Changes In Quality Characteristics And Product Development Of Winter Dates During The Maturity Period Of The Facility Cultivation

Dongzao(Ziziphus jujuba ’Dongzao’)is one of the fresh jujube varieties with good economic benefits and a wide cultivation area in my country.In the past 10 years,the planting scale of Dali Dongzao in Shanxi has grown to 28,000 hm2,of which about 26,700 are Dongzao in Dali County.hm2 has become an important source of local jujube farmers’ economic income and a characteristic industry.However,because jujube farmers want to increase their income in advance of the market,the phenomenon of picking greens generally occurs.Therefore,judging the best harvest period of winter jujube and how to realize the reuse of low-commercial winter jujube has become an urgent industrial problem to be solved.In this paper,the methods of field investigation and sampling and indoor testing are used to analyze the phenological period,cultivation conditions,yield and economic benefits of winter jujube aged 5 to 7 years under three cultivation modes(warm shed,cold shed,and open field),and screen out the economic benefits.The best cultivation mode,and then through the comparison of important indicators such as appearance,nutritional quality and functional factors of the four mature stages of Dongzao under this cultivation mode,the optimal maturity of Dali Dongzao fruit comprehensive quality is revealed;and Taking Dongzao jujube puree as raw material,using compound enzyme enzymolysis and microbial fermentation methods,the development process of Dongzao edible enzyme was studied,and the technical specification for the development of Dali Dongzao enzyme was formed,so as to provide a theoretical basis for the reasonable harvest and reuse of Dongzao.The main results of the paper are as follows:1.Facility cultivation advances the phenological period of winter jujube and prolongs the flowering period and fruit growth and development period of winter jujube.Compared with the open field,the winter jujube in the warm shed matured 45-60 d earlier,and the jujube in the cold shed matured 30 d earlier.The yield per 667 m2 of open field,cold shed and warm shed is 2000-3000 kg,1500-2500 kg and 1250-1750 kg,respectively.The output value of winter jujube in the warm shed reaches 37,500 to 70,000 yuan per mu,which is 7.5 to 14 times and 5 to 9 times that of the cold shed and open field cultivation.The content of soil organic matter in the three cultivation modes is moderate,and the total nitrogen content needs to be supplemented with nitrogen fertilizer.The content of available potassium and total phosphorus is extremely high,which should be regulated.Moderate performance.2.With the growth of winter jujube fruit,the growth rate of single fruit weight and fruit shape index accelerated from the crisp ripe stage to the half red stage,reaching 21.52 g and 1.01 in the half red stage and full red stage respectively;The ripening stage is the highest at 21.22 N,and the hardness declines faster from the crisp ripening stage to the semi-red stage and the full-red stage,which are 17.70 N and 14.49 N,respectively.The full red stage decreased by another 10%;the contents of soluble solids,soluble sugar and Vc showed an upward trend with the fruit development.The contents of the three accumulated the fastest from the white ripening stage to the half red stage,and the content changed slowly from the half red stage to the full red stage.,reached 22.5%,212.18 mg·g-1 and 4.13 mg·g-1 in the semi-red stage,respectively;the contents of titratable acid,total phenols and flavonoids showed a downward trend,and the highest content in the white-ripening stage was 2.29 mg·g-1,respectively.g-1,7.12 mg·g-1 and 4.93 mg·g-1,decreased to 1.57 mg·g-1,2.23 mg·g-1 and 3.32 mg·g-1 respectively in the semi-red stage.Based on the results of principal component analysis,the fruit quality of winter jujube in the semi-red stage was the best harvest period.3.The process of preparing edible enzymes from winter jujube mainly includes two parts:preparation of enzymatic hydrolysis of jujube mud and fermentation of enzymatic hydrolysis of jujube mud.The optimum conditions for the preparation of enzymatically hydrolyzed jujube puree were:pH 5.0～5.5,jujube puree:water=1:2,temperature 55℃,enzymatic hydrolysis time 150 min,hemicellulase(xylanase and β-glucan)Carbohydrase),the enzyme amount is 0.5%,the enzyme activity ratio of xylanase and β-glucanase is 1:1,the enzyme amount of cellulase is 1.0%,Novozymes enzyme and cellulase The enzyme activity ratio of B is 2:1.The best conditions for fermentation enzymatic hydrolysate:inoculate 0.15%yeast,and ferment for 18 h at 26 ℃ to ensure sufficient dissolved oxygen;then inoculate 0.5%Lactobacillus casei,and ferment at 24℃ for 24 h.For aroma production,the number of yeast in the final fermentation broth was 2.35×108 CFU·ml-1,the number of viable lactic acid bacteria was 7.14×108 CFU·ml-1,and the SOD activity was 251.17 U/g.The results of the paper can provide a scientific basis for improving the quality and safety,nutritional value and sensory quality of edible winter jujube,as well as the harvesting of winter jujube,and lay a good theoretical foundation for the development of new products of winter jujube enzymes.