Research On Mechanism And Control Technology Of Softening And Taste Deterioration Of Cherry Tomato Under High Temperature Logistics

Cherry tomato is a kind of fruit well received by consumers.But it is prone to softening and taste deterioration after harvest.Due to the incomplete development of the cold chain in China,all e-commerce platforms can only use non-cold chain transportation,and the rate of bad reviews is high,especially in the summer when the temperature is higher.In order to solve the problem of cherry tomato in high-temperature logistics,this paper first simulated the impact of different transportation temperatures on the quality of cherry tomato under the two logistics modes of"fast"and"slow",and then find out the most important problems under high temperature and explained the reasons.Then,in order to solve the softening problem,the micro-porous packaging was used to replace the large-porous packaging used by the merchants,and explored the effect of micro-porous packaging with different apertures on the softening of high temperature transport cherry tomato.Micro-porous packaging had a good softening inhibition effect on cherry tomato,but it had no significant effect on maintaining the taste,therefore,ethanol fumigation was used as a pre-treatment in combination with micro-porous packaging to study the effect of ethanol treatment on maintaining taste of cherry tomato.Finally,the method of slow-release of ethanol in transportation was used to replace the pre-treatment of ethanol fumigation,then explore its effect and provide a feasible method to reduce the pre-treatment time and improve logistics efficiency.The main conclusions of this paper were as follows:(1)By simulating cherry tomato in two types of logistics time:?fast?(logistics 2days+storage at 4°C for 2 days at refrigerator)and?slow?(logistics 4 days+storage at4°C for 2 days at refrigerator),logistics temperatures were 4?(cold chain),11°C(foam tank plus ice bag),23°C(normal temperature),35°C(high temperature in summer),studied the quality changes and the mechanism of cherry tomato.The results showed that under high temperature conditions,the weight loss rate of cherry tomato was increased,respiration increased,cell wall hydrolase(PG,PME,and Cx)activity increased,protopectin and cellulose content decreased,and hardness decreased.Although the time of"fast"logistics transportation was short,the results indicated that its commerciality was still poor at the end of storage,so for both logistics modes,other measures should be taken to maintain freshness at 35°C.(2)To explore the effects of four packaging methods:hole diameter 8 mm,1 mm,0.3 mm(the number of holes are 8)and non-porous on the hardness and other qualities of cherry tomato under high temperature of 35°C.The results showed that suitable micro-porous packaging could maintain a higher relative humidity in the box,reduce O₂content,weaken respiration,and inhibit the activity of cell wall hydrolases such as PG,PME,Cx and?-Glu,delay the degradation of protopectin and cellulose,effectively maintain the hardness and significantly improves the sensory score.At present,the commonly used 8 mm large-hole packaging caused dehydration,high O₂ content,strong respiration,and large cell wall hydrolase activity,decreased protopectin and cellulose content,resulted in severely softened.Too small pores or no pores will cause O₂content to be too low in the box,result in decay.The experimental results showed that the 1 mm microporous group had the best effect.(3)Studied the influence on taste and other qualities of cherry tomato with different concentrations of ethanol fumigation under the high temperature of 35?at200?L/L(the volume ratio of ethanol solution to the remaining volume of the foam box),400?L/L and 800?L/L in combined with 1 mm micro-porous packaging,the control group with a fumigation concentration of 0 was set at the same time.The results showed that although the hardness of the control group was good,the soluble solids and titratable acid content were both low and the taste was poor.Ethanol fumigation of appropriate concentration enhanced the activity of ADH and PDC,promoted the increase of pyruvate,ethanol and acetaldehyde content,and increased the content of soluble solids,inhibited the decline of titratable acid,maintained the taste of cherry tomato,further improved the sensory score on the basis of micro-porous packaging.Although high fumigation concentration would promote the increase of soluble solids content,but it could also reduce the good fruit rate.From the experimental results,it is known that the 400?L/L ethanol fumigation group had the best comprehensive quality.(4)Packed the cherry tomato in a 1 mm microporous packaging box,set a weighing dish containing 5 m L of ethanol(95%)as the ethanol sustained release device,and used different materials to wrap the weighing dish,40?m PE film(ethanol release rate:0.166 m L/d),8?m PE film(0.237 m L/d),8?m PE+3 holes(pore diameter 0.6 mm)film(0.376 m L/d),to explore the taste and other qualities during high temperature logistics.The results showed that slow-release of ethanol at an appropriate rate could enhance the activity of ADH and PDC,increase the content of ethanol,pyruvic acid,acetaldehyde and soluble solids,delay the decline of titratable acid,and effectively maintain the sweet and sour taste of cherry tomato.However,if the ethanol release rate is too high,the cherry tomato would have an alcohol flavor and reduce the good fruit rate.The experimental results showed that the 8?m PE group(0.237 m L/d)had the best effect,saved logistics time and improved efficiency while maintaining similar effects as ethanol fumigation.