. However, from our personal preference as the whole was the formulation 2. We were a bit wondering why not the formulation 2 be the best result for sensory evaluation. Perhaps due to some error or maybe it was what the members in the class most preferred. Why do we expressed this feeling is because, the best color of wet yellow noodles that we observed on this week was formulation 2 not formulation 1. This result was done by group 4.
Now we can check whether the sensory evaluation was correct or not if we identify the color of the yellow wet noodles with the machine. According to the machine, it shows that +l is for black –l is for white, +a is for red, -a is for green, +b is for yellow and –b is for blue. From the results in table 4, the color intensity analysis show that formulation 2 gave the highest intensity for yellow color which was +b 20. 48 while the lowest yellow color intensity was from the formulation 4 +b 10. 46.
The results indicate that the manual sensory evaluation for color was not tally with the sensory evaluation by using machine. It stated from the manual sensory evaluation that the formulation 1 gave the highest color intensity +b 4. 83 but according to the machine it gave the second last result +b 11. 77 which shows that the color was not as yellow as formulation 2 +b 20. 48. As conclusion, formulation 2 gave the best yellow color among the other four formulations that have been used for this week. The higher the yellow color intensity, the more appealing the yellow wet noodles.