| ObjectiveModern analytical chemistry techniques was used and the leaves and fruits of Artocarpus nitidus subsp.Lingnanensis were taken on as research objects.Study on the chemical components and quality evaluation of Artocarpus nitidus subsp.Lingnanensis leaves was carried out to preliminarily establish a quality control system;research on the nutritional components and their content in Artocarpus nitidus subsp.Lingnanensis fruits was conducted to give an comprehensive antioxidation property evaluation on the fruit juice and to develop a clarified Artocarpus nitidus subsp.Lingnanensis fruit early juice product,thus a scientific basis for the comprehensive development and utilization and quality evaluation of Artocarpus nitidus subsp.Lingnanensis was provided.Methods1.Preliminary study on chemical components and quality evaluation of Artocarpus nitidus subsp.Lingnanensis leavesColumn chromatography method were applied to isolate pure compounds from Artocarpus nitidus subsp.Lingnanensis leaves and the structure of the compounds were elucidated by nuclear magnetic resonance spectroscopy and mass spectrometry methods combined with UV method;HPLC determination method of catechin、Maesopsin 6-O-glucoside and trifolin was performed and TLC method was applied to identify different batches of Artocarpus nitidus subsp.Lingnanensis leaves;the fingerprint chromatograms of 17 batches of Artocarpus nitidus subsp.Lingnanensis leaves was developed by HPLC method,then a preliminary quality evaluation system of Artocarpus nitidus subsp.Lingnanensis leaves was established.2.Comprehensive utilization of Artocarpus nitidus subsp.Lingnanensis fruits-study on the developing prospect of fruit juice productThe moisture content,total ash content,juice yield,juice relative density,soluble solids content,effective acidity and other conventional physical and chemical indicators of Artocarpus nitidus subsp.Lingnanensis fruits were analyzed and determined by direct drying method,direct ashing method,squeezing method,relative density meter method,refractometer method,pH meter method;The content of total proteins in fruit juice was determined by the dying method with coomassie brilliant blue,total amino acids content in fruit juice was determined spectrophotometric method using ninhydrin color reaction,vitamin C content in fruit juice was determined by 2,4-dinitrophenyl hydrazine method.Phenol-sulfuric acid method was used to determine total sugar content and HPLC-ELSD method was used for the content determination of fructose,glucose and sucrose in fruit juice.pH potential titration method was used to determine total acid content and ion chromatography method was used for the content determination of malic acid,oxalic acid and citric acid in fruit juice.All these methods were used to give a comprehensive analysis and determination of main nutritional components in Artocarpus nitidus subsp.Lingnanensis fruits.DPPH radical scavenging,hydroxyl radical scavenging,reducing power and total antioxidant capacity of fruit juice were measured by DPPH method,salicylic acid method,potassium ferricyanide reduction method,total antioxidant capacity kit method to give a comprehensive antioxidant capacity evaluation on Artocarpus nitidus subsp.Lingnanensis fruit juice.Pectinase was used to clarify fruit juice and the optimum processing technology was confirmed according to the transmittance result of single factor experiment and orthogonal experiment;taste formulation design was optimized by adjusting the proportion of original fruit juice,white sugar and the amount of pure water;after further processing procedures were applied to the formulated juice,clarified Artocarpus nitidus subsp.Lingnanensis fruit early juice product was obtained.Results1.Preliminary study on chemical components and quality evaluation of Artocarpus nitidus subsp.Lingnanensis leavesThree compounds were isolated and elucidated from Artocarpus nitidus subsp.Lingnanensis leaves as catechin,Maesopsin 6-O-glucoside and trifolin.The content of catechin was 0.58mg·g-1-2.93mg·g-1,the content of Maesopsin 6-O-glucoside was 3.43mg·g-1～8.55mg·g-1,the content of trifolin was 1.20mg·g-1～4.87mg·g-1 in HPLC determination.Catechin,Maesopsin 6-O-glucoside and trifolin were taken as reference substances in TLC and 17 batches of Artocarpus nitidus subsp.Lingnanensis leaves showed the same spots with reference substances in corresponding position;17 batches of Artocarpus nitidus subsp.Lingnanensis leaves HPLC fingerprints were established in this study and 11 common peaks were found after being processed by fingerprint similarity evaluation software,among which peak 5 and peak 9 were confirmed respectively as Maesopsin 6-O-glucoside and trifolin;The similarity range of 17 batches of samples was 0.916～0.996.2.Comprehensive utilization of Artocarpus nitidus subsp.Lingnanensis fruits-study on the developing prospect of fruit juice productThe moisture content was 78.46%～82.12%,total ash content was 7.16%～7.33%,juice yield was 39.66%～43.05%,juice relative density was 1.087～1.106g·cm-3,soluble solids content was 17.79%～19.73%,effective acidity was 2.91～3.48 in Artocarpus nitidus subsp.Lingnanensis fruits.The content of total proteins was 0.329g·L-1～0.428g·L-1,total amino acids content was 2.50mg·g-1～3.05mg·g-1,vitamin C content was 0· 37mg·g-1～0.45mg·g-1 in Artocarpus nitidus subsp.Lingnanensis fruit juice.Total sugar content of the juice samples was 22.53%～30.17%,the fructose content was 2.77%～4.92%,the glucose content was 2.32%～4.07%,the sucrose content was 4.59%～10.69%;Total acid content of the juice samples was 1.65%～3.68%,the malic acid content was 0.060%～0.123%,the oxalic acid content was 0.0023%～0.0073%,the citric acid content was 1.58%～3.52%.The IC50 of juice DPPH radical scavenging capacity was 3.23mg·mL-1,IC50 of juice hydroxyl radical scavenging ability was 12.13mg·mL-1;reducing power increased with increasing concentration of juice and showed a concentration-effect relationship;the total anti-oxidative capacity for Artocarpus nitidus subsp.Lingnanensis fruit juice was 43.02U·mL-1.The results showed that the optimum condition of adding pectinase was:0.03%pectinase treated at 55℃ for 2.5h;the best clarified fruit juice formulation consisted of original fruit juice 35%(v/v),white sugar 6%(w/v),pure water 65%(v/v);after impurity removal and sterilizing procedures were applied to the formulated juice,a clarified Artocarpus nitidus subsp.Lingnanensis fruit early juice product with clear appearance and excellent flavor was obtained.Conclusion1.Three compounds were first isolated and elucidated from Artocarpus nitidus subsp,Lingnanensis leaves as catechin,maesopsin 6-O-glucoside and trifolin with purity ≥98%,and catechin is assorted to flavanols,Maesopsin 6-0-glucoside is assorted to aurones.The HPLC determination results showed that harvesting time and the maturity of leaf samples had certain influence on the content of three active ingredients in Artocarpus nitidus subsp.Lingnanensis leaves,the content of three active ingredients in young leaves was significantly higher than in mature leaves.2.HPLC fingerprints of Artocarpus nitidus subsp.Lingnanensis leaves were first established and the similarity evaluation and analysis results showed that 17 batches of leaves shared high similarity in their chemical composition.3.Quality control standard of Artocarpus nitidus subsp Lingnanensis leaves was preliminarily established and the minimum content of catechin was limited to 0.5mg·g-1,minimum content of maesopsin 6-O-glucoside was limited to 3mg·g-1 and minimum content of trifolin was limited to 1mg·g-1。4.Artocarpus nitidus subsp.Lingnanensis fruits were nutritious,rich in vitamin C,organic acids and sugars with good antioxidant activity,which made them good healthy juice and beverage sources.The optimum condition and formulation of crude fruit juice was established and a clarified Artocarpus nitidus subsp.Lingnanensis fruit early juice product was invented in this study.The above researches on leaves and fruits of Artocarpus nitidus subsp.Lingnanensis provided a scientific basis for the comprehensive development and utilization and quality evaluation of Artocarpus nitidus subsp.Lingnanensis. |
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