ARS | Publication request: Maintaining Postharvest Quality of Raspberries with Natural Volatile Compounds

Submitted to: International Journal of Food Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 27, 2003
Publication Date: December 1, 2003
Citation: Wang, C.Y. 2003. Maintaining postharvest quality of raspberries with natural volatile compounds. International Journal of Food Science and Technology 2003, 38, 869-875

Interpretive Summary: Raspberries are small fruit crops containing high antioxidant capacity which can offer significant health benefits. Unfortunately, raspberry fruit soften and deteriorate rapidly after harvest. Their storage life is limited by physiological breakdown and fungal decay. We treated raspberries with several natural volatile compounds and found that fruit treated with methyl jasmonate, allyl isothiocyanate, tea tree oil, and absolute ethyl alcohol had less decay than untreated fruit. Among these treatments, methyl jasmonate and tea tree oil treated fruit also maintained high levels of sugars, organic acids, and antioxidant capacity compared to untreated fruit. Therefore, it is possible to improve storage life and maintain quality of raspberries by treatment with natural volatile compounds. This information will be useful to other scientists as well as raspberry growers and packers, and will ultimately benefit consumers.

Technical Abstract: The postharvest quality of raspberries (Rubus idaeus L.) was evaluated after treatment with several natural volatile compounds and storage at 0, 10 or 20°C. At high storage temperature (20°C), raspberries deteriorated rapidly and none of the natural volatile compounds used were effective in extending storage life of the fruit. At low storage temperature (0°C), little difference could be discerned among the various volatile treatments. However, at 10°C storage, raspberries treated with methyl jasmonate (MJ), allyl isothiocyanate (AITC), tea tree oil (TTO), or absolute ethyl alcohol (AEA) had less decay. MJ- and TTO-treated fruit also maintained higher levels of sugars, organic acids, and oxygen radical absorbance capacity (ORAC) compared to untreated fruit. Samples treated with acetic acid (AA) or vinegar vapor did not differ from control fruit. Measurement of oxygen and carbon dioxide concentrations within the containers during storage revealed that none of the treatments caused accumulation or depletion of these gases to a level that would be harmful to raspberries. Color measurements of the berries showed that all raspberry fruit became darker and less red after storage, but fruit treated with MJ were found to have the highest intensity of red color while AITC application caused the berries to appear lighter in color.