Limonoid content of sour orange varieties

Area of Science:

• Agricultural Science
• Food Chemistry
• Plant Biochemistry

Background:

• Modern citrus cultivars originate from pummelo, mandarin, and citron.
• Sweet and sour oranges share common ancestry but differ in fruit properties.
• Limited analysis exists for limonoid content in sour orange varieties.

Purpose of the Study:

• To analyze and compare limonoid profiles in sour orange cultivars.
• To investigate differences between sour and sweet orange limonoid composition.

Main Methods:

• Juice samples from sour orange cultivars were analyzed.
• Quantification of limonoid A-ring lactone, aglycone, and glucoside content.
• Liquid chromatography-mass spectrometry used for glucoside profiling.

Main Results:

• Limonoid A-ring lactone concentrations varied from 11.1 to 44.9 mg L⁻¹.
• Total limonoid aglycone and glucoside concentrations ranged from 2.4–18.4 mg L⁻¹ and 149.0–612.3 mg L⁻¹, respectively.
• Sour oranges exhibited distinct limonoid glucoside profiles compared to other citrus species.

Conclusions:

• Limonoid aglycone and A-ring content are similar in sweet and sour oranges.
• Limonoid glucoside profiles significantly differ between sweet and sour oranges.
• Citrus maderaspatana juice is rich in limonoids, suitable for isolation.