Study On The Quality Control Of Apple Preserved Shelf With Biological Preservatives

In this paper,Fuji apple was used as the test material.Ethylene absorbent,1-methylcyclopropene,biological preservatives(natamycin,quinone-polylysine)and 1-were used respectively.MCP was combined with biological preservatives,1-MCP combined with ethylene absorbent to treat the stored apples,and the quality and physiological changes of the stored fruits were studied.And the use of headspace solid-phase micro-extraction-gas chromatography-mass spectrometry technology and electronic nose analysis of volatile compounds between different treatments.The main findings are as follows: 1.Fuji apples were used as experimental materials,and EA,1-MCP,and 1-MCP+EA were treated respectively after harvest.They were immediately combined with precise temperature control(-0.5±0.3°C)and stored for 10 months.At room temperature,the temperature was 30°C.The shelf-life tests were conducted on 0d,5d,10 d,and 15 d respectively.The results showed that the fruits treated with 1-MCP+EA could effectively slow down the decrease of TA,TSS,and hardness of fruit,and significantly reduced the respiratory intensity of fruits,and the release rate of ethylene in fruits.It has been effectively controlled to maintain the fruit's resilience,cohesiveness,chewiness,and elasticity;at the end of the shelf,1-MCP+EA treatment has maintained the relative content of the flavoring esters and also maintained the aldehydes.The relative content also slows down the content of the main odorant(n-hexanal)of aldehydes,and decreases the main taste substance of alcohols(2-methyl-1-butanol).In the CK group,the hardness decreased to 17.98 on the 10 th shelf and lost its storage value,while 1-MCP+EA remained at 20.57 kg·cm-1 on the 15 th shelf,suggesting that 1-MCP+EA can at least store shelf life.Extended to 15 d.2.Immediately after harvest,combined with precise temperature control(-0.5±0.3°C)for storage 10 months after storage,800 mg/L of natamycin was sprayed on the storage,and 2000 mg/L of y-polylysine was sprayed.The spray treatment was conducted at room temperature 30°C for shelf life tests at 0d,5d,and 10 d respectively.The results showed that the TSS content of CK+P-PL was highest in the shelf-ready period compared with CK without any treatment.CK(10.1%)and NATA(9.8%)were increased by 1.9% and 4.8%;respiratory intensity of CK group was 2.33 times that of CK+?-PL,and CK+?-PL ethylene production rate was the lowest,2.84?L·kg-1 · h-1,only 26.44% of the CK treatment group;at the end of the shelf period,the TA content(0.06589%)of CK+?-PL was CK(0.0634%)and 1.03,1.05 of CK+NATA(0.06239%),respectively.Times,and CK + ?-PL respiratory rate and ethylene production rate are lower than CK.At the same time,different biological preservatives slowed down the hardness,cohesiveness,chewiness,resilience,and elasticity.Using the GC-MS and electronic nose to detect apple volatiles,the LDA method can completely distinguish the different volatile components of biological preservatives.CK+?-PL slows down the main taste substances of esters and alcohols,and maintains the relative content of aldehydes.3.Immediately after harvest,the 1-MCP treatment with a concentration of 1 ?L/L was combined with precise temperature control(-0.5±0.3°C)for 10 months after storage,and then different concentrations of technetium-polylysine(500,1000)were used.,1500 mg/L)was sprayed to study the effect of 1-MCP in combination with different concentrations of pyrene-polylysine on the quality of apples during storage at room temperature after room temperature.The results showed that compared with the untreated control,1-MCP binding-Polylysine treatment effectively maintained the hardness of the fruit,slowed down the soluble solids TSS,TA content and VC content of apples,of which 1000 mg / L of y-polylysine had the best treatment effect.The aldehydes in the CK group showed a downward trend as a whole.The 1-MCP,1000,and 1500 treatment groups showed an upward trend.The 500 treatment group rose first and then decreased.The shelf life was still higher than the initial period.During the shelf life,the relative content of 1000 mg/L aldehydes was the highest,which effectively slowed down the relative content of 2-methyl butyl acetate,the main taste substance of esters.The main substance of alcohols,2-methyl-1-Relative decrease in butanol content.1-MCP combined with y-polylysine treatment can maintain the quality and flavor of apple,and the effect of y-polylysine at 1000 mg/L is the most significant.4.Immediately after harvest,1-MCP treatment with a concentration of 1 ?L/L was stored at(-0.5±0.3°C)for 10 months and then released.Different storage agents(800 mg/L of natamycin,1000 mg/L lanthanum-polylysine was sprayed to study the effect of 1-MCP combined with different biological preservatives on the shelf-temperature and related enzyme activities of apple after storage.The results showed that compared with 1-MCP treatment,1-MCP combined with different biological preservatives effectively retarded the decrease of fruit hardness,slowed down the reduction of nutrients(TSS,TA)in the late shelf life of fruits,and the respiratory intensity and ethylene production of fruits.The rate was also significantly controlled.On the 10 th day of the shelf,the PPO activity in the CK group was significantly higher than that in the other groups(P<0.05).1-MCP,1-MCP+?-PL,1-MCP+NATA were only CK,respectively.82.50%,66.50% and 63.48% of the group showed that the CK group had the fastest aging fruit.The CAT activities of 1-MCP+?-PL and 1-MCP+NATA increased by 24.54% and 12.24%,respectively.The LOX activity of 1-MCP+?-PL treatment group was the lowest,indicating that 1-MCP+?-PL treatment was used.It can effectively inhibit the fruit LOX activity,slow down the destruction of cell membrane and inhibit the increase of respiration.1-MCP combined with biological preservatives is superior to 1-MCP treatment alone,and 1-MCP+P-PL has the best effect.In summary,1-MCP combined with biological preservatives can effectively delay the shelf life of apples during storage and maintain good texture quality and flavor,and the effect is better than 1-MCP treatment alone.Among them,using 1-MCP in combination with 1000 mg/L of bismuth-polylysine had the best effect.At the end of the shelf life,the TSS content and hardness could still be kept at 10.6% and 26.23 kg·cm-1,at least to extend the shelf life after storage.To 15 d.