沙棘、红枣、山楂复合功能饮料的研制

目的：制备沙棘、红枣、山楂复合功能饮料,优化其配方并测定抗氧化活性。方法：采用正交试验确定沙棘汁、红枣汁、山楂汁的复合配比,并在单因素试验基础上,以感官（色泽、气味、组织状态、口感）评分为评价指标,白砂糖、食盐、柠檬酸、羧甲基纤维素钠加入量为影响因素确定响应面试验优化配方,最后测定该复合功能饮料的抗氧化性。结果：沙棘红枣山楂复合饮料的复合配比（沙棘汁∶红枣汁∶山楂汁）为20∶10∶4（V∶V∶V）,白砂糖添加量为5%、食盐添加量为0.06%、柠檬酸添加量为0.03%、羧甲基纤维素钠添加量为0.05%,感官评价为8.9分,在以上条件下,复合功能饮料色泽气味理想,口感良好,组织状态均匀,透明度高,对DPPH自由基的清除能力高达92.60%。结论：沙棘红枣山楂复合饮料具有强抗氧化活性功能,是值得开发的饮料产品。     

黄瓜绿茶保健饮料的研制

以黄瓜、绿茶为主要原料,配以适当的白砂糖、柠檬酸和食盐,研制出口感清爽、风味独特、清凉降火、营养丰富的黄瓜绿茶保健饮料。通过三因素三水平的正交试验确定了黄瓜绿茶保健饮料的最佳配方,并通过单因素试验探讨饮料稳定剂的选择。结果表明：黄瓜绿茶饮料的最佳配方为黄瓜汁25%、绿茶汁45%、白砂糖8%、柠檬酸02%、食盐01%,稳定剂选用02%的海藻酸钠、CMC Na、黄原胶的复合溶液(1∶1∶1)。     

火龙果汁发酵饮品的研制

火龙果不但营养丰富而且具有一定的保健功能。本试验以新鲜的红皮白肉型火龙果果实的榨汁为原料,分别对发酵工艺条件、蔗糖添加量、柠檬酸用量、稳定剂用量等条件进行了研究,通过单因素试验和正交试验,得到火龙果汁发酵饮料的最佳工艺配方。采用该工艺配方制备的发酵饮料澄清透明,具有清新的果香和淡淡的醇香,酸甜可口,口感顺滑。     

栀子功能性饮料制备工艺研究

目的：以栀子果浸提液为主要原料,在配方优化的基础上,研制出口感均衡、具有抗氧化和清热解毒等综合保健功效作用的栀子饮料。方法：采用感官评价及脂质膜电子舌味觉分析系统,通过风味调配正交试验,确定栀子饮料最佳制备工艺和相关参数。结果：栀子饮料原液制备参数为：栀子果粉碎后经1∶50 （g∶mL）比例的纯净水于80 ℃超声浸提30 min,高速离心收集上清液。栀子原液和辅料对该饮料的感官品质有较大影响,最佳配方为栀子原汁：水=1∶3; 糖添加配比为木糖醇6%、蜂蜜1%、甜菊糖0.006%;柠檬酸添加量0.04%。结论：该饮料色泽亮黄、澄清透明、具有栀子特有风味、口感清爽,是一款适合大众口味的栀子功能性饮料。     

双米低脂保健冰淇淋的开发研究

选取新鲜薏米和玉米为原料,以人造奶油代替部分乳脂,依据黏度、膨胀率和感官质量等作为评价指标,通过正交试验获得复合稳定剂的最佳配比为：即瓜尔豆胶:海藻酸钠:卡拉胶:单甘脂:蔗糖酯=6∶3.6∶4∶16∶1,乳化稳定剂添加量为0.4%。双米保健冰淇淋的最佳配方为：脱脂乳粉10%、薏米乳18%、玉米汁17%、人造奶油4.0%,产品质量最好。     

一种新型的富硒茶饮料的研制

实验以普洱生茶为主要原料,纯种接种酵母菌（Saccharomyces cerevisiae）和黑曲霉（Asper-gillus niger）,通过硒含量检测和发酵茶冲泡后茶汤品质的比较,筛选确立酵母菌为硒转化菌株。然后结合普洱茶的自身发酵,酵母菌辅助添加与培养,获得制备富硒茶饮料的原料茶。运用正交实验,分析得出当茶水比为1：50时,调整pH为5．0,并于100℃条件下浸提30min,所得茶汤品质最好;再经过调配研制出一种新型的硒含量达2．2mg／kg的富硒茶饮料,该饮料的最佳配方为：富硒茶汤40mL,Vc 0．04％,白砂糖5．0％,柠檬酸含量为1．0％。     

新型混合诱饵适口性及现场试验研究

选用食盐、白糖、椰子汁、红果汁、奶粉、菠萝汁、柠檬、芝麻、花生、玉米面制成的１０种配方,对小白鼠分别进行了实验室选择性试验,结果表明小白鼠对以奶粉为主要引诱剂制成的６号配方适口性最好,其摄食系数为３．１９。以食盐为主要引诱剂制成的３号配方无引诱力,摄食系数仅为０．４９,认为咸味不能增加引诱力。以６号配方制所的混合毒饵现场灭鼠效果为９０％,市售毒饵现场灭鼠效果仅为３７．５％。新研制的混合毒饵优于市售     

香榧奶茶的制作工艺研究

目的：研究一款以香榧为原料的无糖奶茶。方法：通过单因素试验和正交试验,确定纯牛奶、香榧粉、红茶、麦芽糖醇的添加量对香榧奶茶品质的影响,优化香榧奶茶的配方。结果：各影响因素对香榧奶茶感官评分的影响顺序为红茶添加量＞香榧粉添加量＞纯牛奶添加量＞麦芽糖醇添加量。红茶提取液最佳工艺为料液比 1∶50、茶汤浸提时间7 min、浸提温度100 ℃。香榧奶茶最佳配方为：纯牛奶260 g、香榧粉5 g、红茶4 g、麦芽糖醇24 g。结论：在此条件下制得的香榧奶茶色泽均匀,香味浓郁,滋味协调,感官品质甚佳。     

营养型葛仙米果冻的制作工艺研究

研究营养型葛仙米果冻的制作工艺,为武陵山区葛仙米特色资源的开发提供新途径。将烫漂护色后的葛仙米打浆制得葛仙米汁,以葛仙米汁为主要原料,卡拉胶、魔芋胶为胶体基材,进行营养型葛仙米果冻生产工艺的研究。利用单因素试验和正交试验,通过感官评价和质构指标的综合分析,得到葛仙米果冻的最佳配方为:复合胶含量1%(m卡拉胶∶m魔芋胶=6∶4),柠檬酸含量0.3%,葛仙米汁含量30%,白糖含量14%和β-环糊精含量2%~4%。在此条件下制作的葛仙米果冻口感爽滑,绿色天然、酸甜适口、质地均匀,具有一定的保健功能。     

猕猴桃酸乳的研制

以鲜牛乳和猕猴桃汁为主要原料 ,进行乳酸菌发酵 ,研制出猕猴桃酸乳。通过正交试验 ,选择出最佳配方 :鲜牛乳 90 % ,猕猴桃汁 1 0 % ,蔗糖 7%。     

不同颜色遮阳网遮光对丘陵茶园夏秋茶和春茶产量及主要生化成分的影响

为研究不同颜色遮阳网遮光对夏秋茶与春茶产量和品质的影响,在中国科学院桃源农业生态试验站以“碧香早”茶树为试验材料,选用不遮光和中度遮光（遮光率(50?4)%）的黑色、绿色、银灰色遮阳网开展遮光试验。结果表明：不同季节使用黑色遮阳网能显著增加氨基酸和咖啡碱含量,降低茶多酚含量和酚氨比,与对照茶园比较,夏季、秋季、春季茶叶氨基酸含量分别增加了14.22%、17.07%、6.23%,茶多酚含量分别降低了4.40%、6.43%、27.66%,咖啡碱含量分别增加了9.48%、8.10%、7.28%。夏秋季银灰色遮阳网效果最差,绿色遮阳网效果介于黑色和对照之间,春季三种颜色遮阳网效果均优于对照;茶树遮光后品质明显优于对照,夏秋茶经遮光可达到制高档茶的要求,春茶遮光可达到制名优茶的要求。     

Probing behavior of the tea green leafhopper on different tea plant cultivars

The probing behaviors of the tea green leafhopper, Empoasca vitis (Gothe), on 9 tea cultivars were studied using video-text Direct Current-Electrical Penetration Graph, i.e., DC-EPG. The following 7 types of waveforms produced by the leafhopper stylet probing were determined: A, stylet pathway formation; S, salivation when stylets pierce into and stay in phloems; C, active ingestion before stylets reach phloems; E and F, passive ingestion in phloems; R, the insect resting with its stylet inserted into the leaf tissue and NP without probing. The 9 tested tea cultivars were categorized into 3 groups by the cluster analysis according to the number of probes per insect, waveform durations, or duration per probe of various waveforms on different tea cultivars. Waveforms S, E and F correlated to the main feeding activity of the leafhopper and may provide valuable information on predicting the resis-tance level of the tea plants to the leafhopper. The resistance level of the 9 tea cultivars to the leafhopper was ranked based on the durations of waveforms S, E and F, as well as the duration per probe including various waveforms. The ranking order of the resis-tance was: Longjingchangye > Hangdan > Zhenghedabaicha > Qianmei 601 > Hongyafoshuo > Zhongcha 102 > Zhongcha 302 > Longjing 43 > Anjibaicha, which corresponded to the resistance level determined by the population density (infestation) of the leaf-hopper on the 9 tea cultivars in the tea fields. Our study suggests that this simple and convenient DC-EPG technique might have great potential as a reliable tool to predict the resistance of tea cultivars to the tea leafhopper.     

Probing behavior of the tea green leafhopper on different tea plant cultivars

The probing behaviors of the tea green leafhopper, Empoasca vitis (Gothe), on 9 tea cultivars were studied using video-text Direct Current-Electrical Penetration Graph, i.e., DC-EPG. The following 7 types of waveforms produced by the leafhopper stylet probing were determined: A, stylet pathway formation; S, salivation when stylets pierce into and stay in phloems; C, active ingestion before stylets reach phloems; E and F, passive ingestion in phloems; R, the insect resting with its stylet inserted into the leaf tissue and NP without probing. The 9 tested tea cultivars were categorized into 3 groups by the cluster analysis according to the number of probes per insect, waveform durations, or duration per probe of various waveforms on different tea cultivars. Waveforms S, E and F correlated to the main feeding activity of the leafhopper and may provide valuable information on predicting the resis-tance level of the tea plants to the leafhopper. The resistance level of the 9 tea cultivars to the leafhopper was ranked based on the durations of waveforms S, E and F, as well as the duration per probe including various waveforms. The ranking order of the resis-tance was: Longjingchangye > Hangdan > Zhenghedabaicha > Qianmei 601 > Hongyafoshuo > Zhongcha 102 > Zhongcha 302 > Longjing 43 > Anjibaicha, which corresponded to the resistance level determined by the population density (infestation) of the leaf-hopper on the 9 tea cultivars in the tea fields. Our study suggests that this simple and convenient DC-EPG technique might have great potential as a reliable tool to predict the resistance of tea cultivars to the tea leafhopper.     

不同耕作方式对茶园土壤物理性状及茶叶产量的影响

研究了免耕、旋耕和深松3种耕作方式对茶园土壤紧实度、土壤含水率、土壤容重、茶叶产量构成因素及茶叶产量的影响.结果表明: 3种耕作方式对土壤容重和土壤紧实度的影响效果为深松>旋耕>免耕.旋耕和深松能够打破粘盘层,降低深层土壤紧实度.0～30 cm耕层深松土壤容重较免耕下降16.4%,土壤紧实度下降13.4%～27.5%;深松可以显著增加土壤的储水空间,进而增强土壤持水能力,扩大土壤水库容,深松15～30 cm层含水量与免耕相比增加7.7%.不同耕作方式对土壤孔隙度影响不大.旋耕和深松方式下土壤比表面积增加,土壤气体和液体的比例均明显升高.茶叶的光合速率和蒸腾速率的日变化曲线均为“双峰”型,气孔因素是导致“午休”的主要原因.在深松方式下,茶树叶片蒸腾速率降低,芽叶密度增加,百芽干质量和水分利用效率升高,茶叶产量分别比免耕和旋耕增加17.6%和6.8%.深松是皖东地区茶园较为适宜的耕作方式.     

Effect of green tea and black tea on the metabolisms of mineral elements in old rats

A 2-mo experiment with the white Sprague-Dawley (SD) rats was conducted to investigate the effect of the water extracts of black tea (BTWE) and green tea (GTWE) and the black tea leaves (BTF) and the green tea leaves (GTF) on the metabolism of mineral elements. One hundred eight 12-mo-old white SD rats were randomly divided into 13 groups; 6 of these drank the BTWE or GTWE in which the water extracts concentrations of black tea or green tea were, respectively, 0.6%, 1.2%, and 2.4%, and 6 of these had black tea leaves (BTF) and green tea leaves (GTF) added in which the contents of BTF or GTF were, respectively, 0.5%, 1.0%, and 2.0%, one of these was control. The teas and their water extracts could promote the absorption of manganese and copper. In GTF, BTF, GTWE, and BTWE, the apparent absorption rates of manganese were significantly increased. The manganese contents in the tibia were also elevated, and the differences between GTWE and GTF were significant. The apparent absorption rates of copper and the copper contents in the tibia were increased, but not significantly. The teas and their water extracts inhibited the absorption of calcium (p > 0.05) and iron (p < 0.05). The cerebrum calcium contents were significantly decreased, but the contents of calcium and iron in tibia were not significantly changed. Compared with the control, although the apparent absorption rates of aluminum in all experimental groups were not observed to be different, the aluminum contents in the tibia (p > 0.05) and cerebrum (p < 0.05) were increased. GTF and GTWE decreased the apparent absorption rates of zinc, but BTF and BTWE increased them; the zinc contents in tibia were a little improved, whereas its contents in the cerebrum were gradually decreased with the increase of tea leaves dose and tea concentration.     

茶树根际微生物研究

利用选择性培养基,对土壤肥力肥沃、中等、贫瘠茶园的茶树根际细菌、真菌和放线菌进行了分离。根据菌体形态及培养特征、生理生化指标、DNA的G Cmol％值等,对根际细菌进行了鉴定和分类。研究了不同肥力、不同茶龄的茶园根际细菌的数量和类群的变化;根际真菌的数量变化;根际放线菌的数量变化。主要结果为：土壤肥沃的茶园根际细菌的数量最多,土壤贫瘠的茶园数量最少;相同土壤肥力的茶园,10年生茶园根际细菌的数量最多,4年生的次之,20年生的最少。根际真菌的数量,土壤肥沃茶园的较少,中等和贫瘠茶园的较多。根际放线菌的数量,20年生茶园的明显高于4年生和10年生茶园的,而且,土壤贫瘠茶园的数量较多。从9种不同类型茶园中分离获得的纯化细菌经鉴定分别属于20个属,中等肥力的茶园最适于多数细菌的生长与繁殖,类群最为丰富,但类群的优势度低于另外两种土壤;不同茶龄的茶园随着茶龄的增加,肥沃茶园和中等茶园的根际中有较多的细菌类群定殖,但20a茶龄的类群较少;贫瘠茶园类群的优势度最大。     

Fungi associated with black tea and tea quality in the Sultanate of Oman

Forty-eight samples of four popular commercial brands of black tea ( Camellia sinensis L.) were purchased from the local markets in Muscat area, Sultanate of Oman. Tea leaves were surveyed for mycoflora. Five fungal species were isolated with A. niger as the most dominant in all the brands having percentage contamination ranging between 0.66% and 30.34%. Other fungi isolated were Aspergillus flavus, Penicillium spp. and Pacelomyces spp. but having average percentages of 0.6%, 0.84% and 0.21% respectively. Significant differences were found among the batches contaminated by A. niger. None of the 25 A. flavus strains screened for aflatoxins were found aflatoxigenic. The total ash, water-soluble ash, and mineral concentration of the samples were within the British standards and were not affected by fungal contamination. The results showed that black tea is contaminated by fungi that might constitute health hazards for humans. The post harvest contamination of tea could be eliminated or reduced if processing is conducted under more hygienic conditions. This revised version was published online in June 2006 with corrections to the Cover Date.     

Behavioral responses for evaluating the attractiveness of specific tea shoot volatiles to the tea green leafhopper,Empoaca vitis

Abstract The tea green leafhopper, Empoasca vitis Göthe, is one of the most serious insect pests of tea plantations in mainland China. Over the past decades, this pest has been controlled mainly by spraying pesticides. Insecticide applications not only have become less effective in controlling damage, but even more seriously, have caused high levels of toxic residues in teas, which ultimately threatens human health. Therefore, we should seek a safer biological control approach. In the present study, key components of tea shoot volatiles were identified and behaviorally tested as potential leafhopper attractants. The following 13 volatile compounds were identified from aeration samples of tea shoots using gas chromatography‐mass spectrometry (GC‐MS): (E)‐2‐hexenal, (Z)‐3‐hexen‐1‐ol, (Z)‐3‐hexenyl acetate, 2‐ethyl‐1‐hexanol, (E)‐ocimene, linalool, nonanol, (Z)‐butanoic acid, 3‐hexenyl ester, decanal, tetradecane, β‐caryophyllene, geraniol and hexadecane. In Y‐tube olfactometer tests, the following individual compounds were identified: (E)‐2‐hexenal, (E)‐ocimene, (Z)‐3‐hexenyl acetate and linalool, as well as two synthetic mixtures (called blend 1 and blend 2) elicited significant taxis, with blend 2 being the most attractive. Blend 1 included linalool, (Z)‐3‐hexen‐1‐ol and (E)‐2‐hexenal at a 1 : 1 : 1 ratio, whereas blend 2 was a mixture of eight compounds at the same loading ratio: (E)‐2‐hexenal, (Z)‐3‐hexen‐1‐ol, (Z)‐3‐hexenyl acetate, 2‐penten‐1‐ol, (E)‐2‐pentenal, pentanol, hexanol and 1‐penten‐3‐ol. In tea fields, the bud‐green sticky board traps baited with blend 2, (E)‐2‐hexenal or hexane captured adults and nymphs of the leafhoppers, with blend 2 being the most attractive, followed by (E)‐2‐hexenal and hexane. Placing sticky traps baited with blend 2 or (E)‐2‐hexenal in the tea fields significantly reduced leafhopper populations. Our results indicate that the bud‐green sticky traps baited with tea shoot volatiles can provide a new tool for monitoring and managing the tea leafhopper.