canadian regulations on commercially produced and sold grapefruit juice are that it must be made from clean, mature grapefruit and may contain sugar, invert sugar, dextrose, glucose solids, class ii preservative such as benzoic acid, amylase, cellulase and pectinase. according to canadian standards, grapefruit juice should contain more than 1.15 milliequivalents of free amino acid per 100 milliliters; more than 70 milligrams of potassium per 100 milliliters; and have an absorbance value for total polyphenolics of no less than 0.310. during the production process, the sugar content in the juice, before the addition of sugar, invert sugar, dextrose or glucose solids, should have a brix reading of no less than 9.3. it must contain 0.7% to 2.1% of acid by weight as anhydrous citric acid.