Components of essential oils from different varieties of citronella and evaluation of their preservation effects on Shine Muscat grapes

Citronella essential oil was extracted by steam distillation method, and its components were determined by headspace gas chromatography-mass spectrometry (HS-GC-MS) technology. The effects of different varieties (No. 1, No. 7, and No. 12) of citronella essential oils and different concentrations of No. 12 citronella essential oil on the fresh-keeping quality of Shine Muscat grapes during room temperature storage were studied by fine fruit rate, weight loss rate, firmness, soluble solid content, titratable acid content and vitamin C (Vc) content of fruit as measuring indicators. The results showed that the yield of No. 12 citronella essential oil was the highest, with citronellal as the main volatile component. The main volatile component of No. 1 citronella essential oil was citral, and the main volatile components of No. 7 citronella essential oil were β-myrcene and citral. The sensory quality and fine fruit rate of fruit treated with No. 12 citronella essential oil were significantly better than those of No. 7 and No. 1 citronella essential oils. Compared with those in control group, different concentrations of No. 12 citronella essential oil could obviously reduce fruit decay, significantly inhibit the weight loss of fruit and slow down the decline of fruit firmness, titratable acid content and Vc content. 0.125, 0.250 and 0.500 μL/L essential oil treatments had better effects on inhibiting fruit decay; 0.250 and 2.000 μL/L essential oil treatments had better effects on maintaining the soluble solid content of fruit; 0.250 μL/L essential oil treatment had the best effect on maintaining the sensory quality of fruit, inhibiting the weight loss and slowing down the decline of titratable acid content of fruit; 2.000 μL/L essential oil treatment had the best effect on slowing down the decline in firmness and Vc content of fruit. In summary, 0.250 μL/L No. 12 citronella essential oil treatment is more suitable for the preservation of Shine Muscat grapes. This study provides a theoretical basis for the future application of citronella essential oil in the preservation of fruits and vegetables.