杀菌时间对金针菇泡菜储藏期影响的研究

用90℃热水分别对金针菇泡菜进行不同时间的保温杀菌处理,分析其在储藏期间的pH值、总酸含量和活性乳酸菌数量的变化,研究不同杀菌时间对金针菇泡菜储藏期的影响。结果表明,在10～15℃储藏条件下,所有杀菌处理均比未杀菌金针菇泡菜的pH值偏高、总酸含量偏低;未杀菌、杀菌10 min和15 min、杀菌20 min的金针菇泡菜分别在储藏至14、21、28 d时,乳酸菌数量出现最高值,之后开始下降,分别在21、28、35 d时降至较低水平。因此初步确定金针菇泡菜的最长储藏期分别为:未杀菌的为14 d,杀菌10 min和15 min的为21 d,杀菌20 min的为28 d。     

乳酸高产乳酸菌株的分离与筛选

乳酸作为一种天然有机酸广泛应用于食品、纺织业、化学和制药工业。为了满足乳酸的市场需求,降低生产成本,筛选高产乳酸菌株并应用于工业生产成为当前研究的重点。本研究从自然酸菜发酵液中分离筛选出一株乳酸高产的乳酸菌11MZ-5-1,发酵72 h时,乳酸含量达(24.88±0.21)g/L。利用生理生化及16S r DNA序列分析法对菌株进行鉴定,构建系统发育树,确定种属地位。结果表明,菌株11MZ-5-1的生长温度范围为20~45℃,最适生长温度为30~37℃;Na Cl耐受浓度为0%~12%,最适生长范围为0%~4%;p H耐受范围为3.5~7.5,最适生长为p H 5.5~6.5。16S r DNA部分序列长度为1438 bp,与干酪乳杆菌Lactobacillus casei str.Zhang相似性最高,达99%。结合形态学观察及理化特性,该菌株鉴定为L.casei。L.casei 11MZ-5-1产酸量高,作为食品发酵剂可以缩短发酵周期,抑制杂菌生长,在乳酸工业生产领域有广泛的应用前景。     

乳酸菌和酵母菌发酵黄浆水制备有机酸工艺优化

将黄浆水经乳酸菌、酵母菌发酵后,分析发酵产物的总酸量、p H值、氨基态氮和不同有机酸的含量。通过发酵工艺的优化,重点研究了发酵产物有机酸的含量。结果表明,乳酸菌和酵母菌单一和联合发酵时均显著性提升产物有机酸含量。结果表明,获得乳酸的最佳发酵方式为乳酸菌单一发酵,获得醋酸的最佳发酵方式为酵母菌单一发酵,获得酒石酸的最佳发酵方式为乳酸菌与酵母菌以接种比1∶4发酵,获得丁二酸最佳发酵方式为乳酸菌与酵母菌接种比3∶2发酵。     

不同浓度的食盐 蒜对泡菜发酵中各种微生物的影响

以白菜为原料发酵制作泡菜,通过稀释涂平板法培养菌落,利用统计计数法得到在盐水(质量浓度分别为18.67g/L,28.00g/L,37.33g/L)、蒜(加蒜量分别为23.33g/L,37.33g/L)发酵过程中的细菌总数、乳酸菌、肠杆菌数量变化,并测定溶液pH值及亚硝酸盐含量等相关指标。结果表明,随着食盐浓度的升高,各种微生物数目均减少;加入蒜试样的微生物数目也减少,适量的蒜对乳酸菌的抑制作用不大,其中加入23.33g/L蒜的泡菜水中乳酸菌含量较多,肠杆菌含量少,亚硝酸盐含量较少,故添加23.33g/L蒜的泡菜适合发酵。     

紫薯金针菇复合保健酸乳发酵工艺优化研究

以紫薯、金针菇和脱脂乳粉为主要原料,添加蔗糖和稳定剂,经乳酸菌发酵,在单因素试验的基础上,进行正交试验优化,研制紫薯金针菇复合酸乳的最佳制备工艺。结果表明,影响紫薯金针菇复合保健酸乳品质的因素主次顺序为:紫薯添加量>蔗糖添加量>金针菇添加量>发酵剂接种量;最优配方及制备工艺条件为:紫薯添加量10%,金针菇添加量15%,蔗糖添加量7%,发酵剂接种量5%,复合稳定剂CMC-Na+海藻酸钠(1∶1)的添加量为0.2%,在42℃温度条件下发酵4 h。制得的紫薯金针菇复合酸乳色泽为均匀一致的紫色,组织细腻、稳定,酸甜适口,具有紫薯和金针菇的清香和奶香味,风味独特,营养丰富,是一种良好的保健酸乳。     

人工发酵剂混合发酵对香肠安全品质指标变化的影响

为探讨人工发酵剂混合接种发酵对香肠安全品质及其变化趋势的影响,在香肠中接种质量分数0.08%乳酸菌和质量分数0.04%酵母菌组成的混合发酵剂,于32±1℃下发酵12 h,检测了发酵过程中香肠中的微生物、p H值、水分活度、亚硝酸盐及挥发性盐基氮(TVB-N)的变化。结果表明,在12 h发酵过程中,混合菌种发酵明显影响p H值变化速度,相比对照组,发酵剂组p H值下降得更快,而对水分活度无显著影响;亚硝酸盐在发酵6 h以前发酵剂组和对照组无显著性差异(p0.05),6 h以后发酵剂组亚硝酸盐累积速度低于对照组;发酵剂组挥发性盐基氮始终低于对照组,在12 h发酵过程中对照组挥发性盐基氮始终为上升趋势,而发酵剂组挥发性盐基氮在发酵6 h后含量略微降低;发酵剂组的腐胺、组胺、酪胺、精胺和亚精胺的含量明显低于对照组;发酵剂组大肠菌群数在第6小时前与对照组无显著性差异,在6 h后增长速度远远低于对照组;发酵过程中发酵剂组中无霉菌生长,而对照组始终有一定数值的霉菌。利用乳酸菌和酵母菌混合发酵作用,使得香肠具有更高的安全品质。     

海南近海石油降解菌的筛选、鉴定及降解性能

为筛选出适应海南海洋环境的高效石油降解菌,以柴油为唯一碳源,通过分离、初筛和复筛,从石油长期污染的海南近海海水中分离出1株高效的石油降解菌株X10,经16S r DNA序列分析,该菌株被鉴定为无色菌,其对柴油的降解率为69.39%。同时,研究分析不同p H值、温度、初始接种量、外加碳源对菌株柴油降解能力的影响。结果表明,在试验条件下,菌株X10在初始p H 6.0时降解效果最好,且该菌p H值适应范围较广,偏酸或偏碱的环境下该菌对柴油的降解效果均较好;培养温度对菌株石油降解率的影响较大,最佳温度为30℃,降解率达67.94%;最佳接种量为5%;添加外加碳源葡萄糖、乳糖、甘露醇对柴油降解率均有提高,但3种外加碳源间差异不显著。     

乳酸菌发酵生产酸爽黄背木耳菜的研究

以黄背木耳为原料,利用乳酸菌发酵,在单因素试验基础上,通过正交试验确定黄背木耳菜接种乳酸菌的最佳复配方式和发酵、调味的最佳工艺。结果表明,接种乳酸菌的最佳复配方式为:0.1%短乳杆菌+0.1%干酪乳酸菌;最佳发酵工艺参数为:发酵时间5 d,接种量0.2%,发酵温度32.5℃;最佳调味工艺参数为:pH 3.35、盐2.5%、糖2.0%。与自然发酵黄背木耳菜相比,该条件下生产的酸爽黄背木耳菜产品生产周期短、安全性高。     

黄秋葵酸辣泡菜发酵工艺的研究

以黄秋葵嫩果为主要原料,研究酸辣爽脆黄秋葵泡菜。以感官评价为标准,研究白砂糖添加量、泡菜盐添加量、发酵温度及发酵时间对黄秋葵泡菜品质的影响,并通过四因素三水平正交试验建立黄秋葵泡菜制作的最佳工艺条件。结果表明,黄秋葵泡菜发酵最佳工艺条件为白砂糖添加量3%,泡菜盐添加量6%,发酵温度25℃,发酵时间4 d。     

豆清发酵液中一株产细菌素乳酸球菌的分离鉴定

从豆制品生产副产物豆清发酵液中分离得到1株产细菌素球状菌,编号SQ-12-3。结合菌株生长特征、菌体形态及生理生化性质,初步将其鉴定为乳球菌属(Lactococcus sp.)。排除发酵液中可能存在的有机酸、过氧化氢及菌株菌体的干扰,并检测抑菌物质蛋白酶稳定性,可确定菌株SQ-12-3产细菌素抑菌。研究该菌株产细菌素动态,确定菌株最适生长温度在37℃,菌株在该温度下发酵18 h后菌液p H值低至4.11;当NaCl质量分数大于7%时,菌株生长受到明显抑制。     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.     

Optimization of Extraction Technology and Determination of Content of Total Phenols of Leaves in Acanthopanax giraldii Harms

[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and ortho...     

Cytoplasmic male sterility,resistance to gall mite and mildew,and season of leafing out in black currants

Summary Cytoplasmic male sterility (cms) is described in the F₁ hybrids Ribes × carrierei (R. glutinosum albidum × R. nigrum) and R. sanguineum × R. nigrum. In backcrosses to R. nigrum, progenies with R. glutinosum cytoplasm were either all male sterile, or segregated for full male fertility (F) and complete (S) and partial (I) male sterility. Ratios of F:I+S suggested that two linked genes controlled cms, F plants being dominant for one (Rf ₁) and recessive for the other (Rf ₂).Segregation for cms in relation to three linded genes, Ce (resistance to the gall mite, Cecidophyopsis ribes), Sph ₃(resistance to American gooseberry mildew, Sphaerotheca mors-uvae) and Lf ₁(one of two dominant additive genes controlling early season leafing out) indicated that Rf ₁and Rf ₂were in this linkage group. The gene order and approximate crossover values appeared to be: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqef0uAJj3BZ9Mz0bYu% H52CGmvzYLMzaerbd9wDYLwzYbItLDharqqr1ngBPrgifHhDYfgasa% acOqpw0xe9v8qqaqFD0xXdHaVhbbf9v8qqaqFr0xc9pk0xbba9q8Wq% Ffea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dme% aabaqaciGacaGaamqadaabaeaafaaakeaacaWGdbGaamyzamaamaaa% baGaaiiiaiaacccacaGGWaGaaiOlaiaacgdacaGG0aGaaiiiaiaacc% caaaGaaiiiaiaacccacaGGGaGaamOuaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaaccdacaGGUaGaaiOmaiaacs% dacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaaaacaWGsbGaamOzaSGa% aGOmaOWaaWaaaeaacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccaaaGaamitaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccacaGGGaaaaiaadofacaWGWbGaamiAaSGa% aG4maaaa!6E4D!\[Ce\underline { 0.14 } Rf1\underline { 0.24 } Rf2\underline { } Lf1\underline { } Sph3\]. Crossover values of 0.36 for Ce-Lf ₁, and 0.15 for Lf ₁-Sph ₃were estimated from the relative mean differences in season of leafing out between seedlings dominant and recessive for Ce and Sph ₃.It is suggested that competitive disadvantage of lf ₁-carrying gametes and/or zygotes at low temperatures may be implicated in the almost invariable deficit of plants dominant for the closely linked mildew resistance allele Sph ₃. Poor performance of lf ₁- (and possibly lf ₂-) carrying gametes and young zygotes during periods of low temperature at flowering might also account for the liability of some late season cultivars and selections to premature fruit drop (running off).     

Screening techniques and sources of resistance to parasitic angiosperms

Parasitic angiosperms cause great losses in many important crops under different climatic conditions and soil types. The most widespread and important parasitic angiosperms belong to the genera Orobanche, Striga, and Cuscuta. The most important economical hosts belong to the Poaceae, Asteraceae, Solanaceae, Cucurbitaceae, and Fabaceae. Although some resistant cultivars have been identified in several crops, great gaps exist in our knowledge of the parasites and the genetic basis of the resistance, as well as the availability of in vitro screening techniques. Screening techniques are based on reactions of the host root or foliage. In vitro or greenhouse screening methods based on the reaction of root and/or foliar tissues are usually superior to field screenings and can be used with many species. To utilize them in plant breeding, it is necessary to demonstrate a strong correlation between in vitro and field data. The correlation should be calculated for every environment in which selection is practiced. Using biochemical analysis as a screening technique has had limited success. The reason seems to be the complex host-parasite interactions which lead to germination, rhizotropism, infection, and growth of the parasite. Germination results from chemicals produced by the host. Resistance is only available in a small group of crops. Resistance has been found in cultivated, primitive and wild forms, depending on the specific host-parasite system. An additional problem is the existence of pathotypes in the parasites. Inheritance of host resistance is usually polygenic and its transfer is slow and tedious. Molecular techniques have yet to be used to locate resistance to parasitic angiosperms. While intensifying the search for genes that control resistance to specific parasitic angiosperms, the best strategy to screen for resistance is to improve the already existing in vitro or greenhouse screening techniques.