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为更好地利用塔罗科血橙资源,研究乳酸-超声波提取血橙皮中的果胶工艺,考查超声波功率、提取时间、提取pH、料液比、提取温度等对果胶产率的影响,利用正交试验设计得出果胶提取的最佳工艺条件.结果表明:在料液比为1∶35,提取液pH 2,超声波时间50 min,超声波功率280 W的条件下,其果胶的产率为30.53％,产品果胶总半乳糖醛酸含量为68.76％,脂化度为72.49％,含水率为8.01％,总灰分为3.25％,酸不溶灰分为0.26％.     

生长期和植株性别对工业大麻杆果胶含量及质量的影响

果胶是木质材料中关注较少的化学成分,为了确定果胶在生物质材料中粘结细胞的关键作用,以实现利用果胶酶进行纤维分离。按照称重法、造纸原料-果胶含量的国家标准（GB/T 10742—2008）等测定方法,以工业大麻为对象,研究了不同生长期和植株性别中工业大麻杆的单株质量、果胶含量及果胶质量的变异特性。结果表明,大麻杆在整个生长周期19~186 d内,果胶含量在19.74%~5.68%范围内变化,随着生长天数增加而降低(p<0.000 1);果胶质量随着生长天数的增加而增加(p<0.000 1),质量范围为0.02~22.88 g;生长期相同时,雌株的果胶含量>雄株,约为0.1%~2.21%(p=0.000 5)。果胶主要存在于纤维胞间层和初生壁中,随着纤维细胞次生壁的逐步生成,果胶含量降低;但随着工业大麻秆生长期的延长,细胞数目的增加果胶质量增加。     

微波辅助提取黄皮果肉果胶工艺参数优化

为优化微波辅助提取黄皮果肉中果胶的工艺,采用均匀设计法,考察了微波功率、提取时间、液料比及提取液pH值4个因子对黄皮果胶得率的影响。利用SAS软件对试验数据进行模型拟合和回归分析,确定提取时间和液料比是影响果胶得率的重要因子,并最终获得微波辅助提取黄皮果胶的最优工艺参数为:微波功率600W,提取时间8min,液料比24:1mL/g,提取液pH值2.0。在此条件下果胶得率为3.59%。通过对果胶基本特性的测定分析,该工艺提取的黄皮果胶品质基本符合国家标准,可为黄皮果胶提取的工业化放大提供参考。     

Effect of Calcium Foliar Application on the Characteristics of Blueberry Fruit during Storage

ABSTRACT

Effect of calcium (Ca) foliar application on blueberry fruit characteristics during storage was investigated. Calcium applications began 28 d after flowering, two levels (3.9 g Ca^{2 +} and 39 g Ca^{2 +}) and a control without calcium were used (0.0; 3.0, and 30 mL L^?1). The fruits were harvested on day 103 and were stored for 56 d at 2 ± 1°C. At harvest time the fruits had a significant statistical different concentration, which were maintained until the last day of storage. The fruit from the 30 mL L^?1 treatment was the highest. The lowest texture levels are found with the treatment without calcium, which shows a statistically significant change from storage day 29. The LMP percentage did not varied in the fruit from the treatment with 30 mL L^?1, but did in the fruit without calcium. Hunter L, b, and the index chromes were influenced by the applied calcium levels, significantly greater at 30 mL L^?1; and by the time of storage in the fruits with treatment of 30 mL L^?1.     

Effect of Foliar Application of Calcium on the Quality of Blueberry Fruits

Effect of foliar application of calcium (0.78 g, 4.68 g, and 7.8 g Ca^{2 +}) in pre-harvest, at three different growing conditions (tunnel, mesh, and ambient), on texture and pectin in blueberries (Vaccinium corymbosum) was studied. Calcium contents in leaves as well in fruits were different (P ≤ 0.05), affected by growing conditions and time. Differences (P ≤ 0.05) in calcium content were found in tunnel cultivar fruit, during the period to cell expansion toward harvest, at calcium foliar level of 5 mL per L (7.8 g). Fruit texture was significantly higher at the beginning of the cell expansion period in the tunnel cultivar fruit, and a linear correlation between calcium concentration and texture was established. Increment in low methoxyl pectin (LMP) was influenced by growing conditions, and was different (P ≤ 0.05) for tunnel cultivar fruit. A good correlation between LMP and calcium content was obtained with the high dose of calcium (5 mL per L).     

橙汁魔芋水晶软糖的生产工艺

以魔芋精粉为主要原料,以橙汁作为增味剂并辅以其他食品添加剂,对pH值、果胶量、糖酸比和凝胶温度等因素进行分析并采用正交法优选,制得有橙汁风味、营养丰富的水晶软糖,同时对产品进行感官、理化和微生物分析。结果表明,pH 4.5,果胶含量1.1%,糖酸比90∶1,凝胶温度63℃,最佳干燥时间18 h,干燥温度55℃条件下可研制出组织状态、色泽和口感均优良的软糖。     

不同年限设施菜地番茄细胞壁果胶Cd累积的研究

为探讨不同种植年限和设施菜地番茄细胞壁果胶Cd累积的关系,以种植年限为2年和14年设施菜地番茄为研究对象,测定了不同种植年限下番茄茎、叶细胞壁果胶含量,并对细胞壁果胶含量、果胶甲酯酶(PME)活性与种植年限及Cd累积量之间的相关性进行了分析。结果表明,随着种植年限的增加,番茄植株各器官Cd累积量均有所增加;种植14年设施菜地番茄茎中Cd累积量比种植2年的增加了24.55%,叶片中Cd累积量增加了45.96%;种植14年设施菜地番茄茎细胞壁Cd累积量增加了61.86%,叶片细胞壁Cd累积量增加了57.46%;不同种植年限设施菜地番茄茎和叶细胞壁果胶Cd含量也存在极显著差异(P0.05)。另外,随着种植年限的增加,番茄茎、叶细胞壁果胶含量和PME活性随之升高:与种植2年相比,种植14年设施菜地番茄茎中果胶含量提高了104.51%,叶片果胶含量提高了127.45%;种植14年设施菜地番茄茎中PME活性提高了10.56%,叶片PME活性提高了9.39%。果胶含量及PME活性和细胞壁Cd累积量呈正相关。研究发现不同年限设施菜地土壤全Cd和有效Cd含量有所不同,影响着番茄不同器官果胶含量及PME活性,说明细胞壁果胶在缓解番茄Cd毒害中起着一定的作用。     

南瓜皮果胶提取工艺初探

以南瓜皮为原料,采用酒精沉淀法提取果胶,实验结果表明,最佳工艺条件为:料水比1:35(W/V),浸提液pH 值2,浸提温度90℃,浸提时间90min,用95%乙醇沉淀时,果胶提取率约为12.5%.     

高活性苎麻脱胶菌的选育

苎麻生物法脱胶是一种绿色环保的脱胶方法,具有脱胶质量稳定和不损伤纤维的特点。为了选育稳定、高活性苎麻脱胶菌,以透明圈法和摇瓶发酵法从土壤中分离初筛得到的微生物脱胶菌株(15号)作为出发菌株,采用紫外和亚硝酸复合诱变处理,以青霉素抗性为标记,对大量初筛得到的突变株进行筛选,最终选育得到4株高活性苎麻脱胶菌株。与出发菌株相比,其中U-4使木聚糖酶活提高了15.81%,果胶酶活提高了6.49%,纤维素酶活降低了37.45%,残胶率降低了16.89%。     

小麦根尖细胞壁对铝的吸附/解吸特性及其与耐铝性的关系

研究了耐铝性明显差异的2个小麦基因型西矮麦1号(耐性)和辐84系(敏感)根系对铝毒胁迫的反应与根尖细胞壁组分以及细胞壁对铝的吸附和解吸的关系。结果表明,30mol/L.AlCl3可迅速抑制小麦根系伸长,但对辐84系根系伸长的抑制更为明显,且小麦根系相对伸长率随着铝浓度的提高而急剧降低。在30mol/L.AlCl3处理24h后,西矮麦1号根系伸长的抑制率为33.3%,而辐84系根系伸长的抑制率高达70.9%。小麦距根尖0～10.mm根段的铝含量和细胞壁中果胶糖醛酸含量显著高于10～20.mm根段,且前者对铝的累积吸附量明显大于后者;在0～10.mm根段,敏感基因型果胶含量高于耐性基因型,其根尖含铝量及根尖细胞壁对铝的吸附量都要大于后者。采用1.0.mol/L.NH3.H2O对细胞壁预处理2.h降低果胶甲基酯化程度后,耐性和敏感基因型根尖细胞壁对铝的累积吸附量分别降低了17.1%和20.9%,但对铝的累积解吸率没有影响。由此可见,小麦根尖是铝毒的主要位点,细胞壁果胶含量和果胶甲基酯化程度可能是导致不同小麦基因型根尖细胞壁对铝吸附量、铝积累量的差异及其对铝毒胁迫反应的差异的重要原因。