The Effects of Different pH Levels on Reverse Spherification.
Nimrita Bhogal, lilian Hu
Collingwood School
Floor Location : M 131 F

Abstract

Objectives/Goals
The goal was to determine whether changing the pH level of water with the addition of lemon juice affects the ability of liquids to undergo reverse spherification. Spherification is the process of liquids turning into semi-solid spheres using chemical bondings. To sphericate our liquids, we used a method called Frozen Reverse Spherification which is done by dissolving calcium lactate into the solution that was spherified, freezing it, and then melting it in a bath of a sodium alginate solution. Our hypothesis was that the higher the pH level of the solution the larger the solidified ‘jelly-like spheres’ would become and they would not be symmetrical.

Materials/Procedure
We created 3 solutions to be solidified by using water, lemon juice and 3g of calcium lactate. The 1st solution was 100% water, the 2nd was 75% water with 25% lemon juice and the 3rd was 50% water and 50% lemon juice. The solutions were then mixed with 3 grams of calcium lactate, and then poured into molds and then frozen. We then submerged the frozen solutions into the 0.5% sodium alginate solution, and removed, and rinsed them after 12 minutes. Throughout this process, observations were made and diameters of the spheres were measured at the end.

Summarised Results
After a total of fourteen minutes since initially putting the solidified substances into the sodium alginate bath, we found that Solution 1, which was comprised of a dilution of a 3.33% ratio of calcium lactate to water, (with an approximate pH of 7) after sitting in the diluted had the smallest diameter of 2.3cm out of the three solidified liquids. Solution 2 which was comprised of the same calcium lactate base with the addition of 25% lemon juice content with a PH of approximately 5 had the second smallest diameter of 2.6cm, and Solution 3 with a 50% solution of lemon juice to calcium lactate and water, with a pH of about 4 had the largest diameter of 2.7cm.

Conclusions/Discussions
The data proved the hypothesis to be correct. The less acidic solution worked the best and created nice symmetrical and clear ‘jelly-like spheres’. Based on our results we can infer that less acidic liquids would be more ideal to use in the reverse spherification process when creating desserts and drinks. However, due to the lack of data collected, our results are incomplete.