冬枣冰点及其冰点调节剂的筛选

研究了不同成熟度冬枣的冰点以及冰点调节剂对冬枣冰点的影响。结果表明:冬枣(白熟期)的冰点是-2.70℃;冬枣的冰点与其可溶性固形物含量之间呈良好的负相关关系,回归方程为y=-0.1567x+0.6561;氯化钙是较好的冰点调节剂,当冬枣用3%的氯化钙处理30min后,可以使冬枣的冰点由-2.70℃降低到-3.20℃。表明冬枣的冰点是可调的,适宜的调节剂可以使冬枣的冰点有较大幅度的降低。     

发光二极管绿光照射对精品蔬菜货架期品质的影响

在货架温度下采用发光二极管(LED)绿色光源照射西兰花、芦笋、青椒3种蔬菜,定期观察3种蔬菜在贮藏过程中的感观品质,并测定每种蔬菜叶绿素、维生素C、可溶性固形物和DPPH自由基清除能力的变化.结果表明:LED绿光照射能够抑制货架期西兰花、芦笋叶绿素和维生素C含量的下降(P＜0.05),保持西兰花和芦笋的商品性;LED绿光照射青椒的叶绿素含量低于对照,维生素C和可溶性固形物含量变化幅度较大,但感官上差异不大(P＞0.05),说明LED绿光照射对青椒贮运的影响不明显.     

桃果实品质形成成分与其风味之间的相关性(英文)

测定了白凤桃(PrunuspersicaBatschcv.Hakuho)果实中果汁的糖、酸、氨基酸、挥发性香气成分以及与其相对应的甜味、酸味、香气等风味特性之间的相关关系。结果表明:甜味与可溶性固形物含量呈较高的正相关;酸味与滴定酸呈高的正相关,而与挥发性香气物质十内酯、八内酯、己内酯、可溶性固形物含量呈较高的负相关;3种内酯物质与具有桃芳香风味的特性呈正相关,而与具青气风味特性呈负相关。以风味评定(综合评定)为因变量Y,各种测定成分为主变量X,逐步回归法分析的结果表明,影响桃风味的成分有可溶性固形物含量、滴定酸、十内酯、八内酯、反式-2-己烯醛。其中以酸度和十内酯物质含量的影响为最大。     

南瓜口感评价与营养成分的相关性和回归分析

以31份印度南瓜、12份中国南瓜、4份印度南瓜×中国南瓜种间杂种为研究对象,进行老熟南瓜口感评价及营养成分相关性研究,鉴定影响南瓜口感的关键指标,并建立一种科学评价口感的方法。结果表明:供试南瓜材料干物质含量为28.27~219.12g·kg~(-1)(FW),淀粉含量为4.13~93.68g·kg~(-1)(FW),可溶性糖含量为8.48~128.14g·kg~(-1)(FW),纤维含量为2.46~80.94g·kg~(-1)(FW),可溶性固形物含量为3.2~12.2°Brix(FW),VC含量为17.9~258.2mg·kg~(-1)(FW);含水少、甜、面、质地细腻、平滑的南瓜口感好,反之口感差。从口感与营养成分的整体趋势上看,干物质、淀粉、可溶性糖、VC及可溶性固形物含量升高、纤维含量降低口感变好;反之,口感变差。通过逐步回归分析,剔除了可溶性固形物、VC、纤维含量等贡献率小的营养成分,建立南瓜口感评价公式Y=-5.481+17.974X_1+10.716X_2+12.473X_3(Y为口感得分预测值,X_1为干物质百分含量,X_2为可溶性糖百分含量,X_3为淀粉百分含量),拟合优度指标R~2为0.907,预测口感效果较好。说明利用干物质百分含量、可溶性糖百分含量、淀粉百分含量预测肉用南瓜口感是可行的。     

柿果的冻结特性

以大果牛心柿为试材,利用热镀锡膜铜-康铜热电偶测温技术进行冻结试验研究.结果表明,柿果的典型冻结曲线具有过冷点、初始冰点、平衡冰点、终止冰点等关键特征点;脱涩与不脱涩处理的柿果冻结参数无显著性差异,柿果不同部位的过冷点与冰点均呈现皮下＜果内＜果心的趋势,过冷现象的显著性由皮下组织到果心依次变小;柿果果肉位置的冰点温度从-3.1～-2.4℃,与可溶性固形物含量呈显著负相关.     

甜瓜与3种蔬菜套种的研究

通过对甜瓜与小葱、辣椒和空心菜3种蔬菜套种方法的研究,测定了甜瓜的株高、茎粗、枯萎病发病率、可溶性固形物含量、Vc含量、体积和重量,研究出了适合甜瓜和蔬菜套种的模式。     

琯溪蜜柚果实分级标准研究

2014年10月20日至2015年1月10日在福建省平和县取样,对2 316个琯溪蜜柚单果的6项外观指标及可溶性固形物含量、汁胞粒化率进行测定分析。结果表明:汁胞粒化率变异系数(116.4%)远大于可溶性固形物含量变异系数(8.9%),汁胞粒化率是影响品质的首要因子。按外观指标与汁胞粒化率相关系数绝对值的大小,外观指标排序为体积(r=0.504)质量(r=0.472)、横径(r=0.469)果皮粗度(r=0.271)、体积质量(r=-0.265)果形指数(r=0.108);按外观指标与可溶性固形物含量相关系数绝对值的大小,外观指标排序为体积(r=-0.309)横径(r=-0.265)、质量(r=-0.259)、体积质量(r=0.257)果皮粗度(r=-0.230)果形指数(r=-0.086),各相关系数均达极显著水平(r0.001=0.071)。单果质量分级虽不及果实体积科学,但目前仍不失为好的选择。取200g为单果质量分级幅度基本能保证级别内果实品质的一致性。建议,单果质量800g和2 200g的果实划为等外果,果实分级幅度采用200g,将等级果(800~2 200g)分为4L、3L、2L、L、M、S和2S共7个级别;可溶性固形物含量标准为"特级≥11.5%,一级≥11.0%,二级和三级≥10.5%"。     

蓄冷式保温集装箱在蔬菜流通中的保鲜效果研究

为了满足生鲜农产品公铁联运需求,推动我国冷链物流行业的发展,测试了自主研发的蓄冷式保温集装箱在蔬菜上的实际应用效果。使用温度记录仪采集了蓄冷式保温集装箱的前中后部的温度数据;以色差(L~*、a~*、b~*)、硬度、pH值以及可溶性固形物含量作为评价指标,分析了两种蔬菜(油菜、韭黄)采用蓄冷式保温集装箱不同包装处理运输前后品质的变化情况。结果表明,箱内温度随箱外环境温度的变化而波动,但波动较小,箱内温度后部≥中部≥前部;不同处理组油菜的色差(L~*、a~*、b~*)、硬度和pH值均无显著变化;可溶性固形物含量,泡沫箱组、泡沫箱+冰组的略有下降,筐装组明显上升;泡沫箱组、泡沫箱+冰组的韭黄较运输前偏红、偏蓝,色泽略有变化,筐装组无明显变化,不同处理组韭黄的可溶性固形物含量和pH值均无明显变化。整体上,泡沫箱组、泡沫箱+冰组的蔬菜品质优于筐装组,这为蓄冷式保温集装箱的优化设计提供了参考和依据。     

粉果番茄贮藏期间主要性状变化规律研究

以番茄品种"浙粉202"为试材,研究了不同贮藏温度(1、7、14、20℃)对番茄果实颜色、硬度、可溶性固形物含量、有机酸含量和维生素C含量的影响。结果表明:番茄"浙粉202"果实贮藏13d时,14℃和20℃条件下腐烂率比1℃和7℃条件下腐烂率高,4个储藏温度下果实硬度和可溶性固形物含量均有不同程度下降。贮藏13d时,1℃贮藏条件下番茄硬度和维生素C含量最大,20℃条件下的硬度最小,7℃条件下有机酸含量在整个贮藏期较高,14℃条件下果实颜色值最大,20℃条件下有机酸含量、维生素C含量、果实颜色一直最低,1℃贮藏条件下番茄可溶性固形物、有机酸含量较高。因此,对于番茄"浙粉202"长时间贮藏的温度以1℃为宜。     

不同成熟度哈密瓜贮藏期间的生理变化

以新疆哈密瓜"西州密25号"为试材,定期测定0、2、4、6、8、10℃6个贮藏温度下,不同成熟度哈密瓜(可溶性固形物含量分别为14.5%、16.5%)采后贮藏期间可溶性固形物含量、硬度、细胞膜渗透率等指标随时间的变化,研究几种贮藏温度对采后哈密瓜果实贮藏期间的生理变化及贮藏效果。结果表明:果实在贮藏期间,可溶性固形物含量、果实硬度下降,细胞膜渗透率上升,综合看来,"西州密25号"在6℃左右条件下贮藏效果更佳,温度过低会加重果实表面变色与病斑发生,温度过高会加快果实腐烂与衰老。     

甜瓜数量性状遗传距离与杂种优势研究

将12个甜瓜高世代自交系分成两组,按NC-Ⅱ设计配制36个杂交组合。对12个自交系和36个组合的15个数量性状进行了主成分分析,7个最大的特征根累计百分率为86.27%,在影响甜瓜的数量性状中,首先考虑中心可溶性固形物含量及果肉厚度、可溶性糖、干物质重,其次是果皮硬度、蛋白质、果实发育期,最后是有机酸。利用亲本15个数量性状计算遗传距离。以遗传距离为自变量,杂种优势为依变量,进行回归分析。结果表明:单果重和游离氨基酸杂种优势与遗传距离之间均为显著直线关系,回归方程分别是Y=118.8425-39.5625X和Y=-15.1048+9.7646X;而果肉厚度杂种优势与遗传距离之间不存在直线关系,却较好地符合Density模型,且达显著水平,回归方程为Y=(1.0000+0.1000X)^(-1/1.0000)。     

长豇豆和丝瓜美洲斑潜蝇防治指标研究

连续自然接虫研究表明,长豇豆和丝瓜开花结实期美洲斑潜蝇产量损失与幼虫密度关系分别符合上列方程：Ｙ＝－０．０１１３８＋０．０００３５Ｘ（ｒ＝０．９９５３）;Ｙ＝－０．００５５２７＋０．０００６１Ｘ（ｒ＝０．９６３４）。根据当前价格和防治费用等因素,得出两种蔬菜在开花结实期的美洲斑潜蝇幼虫防治指标分别为百株８８４－１０２９头和１７７２－１９４５头。     

Leaf pruning intensities at flowering of banana (Musa AAA,cv. Grande Naine) did not influence fruit green and yellow life and quality

This study examined the effects of leaf pruning intensities at flowering on the green and yellow life and fruit quality of bananas (Musa AAA, cv. Grande Naine). The fruit from banana plants that retained 7, 9, 11 and 13 leaves after pruning were packed in carton boxes of 13.7 kg and stored in a cold room at 14 °C for 21 days to simulate transportation conditions. During this period, eight visual evaluations of fruit peel colour were made. Next, fruits were induced to commercial ripening using ethylene at 100 μl/ml. Four evaluations (every 2 days) on fruit firmness, soluble solids, titratable acidity, fruit weight and peel colour were made to assess fruit yellow life. No interaction between evaluations and number of leaves retained was found for pulp firmness, soluble solid percentage, fruit acidity, fruit weight and maturation grade. The fruit green life and peel colour was similar for plants retaining different number of leaves. After the application of ethylene, there were no differences in fruit firmness (P > 0.62), percentage of soluble solids (P > 0.24) nor in the percentage of acidity (P > 0.32). No difference in fruit weight (P > 0.07) and ripening grade (P > 0.17) were observed among plants retaining different number of leaves. The results suggest that in tropical commercial banana plantations, producing for international markets, it is possible to defoliate the banana plants to seven leaves at flowering without causing a reduction on the green and yellow life and quality of fruit.     

Soil and rootstock influence on fruit quality of plums (Prunus domestica L.)

Soil and rootstock can particularly affect the ‘Rainha Claudia Verde’ (Prunus domestica) fruit quality, mainly its firmness characteristics. To investigate the variation in fruit quality, plums were harvested at commercial maturity from trees grafted on Marianna GF8-1 (Prunus cerasifera × munsoniana) and Marianna GF10-2 (P. cerasifera × munsoniana) rootstocks on two different soils: Haplic Luvisol and Vertic Luvisol. After harvest fruits were stored at 2 °C for 3 weeks. At the harvest day a small group of fruits were analysed without cold storage. During storage fruits were tested for firmness, soluble solids content, titratable acidity and fruit mineral content. Tree vigour was evaluated from trunk cross-sectional areas values.The GF8-1 rootstock promoted the highest vegetative development, comparing to GF10-2. This rootstock promoted the largest fruits size and the higher calcium fruit level. Positive correlations were found between higher concentrations of calcium in the pulp fruits and firmness. Fruits from two different rootstocks showed the same firmness at harvest but during cold storage, fruits from GF10-2 rootstock exhibited the highest firmness pulp values. There weren’t significant differences in fruit nitrogen and potassium levels for any studied factor.At harvest solids soluble content and solids soluble content/titratable acidity ratio weren’t affected by soil type or rootstock. As expected, solids soluble content during cold storage increased and solids soluble content/titratable acidity had a slight increase.GF10-2 revealed to be a good option as a ‘Rainha Claudia Verde’ rootstock for plums growers due to its intermediate-vigour. Also GF10-2 fruits presented better quality during storage comparing with GF8-1.     

电导法研究盐类对黄瓜冻害的预防作用

选用5种无机盐常温浸泡黄瓜,以电导法测定黄瓜冻害伤害率,研究了盐的种类、盐液pH值、盐浓度、浸泡时间等因素对黄瓜冻害的影响.试验结果表明,所选5种盐KNO3,MgSO4,NaCl,CaCl2和MgCl2中,经MgCl2浸泡后黄瓜耐冻害能力最强,最佳浸泡工艺为:MgCl2浸泡浓度为0.03 g/100 mL,pH值8.0,浸泡时间20 rain.在-18℃冷冻100 min后.空白组伤害率为57.8%,经MgCl2浸泡组为30.7%,伤害率降低了27.1%,抗冻害能力提高了46.8%.经浸泡后黄瓜呼吸强度明显降低,浸泡20min后黄瓜的呼吸强度由对照的33.8mg·(kg·h)-1降低到15.8mg·(kg·h)-1,显示盐类提高黄瓜抗冻害能力与降低其呼吸强度之间有一定关联.     

抗青枯病番茄新品种‘渝抗10号’

‘渝抗10号’番茄是新育成的一代杂交种,无限生长型,中晚熟;果实圆形,成熟果红色,平均单果质量140g;可溶性固形物含量5.12%,维生素C含量0.181mg·g-1,可溶性糖含量3.62%,可滴定酸含量0.38%;果实硬度0.71kg·cm-2,耐贮运;高抗青枯病,抗ToMV和枯萎病;露地栽培平均产量53.7t·hm-2。     

1-MCP 对新红星苹果乙烯代谢和贮藏品质的影响

 以新红星苹果为试材, 研究了室温贮藏和低温贮藏两种条件下1-MCP (1 - 甲基环丙烯) 对果实乙烯释放量、内源乙烯浓度、硬度、可滴定酸含量及可溶性固形物含量的影响。结果表明, 300 nL·L ^-1浓度的1-MCP 能显著抑制果实乙烯释放, 延缓乙烯高峰的出现, 延缓果实硬度和可滴定酸含量的下降, 但对可溶性固形物含量无影响。     

Partial rootzone drying maintains fruit quality of ‘Golden Delicious’ apples at harvest and postharvest

Partial rootzone drying (PRD) has been evaluated at harvest, but its effects on apple fruit postharvest life is little known for apples grown in semi-arid regions. The objective of this study was to test the hypothesis that water savings via PRD may affect fruit quality at harvest and postharvest-life of ‘Golden Delicious’ apples grown in a semi-arid region. The experiment was conducted from 2005 to 2007. The irrigation treatments were commercial irrigation as control (CI) and PRD. After 3 years of evaluation, fruit quality at harvest, measured as fruit weight, flesh firmness, and total soluble solids concentration, was similar between CI fruit and PRD fruit. Dry matter concentration (DMC) was higher in PRD fruit than in CI fruit in 2005. The fruit quality after 18 days storage at room temperature (13–18 °C and 51–56% relative humidity) was similar between CI fruit and PRD fruit. The DMC was the highest in PRD fruit in the 2005 and 2007 growing seasons, and tended to be higher in PRD fruit than in CI fruit in 2006. Total soluble solids concentration was ≈8.7% higher in PRD fruit than in CI fruit in 2007. Fruit weight loss was similar between treatments. This study suggests that water deficit via PRD did not damage fruit quality at harvest or after storage at room temperature. Additionally, PRD irrigation saved about 3240 m³ of water per hectare. Therefore, PRD can be recommended for commercial use in semi-arid regions and to those growers interested in either long-term storage or distant markets.     

果梅种质枝条抗寒性鉴定

通过电导法对28份果梅种质的枝条抗寒性进行了比较分析,同时研究了枝条的可溶性蛋白、可溶性糖和丙二醛(MDA)的含量与果梅种质抗寒性的关系。结果表明:果梅种质资源的枝条抗寒性存在着很大的差异,经12h低温处理,其枝条的半致死温度为-9.3℃--20.2℃,其中丰后、高田丰后、软条红梅等种质比较抗寒,半致死温度分别为-20.2℃、-17.7℃、-19.3℃;东青、开蒂和红顶等种质抗寒性较差,半致死温度分别为-9.4℃、-9.4℃、-9.3℃;果梅枝条中可溶性蛋白和糖类与种质的抗寒性呈正相关关系,相关系数分别为0.93959和0.86709,而与丙二醛含量呈负相关关系,相关系数为-0.952122。