Biological Activities From Citrus Species

Cultivated Citrus may have been derived from as few as four ancestral species. Numerous natural and cultivated hybrids include commercially important fruits such as oranges, grapefruits, lemons, limes and tangerines. Citrus fruits are consumed as fresh fruit or utilized for juice extraction (freshly squeezed, frozen concentrated, pasteurized, etc.) and can also be processed to obtain jams and jellies. Production of citrus juices generates a considerable amount of by-products that can be used to obtain essential oils with bioactive compounds. This study considers two aspects in the first one, distillated fractions of essential oil with different compositions were obtained by a new technology (Patent JL/A/2001/000027) consisting of an equipment and the development of the corresponding process for the continuous distillation of essential oils from citrus juices. With this process (JL/A/2001/000027) essential oils can be separated in a more economic and efficient way, as well as obtain fractions with different compositions. The statistical analysis demonstrates that there is no significant difference between antioxidant capacities in different fractions. Also, the fractions did not show significant differences in the antioxidant activity when compared to oil obtained by batch distillation in the second one the composition and antimicrobial activity of citrus essential oils obtained from epicarps and seeds of sweet orange and grapefruit were evaluated. The by-products were extracted using steam distillation and by pressing them trough a roller mill. The volatile profiles of distilled and coldpressed oils were determined by GC and GC-MS. The main component in the essential oils analyzed was limonene (94-95%), followed by myrcene (1.82-2.0%) and a-pinene. All the tested essential oils showed antimicrobial activity, but the grapefruit oil obtained by hydrodistillation showed the highest inhibition over S. aureus and E. coli. The MIC for E. coli and S. aureus was 0.25% v/v of oil, whereas for B. subtilis and C. albicans it was of 0.8 and 0.5% respectively.