Chemical guide parameters for Spanish lemon (Citrus limon (L.) Burm.) juices

• Hundred eighty-four direct and reconstituted juices from Spanish lemons were analysed.
• Sugars, organic acids, amino acids and mineral profiles were determined.
• Ranges of authentic juices obtained from the lemon varieties ‘Verna’ and ‘Fino’ were established.
• These findings were compared to the current reference guideline for lemon juice.
• New criteria for authenticity and identity control of lemon juice are proposed.

To contribute for setting reference guideline for commercial juice extracted from the Spanish lemon varieties, chemical composition of 92 direct and 92 reconstituted samples were investigated. In direct lemon juice, titratable acidity was 52.4 g/L, being the citric acid the main component. Glucose, fructose and sucrose concentrations were 7.9, 7.3 and 4.5 g/L, respectively. Predominant mineral was potassium (1264.2 mg/L), followed by phosphorous (306 mg/L), calcium (112 mg/L) and magnesium (92.6 mg/L). Hesperidin ranged from 257 to 484.8 mg/L, while water soluble pectins varied between 164.8 and 550 mg/L. Similar values were obtained in reconstituted lemon juice. There are different parameters that did not reach or exceeded the limits proposed by the European Association of the Industry of Juices and Nectars. These levels should be taken into account to modify the present reference guideline and that Spanish lemon juices are not discarded for to have lower or bigger values.