Fresh squeezed orange juice odor: a review

Area of Science:

• Food Chemistry
• Sensory Science
• Analytical Chemistry

Background:

• Fresh orange juice is a popular but unstable beverage.
• Previous studies overemphasized high-concentration volatiles in orange juice aroma.
• Understanding the volatile composition is crucial for preserving juice quality.

Purpose of the Study:

• To review analytical findings on orange juice odor.
• To identify key aroma-active components and their variations.
• To investigate the influence of processing and artifacts on juice aroma.

Main Methods:

• Gas Chromatography-Mass Spectrometry (GC-MS) for volatile identification.
• Gas Chromatography-Olfactometry (GC-O) for aroma activity assessment.
• Review of literature on juicing methods, peel oil, and microbial/enzymatic artifacts.

Main Results:

• Over 300 volatiles identified, but 36 consensus aroma-active components (aldehydes, esters, terpenes, alcohols, ketones) are crucial.
• (+)-Limonene is a key component, though its precise role is unclear.
• Mechanically squeezed juices have 3-10x more volatiles due to peel oil, altering odorant proportions.

Conclusions:

• Fresh orange juice aroma is complex, with trace components playing a significant role.
• Juicing methods and peel oil content significantly impact the volatile profile and aroma.
• Microbial contamination can introduce artifactual odorants, affecting perceived freshness.