Girennavar Basavaraj, Jayaprakasha G K, Mclin Sara E, Maxim Joe, Yoo Kil Sun, Patil Bhimanagouda S
Department of Horticultural Sciences, Vegetable and Fruit Improvement Center, Texas A&M University, College Station, Texas 77843-2119, USA.
J Agric Food Chem. 2008 Nov 26;56(22):10941-6. doi: 10.1021/jf801812h.
Phytochemical levels in fruits and vegetables can be affected by several postharvest factors. In the present study, the effect of electron-beam (E-beam) irradiation was studied on grapefruit bioactive compounds. 'Rio Red' and 'Marsh White' grapefruits were irradiated with E-beam at 0, 1.0, 2.5, 5.0, and 10.0 kGy. Changes of various bioactive compounds, such as vitamin C, flavonoids, carotenoids, furocoumarins, and limonoids, were measured. The acidity decreased slightly with an increasing E-beam dose, whereas the total soluble solids were increased. Irradiation did not affect the vitamin C content at 1 kGy; however, doses beyond 1 kGy significantly reduced the vitamin C content. Lycopene and beta-carotene did not change significantly from the irradiation. Lycopene levels decreased as the E-beam dose increased, while the beta-carotene content slightly increased. Dihydroxybergamottin levels exhibited a decreasing trend, while the bergamottin content did not change. Naringin, a major flavonoid of grapefruit, showed a significant increase over the control at 10 kGy in both 'Rio Red' and 'Marsh White'. Nomilin continued to decrease with an increasing dose of E-beam irradiation, while limonin levels remained the same at all of the doses. Low-dose E-beam irradiation has very little effect on the bioactive compounds and offers a safe alternative to existing postharvest treatments for the disinfection and decontamination of grapefruits.
水果和蔬菜中的植物化学物质水平会受到多种采后因素的影响。在本研究中，研究了电子束（E-beam）辐照对葡萄柚生物活性化合物的影响。用0、1.0、2.5、5.0和10.0千戈瑞的电子束辐照“里约红”和“马什白”葡萄柚。测定了各种生物活性化合物的变化，如维生素C、类黄酮、类胡萝卜素、呋喃香豆素和柠檬苦素。随着电子束剂量的增加，酸度略有下降，而总可溶性固形物增加。1千戈瑞的辐照剂量对维生素C含量没有影响；然而，超过1千戈瑞的剂量会显著降低维生素C含量。番茄红素和β-胡萝卜素在辐照后没有显著变化。番茄红素水平随着电子束剂量的增加而降低，而β-胡萝卜素含量略有增加。二羟基佛手柑素水平呈下降趋势，而佛手柑素含量没有变化。柚皮苷是葡萄柚的主要类黄酮，在“里约红”和“马什白”中，10千戈瑞时与对照相比均显著增加。诺米林随着电子束辐照剂量的增加而持续下降，而柠檬苦素水平在所有剂量下均保持不变。低剂量电子束辐照对生物活性化合物的影响很小，为葡萄柚采后消毒和去污的现有处理方法提供了一种安全的替代方案。
