百香果採收成熟度之研究（二）對果汁中碳水化合物之影響

Studies on the Picking Maturity of Passion Fruit (2) Effect on the Carbohydrate Content of Juice

由HPLC分析得知百香果自授粉至發育35、42及49天等果汁中蔗糖含量是先增加後減少，而果糖及葡萄糖則繼續隨果實成熟而增加。二者比率近於１，貯藏後蔗糖與葡萄糖增加的原因可能是因為澱粉之水解等原因促成。澱粉含量以自然落果時的果汁中含量最低。HPLC分析出百香果汁中含有18種非揮發性有機酸，主要為檸檬酸約佔90%以上，蘋果酸、琥珀酸、乳酸、草酸及烏頭酸依次存在。不同採收成熟度百香果汁中碳水化合物之變化可提供果汁加工及品管檢驗上之參考。

Results indicate that sucrose content in passion fruits always increase in earlier maturation period and decrase at full mature stage as analyzed by high performance liquid chromatography. It was also shown that fructose and glucose contents increase during fruits maturation, and their ratio are near 1. The cause for sucrose and glucose increases is the starch hydrolysis during fruits storage. There are 18 kinds of non-volatile organic acids present in passion fruit juice, but the main one is citric acid with about 90% in the total acids, while malic, succinic, lactic, oxalic and aconitic acids arc present in smaller amounts in the order as listed. The informations obtained about the changes in carbohydrates in passion fruits during maturation and storage would be useful as good reference for passion fruit juice processing, quality control and inspection of the juice authenticity.