【Objective】3-year-old Shine Muscat grape under two-crop-a-year cultivation was used as the material to investigate the differences of physical and chemical indexes of basic quality, flavonoid components and contents between summer grape and winter grape, which would provide the theoretical basis for the quality control of Shine Muscat grape under two-crop-a-year cultivation.【Method】The climatic data, such as the sunshine duration, light intensity, temperature and rainfall during the whole growth period of Shine Muscat grape, were recorded. The physical and chemical indexes of basic quality in berries of summer and winter grapes of Shine Muscat were determined at the young fruit stage, expansion stage, softening stage, beginning maturity stage, and maturity stage, respectively. Meanwhile, the components and contents of flavonols and flavanols in the peel of summer and winter grapes of Shine Muscat grape were detected by LC-MS/MS.【Result】In terms of the climate factors, the summer grape of Shine Muscat displayed weak illumination and low temperature at early growth stage but strong illumination and high temperature at late growth stage of the whole developing period, while the winter grape was opposite. The average sunshine duration, average temperature and effective accumulated temperature in the growth period of summer grape were higher than those of winter grape, but the rainfall was lower than that of winter grape. The hydrothermal coefficient of summer grape was higher than that of winter grape from the beginning of maturity stage to maturity stage. In terms of the basic quality, the content of soluble solid of summer grape was significantly higher than that of winter grape at maturity stage, and the peel thickness of summer grape was significantly lower than that of winter grape. There was no significant difference in the single berry weight, fruit equatorial and longitudinal diameter and titratable acid content between summer and winter grape. In terms of the components and contents of flavonols, the content of total flavonols in peels of summer and winter grape showed a downward trend during the fruit developing stage. The content of total flavonols in different periods of summer grape was significantly higher than that of winter grape. The main flavonol in summer grape was quercetin-3-O-glucoside, while the main flavonol in winter grape was kaempferol-3-O-galactoside. In terms of the components and contents of flavanols, the content of total flavanols in summer and winter grape also showed a downward trend. The eight identical flavanols were detected in the peels of both summer and winter grape, and the main flavanols were catechin, epicatechin and procyanidin B1. The contents of total flavanols, catechin, epicatechin and procyanidin B1 in summer grape were significantly lower than those in winter grape during fruit development. The contents of gallic catechin, epigallocatechin, epicatechin gallate, epigallocatechin gallate, and procyanidin B2 at fruit maturation stage of summer grape were significantly higher than those of winter grape. The principal component analysis showed that there were differences in flavonols between summer and winter fruits. The regression analysis showed that catechin, quercetin-3-O-Glucoside and procyanidin B1 were the main components for distinguishing the flavonoids from summer and winter grapes.【Conclusion】In the study conducting year, the quality of summer grape of Shine Muscat was better than that of winter grape. During the whole grape developing stage, the content of total flavonols in summer grape was significantly higher than that in winter grape, while the content of total flavanols in summer grape was significantly lower than that in winter grape. The main components of flavonols were different between summer and winter grape of Shine Muscat, while the main components of flavanols were the same, namely catechin, epicatechin and procyanidin B1. The content of the main components of flavanols in winter grapes was significantly higher than that in summer grape, which might probably explained why the astringency taste of winter grape was stronger than that of summer grape. The differences in light and temperature during the growth period may be an important factor that caused the difference in the components and contents of summer and winter grapes of Shine Muscat.

[目的]明确黄意大利、金手指和摩尔多瓦葡萄冬果的挥发性香气成分,为各品种一年两收栽培冬果的开发和利用提供理论依据.[方法]以顶空固相微萃取技术(HS-SPME)结合气相色谱—质谱联用技术(GC-MS)分别对3个鲜食葡萄冬果的挥发性香气成分进行定性定量分析,测定其香气成分和相对含量.[结果]黄意大利、金手指和摩尔多瓦葡萄冬果基本品质综合表现较好,其可溶性固形物含量均超过15.00％,总糖含量均高于170.00 mg/mL,可滴定酸含量分布在6.51～7.10 mg/mL,糖酸比在28.00左右.挥发性香气成分分别鉴定出46、34和38种,包括醛类、醇类、酯类、酮类、萜烯类和酸类等香气成分.3个葡萄品种香气成分相对含量最高的均为醛类化合物,且以C6醛类化合物为主,表现为草本香和果香;相对含量位居第二的均为醇类化合物,其中,黄意大利和摩尔多瓦冬果以C6醇为主,表现为草木香和果香,金手指则以C7醇为主,通常表现为花香.黄意大利、金手指和摩尔多瓦葡萄冬果醛类总相对含量分别为63.59％、68.91％和85.35％,其中,黄意大利冬果香气成分相对含量最高的是正己醛(52.41％),而金手指和摩尔多瓦为2-已烯醛(48.52％和53.69％).[结论]黄意大利、金手指和摩尔多瓦葡萄冬果的基本品质较优,香气种类较丰富,在一年两收栽培模式下发展冬果栽培具有良好前景.

以“龙滩”珍珠李为试材,采用正交实验设计方法,对硬化剂浓度、护色剂配方、护色时间、甜味剂浓度、填充剂配方、糖煮时间和超声波渗糖等关键加工工艺条件进行了优化确定,为延长珍珠李供应期,提升附加值提供参考依据.结果表明:“龙滩”珍珠李低糖果脯最佳加工工艺条件为0.4％ CaCl2、0.20％D-异抗坏血酸钠、0.30％抗坏血酸、0.15％L-半胱氨酸盐酸盐混合溶液中硬化护色3 h;50％甜味剂(白砂糖∶葡萄糖粉=4∶1)、0.20％瓜尔胶、0.10％黄原胶、0.25％CMC-Na的混合液中糖煮20 min;再经超声功率300W、料液比1∶ 1g·g-1、超声4h.在此条件下,可制得形态饱满、色泽均匀、酸甜适度、软硬适中的“龙滩”珍珠李低糖果脯.

本文以龙滩珍珠李为原料,采用常压、真空、微波和超声波4种渗糖技术加工果脯,研究不同渗糖技术对龙滩珍珠李果脯感官品质、理化营养品质、质构特性以及对龙滩珍珠李果实细胞结构的影响.结果表明:真空渗糖制备的龙滩珍珠李果脯色泽最佳、褐变度最低(1.95),Vc含量最高(58.33μg/g),总糖含量较低,但组织状态和口感差;微波渗糖得到的果脯色泽最差,褐变度最高(3.18),Vc含量最低(41.34μg/g),且均与常压处理存在显著性差异(P<0.05),硬度、咀嚼性、弹性和胶着性均最低,分别为508.33 g、10.57 mJ、3.44 mm和256.33 g;超声波渗糖获得的龙滩珍珠李果脯感官总分、总糖含量、硬度、咀嚼性、弹性和胶着性均为最高,分别为82.13分、49.22％、868.33 g、16.00 mJ、3.68 mm和452.33 g,显著高于常压处理的(P<0.05),复水率最低(106.48％～128.66％),且明显降低了对龙滩珍珠李果实细胞结构的破坏.可见,超声波渗糖技术对龙滩珍珠李果脯品质及果实细胞结构的保护效果最好.