Antisepsis and Fresh-keeping Effects of Natamycin Coating Compounds Treatment on Red Global Grape

The aim was to research fresh-keeping effects of natamycin on cold-pre- served grape. Red globe grapes were processed with compound coating liquid of chitosan with mass fraction at 1% and natamycin with mass fractions at 0.20% （T1）, 0.40% （T2） and 0.60% （T3）, respectively. Grapes processed with water （CK3） and 1% chitosan （CK2） were taken as control groups. Rotten rate, seed shattering rate, mass loss rate, respiratory intensity and related physiological quality in test and control groups were compared. The results indicated that respiratory intensity, mass loss rate, rotten rate and seed shattering rate in CK1 were all higher than those in CK2. In addition, T1, T2 and T3 were lower in the indices than CK1 and CK2, but still kept at a high level in fruit hardness. Furthermore, mass fractions of Vc and titratable acid declined more slowly in T1, T2 and T3, compared with CK1 and CK2. Natamycin better preserved grapes and prolonged storage period. In general, natamycin with mass fraction at 0.4% proved best in fresh-keeping.

Model of gas exchange dynamics for modified-atmosphere packages containing fresh produce

A model for modified-atmosphere packaging （MAP） systems containing fruits and vegetables was developed.The computer simulation was performed to predict the gas mass concentrations inside the packages and was successfully verified by experiments with yellow peaches at 5,15 and 25 ℃ using two types of packaging films.A Michaelis-Menten type respiration model with noncompetitive inhibition mechanism due to CO2 was adopted while the respiration rates were measured with an improved permeable system method suitable for either steady or unsteady state.The applicability of the model in the design of MAP systems was demonstrated with a calculation to evaluate film specification and equilibrium concentrations of O2 and CO2 in the package containing yellow peaches.

Effects of Nine Kinds of Household Vase Solutions on Fresh-keeping Effect of Lilium Cut Flowers

[Objective]The paper was to study the effects of nine kinds of household vase solutions on fresh-keeping effect of Lilium cut flowers.[Method]Using Lilium"Sorbonne"as the material,nine kinds of household vase solutions were prepared by edible white granulated sugar,white vinegar,akafen powder and vitamin C tablets,respectively.The morphological and physiological indexes of Lilium cut flowers,including vase life,ornamental grade,flower diameter,fresh weight of flower branches,water balance value,soluble protein content and MDA content of petals,were observed,and the effects of nine kinds of household vase solutions on fresh-keeping effect of Lilium cut flowers were studied.[Result]The household vase solution F8(20 g/L white granated sugar+1 packet/L acafen powder+2 tablets/L vitamin C tablets)had the best fresh-keeping effect on Lilium cut flowers,which was beneficial to prolong the vase life and improve the ornamental value of Lilium cut flowers.[Conclusion]The household vase solution of Lilium cut flowers is optimized,which is not only environmentally friendly but also convenient for ordinary families.

Fresh-keeping Effects of Different Concentrations of 6-BA and B9 on Carnation Cut Flower

Using sucrose, citric acid and vitamin C as the basic liquid, different concentrations of 6-BA and B9 preservatives were added, and the carnation variety ＇ Master＇ was treated. The results showed that the formula of 3% sucrose ＋ 50 mg/L citric acid ＋ 600 mg/L vitamin C ＋ 20 mg/L 6-BA could effectively maintain the water balance of the cut flower, prolong the vase life of the cut flower to 16.4 d, and maximize the flower diameter and the crown height.

Kiwi Fruit Fresh-keeping Technology

The vitamin C rich-kiwi fruit-the king of fruits-is good to taste but hard to store. Only a few countries can prevent mildew on the fruit stalk during the storage process. The fresh-keeping technology developed by the Shaanxi Teachers University has enabled China to catch up with the advanced countries in this field.

Fresh-Keeping Decision and Coordination of Fresh Agricultural Product Supply Chain Considering Carbon Cap-and-Trade under Different Dominance

In the context of low carbon,this paper discussed the impact of the carbon cap-and-trade policy on the fresh-keeping decision-making of two-echelon fresh agricultural product supply chains under different dominance,and designed cost-sharing contracts to coordinate the supply chain of fresh agricultural products dominated by suppliers and retailers respectively.The results showed that:dominance has no effect on the fresh-keeping decision and total revenue of fresh agricultural product supply chain,but it affects the internal income distribution,and dominance does not always bring more benefits;the implementation of carbon cap-and-trade reduces the fresh-keeping decision-making of fresh agricultural products supply chain and reduces the free-rider income of followers;the role of higher carbon trading price is twofold,which not only brings about the speculation of leading enterprises,but also promotes the application of low-carbon technologies;consumers’high preference for freshness,low-cost and high-efficiency low-carbon technology are all conducive to improving the fresh-keeping efforts and benefits of the supply chain;cost-sharing contracts can coordinate the supply chain of fresh agricultural products.

Study on the Preservation of Fresh Chinese Wolfberry Fruit at Room Temperature by Chitosan Coating

[Objective] The aim was to study the preservation of fresh Chinese wolfberry fruit via chitosan coating. [Method] Using Chinese wolfberry "Ningqi No. 1" as experimental material, the fresh fruits were coated by different concentrations of chitosan(0.75%, 1.00%, 1.25%, 1.50% and 1.75%) at room temperature to study the changes in weight loss rate, rate of rotten fruits rot, soluble solid content and vitamin C(Vc) content. [Result] Of all the treatments, the fruits coated with 1.25% chitosan showed lowest rate of rotten fruit and weight loss rate, and highest Vc and soluble solid content, presenting the optimal fresh-keeping effect. [Conclusion] Chitosan coating is helpful for the preservation of fresh Chinese wolfberry fruit at room temperature.

Effect of Different Preservation Treatments on the Room Temperature Storage of “Gala” Apple

In this experiment," Gala" apples were used as test materials,and 1-MCP treatment and fresh-keeping film packaging were used for storage at room temperature.The results showed that the storage effects of 1-MCP treatment and fresh-keeping film packaging were better than those of the control.Moreover,1-MCP treatment was better than fresh-keeping film packaging in hardness,soluble solids content,titratable acid content,and inhibition of ethylene release.

Discussion on Refrigerator Fresh——Keeping Technologies

This paper analyzes the status and the development trend of refrigerator fresh-keeping technologies domestically and internationally, introduces several popular fresh-keeping technologies, elaborates on the principles and characteristics of several fresh-keeping technologies, and put forth that the future research should be focused on the different needs of customers.

Effects of Storage and Preservation of Postharvest Gonggan Mandarin(Citrus reticulata)Fruit Immersion in Salicylic Acid Combined with Calcium Chloride

[Objectives]To investigate the effects and mechanism of fruit immersion treatment with salicylic acid(SA),calcium chloride(CaCl_(2))solutions at different concentrations or their combinations on post-harvest preservation of Gonggan Mandarin(Citrus reticulata)fruit.[Methods]13 experiments(2 storage temperatures,3 control treatments,3 concentrations of SA solution,4 concentrations of CaCl_(2) solution and 3 combinations of SA+CaCl_(2) solution for fruit immersion treatment)were conducted for 90 d.Gonggan fruit weight loss rate,rotting rate,disease index,disease type,soluble solids and organic acids content,and the differences in the activity of six enzymes(APX,PPO,CHI,CAT,SOD,PAL)related to fruit disease resistance were detected regularly.[Results]With the increase of storage days,the weight loss rate,rotting rate and disease index increased,the content of soluble solids and organic acids decreased,the activity of APX,PPO,CHI and SOD increased,and the activity of CAT and PAL decreased.However,the increase or decrease of fruit loss at low temperature was the smallest,and the increase or decrease of fruit at natural room temperature was the largest.Gonggan fruit cleaning before storage is an effective preservation and fresh-keeping technology,but its preservation and fresh-keeping effect is far less than that of fruit immersion by SA,CaCl_(2) and SA+CaCl_(2) compound solution.The effect of fruit immersion by SA solution was greater than that of fruit immersion by CaCl_(2) solution;the best concentration of SA alone was 6.0 mmol/L,which was not significantly different from 3.0 mmol/L,but the effect of 9.0 mmol/L decreased;the best concentration of CaCl_(2) alone was 6.0 mmol/L,which was significantly better than 3.0 and 9.0 mmol/L;the optimal concentration combination of SA+CaCl_(2) compound solution for fruit immersion treatment was 6.0 mmol/L SA+3.0 mmol/L CaCl_(2).[Conclusions]The fruit immersion by SA,CaCl_(2) and their compound solutions induced the increase of activity of six enzymes related to disease resistance in Gonggan fruit,and PPO and CHI were judged to be two key enzymes based on response intensity.

Effect of sodium alginate/phosphate-stabilized amorphous calcium carbonate nanoparticles on chitosan membranes

Biodegradable chitosan(CS)films can meet the demand for sustainable development.However,the performance of pure CS membrane still exists a particular gap compared with the traditional film.Inorganic nanomaterials with the controllable release are added to improve its physical and chemical properties.Herein,a series of CS/phosphate-stabilized amorphous calcium carbonate(CS/ACCP)and CS/sodium alginate/ACCP(CS/Alginate/ACCP)composite films were prepared by the flow method.The effects of ACCP and Alginate/ACCP nanoparticles on the physical and chemical properties of the composite membrane were investigated.The results showed that the composite nanoparticles could significantly improve CS film’s compactness,hydrophobicity,and mechanical properties and enhance its ultraviolet(UV)blocking ability,water resistance,and water vapor blocking ability.When the number of nanoparticles was 8%,the mechanical properties of the CS composite membrane reached optimum value,and the comprehensive performance was better.In addition,the controlled-release properties of CS composite membranes were also studied,and the antioxidant,antibacterial,biocompatibility,and fresh-keeping effects of the composite membranes were explored.The results indicated that the CS composite membranes had not only excellent bacteriostatic(72%)properties(Escherichia coli)but also presented well fruit preservation(15 days)properties(sugar orange).In particular,the controlled release range of CS composite membrane at 12 h was between 30%and 90%,which provided a theoretical basis for its use as an edible membrane.Therefore,based on ACCP and Alginate/ACCP nanoparticles,CS composite membranes with more excellent application value in the biological field were prepared through further optimization design.