不同肥料用量组合对Yacon产量的影响

研究了氮、磷、钾肥的用量对Yacon产量的影响．通过计算机模拟寻优，选出最佳施肥方案为：纯氮202．47～221．09kg／hm^2，磷肥96．6～143．4kg／hm^2，钾肥193．91-286．09kg/hm^2．

Yacon适宜移栽期的确定

为了丰富我国作物资源,将Yacon引种到吉林省,进行了适宜移栽期的研究。试验结果表明:5月5日移栽的植株在生长前期地上部外观表现最好,但在生长后期衰老最严重;4月20日移栽的植株产量最高,为2079.00克/株;4次移栽的块根,总糖和可溶性蛋白质含量无差异,维生素C含量存在差异,4月25日移栽的Vc含量最高,为2.9504%。

Yacon的栽培技术

为了丰富我国作物资源,将Yacon引种到吉林省延边地区,进行了适宜栽培技术的研究。结果表明:4月20日大田移栽,移栽时覆盖地膜,移栽密度为80 cm×40 cm,施用氮肥202.47～221.09 kg/hm2、磷肥96.6～143.4 kg/hm2、钾肥193.91～286.09 kg/hm2时,能获得优质高产。

Effects of 1-MCP and Chitosan on Active Oxygen Metabolism and Quality of Fresh-cut Potato during Storage

[Objective] The research aimed to study the effects of 1-methylcyclopropene （1-MCP） and chitosan on active oxygen metabolism and quality of fresh-cut potato during storage. [Method] The fresh-cut potato slices were respectively treated with 1- MCP （2 μl/L）, chitosan or 1-MCP ＋ chitosan. During the storage period, the contents of superoxide anion （02）, malondialdehyde （MDA）, hydrogen dioxide （H202） and Vita- min C （Vc）, the activities of polyphenol oxidase （PPO）, peroxydase （POD） and super- oxide dismutase （SOD） as well as the respiratory rate of the fresh-cut potatoes in all the treatments were determined every day. The fresh-cut potato slices treated without any reagents were used as control. [Result] 1-MCP Treated could significantly de- creased the respiratory rate, PPO activity and the accumulations of 02 , H202 and MDA, increased the activities of SOD and POD and slowed down Vc content reduc- tion. On the contrary, potato treated with chitosan significantly inhibited the POD activi- ty in fresh-cut potato. Compared with the control, the combination of 1-MCP and chi- tosan showed a little but not significant better effects on potato preservation. [Conclu- sion] 1-MCP Treated showed the best effects on potato preservation.

Yacon适宜移栽密度的确定

为了丰富我国作物资源,将Yacon引种到吉林省延边地区,进行了适宜移栽密度的研究.试验结果表明:Yacon在移栽密度为80cm×50cm时单株产量最高,总糖含量最高;在移栽密度为80cm×40cm时公顷产量最高,蛋白质含量最高.随着移栽密度的增加或减少,产量均成降低态势.

Effects of fresh-cut and storage on glucosinolates profile using broccoli as a case study

Glucosinolates(GLS) contribute to the unique flavour, nutrition, and plant defence of the Cruciferous vegetables. Understanding the GLS changes through postharvest processing is essential for defined preservation. In this study, four different fresh-cut types, whole flower(W),floret(F), quarterly cut floret(QF) and shredded floret(FS) of broccoli, were stored for 0, 1, 2 and 3 day(s) to explore GLS responses to postharvest treatments. As a result, seven GLS were identified, mainly including glucoraphanin(RAA), neoglucobrassicin(NEO), and glucobrassicin(GBC)and accounting for 52.69%, 20.12% and 14.99% of the total GLS(21.92 ± 0.48) μmol · g ^(-1 )DW, respectively. FS had the sharpest decrease in GLS after three days of storage(6.55 ± 0.37) μmol · g-1DW, while QF had the least(10.16 ± 0.33) μmol · g ^(-1 )DW. All GLS components decreased over storage, except for 4-methoxyglucobrassicin(4 ME) in FS and QF, suggesting its key role in serious wound defence. The results suggested certain postharvest approaches influenced the flavour and nutrition of broccoli.

Effect of Storage Conditions on the Sensory Quality, Colour and Texture of Fresh-Cut Minimally Processed Cabbage with the Addition of Ascorbic Acid, Citric Acid and Calcium Chloride

The aim of this study was to investigate the effect of storage conditions on the sensory quality, colour and texture of fresh-cut cabbage during the addition of ascorbic acid, citric acid and calcium chloride. Ascorbic acid maintained the overall quality for 14 days at 0℃ and 7 days at 5℃;no difference, however, was observed regarding browning of cut surface compared to the control sample at both storage temperatures. Calcium chloride maintained the overall quality and cut surface browning for 14 days at both storage temperatures. It was also found that citric acid 1% can be used for minimally processed cabbage. Soaking with citric acid helped retain the color and increased the overall acceptance and organoleptic quality of fresh cut cabbage;it reduced browning of the cut surface and protected against formation of black specks. Citric acid treatment combined with low temperature storage (0℃) prolonged the shelf life of minimally processed cabbage for 22 days, time sufficient for acceptable marketing of the product. The lightness of minimally processed cabbage decreased linearly from 70.94 ± 6 to 63.8 ± 8.5 - 61.3 ± 8 units for the chemical treatments during 22 days of storage at 0℃. Hue angle values during storage time were also significantly influenced by chemical treatments mainly at 0℃.

Effects of Stable Chlorine Dioxide on Sterilization and Preservation of Fresh-cut Narrow-leaf Cattail

At present, chlorine dioxide has been widely used as a bactericide that may become an alternative to chlorine. In this study, fresh-cut narrow-leaf cattail was soaked with 45, 70 and 95 mg/L chlorine dioxide solution, respectively. Fresh-cut narrow-leaf cattail samples were collected regularly to determine changes in surface microbe amount, cellulose content, Vc content, reduction sugar content and sensory quality of narrow-leaf cattail, thus analyzing the effects of chlorine diox- ide on sterilization and preservation of fresh-cut narrow-leaf cattail. The results showed that all three concentrations of chlorine dioxide solution could significantly reduce the amount of microbes on the surface of fresh-cut narrow-leaf cattail and improve the edible safety of products. The initial sterilization efficiency was im- proved gradually as the concentration of chlorine dioxide increased. In addition, chlorine dioxide treatment postponed the increase of cellulose content of fresh-cut narrow-leaf cattail. However, chlorine dioxide oxidized Vc and reducing sugar, and its bleaching effect also exerted a certain impact on the sensory quality of fresh- cut narrow-leaf cattail. Based on comprehensive comparisons, 45 - 70 mg/L chlorine dioxide solution exerted the best effects on sterilization and preservation of fresh-cut narrow-leaf cattail. This study laid the foundation for the production and application of chlorine dioxide solution and promotion of rapid development of nar- row-leaf cattail industry.

Optimization of Preservation on Fresh-cut Yam under Simulated Cold-chain Process

[Objectives]This study was conducted to investigate the effect of compound fresh-keeping liquid on the browning and quality of fresh-cut yam during the cold chain process.[Methods]Under the simulated cold chain condition of 4℃,a uniform design(U6*(64))experiment was carried out to optimize the compound preservative formula,and a better compound preservative formula was obtained using the regression equation.[Results]The compound preservative formula was:AA 0.25%,CA 0.5%,Nisin 0.09%,GSH 0.15%.The compound fresh-keeping liquid effectively delayed the browning of fresh-cut yam and the accumulation of MDA,maintained the content of TSS,inhibited the activity of PAL and delayed the appearance of the maximum activity of POD and POD.[Conclusions]This study provides technical support for the actual extension of the shelf life of fresh-cut yam.

Studies on Genetic Transformation of Fresh-cut Chrysanthemum Using DREB1A Promoted by Stress-induced Promoter rd29A

In this study, DERB1A transcription factor and stress-induced promoter rd29A were isolated respectively and amplified from Arabidopsis thaliana, se- quenced and analyzed by DNAsis. In addition, the stress-induced promoter rd29A was utilized to construct the plant expression vector of DERB1A, which was transformed into Agrobacterium tumefaciens. Furthermore, the transgenic regeneration system of fresh-cut chrysanthemum from callus to plantlets was established successfully. On this basis, chrysanthemum leaf-disc explants were genetically transformed with Agrobacterium-mediated method. Two positive transgenie plantlets were obtained in vitro. Based on PCR detection, DREB1A transcription factor was integrated into chrysanthemum genome, which laid the foundation for breeding new transgenie cultivars of fresh-cut chrysanthemum with high comprehensive stress resistance, good cmalitv and high field.

Bacterial Community Associated with Autotrophic and Heterotrophic Cultures of Medicinal Plant Smallanthus sonchifolius (Yacon)

Several unfruitful attempts to grow axenic shoot cultures of Smallanthus sonchifolius, also known as yacon, were made before healthy shoots grew in association with bacteria on half strength Murashigue and Skoog media supplemented with 2.2 μM benzylaminopurine. Twenty-one bacterial isolates were obtained from in vitro S. sonchifolius plantlets, eight of these isolates were identified as Flavimonas oryzihabitans, Curtobacterium pusillum, Sphingomonas paucimobilis, and Microbacterium imperiale. These microorganisms produced indole acetic acid (IAA) at amounts varying between 8.89 to 47.45 μg/mL, reason for being classified as plant growth promoting bacteria (PGPB). The results show that buds associated with bacteria cultured on sucrose free media produced 3.77 new roots measuring 18.33 cm in length after a 30-day growing period. In contrast, buds growing on sucrose supplemented media, the number of roots induced was higher (6.67 to 14 roots/explant) but shorter in length, 4.67 to 5.83 cm. During plant acclimatization to soil, photosynthesis and water efficiency were measured showing that the plants were healthy and vigorous. A slightly higher rate of photosynthesis and water use efficiency was recorded in the plants produced on heterotrophic conditions as compared to plants grown in sucrose free media. Plants adapted well in the soil demonstrating that the PGPB community associated to S. sonchifolius in shoot cultures was not harmful to plant production. The purpose of this study was to demonstrate that the bacteria associated with in vitro S. sonchifolius shoot cultures was not the result of microbial contamination, but rather from symbiotic associations that extended from cultivation in the greenhouse, to culture and back to soil. This is the first report to show that autotrophic cultures may represent a viable alternative to grow healthy plants without eliminating beneficial bacteria associated with the host.

Yacon Product(PBY)Modulates Intestinal Constipation and Protects the Integrity of Crypts in Wistar Rats

This study investigated the use of a product based on yacon (PBY) in microbiological, physical-chemical and intestinal characteristics of Wistar rats artificially constipated with Loperamide&reg;. Thirty-two rats were divided into four groups: Control (C), Constipated Control (CC), PBY (not constipated) and Constipated PBY (PBYC). The dosage of 0.14 g of FOS+ inulin/kg was tested. Microbiota, pH and faeces characteristics of faeces and caecal contents were evaluated. Caecal weight, morphometry of caecal villi and the concentration of short-chain fatty acids were determined. Higher caecal weight was identified in the PBYC animals as well as higher width, height and depth of cripts. The PBY group showed the highest (p < 0.05) concentration of butyrate (93.2 ± 65.5 mmol/L). The supplementation with PBY positively altered the intestine epithelial tissue in constipated animals, keeping the integrity of the caecum crypts.

The in Vitro Antioxidant Capacities of Hydroalcoholic Extracts from Roots and Leaves of Smallanthus sonchifolius (Yacon) Do Not Correlate with Their in Vivo Antioxidant Action in Diabetic Rats

Leaf and root extracts of Smallanthus sonchifolius (yacon), have antihyper-glycemic activity and antioxidant properties. The present study aims to compare the in vivo hepatic antioxidant activity of hydroalcoholic extracts of yacon leaves and roots in rats with streptozotocin-induced diabetes in terms of their in vitro antioxidant capacity. Rats were treated during 14 days with 1060 mg·Kg-1 root extract or 400 mg·Kg-1 leaf extract. The latter was richer in phenolics and possessed a much higher in vitro antioxidant activity. Both extracts prevented hyperglycemia in diabetic rats. The liver of diabetic rats presented increased levels of protein carbonyls and ROS and decreased activities of antioxidant enzymes. Treatment with both root and leaf extracts restored the protein carbonyl levels to normality. The root extract also restored the ROS levels to normality, but the leaf extract was not effective. The root extract was also more effective in restoring the activity of at least two important antioxidant enzymes (glucose 6-phosphate dehydrogenase and glutathione peroxidase). In terms of the antioxidant load (which was 17 times lower in the root extract treatment), the in vivo action of the root extract was more effective than the leaf extract in reducing the hepatic oxidative stress that accompanies diabetes.

Effect of Storage Temperature on the Quality of Fresh-cut Cattail

Fresh-cut cattail was extremely not resistant to store at room temperature.In the first day,it began to etiolate and rot,the fiber content increased,but the vitamin C content and reducing sugar content decreased.The aerobic bacterial count increased,the weight loss rate sharply increased,and the sensory quality and food value were gradually lost.Low temperature storage could decrease the loss of vitamin C and reducing sugar of fresh-cut cattail,reduce the weight loss rate and delay the increase of fiber content,maintain the water and nutrient of fresh-cut cattail,and the storage effect of 0 ℃ was better than 4 ℃.

Effect of Boron Fertilizer on the Root Growth Characteristics and Nutrient Contents of the Tuberous Root of Yacon

[Objectives]This study was conducted to investigate the effects of boron fertilizer on the root system and nutrient contents of yacon.[Methods]By the field test method,high-and low-dose of boron fertilizer(Na2B8O13,9000 and 3000 g/hm2)and equal amount of clean water(CK)were sprayed 3 times in the soil area where plants were grown in the early,middle and late stages of yacon growth,and the effects of applying boron fertilizer on the growth and fruit quality of yacon were analyzed.[Results]The indexes of the root system of yacon treated with boron fertilizer were significantly higher than those of the CK.The yield and total sugar,vitamin C,ash,Ca,Fe,Zn and other nutrients of the boron fertilizer treatments increased significantly compared with the CK.The yields of the low-and high-dose treatments increased by 77.2%and 211.2%,respectively,compared with the CK;and the contents of total sugar,vitamin C,ash,Ca,Fe and Zn in the high-dose treatment increased by 28.4%,163.6%,33.2%,73.3%,41.2%and 56.2%,respectively,compared with the CK.The nutrients in yacon treated with the low dose of boron fertilizer were lower than those with the high dose.The application of boron fertilizer could increase the yield of yacon,improve its quality and increase the contents of nutrients such as Ca,Fe,Zn and total sugar.[Conclusions]This study provides a reference for the reasonable application of boron fertilizer in the production of yacon and the improvement of the quality of yacon.

Effects of Lactoperoxidase System Activation-Oregano Essential Oilor Chlorine on the Quality of Modified Atmosphere Packaged Fresh-Cut Iceberg Lettuce

The present work focused on the effects of the Modified Atmosphere Packaging (MAP) 1 (5% O2 and 10% CO2) or 2 (2% O2 and 5% CO2) and the previous addition of Lactoperoxidase System (LPS) and Oregano essential oil or chlorine washing on the quality of fresh-cut lettuce during refrigerated storage at +4?C. Our results showed the significant effect of this combined treatment on quality improvement during storage. Thus, mesophilic bacteria was reduced in treated samples compared to those untreated with number which not exceeded the critical of 5 × 107 UFC?g-1 (p 2 and CO2 levels created by both atmosphere were not significantly different between the two treatments (p > 0.05). Brightness of lettuce samples was significantly reduced during storage. Thereafter, the PCA data showed the effect of combined treatment on the preservation of hygienic, physico-chemical and sensory quality up to the 7th day of refrigerated storage of these treated samples. The results obtained draw attention to modified atmosphere packaging lettuce and the addition of bio-preservatives which could be an alternative of choice to replace chlorine to preserve the sanitary quality of green products.

Influence of cutting size and packaging materials on the quality of fresh-cut winter squash (var. Ajijimang)

Winter squash (var. Ajijimang) washed in 100 mg.L-1 chlorine water and cut into 4 and 8 parts was packed in different packaging materials, 35 μm micro-perforated P-Plus (MPP), 50 μm polyethylene (PE), 80 μm nylon/PE (Ny/PE), and 90 μm PE films separately. Fresh-cut samples were then stored at 10℃ for up to 17 days. The 35 μm MPP having a high oxygen transmission rate (OTR) has the most stable gas exchange ratio while the 80 μm Ny/PE was the most unstable. Firmness of the mesocarp remained acceptable until the end of storage regardless of the cutting size. Soluble solids content (SSC) remained stable and even slightly increased to a certain extent within 6 days. An increase in pH after 10-day storage suggested the activity of microorganisms within the packaging films. Strong off-odor was detected in samples packaged in 80 μm Ny/PE film after 13 days of storage. Mold was observed in all 1/4 cut samples on day 13 except the sample packaged with 80 μm Ny/PE film. However, no mold was found in all 1/8 cut samples except 35 μm MPP film on day 13. Severe mold invasion was apparent on the onset of the 17-day storage in 35 μm MPP film and 50 μm PE film. Samples cut into 8 parts and packed in 80 μm Ny/PE and 90 μm PE films had less mold incidence compared with other two packaging films. Fresh-cut winter squash packaged in 90 μm PE film maintained quality with shelf-life of 10 days at 10℃. Winter squash as fresh-cut commodity, with the right packaging material has the potential for longer period of storage in retail stores.

Research and Development of Foshou Yam and Yacon Compound Beverage

[Objectives]Foshou yam and yacon were used as raw materials to prepare a compound beverage.[Methods]With Foshou yam and yacon as raw materials,single factor experiments and response surface method were used to optimize the optimal processing parameters of the compound beverage.[Results]The best processing parameters of the compound beverage were Foshou yam pulp 20%,yacon juice 30%,sugar 6%and citric acid 0.05%.Under the best conditions,the compound beverage scored 91.7 points,with a light yellow color,delicate taste,good Foshou yam and yacon flavor,moderate sour and sweet taste.[Conclusions]This study provides a new way for the development and utilization of Foshou yam and yacon.

Effect of Magnetic Field Technology on Preservation Quality of Fresh-cut Apple

[Objectives]The paper was to study the effect of magnetic field technology on physicochemical properties of fresh-cut apple during storage.[Methods]Using fresh-cut apples as materials,magnetic field assisted refrigeration and conventional refrigeration control groups were set up,and the preservation effects of magnetic field assisted refrigeration on fresh-cut apples were tested by measuring the changes of microorganisms and physicochemical indicators.In this experiment,the conditions of magnetic field assisted refrigeration group was set as follows:temperature 4℃,magnetic field intensity 5 mT,static magnetic field,and storage for 6 d.[Results]At 6 d post storage,the weight loss rate,total number of colonies and total number of fungi of fresh-cut apples increased;the L value and hardness showed a downward trend;the soluble solid content first increased and then decreased;and the total acid decreased first and then increased.The above indicators in magnetic field assisted refrigeration group changed more gently than that in conventional refrigeration group.Compared with conventional assisted refrigeration,the weight loss rate of fresh-cut apples treated by magnetic field combined with 4℃refrigeration was reduced by 68.00%;the hardness was increased by 12.23%;the total number of colonies and total number of fungi were reduced by 64.15%and 37.50%;and the L value did not change much.High content of soluble solids and total acid was maintained.[Conclusions]Magnetic field assisted refrigeration delays quality deterioration of fresh-cut apples during storage,prolongs shelf life,and further improves their edible quality and commodity value.

Effects of 2,5-Norbornadiene （NBD） on Physiological and Biochemical Responses of Fresh-cut Winter Squash

Ethylene is one of the most important plant hormones that regulate physiological responses, maturity and senescence of postharvest fruits and vegetables. The determination of its role in the wound-healing response of fruits and vegetables is helpful in understanding the wound responses. 2,5-Norbornadiene （NBD）, inhibitor ethylene binding were used to determine the effect of ethylene action on wound-induced response of fresh-cut winter squash, a kind of vegetables known to produce ethylene markedly after cutting. The effect of NBD on the physiological and biochemical changes of fresh-cut winter squash was investigated in this experiment. The results showed that NBD had great effects on physio-biochemical metabolism of fresh-cut winter squash. Ethylene production was inhibited significantly by NBD. NBD also had an inhibition effect on polyphenol oxidase （PPO）, peroxidase （POD） and phenylalanine ammonia lyase （PAL） activity. The effect of NBD on lipoxygenase （LOX） activity and superoxide dismutase （SOD） was not obvious. NBD treated sample showed a more rapid increase in catalase （CAT） activity, which may help in healing the damage of the tissue. These information are important in understanding the fundamental biology of wound response and in the development of new technology to hasten wound-healing and, thereby, to minimize costly wound-related problems in fresh-cut industry.