预冷前后1-MCP处理对杨梅采后贮藏品质的影响

本研究以‘硬丝’杨梅为试材,比较预冷前后进行1-MCP处理,及贮藏温度对杨梅采后贮藏品质及货架期的影响。预冷结合1-MCP处理,可延缓贮藏期间杨梅果实单果重、硬度的下降,抑制膜脂过氧化产物MDA含量和呼吸强度的上升,延缓贮藏6 d内果实可溶性糖、可滴定酸含量的降低,但对延缓花色苷含量降解效果不明显。预冷前或后进行1-MCP处理,在延缓果实品质劣化方面并无显著差异。预冷处理可有效降低果实入库时的呼吸强度,但需结合1-MCP处理才能有效维持贮藏期间果实呼吸强度处于较低水平。预冷后1-MCP处理,杨梅果实可贮藏于7 ℃中5 d,出库后,货架期可达5 d,腐烂率<10%,与贮藏于4 ℃中无显著差异,可有效降低冷库能耗成本,贮藏效果优于预冷前1-MCP处理。考虑生产实际,杨梅采后处理应及时装箱,加冰壶,置于4 ℃预冷处理,冷藏运输应控制在5 h以内。入库前使用7 μL/L的1-MCP于4 ℃冷库中熏蒸18 h。贮藏期可置于4~7 ℃冷库中贮藏5 d,于第6天上架销售,货架期可达5 d,具有较好的应用前景。     

UV-C处理对甘薯贮藏品质的影响

以海南桥头产区的“高系14”甘薯为材料,分别进行10、20、30 min的UV-C照射处理,统计甘薯贮藏60 d内的腐烂率、失重率和发芽率,并同时记录5种生理指标的变化,以探讨UV-C处理对甘薯贮藏品质的影响。结果表明：UV-C处理显著降低了甘薯贮藏期间的腐烂率,但同时促进了发芽,而对失重率无显著影响。生理指标方面,30 min的UV-C照射提高了可溶性蛋白的积累,减少可溶性固形物的损耗,并促进了POD、SOD和CAT的总体酶活性。综合来说,UV-C处理若要应用于甘薯贮藏保鲜,还需辅助使用其他的抑芽手段。     

低温胁迫对‘热研1号’槟榔新品种生理特性的影响

为进一步完善‘热研1号’槟榔新品种的生物学特性,以1年幼苗为材料,在26、20、14、8 ℃的温度梯度下,分别生长0,10,20和30 d后,测定植株的相对含水量、电导率、叶绿素、脯氨酸(Pro)、丙二醛（MDA）、过氧化物酶（POD）、超氧化物歧化酶（SOD）等生理指标的变化,探讨供试材料在低温胁迫下的耐受性。结果表明：在26 ℃/10 d、26 ℃/20 d、26 ℃/30 d处理条件下各指标表现正常;20 ℃/10 d、20 ℃/20 d低温处理时各指标数值开始出现小幅度变化,但在20 ℃/30 d条件下变化明显,表现为多个指标数值差异显著;当处理温度在14、8 ℃条件下,处理时间为10 d时各指标数值间差异达显著水平,特别是随着低温胁迫程度的加强,在8℃/30d时脯氨酸、丙二醛、POD、SOD活性均出现了持续上升后再下降的趋势,结合植株濒临死亡的外观症状,证明了在8 ℃/30 d条件下幼苗严重受损直至死亡。     

温度对采后香蕉果实糖代谢及其酶活性的影响

以香蕉为试材,研究采后不同温度(20、4℃)贮藏对果实的呼吸作用、糖代谢及其相关酶活性变化的影响。结果表明:20℃贮藏早期(0~8d),果实呼吸作用平缓上升,SPS、NI和AI酶活性较低,蔗糖、果糖和葡萄糖含量较少;随着果实进入快速软化阶段(8~13d),3种酶活性与蔗糖含量分别在第13天和第12天达到峰值,然后急剧下降,变化趋势类似于CO2释放量。而果糖和葡萄糖含量在20℃贮藏过程中持续上升,SS活性无明显变化。相比之下,4℃贮藏可明显抑制果实的呼吸作用,CO2含量先降低后缓慢增加,SPS、NI和AI酶活性和糖含量上升缓慢,SS活性下降。由此,低温贮藏可明显抑制香蕉体内碳素代谢,降低代谢酶活性和糖分积累速度,有利于提高果实品质,延缓贮藏时间。     

保鲜剂联合热处理对木薯品质及贮藏效果的影响

以华南9号木薯为试验材料,采用不同保鲜剂浸泡经热处理(60℃,5 min)后的木薯,通过测定其贮藏过程中的理化、生化指标来评价不同处理方式对木薯品质及保鲜效果的影响。结果表明:与对照相比,保鲜剂C(1.5%壳聚糖+0.15%柠檬酸+0.25%氯化钙)可显著延缓木薯块根硬度的下降,抑制色泽(L*)值的上升,延缓淀粉的降解和可溶性固形物(TSS)的增加,维持了较高水平的超氧化物歧化酶(Superoxide dismutase,SOD)活性,延缓过氧化物酶(Peroxidase,POD)活性的增加,降低了总酚含量,有效地延长了采后木薯块根的贮藏期,抑制了其品质的劣变。     

正己醇对机械伤香蕉采后生理特性影响及磷脂酶D的抑制作用

为保持采后香蕉贮藏品质,延长贮藏期限,以桂蕉6号香蕉为实验材料,探究正己醇在常温贮藏条件下对采后香蕉果实品质和耐贮性的影响。挑选果实外观完好及成熟度、大小相近的香蕉果实,随机分成对照组和处理组2组,分别用蒸馏水和0.1%浓度正己醇处理,取出晾干后置于PE保鲜袋中扎口包装,于25℃下贮藏15 d,每3 d取样观察测定香蕉果实的硬度、可溶性固形物（TSS）含量、呼吸强度、病情指数、丙二醛（MDA）含量、膜透性和PLD活性的变化,利用实时荧光定量PCR(qRT-PCR)分析贮藏期间PLDγ和PLDζ表达量的变化。研究结果显示：正己醇处理可显著延缓采后香蕉果实软化的进程（P<0.05）,其中,9、12 d延缓效果极显著（P<0.01）;在9 d后,正己醇处理极显著抑制TSS含量和病情指数的上升;6 d起,正己醇处理显著抑制呼吸强度,其中,9 d达到呼吸峰值,较对照组极显著降低33.93%;12 d后,与对照组相比,正己醇处理极显著降低MDA含量和膜透性的上升,分别于15 d降低了26.70%和62.20%。此外,正己醇处理显著抑制采后香蕉果实PLD活性,尤其是6～12 d,抑制效果...     

温度预处理对枇杷贮藏品质及活性氧代谢相关酶的影响

以“早钟六号”枇杷为试材,研究经6℃(CK)、12℃、20℃(室温)、30℃温度预处理2天后,在6℃下贮藏对采后贮藏品质及活性氧代谢相关酶的影响。结果表明：低温贮藏下,随贮藏时间的延长,过氧化物酶(POD)活性和超氧化物岐化酶(SOD)活性呈现上升趋势,过氧化氢酶(CAT)和丙二醛(MDA)含量呈现先上升后下降趋势。12℃预处理能显著延缓“早钟六号”果实可滴定酸(TA)含量和维生素C(Vc)含量的下降及果皮电导率(REC)和果实硬度的上升,但不能延缓可溶性固形物(TSS)含量的下降。12℃预处理果实最耐贮藏,在贮藏后期SOD、CAT与POD能较好地协同作用清除O2-,降低果实受自由基伤害程度,使衰老得以延缓,果实在贮藏后期仍能维持较好的风味。6℃(CK)预处理果实在贮藏后期风味劣变。20℃(室温)、30℃预处理果实后期失重、腐烂严重,不耐贮藏。     

程序降温处理对黄皮果实贮藏品质和采后生理的影响

以‘无核’黄皮果实为实验材料,研究程序降温(LTC)处理对黄皮果实贮藏品质及采后生理的影响。将采后黄皮果实分别经LTC Ⅰ(12℃,4 d)、LTC Ⅱ(8℃,4 d)、LTC Ⅲ(12℃,2 d后转至8℃,2 d)处理后,转至低温(3.0±0.5)℃贮藏12 d,每4 d测定各项品质和生理指标。结果表明:与对照相比,程序降温处理有效减轻了黄皮果实的褐变,促进了可溶性固形物(TSS)和维生素C含量的积累,促进了可滴定酸(TA)的降解,减少丙二醛(MDA)的积累,维持较高的超氧化物歧化酶(SOD)和苯丙氨酸解氨酶(PAL)活性,抑制过氧化物酶(POD)和多酚氧化酶(PPO)活性,同时保持较高的总酚和类黄酮含量,从而延缓了果实采后衰老速度,有利于减轻黄皮果实褐变和提高贮藏品质,其中以LTC Ⅱ处理的保鲜效果最为显著。     

NaCl和Na_2CO_3胁迫对水稻根系生长的影响

采用根箱土培的方法对NaCl和Na_2CO_3胁迫下水稻不同土层根系生物量(即根系鲜质量)和主根的长度、根系生长速率及侧根的生长等进行了研究。结果表明,水稻根系生物量随着土层深度的增加逐渐减少,每个区段的根系生物量均表现为Na_2CO_3胁迫处理低于NaCl胁迫处理,Na_2CO_3胁迫处理在土表下20 cm以下部分没有根系分布。同一Na~+浓度下,水稻主根的长度、根系生长速率和侧根的长度、数量和直径等指标值均表现为Na_2CO_3胁迫处理低于NaCl胁迫处理。100 mmol/L NaCl胁迫显著(P0.05)降低了水稻主根的长度、根系生长速率,极显著(P0.01)降低了侧根的数量;50 mmol/L(Na~+浓度)Na_2CO_3胁迫处理显著降低了水稻根系生长速率和侧根数量。     

加热熏蒸CIPC对马铃薯萌芽及品质的影响

为研究加热熏蒸抑芽剂氯苯胺灵(CIPC)对马铃薯抑芽效果及品质的影响,试验采用加热熏蒸和喷施2种方法,在室温20℃的条件下,贮藏第30 d时对马铃薯进行处理,空白对照不做任何处理,测定马铃薯萌芽情况及品质关键指标。结果表明,相比空白对照,在马铃薯贮藏过程中,喷雾CIPC和加热熏蒸CIPC均能显著抑制马铃薯发芽,处理后薯块普遍出现芽萎缩变黑的现象;2种处理后干物质含量、淀粉含量均极显著高于对照,可溶性糖含量、α-淀粉酶活性极显著低于空白对照;相比之下,喷雾施用CIPC较加热熏蒸对马铃薯的抑芽效果和薯块品质的保持更佳,但二者都具有明显的抑芽效果。考虑操作性、成本、对马铃薯的机械损伤等因素,认为加热熏蒸比喷雾的优势更加显著,在实际生产中具有更好的推广潜力。     

Mineral composition of some traditional Mexican teas

Teas of plant origin traditionally consumed by the Mountain Pima of Chihuahua, Mexico, were analyzed for mineral nutritional content. Fe, Cu, Zn, Ca, and Mg composition was determined for native teas made from shoots ofTagetes lucida, T. filifolia, Elytraria imbricata, andHolodiscus dumosus, and from root xylem ofCeanothus depressus andPhaseolus ritensis. Native uses of these teas are also described.     

Studies on natural repellents against potato tuber moth (Phthorimaea operculella Zeller) in country stores

Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.     

Comparative Assessment of the Efficacy of Various Nitrogen Fertilizers

Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.     

Redox Status and Neuro Inflammation Indexes in Cerebellum and Motor Cortex of Wistar Rats Supplemented with Natural Sources of Omega-3 Fatty Acids and Astaxanthin: Fish Oil,Krill Oil,and Algal Biomass

Health authorities worldwide have consistently recommended the regular consumption of marine fishes and seafood to preserve memory, sustain cognitive functions, and prevent neurodegenerative processes in humans. Shrimp, crabs, lobster, and salmon are of particular interest in the human diet due to their substantial provision of omega-3 fatty acids (n-3/PUFAs) and the antioxidant carotenoid astaxanthin (ASTA). However, the optimal ratio between these nutraceuticals in natural sources is apparently the key factor for maximum protection against most neuro-motor disorders. Therefore, we aimed here to investigate the effects of a long-term supplementation with (n-3)/PUFAs-rich fish oil, ASTA-rich algal biomass, the combination of them, or krill oil (a natural combination of both nutrients) on baseline redox balance and neuro-inflammation indexes in cerebellum and motor cortex of Wistar rats. Significant changes in redox metabolism were only observed upon ASTA supplementation, which reinforce its antioxidant properties with a putative mitochondrial-centered action in rat brain. Krill oil imposed mild astrocyte activation in motor cortex of Wistar rats, although no redox or inflammatory index was concomitantly altered. In summary, there is no experimental evidence that krill oil, fish oil, oralgal biomass (minor variation), drastically change the baseline oxidative conditions or the neuro-inflammatory scenario in neuromotor-associated rat brain regions.     

Potential of dry fractionation of wheat bran for the development of food ingredients,part II: Electrostatic separation of particles

Wheat bran is a composite material made of several layers, such as pericarp, testa and aleurone. It could be fractionated into purified fractions, which might either be used as food ingredients, or serve as a starting material for extraction of bioactive compounds. The aim of this work was to evaluate the potential of using electrostatic separation as a way to obtain purified fractions from wheat bran. Ultrafine-ground bran obtained either by cryogenic grinding or by grinding at ambient temperature was used as starting material. The ultrafine bran was then charged by tribo-electrification and introduced in a chamber containing two high voltage electrodes, where bran particles were separated depending on their acquired charge, allowing positively and negatively charged fractions to be collected separately. The particle size distribution, microstructure and biochemical composition of the obtained fractions were studied. The charge of the particles was influenced by their biochemical composition: particles rich in highly branched and cross-linked arabinoxylans (pericarp) were separated from particles rich in β-glucan, ferulic acid and para-coumaric acid (aleurone cell walls). The testa and the intracellular compounds from aleurone were not highly charged, neither positively nor negatively. The most positively charged fraction represented 34% of the initial bran, and contained 62% of the ferulic acid present in the initial bran. The yield of the separation process was good (5.4% loss), and could be further increased.     

In vitro antimicrobial activity of different accessions ofSolanum commersonii Dun. from Uruguay

Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.     

Pharmacokinetics of Marine-Derived Drugs

Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future.     

Novel food and non-food uses for sorghum and millets

Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.