Effects of latitude and weather conditions on sugars,fruit acids and ascorbic acid in currant (Ribes sp.) cultivars

BACKGROUND: Sugars, acids and vitamin C are essential components influencing the sensory and nutritional properties of currants (Ribes sp.). In this study the effects of growth latitude and weather conditions on these components in red, white and green currant cultivars were systematically investigated for the first time. RESULTS: Red Dutch (a red Ribes rubrum cultivar) contained more malic acid but fewer sugars and had a lower sugar/acid ratio than Vertti (a green Ribes nigrum cultivar) and White Dutch (a white R. rubrum cultivar). Fructose (27–56 g L^?1 juice) and glucose (21–54 g L^?1) were the major sugars in all currant samples, but sucrose (7–20 g L^?1) was present only in Vertti. Vertti contained the most ascorbic acid. Sugars, malic acid and the sugar/acid ratio in Red Dutch were 11–28% higher in southern Finland than in northern Finland. The corresponding values in Vertti were 6–16% lower in the south than in the north, but no differences were found in White Dutch. As the relative humidity decreased, the amounts of citric acid and total acid increased in all cultivars, while the amount of sugars increased in Vertti but decreased in White Dutch and Red Dutch. In Red Dutch, high temperature and radiation levels increased the sugar content. CONCLUSION: The influence of latitude and weather conditions on qualitative parameters of currants varies with the cultivar. This study provides important guidance for currant cultivation and for further physiological and enzymological studies. Copyright © 2009 Society of Chemical Industry     

Carotenoid Pigments and Colour of Hermaphrodite and Female Papaya Fruits ( Carica papaya L) cv Sunrise During Post-Harvest Ripening

The predominant carotenoids in extracts of female and hermaphrodite Papaya fruits (Carica papaya L) Solo cv Sunrise were determined by high-performance liquid chromatography on a C₁₈ reversed-phase column using a diode-array detector. Three classes of carotenoids were separated and identified from the papaya extract without saponification; these were xanthophylls, hydrocarbon carotenoids and carotenol fatty acid esters. The xanthophylls were identified as trans-zeaxanthin, cryptoflavin and β-cryptoxanthin; other xanthophyls were detected in very small quantities. The major hydrocarbon carotenoid was identified as lycopene. Carotenol fatty acid esters were identified as carotenol fatty acid esters of β-cryptoxanthin, cryptoxanthin-5,6-epoxide, lutein, zeaxanthin and violaxanthin. There were no qualitative differences among the carotenoid pattern of female and hermaphrodite papaya fruits. Changes in carotenoid composition during ripening in hermaphrodite and female papaya fruits (cv Sunrise) were investigated in three different stages of ripeness. These changes could be shown in terms of Hunter colour values.     

浅探水果快递纸箱的绿色化优化思路与方法

近年来,由于人们消费观念的转变,水果电商快速发展,由此带来大量水果快递包装。本文以水果快递纸箱这一特定领域,分析了目前水果快递纸箱的环保现状,从选材、设计与回收等方面,提出了水果快递纸箱的绿色化、可循环、标准化与减量化的优化思路与方法,为水果快递纸箱的设计、开发与生产提供有效借鉴。     

Functional properties of reduced moisture fruits as ingredients in food systems

Fruit pieces of some species have been processed to be used as ingredients in various food systems, either by partial dehydration alone or by osmosis and partial dehydration, to achieve different levels of water activity and solids contents in the final products.

The relationships existing among processing, phase composition after processing and functional properties of the products have been assessed within a useful range of water content and water activity.

The functional properties are expressed as diagrams relating the phase composition (soluble solids, insoluble solids and water) to the range of consistencies obtainable at various water activities. These diagrams provide a useful tool for preparing fruit ingredients suitable for specific food systems.     

柑桔加工下脚料提取类胡萝卜素、橙皮苷、果胶和柠檬苦素

介绍了从柑桔加工下脚料提取类胡萝卜素、橙皮苷、果胶和柠檬苦素类产品的工艺方法 ,并简述了这些产品在医药、食品、日化等方面的应用     

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。     

图像处理与识别在果蔬成熟度监测中的研究及应用

目的 分析了果蔬成熟度自动监测对发展智慧农业的重要意义,对图像处理与识别技术在监测果蔬成熟度领域的研究与应用现状进行综述、总结与展望,以期为我国发展果蔬成熟度在线或自动检测识别技术提供参考。方法 对图像处理与识别在监测果蔬成熟度中的原理、优势进行分析,对特征提取、深度学习中的神经网络在该领域中的应用研究进展进行综述。结果 采用以图像处理和识别为核心的计算机视觉检测技术对果蔬的颜色、纹理等外部特征进行成熟度检测具有优势,结合神经网络对果蔬成熟度进行检测的识别率高,可在采摘、运输等场景对果蔬成熟度进行监测。结论 图像处理与识别技术在果蔬成熟度监测领域有望得到突破,将催生更多新的应用场景。     

基于灰色回归模型广州市果蔬类生鲜农产品冷链物流需求预测

目的 通过对不同预测方法的误差进行对比研究,选取预测精度较高的方法,促进部门科学化决策。方法 从农产品供给、社会经济水平、冷链物流保障、居民规模与消费能力四大维度选取15个指标来构建影响因素指标体系,对影响因素与冷链物流需求进行灰色关联度分析。采用GM(1,1)、GM(1,6)与主成分-多元回归线性模型对果蔬类生鲜农产品冷链物流需求进行预测。结果 GM(1,1)预测模型、GM(1,6)预测模型、主成分-多元回归线性预测模型的预测误差分别为2.97%、1.70%、2.53%。结论 GM(1,6)预测模型预测精度最高,该模型适用于中短期的冷链物流需求预测,具有较高的应用价值。     

不同银杏果添加量对花露烧酒风味的影响

目的 通过风味分析确定花露烧酒新品中银杏果的最佳添加量。方法 采用固相微萃取-气质联用(solid phase microexteaction-gas chromatography-mass spectrometry, SPME-GC-MS)和感官评价技术测定比较了不同银杏果添加量的花露烧酒的挥发性风味成分。结果 共鉴定出49种挥发性风味成分,各样品中香气成分的种类和含量有明显差异;经与糯米混合发酵后,银杏果中青草风味成分如壬醛、正己醛等显著下降或未检出;采用主成分分析法得出银杏花露烧酒香气与辛醇、八甲基四硅氧烷、乳酸乙酯、乙酸异戊酯等风味成分有关。由感官分析可知银杏果添加量为25%的样品C整体感官品质最佳,尤其是香气方面,产生了令人愉悦的正己酸乙酯、乙酸异戊酯等风味成分。结论 添加25%银杏果的花露烧酒的风味较好,为传统特色产品花露烧酒的创新提供了新思路,对银杏花露烧酒的风味控制提供了理论依据。