采前喷硼和采后壳聚糖涂膜对龙眼品质及耐贮性的影响

在龙眼假种皮发育期间,树冠喷施硼营养剂和清水2次,并在果实采收时进行浓度为3g/L、6g/L的壳聚糖溶液涂膜处理,以探讨硼营养和壳聚糖对龙眼果实品质和耐贮性的影响。结果表明：采前喷硼改善了龙眼果实的内在品质,提高了果实的耐贮藏性;采后壳聚糖涂膜处理都明显提高了贮藏期间龙眼果实的好果率、降低失重率,有效减缓了果肉营养成分的变化,其中采前喷硼和采后壳聚糖涂膜相结合处理的效应优于其它处理,但两个浓度壳聚糖处理产生的效应差异不明显。     

施肥方式对沃柑果实产量和外观品质的影响

为验证沃柑测土配方施肥的效果,推进化肥减量增效,探究有机肥、中微量元素肥料与化肥配施对沃柑果实产量和外观品质的效应,在沃柑园设置随机区组小区精确试验,试验处理包括当地习惯施肥、测土配方推荐施肥、优化施肥、优化施肥兼叶面喷施0.2%硼酸、优化施肥兼叶面喷施0.05%钼酸铵、优化施肥兼叶面喷施4%硫酸镁。结果表明,测土配方推荐施肥相较于习惯施肥增产效果显著。在同等养分施用量的情况下,用有机肥代替部分化肥处理与全化肥处理比较产量无显著差异,但前者比后者增效4.03%。在土壤交换性镁贫乏的情况下,沃柑叶面施镁可以获得极显著而稳定的增产效果。在土壤不缺硼的情况下,叶面施硼可能无效。在土壤有效钼不足时沃柑叶面施钼能够增产,但连年施用效果不稳定。由此可见,伴随果实外观品质的提升,化肥减量增效在沃柑生产上是可行的;沃柑施肥的增产潜力较大,如果配方和选材得当,可以发挥更大效益。     

不同施硼措施对云烟87生长和产质量的影响

在大田条件下,研究了不同施硼措施对烤烟生长及产质量的影响,结果表明：与基施（P0）或不施硼肥（CK）处理相比,叶面喷施对促进烤烟生长,增加烟叶产量,提高烟叶质量有更显著的作用,且叶面整株喷硼（P4）的烟株其产值分别比基施硼肥,喷施上部叶（P1）、喷施中部叶（P2）、喷施下部叶处理（P3）高12.4%、56.1%、37.3%、48.1%。叶面喷硼处理对中部叶糖含量、钾含量以及烟碱含量的调控有积极的作用,整株叶面喷施硼肥处理的烟叶烟碱含量明显低于其他处理。     

钙硼营养对龙眼果实品质及耐贮性的影响

果园土壤低硼条件下,于龙眼假种皮发育期间,树冠分别喷施1%CaCl2、0.2%H3BO3、1%CaCl2+0.2%H3BO3溶液及清水3次,探讨Ca、B营养对龙眼果实品质及采后耐贮性的影响。结果表明,0.2%H3BO3、1%CaCl2+0.2%H3BO3处理显著提高了果实组织B含量,对增大龙眼果型、提高单果重、增加果实的可食率和果肉糖含量有明显效应,但0.2%H3BO3处理的效果优于1%CaCl2+0.2%H3BO3处理,两处理均降低了贮藏期间果实失重率、提高好果率,减缓了果肉营养成分的变化;1%CaCl2处理显著提高了果实组织Ca含量,也提高了龙眼果实的耐贮藏性,但对果实品质的影响不明显。     

不同芽孢杆菌处理对杏采后保鲜效果及诱导抗性的影响

为明确芽孢杆菌对杏采后保鲜效果和诱导抗性机理,以"金太阳"杏果实为试材,营养肉汤(NB)培养基和无菌水作为对照,采用3种芽孢杆菌(HB-2、B1、B271)处理液分别对杏果实进行采前10天喷施处理和采后浸泡处理,并测定其贮藏过程中的腐烂率、抗病性相关酶活性及营养品质指标。结果表明:采用芽孢杆菌采前喷施处理后的杏果实在贮藏过程中感官品质显著好于对照组(P0.05),且能有效降低果实腐烂率。采后浸泡芽孢杆菌处理也能有效降低腐烂率,HB-2和B1显著好于B271及对照组(P0.05)。在采前喷施和采后浸泡两种方式处理中,HB-2效果均好于其他处理。同时,芽孢杆菌能提高杏果实的多酚氧化酶(PPO)和过氧化物酶(POD)活性,增强果实抗病性,延缓果实衰老。在采后贮藏过程中,3种芽孢杆菌亦能显著减缓杏果实VC含量、可滴定酸含量及硬度的降低(P0.05),有效抑制丙二醛(MDA)的积累,维持果实品质。综合来看,芽孢杆菌处理在杏采后贮藏保鲜中具有较好潜力。     

采前不同植物生长调节剂处理对淮安红椒室温贮藏品质的影响

为研究采前植物生长调节剂喷施处理对淮安红椒采后室温贮藏生理与保鲜品质的影响,于淮安红椒转红期,分别用不同分子量壳聚糖、海带多糖(HDG)、赤霉素(GAs)和水杨酸(SA)进行喷施处理,处理14天后采收红椒,以失重率、腐烂指数、维生素C、丙二醛(MDA)含量、多酚氧化酶(PPO)和过氧化物酶(POD)活性为指标,研究采前植物生长调节剂处理对采后红椒室温贮藏期品质的影响。结果表明：低分子量壳聚糖(LWG)处理能显著降低采后红椒室温贮藏过程中的失重率,LWG、HDG和SA处理能显著降低腐烂指数和MDA含量,显著提高维生素C含量,而LWG和SA处理显著提高红椒贮藏期的POD和PPO活性,延缓衰老。可见,采前0.5% LWG和0.8 mmol/L SA处理有利于采后红椒室温贮藏,具有一定的推广价值。     

热空气处理对‘白玉’枇杷品质及冷害的影响

为研究热空气处理对“白玉”枇杷贮藏品质及冷害的影响,本文以“白玉”枇杷为试材,探索了46℃热空气处理对蛋白组分含量变化的影响,并对各处理（6±1）℃冷藏期间果实冷害指数、可溶性固形物、可滴定酸、失重率、腐烂率和果实硬度进行测定。试验结果表明：冷藏及货架期间,46℃热空气处理果实可维持较高的可溶性蛋白和热稳定蛋白含量;抑制了冷藏期间果实可溶性固形物、可滴定酸含量的下降,保持了较高的果实硬度,显著降低了果实的腐烂率、失重率和冷害指数,其中以46℃热空气处理30min后冷藏效果最好。以上结果显示,果实蛋白组分含量的变化与果实采后冷藏过程中抗冷性有关,且热空气处理提高了果实的贮藏品质。     

采前水杨酸喷施对红地球葡萄采后品质的影响

以红地球葡萄为试材,采用不同浓度水杨酸(SA)分别在膨大期、转色期和采收前2天(预收期)喷施葡萄果实,采收、预冷后在0℃条件下贮藏,研究其对葡萄采后品质的影响。结果表明,SA处理能有效抑制葡萄果实的腐烂率、落粒率、失重率和果梗褐变的增加,延缓果实硬度的下降,同时有效维持葡萄果实中可溶性固形物和可滴定酸含量。1.0 mmoL/L SA为适宜喷施浓度,此浓度SA处理能提高葡萄贮藏期间的苯丙氨酸解氨酶(PAL)、过氧化氢酶(CAT)、多酚氧化酶(PPO)和β-1,3葡聚糖酶(GLU)活性。综上所述,采前SA喷施可有效提高鲜食葡萄采后贮运的外观和内在品质,并能提高葡萄的抗病性。     

叶面喷施钾肥对砀山酥梨叶片钾素含量和果实品质的影响

【研究目的】为改善砀山酥梨树体营养状况,提高果实品质;【方法】在砀山酥梨果实发育期（4-8月）,对叶面喷施不同水平（0.2%,0.4%,0.6%）钾肥（KCl）4次。【结果】结果表明,喷施钾肥提高了砀山酥梨叶片钾素含量;提高了果实可溶性固形物、可溶性糖、维生素C含量以及果肉硬度;增加了叶面积、百叶重及叶片叶绿素含量。【结论】综合果树生长状况、果实品质及经济效益等因素,在果实膨大期（6-8月）,叶面喷施2-3次0.4%KCl效果最佳。     

采前喷施壳聚糖和油菜素内酯对葡萄采后落果的影响

以新疆无核白葡萄为试材,采前喷施油菜素内酯（BRs）和壳聚糖（CH）,观察贮藏期葡萄落果率变化,并分析对葡萄品质和衰老相关酶活的影响。结果表明,两种处理在贮藏前期均能有效降低贮藏期葡萄落果率,壳聚糖效果好于油菜素内酯。二者均降低了果实酸度,提高了果实糖酸比,对果实总维生素C（抗坏血酸）含量没有影响,但明显提高了VC的还原度,使PG、POD和LOX等果实成熟衰老相关酶的活力高峰向后推迟了15～30天。推论BRs和CH可能是通过延迟无核白葡萄果实成熟衰老进程来减少落果,也暗示了无核白葡萄迅速的成熟可能是导致果实过早脱落的原因。     

Chitosan applications pre- or postharvest prolong raspberry shelf-life quality

Raspberries are fruit with high metabolism that makes them very perishable, impairing their storage and shelf-life. Chitosan coatings have the potential to improve their postharvest life by reducing water loss, respiration rate and decay incidence. The purpose of this work was to study the effect of different concentrations of chitosan, applied pre- or postharvest, on the retention of quality attributes of fresh raspberries. The chitosan concentrations tested were 0 (control), 0.5, 1.0 or 2.0%. The postharvest treatment was applied immediately after harvest, dipping the fruit in the solutions for 5 min. The pre-harvest treatment was done with one hand-spray application per week for three weeks, starting when the fruit were just turning pink. In both experiments the fruit were stored at 0 °C and 90% RH. Pre- or postharvest use of chitosan at 1 or 2% was effective in maintaining titratable acidity and retarding respiration and ethylene production, weight loss and decay incidence. Application by both means resulted in the highest chitosan concentrations accelerating a reduction of ascorbic acid contents. Firmness was maintained only when the fruit were treated pre-harvest at 2%. Thus, application of chitosan at 1 or 2% postharvest and 2% pre-harvest was able to retain key raspberry quality attributes for 15 and 12 days, respectively.     

壳聚糖涂膜对常温贮藏兔眼蓝莓果实品质的影响

以“圆蓝”兔眼蓝莓为试材,研究了0．5％壳聚糖（0．4％高分子壳聚糖＋0．1％低分子壳聚糖）涂膜对常温贮藏蓝莓果实品质的影响。结果表明,在20℃常温条件下贮藏20d的过程中,壳聚糖涂膜可以有效减缓蓝莓果实感官品质及果实硬度的下降速度,降低腐烂率和失重率,保持较稳定的TSS和有机酸含量;抑制PPO活性的快速升高和MDA的大量积累：有效延长常温条件下的贮藏期,有利于保持采后蓝莓的品质。但对采后蓝莓果实中的花色苷含量无明显影响．对类黄酮的增加有一定的抑0作用。     

水溶性壳聚糖在葡萄保鲜中的应用

因为葡萄易腐烂、保质期短。所以该试验以葡萄为试材,通过喷涂的方法,在常温下测定贮藏期间葡萄的坏果率以及感官品质的变化,研究了不同浓度的壳聚糖膜对葡萄的保鲜效果。结果表明,用壳聚糖涂膜处理能降低葡萄的腐烂率,保持葡萄的色泽和亮度,明显降低贮藏葡萄的呼吸代谢强度和水分的散失程度。其中以1%壳聚糖膜处理的保鲜效果最好。     

壳聚糖涂膜对芒果采后品质及生理特性的影响

为了探讨壳聚糖涂膜保持芒果采后品质的相关生理机制,以‘台农1号’芒果(Mangifera indica L.‘Tainong No.1’)为材料,研究了1.0%壳聚糖涂膜处理对芒果在常温(28~30℃)贮藏条件下果实品质及生理特性的影响。结果表明,与对照相比,壳聚糖涂膜处理显著降低了果实的失重率和病果率,延缓了果皮颜色的转黄,保持较高的果实硬度;并且,壳聚糖涂膜有效保持了果实品质,能够显著延缓芒果可滴定酸(TA)含量的降低和可溶性固形物(TSS)含量的升高,维持芒果果实较高的Vc含量;同时,壳聚糖涂膜也提高了芒果果实贮藏后期超氧化物歧化酶(SOD)和过氧化物酶(POD)的活性,并抑制MDA含量的积累,降低膜脂过氧化程度,从而延缓了采后芒果的后熟衰老进程。     

Preharvest calcium applications inhibit some cell wall-modifying enzyme activities and delay cell wall disassembly at commercial harvest of ‘Fuji Kiku-8′ apples

To improve apple firmness during the postharvest chain, detailed knowledge of the biochemistry underlying ripening-related cell wall disassembly, a very complex event, is required. Apple softening is reportedly mediated by calcium loss from the middle lamella, and accordingly calcium applications are expected to preserve fruit firmness. In this work, pre-harvest calcium sprays (7 weekly applications at 1.6%, w/v, 81-123 days after full bloom) were applied to ‘Fuji Kiku-8′ apples, with the purpose of examining treatment effects on cell wall metabolism during on-tree fruit maturation and ripening. Applied calcium improved cell-to-cell adhesion as indicated by better preservation of the middle lamella and by higher contents of ionically bound pectins in treated fruit, leading to higher fruit firmness levels at commercial harvest. Matrix glycan breakdown was also delayed in response to calcium treatment. Calcium applications partially suppressed pectinmethylesterase, pectate lyase, β-galactosidase, α-l-arabinofuranosidase and β-xylosidase activities, without any apparent relationship with ethylene production rates.     

不同杀秧时间对马铃薯周皮形态及生理变化的影响

为确定适宜的马铃薯杀秧时期,达到降低采收损伤、提高块茎贮藏品质的目的,以马铃薯青薯9号为试材,研究了采收前0、7、14 d进行机械杀秧处理对马铃薯产量、品质和块茎表皮擦伤程度的影响,并在此基础上对贮藏期间块茎的呼吸强度、苯丙氨酸解氨酶（PAL）活性、过氧化物酶（PPO）活性、木质素含量、表皮微观组织结构、失重率和腐烂率的变化进行研究。结果表明,与对照相比,在采收前14 d杀秧处理虽然一定程度降低了马铃薯产量和大中薯率,但促进了块茎周皮木栓层的形成,采收时表皮擦伤程度降低44.66%,同时降低了块茎贮藏期间的呼吸代谢速率,抑制了表皮PAL及PPO活性的升高,促进了表皮木质素的积累,减缓了块茎失重率和腐烂率的上升。综合分析,采收前14 d杀秧处理的采后减损效果优于不杀秧和采收前7 d杀秧处理,该研究可为马铃薯采前杀秧提供一定的技术指导和理论参考。     

壳聚糖复合涂膜保鲜剂对采后青圆椒保鲜效果的研究

为延长青圆椒的贮藏时间,采用正交试验法研究壳聚糖、柠檬酸、氯化钙复合涂膜对青圆椒的保鲜效果,并进行验证,筛选出较优的壳聚糖复合涂膜保鲜剂质量浓度组合。结果表明,贮藏期间,氯化钙是影响青圆椒质量损失率、可滴定酸含量、可溶性固形物（TSS）含量的主要因素,柠檬酸是影响青圆椒VC含量的主要因素。10 g/L壳聚糖,15 g/L柠檬酸,15 g/L氯化钙为复合涂膜保鲜剂较优组合,该复合涂膜保鲜剂可减轻青圆椒果实软化程度,减少其贮藏期内质量损失,延缓果实可溶性固形物、可滴定酸、VC等营养物质的消耗及叶绿素的下降速度,抑制酚类物质含量的下降,维持较高的抗氧化活性,具有较好的保鲜效果。     

Effects of carboxymethyl cellulose and chitosan bilayer edible coating on postharvest quality of citrus fruit

There is increasing public interest in development of edible natural biodegradable coatings to replace the currently used commercial synthetic waxes for maintaining postharvest quality of citrus fruit. We tested the efficacy of a newly developed polysaccharide-based edible bilayer coating comprising carboxymethyl cellulose (CMC) and chitosan in preserving postharvest quality of various citrus fruit, including ‘Or’ and ‘Mor’ mandarins, ‘Navel’ oranges, and ‘Star Ruby’ grapefruit after simulated storage and marketing. In all citrus species, it was found that the CMC/chitosan bilayer coating was equally effective as the commercial polyethylene wax in enhancing fruit gloss. Furthermore, the CMC/chitosan bilayer coating slightly increased fruit firmness, especially of oranges and grapefruit, but was mostly not effective in preventing post-storage weight loss. Both the CMC/chitosan bilayer coating and the commercial wax had no significant effects on juice total soluble solids and acidity levels, and had similar effects on gas permeability, as indicated by only slight increases in internal CO₂ levels and in juice ethanol accumulation after storage. Sensory analyses revealed that neither the CMC/chitosan bilayer coating nor the commercial wax coating had any deleterious effects on flavor preference of ‘Navel’ orange and ‘Star Ruby’ grapefruit. However, application of the commercial wax, and moreover the CMC/chitosan bilayer coating, resulted in a gradual decrease in flavor acceptability of ‘Or’ and ‘Mor’ mandarins because of increased perception of off-flavors. Overall, we showed that the CMC/chitosan bilayer edible coating sufficiently enhanced fruit gloss, but was not effective in preventing postharvest weight loss. Furthermore, flavor quality was slightly impaired in mandarins but not in oranges and grapefruit.