不同成熟期番石榴果实品质特征与评价

Quality characteristics and evaluation of guava fruit at different maturity stages

目的比较不同品种、不同成熟期的番石榴(Psidium guajava Linn.)果实品质特征。方法采用国家标准方法,对不同品种不同成熟期番石榴果实的食用品质、外观品质和营养品质进行测定和评价。结果番石榴各品种食用品质随果实发育成熟而明显提高,始熟期均表现出质地硬、汁液少、涩味重等共性,至完全成熟期食用状态最佳,‘水蜜’番石榴食用品质最好,‘珍珠’次之。不同成熟期红宝石的纵径、横径、单果重均显著高于相同成熟期的其他品种(P<0.05)。同一品种不同成熟期果实的纵径、横径和单果重,从始熟期至成熟期再至完全成熟期,均表现出显著上升的趋势(P<0.05),‘水蜜’的果形指数维持在<1.0,其余3个品种果形指数均维持在≥1.0。从始熟期至完全成熟期,4个品种番石榴果实含水量显著提高(P<0.05),淀粉、粗纤维含量均显著下降(P<0.05)。4个番石榴品种的总糖均主要由还原糖和蔗糖组成,且对于每个品种每个成熟期还原糖含量均高于蔗糖,还原糖、蔗糖、总糖含量随着果实成熟度的提高显著上升。在果实完全成熟期,还原糖、蔗糖、总糖均以‘红宝石’的含量最高,分别为32.74%、28.97%、63.16%,4个品种果糖含量范围为9.77%~12.05%,葡萄糖为3.70%~10.17%,每个品种的果糖含量均高于葡萄糖,品种之间葡萄糖含量差异较大。不同成熟期总酸含量均以‘珍珠’最高,其含量范围为5.32~7.58g/kg。结论各成熟期‘水蜜’食用品质均最好,但外观差,‘西瓜’食用品质最差、含糖量最低。完全成熟期,‘珍珠’食用品质仅次于‘水蜜’,含糖量仅次于‘红宝石’,蛋白质含量最高,果实综合品质最佳,适于鲜食、制果汁,‘红宝石’含糖量高、个大,适于果茶、果酒加工。

Objective To compare the fruit quality characteristics of different varieties and maturity of Psidium guajava Linn.Mehtods The edible quality,appearance quality and nutritional quality of different guava varieties at different maturity stages were measured by national standard method.Results The edible quality of each guava variety increased obviously with fruit development and maturity.At the initial maturity stage,four guava varieties all showed hard texture,little juice and strong astringency.The edible quality of guava reached the best at the full mature stage for all varieties,and the edible quality of‘Shuimi’was the best,followed by‘pearl’.The vertical diameter,transverse diameter and single fruit weight of‘Ruby’at different maturity stages were significantly higher than those of other varieties at the same maturity stage(P<0.05).The vertical diameter,transverse diameter and single fruit weight of the same variety at different maturity stages showed a significant increase trend from the initial maturity stage to the mature stage and then to the full maturity stage(P<0.05).The fruit shape index of‘Shuimi’maintained at<1.0,while those of the other three varieties maintained at≥1.0.From the initial stage to the full maturity stage,the water content of the four varieties of guava fruit significantly increased(P<0.05),and the starch and crude fiber contents significantly decreased(P<0.05).The contents of reducing sugar,sucrose and total sugar increased significantly with the increase of fruit maturity.The total sugar of the four guava varieties was mainly composed of reducing sugar and sucrose,and the reducing sugar content was higher than sucrose for each variety at each mature stage.The contents of reducing sugar,sucrose and total sugar increased significantly with the increase of fruit maturity.At the full mature stage,the contents of reducing sugar(32.74%),sucrose(28.97%)and total sugar(63.16%)of‘Ruby’were highest.The fructose content of the four varieties at the full mature stage ranged from 9.77%to 12.05%,and the glucose content ranged from 3.70%to 10.17%.The fructose content of each variety was higher than that of glucose,and there was a big difference between the varieties.The total acid content of‘Pearl’was the highest at different maturity stages,and the content range was 5.32-7.58 g/kg.Conclusion At each mature stage,the edible quality of‘Shuimi’is the best,but its appearance quality is poor;the edible quality of‘watermelon’is the worst and the sugar content is the lowest.At the full mature stage,the edible quality of‘Pearl’is second only to‘Shuimi’,and its sugar content is second only to‘Ruby’,and protein content are the highest,thus the fruit comprehensive quality of‘Pearl’guava was the best which is suitable for fresh eating and juice making.‘Ruby’has high sugar content with large fruit size which is suitable for processing fruit tea and fruit wine.