Structural changes,chemical composition and antioxidant activity of cherry tomato fruits (cv. Micro‐Tom) stored under optimal and chilling conditions

BACKGROUND: Cherry tomato fruits cv. Micro‐Tom, a model plant for tomato genetics, were analysed in order to determine the main structural and chemical changes under optimal and chilling storage conditions. The comparison of Micro‐Tom to standard tomato cultivars will give an insight into suitability of this dwarf cultivar as a model for studying the influence of low‐temperature conditions on tomato fruits. RESULTS: During chilling, fruit tissue was progressively destroyed due to the collapse of the deep layers of the pericarp. Chilling lowered the typical tomato kinetics of ripening in sugars (glucose, fructose, sucrose), organic acids (tartaric, malic, citric, ascorbic and succinic) and the antioxidants phenol and lycopene, while carotenoid synthesis seemed to be blocked. Glutathione level was elevated and the activity of ROS scavenging enzymes was altered. Essentially, Micro‐Tom fruits showed a quality evolution that was similar to that described for standard tomato cultivars. CONCLUSION: The cherry tomato cultivar Micro‐Tom could be used as a model for studying the influence of low temperature on biochemical and structural changes taking place during chilling injury conditions. Copyright © 2009 Society of Chemical Industry     

减压贮藏对番茄果实抗氧化物质和抗氧化酶的影响

为了研究不同减压处理对番茄果实后熟过程中抗氧化性的影响,以粉冠番茄为材料,研究了在43.6、73.0kPa和常压三个压力条件下,番茄中维生素C、番茄红素和谷胱甘肽含量,以及超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)的活性变化规律。结果表明,减压贮藏显著推迟了番茄中维生素C含量的高峰,在一定程度上延迟了番茄红素和谷胱甘肽含量的高峰,并且压力越低效果越显著(p<0.05);在果实后熟过程中SOD、CAT活性逐渐下降,而减压处理可显著抑制SOD活性下降(p<0.05)。POD活性在贮藏期间呈现先降后升的趋势,减压处理可以有效地保持较高的抗氧化酶活性。结论:减压处理贮藏可以显著保护番茄果实中的抗氧化物质和抗氧化酶活性,而且一定范围内压力越低效果越好。      

Effect of increasing manganese concentration in nutrient solution on the antioxidant activity,vitamin C,lycopene and polyphenol contents of tomato fruit

ABSTRACT

This study evaluated the effect of increasing manganese (Mn) nutrition on the content of antioxidative compounds such as vitamin C, lycopene and polyphenols, and the antioxidant activity of tomato (Lycopersicon esculentum Mill., cvs ‘Alboney F1’ and ‘Emotion F₁’) fruit. Plants were grown in rockwool using a nutrient solution with the following content of Mn (mg dm^–3): 0.0, 0.3, 0.6, 1.2, 2.4, 4.8, 9.6 and 19.2. The level of vitamin C and lycopene decreased with the increasing Mn nutrition. Since the colour of fruits was correlated with the change in carotenoid content, the decrease in lycopene content promoted the reduction of redness and increase of yellowness of fruits. However, total polyphenol content and antioxidant activity significantly increased when plant were exposed to toxic levels of Mn. Observed changes could be the result of the oxidative stress induced by high concentrations of Mn. Polyphenolic compounds play a crucial role in the plant’s response to Mn stress and affect predominantly the total antioxidant properties of fruits, which could be used as a source of phenolics. Moreover, total phenolic content measurement, as an easy and inexpensive method, could be used as an indicator of Mn-induced stress in fruits of tomato.     

黄花蒿残膏的挥发性成分分析及其抑菌和抗氧化活性研究

采用无水乙醇浸提法提取黄花蒿残膏中的挥发性成分,对其成分进行GC-MS分析,并通过纸片抑菌实验和抗氧化实验对挥发油抑菌和抗氧化活性进行测定。结果表明:黄花蒿残膏挥发油中鉴定出包括石竹烯氧化物（15.27%）、樟脑（8.71%）和冰片（8.57%）在内的29种成分,占总挥发油的81.23%。纸片法抑菌活性测试表明黄花蒿残膏挥发油对四种实验供试菌均有明显的抑制作用,大肠杆菌、金黄色葡萄球菌、鼠伤寒沙门氏菌的最小抑菌浓度为0.5%相似文献   

低糖樱桃番茄果脯渗糖工艺研究及品质评价

为了探讨果脯品质的量化评价指标,本文以樱桃番茄为研究对象,对不同渗糖梯度、食盐浓度制成的果脯进行感官评定和质地多面分析法(Texture Profiles Analysis,TPA)评价,优化了樱桃番茄果脯的生产工艺参数;同时对感官评定和TPA评价指标进行相关性分析。结果表明:制作樱桃番茄果脯较优工艺参数为渗糖梯度20%~30%~40%~50%,食盐浓度1%;TPA指标中的硬度、胶粘性和咀嚼性与感官评定指标存在显著相关性,并得到了以TPA指标为自变量,感官评定指标为因变量的具有统计学意义(p<0.05)的线性回归方程,此结果对感官评定指标进行了有效的补充,可为果脯品质的定量评价提供理论依据。      

Effects of organic fertilisers and irrigation level on physical and chemical quality of industrial tomato fruit (cv. Nautilus)

BACKGROUND: The objective of this work was to study the influence of irrigation and organic fertilisation on quality attributes of tomato fruit (cv. Nautilus) grown for the canning industry. The assay was carried out during two consecutive years (2006 and 2007) in agricultural soil. Nine treatments resulting from the combination of three fertilisation types (sheep manure, a mixture of sheep manure and peat and an inorganic fertiliser (control)) with three levels of drip irrigation (3.30, 5.00 and 6.70 mm day^?1) under black polyethylene mulch were applied (n = 3). RESULTS: For the chromatic attributes L*, H*, C* and S* the highest values corresponded to the treatments with organic matter. However, the a*/b* ratio and colour index value were higher for the control treatment. In all cases the estimated optimal ripening time was the same, and on this date a decline in the ratios was observed. The values of the physical properties increased with increasing irrigation, higher values always being obtained in the treatments with organic fertilisers. The highest production for all irrigation levels corresponded to the treatment with mixed sheep manure and peat fertiliser. CONCLUSION: Cultivation involving fertilisation with the manure/peat mixture and an irrigation level slightly above 5.00 mm day^?1 can be recommended as optimal, since it gave the most satisfactory values with respect to the quality attributes of tomato fruit grown for the canning industry. Copyright © 2009 Society of Chemical Industry     

果酿啤酒的酿造工艺和品质研究进展

果酿啤酒的品质受众多因素影响,特别是水果特性差异和产品质量标准缺失使得果酿啤酒的酿造工艺存在较大差别,产品质量难以稳定。为进一步提升果酿啤酒品质,该文对近年来果酿啤酒的研究现状进行综述,探讨水果榨汁处理、灭菌方式,发酵过程中原麦汁浓度、主发酵温度、果汁添加量及添加阶段、酵母菌种选择等因素对果酿啤酒品质的影响,分析果酿啤酒的风味成分及风味劣变、活性成分及抗氧化活性,并对果酿啤酒的发展趋势及品质提升进行展望,以期实现不同果酿啤酒的精准调控,为实际生产中果酿啤酒的酿造提供借鉴。     

超声波辅助酶法处理对百香果出汁率及品质的影响

近年来,国内外市场对百香果果汁需求量逐渐增高,但传统物理压榨法出汁率较低,为提高百香果出汁率,本试验以台农1号百香果为原料,利用超声波辅助复合酶法,通过研究超声温度、超声时间、酶解时间、酶解温度、复合酶配比和加酶量等因素对百香果果汁的影响,在单因素的基础上进行正交试验,以出汁率和感官评价结果为依据,得出最佳加工工艺,并对运用该工艺提取的百香果果汁进行品质分析。结果表明:最佳工艺为超声温度为20℃、超声时间为30 min、酶解时间为60 min、酶解温度为20℃、酶配比为1:1(果胶酶:纤维素酶)、加酶量为0.24%,与直接压榨果肉相比出汁率提高23.29%,维生素C含量损失率降低了20.88%,可溶性糖含量提升了42.41%、总抗氧化能力、ABTS清除能力和DPPH清除能力和总酚含量分别提升了55.23%、7.73%、73.18%和37.61%,对氨基酸含量的影响差异不显著。因此,采用超声波辅助酶法处理百香果可以显著提升百香果出汁率及抗氧化能力。     

山葡萄单株留果量对产量和果实品质的影响

为提高山葡萄生产栽培果实质量和产量,以双红、双优和左优红为试材,进行单株不同留果量的试验。结果表明：随着单株留果量和产量的增多,植株萌芽率、穗重、粒重、果实含糖量和出汁率大幅度降低,而果穗小青粒和果实总酸大幅度增高;适宜的单株留果量为50～70个。