Hydrolysis Utilization Of Coffee Residue And The Effects Of The Hydrolysates On The Yield And Quality Of Anji Albino Tea

Based on the analysis of the main components of coffee residues,the characteristics of the acid-base hydrolysate of and the biochar derived from coffee residues were investigated.With pot and field experiments,the effects of spraying hydrolysate from coffee residues and a typic amino acid in the hydrolysate on the yield and quality of Anji albino tea were studied for the development of new water-soluble fertilizers and the sufficient utilization of coffee residues.The main results were as follows.1.Thirty samples of coffee residues were collected.The analysis results showed that the moisture contents of all samples ranged from 38.1 to 65.0 g/100g with an average of 56.6±6.4g/100g,the organic carbon contents ranged from 21.3 to 28.9 g/100g with an average of 24.8±1.8g/100g,the ranges of total nitrogen,phosphorus,potassium,calcium,magnesium contents were4.12～8.42（mean of 6.10±1.25）,0.53～1.09（mean of 0.73±0.12）,3.58～9.98（mean of 6.88±1.80）,8.65～28.93（mean of 18.43±6.66）,2.02～5.19（mean of 3.21±0.96）g/kg,respectively.According to the concentrations of total nitrogen and amino acid nitrogen in the hydrolysate,the suitable conditions for acid hydrolysis of coffee residue were determined as sulfuric acid concentration of3.0 mol/L with 180 minutes hydrolysis time.The organic carbon in the acid hydrolysate of coffee residues mainly existed in the form of carbohydrate organic carbon,the content of ammonium nitrogen was much low,and the organic nitrogen content was about ten times that of the ammonium nitrogen,the content of non-amino acid nitrogen in organic nitrogen was slightly higher than that of amino acid nitrogen.The average values of organic carbon and organic nitrogen hydrolysis rates in coffee residues were 28.53±1.77%and2.45±0.44%,respectively.The average value of hydrolysis rates of organic carbon in the alkaline hydrolysis solution of the acid hydrolysis residues was 3.24±0.29%.2.Under the common preparation condition,the biochar yields of acid-alkali hydrolysis residue（AAR-B）,initial coffee residue（CG-B）and acidolysis residue（AR-B）were 61.08%,27.97%and24.39%,respectively;the p H values were 12.37,9.33 and 6.65 respectively,and the methylene blue adsorption capacity were 20.92,9.25 and 13.94 mg·g^-1,respectively.The pore structure of AAR-B was more complex,with a large number of pores,and the functional groups such as carboxyl,ester or aldehyde groups on the surface were more abundant than CG-B and AR-B,AAR-B had good acidity adjustment and adsorption performance.3.The results of the pot experiment showed that spraying different dilution ratios of alkali hydrolysate of coffee residue acidolysis residue could significantly promote the growth of Anji albino tea seedlings.H1（the original solution）and H2（one-time diluent）treatments significantly increased the fresh weight and dry matter content of young leaf,the content of free amino acid was higher than other treatments,and the contents of tea polyphenols,caffeine and phenol-ammonia ratio were lower than other treatments even reached significant levels,which was beneficial to improve the quality of fresh leaves.Among each treatment,the H1 treatment had the highest total nitrogen,phosphorus,and potassium nutrient elements contents,which were 30.68,4.72,15.46 g/kg,respectively,significantly higher than the other treatments（P<0.05）.Analyzing the photosynthetic pigment contents of each treatment,it was found that the content of carotenoids was the highest in the H1 treatment,and the difference reached a significant level from the other treatments.The total chlorophyll content in H2 treatment was the highest,which was not significantly different from H3,H4 and H6 treatments,but significantly higher than H1,H5 and CK treatments（P<0.05）.H1 and H2 treatments were better in improving net photosynthetic rate and intercellular CO₂ concentration of functional leaves of albino tea than other treatments,which was conducive to the synthesis of photosynthate.Through the correlation analysis found that fresh weight,dry weight,dry matter content and soluble sugar content were significantly correlated with net photosynthetic rate of albino tea leaves,and the correlation coefficients were 0.611,0.656,0.614,0.463,respectively.Therefore,the alkali-hydrolysate from acidolysis residue of coffee residues or 1 time diluent could be used as organic foliar fertilizer,which was beneficial to promote the synthesis of photosynthetic products of Anji albino tea leaves,and had a better effect on increasing the yield and quality of young leaves of albino tea.4.The results of the field test showed that spraying amino acid and potassium mixed solution（AA-K1 and AA-K2 treatments）could increase the early young leaf yields of tea with comparison to spraying water treatment.There were no significant differences in tea 100 bud weight and dry matter content among each treatment.Compared with CK,fertilization treatments could significantly increase the contents of nitrogen and phosphorus in leaves（P<0.05）,and had no significant effect on the potassium content in leaves.With the observation of chloroplast ultrastructure,it was found that the starch grains at the regreening stage of the leaves treated with AA-K1 were obviously enlarged.K1 and K2 treatments could significantly increase the total chlorophyll content of Anji albino tea in the early albino phase and regreening stage,and K2treatment significantly increased the carotenoid content in leaves at the pre-albinistic stage,albinistic stage and regreening stage.The contents of soluble sugar in K2 and AA-K1 treatments were not significantly different but were significantly higher than other treatments（P<0.05）.Compared with CK treatment,spraying amino acid and potassium mixed solution（AA-K1 and AA-K2 treatments）could increase the contents of total amino acids even significantly,catechins contents significantly increased and the caffeine contents were not significantly different.In conclusion,spraying amino acid and potassium mixed solution（AA-K1 and AA-K2 treatments）had the best effect on increasing the early young leaf yield of Anji albino tea,improving the quality of tea to a certain extent.This fertilization mode provided a theoretical basis for the development of a new type of amino acid water-soluble fertilizer.