Phenolic and carotenoid profiles of papaya fruit (Carica papaya L.) and their contents under low temperature storage

BACKGROUND: Tropical fruits are rich in phenolic and carotenoid compounds, and these are associated with cultivar, pre‐ and postharvest handling factors. The aim of this work was to identify major phenolics and carotenoids in ‘Maradol’ papaya fruit and to investigate their response to storage temperature. RESULTS: Ferulic acid, caffeic acid and rutin were identified in ‘Maradol’ papaya fruit exocarp as the most abundant phenolic compounds, and lycopene, β‐cryptoxanthin and β‐carotene were identified in mesocarp as the major carotenoids. Ranges of contents of ferulic acid (1.33–1.62 g kg^?1 dry weight), caffeic acid (0.46–0.68 g kg^?1 dw) and rutin (0.10–0.16 g kg^?1 dw) were found in papaya fruit, which tend to decrease during ripening at 25 °C. Lycopene (0.0015 to 0.012 g kg^?1 fresh weight) and β‐cryptoxanthin (0.0031 to 0.0080 g kg^?1 fw) were found in fruits stored at 25 °C, which tend to increase during ripening. No significant differences in β‐carotene or rutin contents were observed in relation to storage temperature. CONCLUSION: Phenolics and carotenoids of ‘Maradol’ papaya were influenced by postharvest storage temperature with exception of β‐carotene and rutin. Ripe papaya stored at 25 °C had more carotenoids than those stored at 1 °C. Low (chilling) temperature (1 °C) negatively affected the content of major carotenoids, except β‐carotene, but preserved or increased ferulic and caffeic acids levels, as compared to high (safe) temperature (25 °C). Copyright © 2010 Society of Chemical Industry     

番木瓜果酒发酵及其抗氧化能力分析

以番木瓜为原料,经破碎、酶解、成分调整后接种葡萄酒活性干酵母,于（22±1） ℃发酵制备番木瓜果酒。研究发酵过程中总糖、还原糖、滴定酸含量与抗氧化能力的变化,明确番木瓜果酒的理化指标与感官品质。结果表明,番木瓜果酒发酵过程中总糖、还原糖含量逐渐降低,滴定酸含量增加,总酚含量、DPPH自由基清除率和亚铁还原能力（FRAP值）降低,pH值变化无规律性。番木瓜果酒酒精度10.7%vol,残糖量4.4 g/L,滴定酸4.5 g/L,总酚含量3.0 g/L,DPPH自由基清除率63.0%,FRAP值2.33 mmol/L,属半干型果酒,抗氧化能力较强,理化与感官品质均符合相关果酒标准要求。     

不同处理方式对厚皮甜瓜贮藏品质的影响

以‘千玉1号’厚皮甜瓜为试材,采用噻苯咪唑（TBZ）熏蒸、焦亚硫酸钠（Na2S2O5）、1-甲基环丙烯（1-MCP）结合气调贮藏等处理方法,研究了不同处理方式下厚皮甜瓜贮藏期间果实品质的变化。结果表明,厚皮甜瓜经TBZ熏蒸后置于贮藏环境中,放入Na2S2O5和1-MCP,在气体成分5%O2+7%CO2+88%N2、温度（1.0±0.5）℃、相对湿度85%⁹0%条件下贮藏,能延缓果实可溶性固形物含量和可滴定酸含量下降,减少水分散失,抑制相对电导率上升,有效地保存总糖含量和原果胶含量,降低果实腐烂损失,使果实硬度保持在较高水平。经该处理后贮藏50 d,甜瓜商品果率91%,果实外观新鲜,感官品质良好,保鲜效果理想。      

乙醇熏蒸对番木瓜采后品质和生理指标的影响

为研究乙醇熏蒸对番木瓜采后的保鲜效果,本次实验用不同浓度的乙醇对番木瓜进行熏蒸处理。实验结果表明乙醇熏蒸能够明显减少其可滴定酸、可溶性固形物和VC含量的损失,延缓果实硬度的下降,降低多酚氧化酶活性等生理指标的变化速率。特别是浓度为2.0 m L/kg的乙醇的保鲜效果最佳。这为乙醇熏蒸作为保鲜方法应用于果蔬生产中提供参考依据。      

不同冻结速率对冻后番木瓜品质的影响

研究木瓜在不同冻结方式下的冻结特性（冻结曲线、冻结速率、通过最大冰晶带时间、冻结点等）和品质变化。研究表明木瓜的冻结点随着速冻速率的改变而有所变化,但整体变化幅度不大,在-1.1^-1.7℃之间。提高冻结速率可减少通过最大冰晶带的时间。冻结后木瓜的p H均降低,且随着冻结速率的增大,干耗率、汁液损失率、褐变度逐渐减小,但冻结速率对木瓜中的VC、可溶性固形物含量影响很小。冻结对木瓜的PPO和POD酶活性有一定的抑制作用,随着速冻速率的增大,两种酶活性均呈先增大后减小的趋势。综合理化指标和感官评价结果,冻结速率快有利于保持木瓜的品质。      

番木瓜中糖类成分的纯化与鉴定

目的：研究番木瓜果肉的糖类成分,以寻找活性化合物。方法：干燥的番木瓜干经95%乙醇提取,石油醚萃取脱脂后的水相采用聚酰胺、MCI、ODS、ODS-AQ柱层析进行纯化,并通过MS和NMR鉴定。结果：从番木瓜果肉乙醇提取物中分离并鉴定出4个糖的衍生物,分别为乙基α-D-果糖苷(Ⅰ)、乙基β-D-果糖苷(Ⅱ)、苄基β-D-葡萄糖苷(Ⅲ)、2-O-β-D-葡萄糖苷-3,6-二羟乙基-5-苯基-1,4-二氧已基-2-醇(Ⅳ)。     

液浸速冻番木瓜浆冻藏色泽变化研究

以番木瓜浆为研究对象,测定色泽参数(L、a、b、ΔE)、番茄红素及β-胡萝卜素含量,研究液浸式速冻对番木瓜浆冻藏色泽变化的影响。结果表明:冻藏过程中,液浸式速冻番木瓜浆色泽稳定性优于空气对流冻结;番茄红素的降解是导致冻藏番木瓜浆色泽变化的主要原因;相比空气对流冻结,液浸式速冻能提高番茄红素降解活化能近2倍,有利于抑制番茄红素的降解损失,保持色泽稳定。     

乙烯催熟对采后果实贮藏品质的影响

乙烯是一种植物催熟激素,目前已经被广泛应用于采后果实的催熟。本文综述了乙烯对呼吸跃变型果实和非跃变型果实贮藏品质的影响。采后乙烯处理能够促进两种呼吸类型果实的褪绿转黄,改善果实色泽,并且能够引起两类果实硬度的下降,促进果实软化。乙烯处理能够促进跃变型果实贮藏过程中风味提升、香气改善、抗氧化能力提高,然而,乙烯对于非跃变型果实的这些品质并无显著影响。因此,对于在生产上应用乙烯催熟非跃变型果实,应在其食用品质达到商业要求之后方可采收。