Jelly grade determination

After many years of discussion over the standard jelly for the jelly grade determination, work on a standard method was undertaken by a committee of the IFT. The committee worked for several years on pectin standardization. They selected the Exchange Ridgelimeter as the standard Instrument to measure jelly SAG because it was compact, inexpensive, easy to use, and it also gave reproducible results. 

The proportion of sugar which pectin will form into a firm jelly determines the jetty grade of the pectin. In a jelly, jam, or marmalade, the propoitions of total solids of sugars, die pH. and the proportion and nature of the pectin used will determine the extent of jellification obtained. The use of pectin in fruit jams and related products is approved by most food regulators because the addition is believed to compensate for an incidental natural deficiency. 

An experiment was conducted in which the pH of SAG jellies was varied. The objective was to determine the effect pH has on SAG grade. Jellies were prepared at pH s between 2.3 and 3.1. The pH was varied by changing the amount of tartaric acid used. Pectin dosage was held constant at. 433g. For comparative purposes two different pectins were used, one which is known to be a pure lime peel citrus pectin, and another citrus pectin with mixed peel... 

---