可可毛色二孢菌F6胞外多糖在草莓保鲜中的应用

目的 探究可可毛色二孢菌F6胞外多糖在草莓保鲜中的作用。方法 采用形态学和分子生物学对从赣南野生松木上分离得到的产胞外多糖真菌F6进行鉴定;从碳、氮源及培养基初始pH方面优化F6菌生长和产多糖发酵条件;用F6胞外多糖浸泡草莓,测量草莓的失重率、腐烂率、有机酸、维生素C含量及感官品质。结果 经形态学与分子生物学鉴定,F6为葡萄糖座科可可毛色二孢属(Lasiodiplodia theobromae); F6产多糖发酵的碳源为蔗糖,不加氮源,初始pH为6;浸泡F6胞外多糖溶液能有效的保持草莓的风味、减少失重、减少腐烂、减缓维生素C含量降低及有机酸降解,多糖浓度6%时效果最佳。结论 F6产胞外多糖发酵成本低,胞外多糖可离心分离,浸泡草莓具有很好的保鲜效果,这为F6胞外多糖在果蔬保鲜及工业应用奠定了良好基础。

Application of exopolysaccharides from Lasiodiplodia theobromae F6 in strawberry preservation

Objective To explore the effects of exopolysaccharide from Lasiodiplodia theobromae F6 in strawberry preservation. Methods A strain F6 produced exopolysaccharides and isolated from Southern Jiangxi wild pine was identified by morphology and molecular biology. The conditions of F6 growth and polysaccharide fermentation were optimized from the aspects of carbon, nitrogen source and initial pH of medium. The weight loss rate, decay rate, titratable acid, vitamin C content, as well as sensory quality at every 24 h were were measured by soaking the strawberries with F6 exopolysaccharide. Results F6 was identified by morphology and molecular biology a Lasiodiplodia theobromae. The carbon source for F6 exopolysaccharides fermentation was sucrose, without nitrogen source. The suitable initial pH of medium was 6. Soaking F6 exopolysaccharide solution could effectively maintain strawberry flavor, reduce weight loss, reduce decay, slow down the reduction of vitamin C content and titratable acid degradation, and the best effect was 6% polysaccharide concentration. Conclusion The fermentation cost of exopolysaccharides produced by F6 is low, the exopolysaccharides can be separated by centrifugation, and the fresh-keeping effect of soaked strawberry is good, which lays a good foundation for the preservation and industrial application of exopolysaccharides produced by F6 in fruits and vegetables.