壳聚糖保鲜剂对芒果保鲜效果的影响

研究了3种壳聚糖保鲜剂对常温贮藏芒果的保鲜效果.结果表明,壳聚糖对芒果贮藏具有一定的保鲜效果,果实保青指数升高,腐烂指数下降,有机酸与VC等含量显著增加且优于化学保鲜剂施保克.但3种壳聚糖保鲜剂的保鲜效果差异较大,对芒果保青作用以自制保鲜剂最佳,其次是双林;防腐效果以双林最佳;对果实有机酸含量的增加依次是自制保鲜剂＞鲜倍得＞双林;果实VC含量增加依次是鲜倍得＞自制保鲜剂和双林;而果实可溶性糖含量,鲜倍得处理高于ck,双林处理低于ck.     

常温薄膜包装和乙烯吸收剂对粉蕉贮藏效果的影响

以‘粉杂一号’粉蕉为材料,研究了薄膜包装(MAP)和不同处理后在常温(25±2)℃下贮藏保鲜的效果。采用双向拉伸聚丙烯(BOPP)薄膜袋包装,以52℃ 1 min热水、400 mg/L施保克、自主研发的乙烯吸收剂等对果实进行单一或复合处理。结果表明：采用施保克 乙烯吸收剂保鲜效果最好,贮藏时间达到30天,好果率高,果实后熟色泽风味好;其次为采用热水 乙烯吸收剂,贮藏时间也达21天。两者与对照或单一处理相比,明显保持果实的品质及延缓硬度下降、果皮变黄等。常温下用热水或施保克处理后加入乙烯吸收剂,用BOPP薄膜袋包装,可延长粉蕉贮藏时间3倍以上,该技术操作简易、可行有效,适合广大果农在生产上推广应用。     

不同保鲜处理对甜瓜采后贮藏性状的影响

为探究不同保鲜处理类型对甜瓜采后的影响,以新疆精品甜瓜‘西州密25号’为试材,研究室温条件下保鲜剂(1-MCP)、杀菌剂以及杀菌剂复合1-MCP等3种不同处理方式对甜瓜采后贮藏性状的影响。试验结果表明,常温贮藏过程中,1-MCP处理对延缓果实硬度及可溶性固形物含量的下降,保持果品水分含量,并保持果皮颜色等方面效果显著。杀菌剂则对腐烂率降低效果更显著。复合保鲜处理能够有效发挥两者优势,对生理失调和病害衰老引起的采后问题有良好抑制效果。综合来看,常温条件下复合保鲜处理的贮藏效果最佳,能够有效保持甜瓜品质,降低果实腐烂率。     

不同杀菌剂对能源甜菜乙醇发酵的效果

为了进一步提高能源甜菜发酵乙醇的转化率,本研究采用三种杀菌剂对发酵底物进行试验。结果表明：与对照相比,分别使用漂白粉、甲醛和五氯苯酚钠三种杀菌剂后发酵效果均有提高,且三种杀菌剂均为水平2效果最好。三种杀菌剂的发酵效果顺序为：五氯苯酚钠>甲醛> >漂白粉,采用发酵前利用0.004%五氯苯酚钠50?C处理半小时。四种处理发酵前后pH值的变化幅度依次为：空白（CK）>甲醛>五氯苯酚钠>漂白粉,但根据乙醇转化率的高低确定使用五氯苯酚钠作为杀菌剂。     

不同贮藏温度对赣南脐橙果实有机物质含量的影响

研究在3℃、5℃和7℃的贮藏温度下,赣南脐橙果实贮藏期间主要有机物质(可溶性固形物、总糖、可滴定酸、vc)含量、呼吸强度、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、失重率和腐烂率的变化趋势,探讨3种贮藏温度下的贮藏效果。结果表明：综合比较,3℃的贮藏效果最好,5℃的贮藏效果次之,7℃的贮藏效果最差。     

双面紫外照射对鲜切苹果表面微生物及品质的影响

利用自行设计的双面紫外杀菌照射装置,探究了紫外照射对鲜切苹果表面微生物的杀菌效果。从5个紫外照射剂量(0.48 k J/m2,0.96 k J/m2,2.88 k J/m2,4.80 k J/m2,9.60 k J/m2)中选出了杀菌效果最佳的剂量,并研究了该剂量处理后鲜切苹果在贮藏期间表面沙门氏菌、霉菌和酵母及品质的变化。试验以传统含氯杀菌剂0.36%的次氯酸钠处理作为对照。结果发现,当双面紫外照射剂量为0.96 k J/m2时杀菌效果达到最佳;0.96 k J/m2的双面紫外照射处理初始杀菌效果显著优于0.36%的次氯酸钠处理(p0.05)。虽然两种处理对鲜切苹果贮藏期间的品质影响没有显著差异,但双面紫外处理在贮藏过程中对微生物的控制效果不佳。因此,需要紫外杀菌结合其他保鲜方式,对鲜切苹果贮藏期间微生物的有效控制进行更加深入的研究。     

新型鲜切果蔬杀菌技术研究进展

鲜切果蔬是一种新型的安全、绿色、环保的果蔬产品,符合现代社会对健康食品的要求,有很大的发展前景。杀菌是保证鲜切果蔬品质安全的重要环节,目前应用最多还是含氯杀菌剂,但因其含有诸多弊端,因此新型的替代杀菌技术得到了广泛的研究。从新型化学杀菌技术、物理杀菌技术和生物杀菌技术3方面,系统总结了近些年出现的取代含氯杀菌剂的新型鲜切果蔬杀菌技术,阐述了新型杀菌技术的杀菌效果及其优缺点,并对其未来的应用前景进行了展望。     

鲜食蓝莓产地保鲜技术研究初报

针对蓝莓鲜果采后保鲜难度大、货架期短等技术难点,以新鲜蓝莓为材料,在冷藏和常温贮藏前用臭氧水、灰霜特、绿液、气调袋等处理,通过对其在贮藏期间相关品质指标（霉烂率、失质量率、硬度、可滴定酸和可溶性固形物）的测定来确定其对蓝莓保鲜效果及品质的影响。结果表明,臭氧水处理对果实保鲜效果最好,该处理可明显抑制蓝莓的腐烂,抑制贮藏期间果实硬度和可溶性固形物的下降和失质量率的上升,效果明显好于其他处理。臭氧水处理可显著降低蓝莓果实呼吸代谢活动,可维护果实品质。各处理对蓝莓保鲜效果的顺序为：臭氧水〉灰霜特〉绿液〉气调袋。     

多菌灵、抑霉唑和咪鲜胺在荔枝贮藏过程中的残留量基本明确

<正>广东省农业科学院农产品公共监测中心等单位合作以荔枝上常使用的多菌灵、抑霉唑和咪鲜胺为试验对象,研究了其在荔枝采后低温贮藏中的残留动态变化规律及其对荔枝的保鲜效果。试验结果表明,多菌灵、抑霉唑和咪鲜胺3种杀菌剂在荔枝果实上的残留物都主要存在于果皮上,贮藏期间果皮中残留物含量显著高于果肉。在低温贮藏中,果皮残留物含量均随时间的变化总体呈逐渐下降的趋势,而     

低温等离子体活化水对采后蓝莓杀菌效果及贮藏品质的影响

为探究低温等离子体活化水（PAW）处理对采后蓝莓杀菌效果及贮藏品质的影响,以‘优瑞卡’蓝莓为试材,采用大气低温等离子体激活去离子水得到不同处理时间（0、20、40、60 min）的PAW,并于25℃下通过喷洒和浸泡两种方式处理蓝莓果实。结果表明：与PAW浸泡组相比,PAW喷洒处理能增加蓝莓果实的亮度,PAW40喷洒处理在10 d贮藏期内产生的色差最小;与其他PAW处理组相比,PAW20浸泡和喷洒处理可以更好地维持蓝莓果实的硬度;PAW20喷洒组和PAW60喷洒组的抑菌效果较好,能够有效地抑制蓝莓果实表面霉菌和酵母菌的生长;PAW60组的腐烂率最低,并且PAW喷洒处理降低蓝莓腐烂的效果优于浸泡处理;喷洒相比浸泡处理可以更好地维持蓝莓果实的花青素含量。综上,PAW喷洒处理是一种可行的蓝莓果实采后贮藏方法。     

海南石斛兰叶片黑点病的病原鉴定及室内药剂毒力测定

为明确石斛兰黑点病的病原物种类,对其病原菌进行了分离、纯化和致病性测定,以及室内6种杀菌剂的毒力测定。结果发现,从患黑点病的兰花叶片上分离到一个真菌分离物,该分离物接种石斛兰嫩叶20天后,发现能引致与田间自然发病相似的症状。rDNA-ITS序列分析发现该菌株与Phyllosticta sp.的同源性为100%。6种杀菌剂室内平板抑菌实验结果表明：凯润、施保克都有较好的防治效果。本研究为石斛兰黑点病的防治提供了理论依据。     

Control of blue mold of apple by combining controlled atmosphere,an antagonist mixture,and sodium bicarbonate

‘Golden Delicious’ apples were wound-inoculated with Penicillium expansum and treated with various combinations of sodium bicarbonate and two antagonists (Metschnikowia pulcherrima, Cryptococcus laurentii), and then stored in air or controlled atmosphere (CA = 1.4 kPa O₂ and 3 kPa CO₂) for 2 or 4 months at 1 °C. The antagonists survived and their populations increased during both air and CA storage. The antagonists alone reduced blue mold but were more effective when combined. Sodium bicarbonate tended to reduce lesion size when used with these antagonist, either when they were used alone or combined. Storage under CA conditions also increased the effectiveness of both antagonist, when used alone or in combination. The only treatment that completely eliminated P. expansum-incited decay was the combination of the two antagonists and sodium bicarbonate on fruit stored under CA conditions. The proper combination of alternative control measures can provide commercially acceptable long-term control of fruit decay and could help reduce our dependency on fungicides.     

Control of lemon postharvest diseases by low-toxicity salts combined with hydrogen peroxide and heat

The effectiveness of potassium sorbate, sodium bicarbonate and potassium phosphite combined with heat and hydrogen peroxide in the presence of CuSO₄ to control major lemon postharvest diseases was investigated on artificially infected fruit. Green and blue molds, which both require wounds for infections to occur, were controlled by combination of hydrogen peroxide followed by inorganic salts, even when the temperature solutions were 25 °C. Control of sour rot was poor with salt solutions alone but significantly improved in treatments including hydrogen peroxide followed by potassium sorbate or sodium bicarbonate at 50 °C. Phomopsis stem-end rot was effectively controlled by potassium sorbate and potassium phosphite at 20 °C, and diplodia stem-end rot was partially controlled only by potassium sorbate. Applications of either potassium sorbate or a sequence of hydrogen peroxide followed by potassium phosphite were the most promising treatments, primarily because they controlled most of the diseases without the need to heat the solutions. These treatments controlled postharvest citrus diseases to useful levels and could be suitable alternative to conventional fungicides, or could be applied with them to improve their performance or to manage fungicide resistant isolates.     

Imazalil residue loading and green mould control in citrus packhouses

Imazalil (IMZ) is commonly applied in South African citrus packhouses for the control of green mould, caused by Penicillium digitatum, yet the disease still causes significant postharvest losses. The maximum residue limit (MRL) for IMZ on citrus fruit is 5 μg g⁻¹, whereas 2-3 μg g⁻¹ is a biologically effective residue level that should at least inhibit green mould sporulation. Standard compliance auditing of residue levels of citrus fruit, however, indicate that fruit from the majority of packhouses have residues of ≈1 μg g⁻¹. Poor disease control from insufficient residue loading might further be compounded by the presence of IMZ-resistant isolates of P. digitatum in packhouses. This study was conducted to assess the current status of IMZ application in South African packhouses, to determine the adequate residue levels needed to control green mould and inhibit its sporulation using both IMZ sensitive and resistant isolates, to investigate IMZ application methods and resultant residue levels in commercial citrus packhouses, and to study optimisation of modes of IMZ application in citrus packhouses. Factors studied were IMZ concentration, application type (spray vs. dip and drench), exposure time, solution temperature and pH, as well as curative and protective control of P. digitatum. The packhouse survey showed that the majority of packhouses applied IMZ in a sulphate salt formulation through a fungicide dip tank, and loaded an IMZ residue of ≈1 μg g⁻¹. In dip applications, IMZ had excellent curative and protective activity against Penicillium isolates sensitive to IMZ. However, curative control of IMZ resistant isolates was substantially reduced and protective control was lost, even at twice the recommended concentration, nor was sporulation inhibited. The use of sodium bicarbonate (2%) buffered imazalil sulphate solutions at pH ±8, compared with pH ±3 of the unbuffered solutions, markedly increased IMZ residue loading on Navel and Valencia oranges and improved curative and protective control of IMZ resistant isolates. Exposure time did not affect IMZ residue loading in IMZ sulphate solutions at pH 3, although the MRL was exceeded after 45 s exposure in pH 8 solutions. Imazalil applied through spray or drench application improved residue loading, but green mould control was less effective than after dip application.     

不同化学保鲜剂对W.默科特柑橘保鲜效果的研究

研究了在地下室内用不同化学保鲜剂处理贮藏W.默科特柑橘的保鲜效果。试验结果表明,与对照相比,以3%碳酸氢钠＋0.67 g/L抑霉唑＋0.67 g/L双胍盐＋0.27 g/L 2,4-D＋塑料袋单果包装贮藏W.默科特柑橘,可有效地减少果实的腐烂率和失重率,在地下室可以贮藏60 d左右。     

碳酸钾与碳酸氢钠对苜蓿茎叶解剖结构的影响

采用2.5%的碳酸钾溶液和2.5%碳酸氢钠溶液分别对苜蓿茎、叶进行处理,对其解剖结构进行观察,结果表明:两种溶液对苜蓿茎、叶表层的角质膜均有一定的破坏作用,能够加快苜蓿茎、叶内的水分蒸发,其中碳酸钾的作用效果要明显大于碳酸氢钠.同时,苜蓿茎秆经2.5%碳酸钾溶液处理后,不但表皮角质膜被破坏,其茎部皮层薄壁细胞间隙较处理前也明显增大,从而减少了茎秆内水分移动的阻力.     

苹果褐斑病的治疗药剂及有效施药时期研究

通过先接种后施药的方法,在海棠苗和富士苹果幼树上测试了11种杀菌剂对苹果褐斑病的治疗效果。结果表明：爱可、敌力脱、福星和使百克2号4种杀菌剂对苹果褐斑病具有显著的治疗效果;世高、宝丽安、全福和高扑对苹果褐斑病有一定治疗效果,但不显著;凯润、百泰和多菌灵对苹果褐斑病无任何治疗效果。有效施药时期的试验结果表明：爱可、敌力脱、福星和使百克2号4种杀菌剂在病斑显症前使用,能有效抑制病斑产生,且用药时间越早治疗效果越好。4种药剂在病菌侵染后第3d施用,平均防效达96%,第5d施用,平均防效达77%;4种药剂在病斑显症初期施用,能有效抑制病斑扩展和产孢;在病斑产孢初期施用,能有效抑制病斑产孢。据此结果,田间治疗苹果褐斑病的有效施药时期为病原菌侵染后的1周之内。     

几种碱性试剂对循环水养殖系统中pH值调节的研究

在循环水养殖系统中pH值会因为鱼类所排放的CO2和硝化反应所产的酸而降低,过低的pH值会对鱼类生长产生十分不利的影响。因此加碱调节pH值对于维持循环水养殖的稳定运行时非常重要的。目前关于这方面的研究以理论分析为主,具体实验研究较少见。采用氢氧化钠、碳酸钠、碳酸氢钠溶液对采集于淡水循环水养殖系统中的水样进行滴定实验,得到相应的滴定曲线,与同等条件下滴定的去离子水曲线比较后发现,淡水循环水养殖系统中的水体具有缓冲性。氢氧化钠的滴定曲线与碳酸钠、碳酸氢钠的滴定曲线相比,在突越点前和在突越点后,pH值的变化都相对剧烈,为了避免加碱后会对水体pH值产生较大波动,宜选择碳酸钠、碳酸氢钠等弱碱性物质。同时,在pH值降至突越点之前,补充碱性试剂是一个较合适的时机。     

江苏省防控小麦赤霉病主要药剂及其复配剂药效评价

为明确当前小麦赤霉病防控药剂的防效,探明不同药剂种类在小麦赤霉病重发生及轻发生地区防治效果差别,采用两地药剂小区试验同时测定13个农药品种对小麦赤霉病的防效。试验结果表明,在气象条件不利于小麦赤霉病发生而发病较轻的地区,参试药剂均具有较好的防效。而在气象条件适合,赤霉病重发生地区,参加试验的药剂其防效均低于70%,表现不佳。其中多菌灵及其复配药剂均对小麦赤霉病保持较高的防效,戊唑醇及其复配剂对赤霉病防效相对较差。