不同品种龙眼果实加工特性比较研究

Comparative Studies on Processing Characteristics of Different Longan Cultivars

以18个龙眼品种的果实为试材,利用常规的加工特性分析方法,进行果实的组成、理化指标、可溶性蛋白、总酚和总抗氧化能力的分析。结果表明:龙眼品种间果实出汁率、可溶性固形物含量、可食率、总酸、糖酸比差异较大,出汁率为36.02%～55.74%,水眼最高(55.74%);华路广眼最低(36.02%),可溶性固形物为11.3%～21.77%,白花木最高(21.77%),青壳宝园最低(11.3%)。18个龙眼品种的多酚氧化酶(PPO)、过氧化物酶(POD)的活性和色泽稳定性差异较大,PPO为0～6.6U,POD为72.7～1816.7U,色泽变化值(ΔE)在30℃时为0.24～3.68,100℃时为7.62～63.53。初步评价:石硖、储粮、白花木、华路广眼和双孖木是适宜于果汁和果酒加工的优良品种。龙眼的总抗氧化能力值在3.73～20.39mmol/L之间,双孖木最高(20.39mmol/L),青壳宝园最低(3.73mmol/L);可溶性蛋白含量分布变幅为45.82～88.8mg/L,石硖最高(88.8mg/L),鸡卵眼最低(45.82mg/L);总酚含量在13.02～749.95mg/L之间,华路广眼最高(749.95mg/L),鸡卵眼最低(13.02mg/L)。

Fruits of 18 longan cultivars were analyzed for physical and chemical parameters,total antioxidant capacity,soluble protein and total phenolics.Results showed that there were remarkable differences in fruit juice rate,contents of total soluble solids and total acids,edible pulp rate and ratio of sugars to acids of tested longan cultivars.Fruit juice rate ranged from 36.02% to 55.74%,and the highest was exhibited in Shuiyan cultivar（55.74%） and the lowest in Hualuguangyan（36.02%）.Total soluble solids content ranged from 11.3% to 21.77%,and the highest was exhibited in Baihuamu（21.77%） and the lowest in Qingkebaoyuan（11.3%）.Besides,notable differences were also observed in PPO and POD activities and color stability of these longan cultivars.PPO ranged from 0 to 6.6 U,and POD from 72.7 to 1816.7 U.Longan fruits exposed to 30 ℃ and 100 ℃ revealed a total color difference（ΔE） value ranging from 0.24 to 3.68 and from 7.62 to 63.53,respectively.It was preliminarily evaluated that Shixia,Chuliang,Baihuamu,Hualuguangyan and Shuangzimu were excellent cultivars for longan juice and longan wine making.Among these longan cultivars,Shuangzimu and Qingkebaoyuan exhibited the highest and lowest total antioxidant capacity of 20.39 mmol/L and 3.73 mmol/L,respectively.Soluble protein content was fluctuated in the range of 45.82（Jiluanyan） to 88.8 mg/L（Shixia）.The highest total phenolics content valued at 749.95 mg/L was observed in Hualuguangyan,and the highest at 13.02 mg/L in Jiluanyan.