板栗腐烂机理及防腐保鲜技术的研究

Research for the Mechanism of Chinese Chestnut Putridity and the Antiseptic and Fresh keeping Technique

板栗腐烂由生理病变和微生物侵染所致 .研究了由病理引起板栗腐烂的原因及防腐保鲜方法 .试验结果表明 ,引起板栗腐烂的原因是 ,一方面 ,泡囊假单胞杆菌 Pseudomonas vesicularis Galarneault & L eifson和多主小穴壳菌 Dothiorella ribis Gross etDuggar分泌的纤维素酶和淀粉酶使板栗果壳的纤维素和果仁的淀粉分解产生各种糖 ,为泡囊假单胞杆菌和多主小穴壳菌的生长和蔓延提供营养并破坏其组织结构 ,使板栗变褐变黑并发出腐臭味 ;另一方面板栗的不同品种与腐烂有密切关系 ,含水量高或贮藏期失水率大 ,含糖多 ,淀粉酶活性强 ,是导致栗果腐烂的内在原因 .板栗贮藏环境对致腐微生物的感染、繁殖有密切关系 ,从而影响栗果防腐保鲜 .多主小穴壳菌在低温条件下生长受到抑制 ,淀粉和纤维素作碳源时生长不快 ;紫外线处理和黑暗培养都生长不好 ;在 p H值为 6.2时适合其生长且菌丝干质量最大 .泡囊假单胞杆菌能很好的利用各种糖 .防腐保鲜措施的研究表明 ,杀菌剂以 75 %托布津 5 0 0倍液抑制多主小穴壳菌生长的效果最好 ,抗生素以庆大霉素 2 0 0 0 mg/L和链霉素 160 mg/L 抑制泡囊假单胞杆菌生长效果最好 .对9个板栗品种进行贮藏试验 ,筛选出锥栗、铁栗它、和韶栗 18号为耐贮藏品种 ,防腐保鲜方法以 5℃低温贮藏?

Physiological diseases and microbial infection make Chinese chestnut putrid. This experiment mainly explores the cause of putridity and the antiseptic and fresh keeping technique. 14 genera of microbes have been found in putrid chestnut through two years' experimental identification. Among them, Pesudomonas vesicularis Galarneault & Leifson and Dothiorella ribis Gross et Dugger are predominantly pathogenous. Through experiment, we realize the mechanism of chestnut putridity is that: on one hand Pesudomonas vesicularis and Dothiorella ribis can secret cellulase and amylase , which make chestnut crust's cellulose and chestnut kernel's starch hydrolytic and produce sugar, and they can utilize this kind of nutrious substance to grow and spread, also to destroy chestnut tissue and texture, and at last,to make chestnut become brown and black and give off rancid odour; on the other hand, the variety of chestnut is closely related to putridity; it is chestnut's high rate of lost water, high sugar content and strong amylase activity in storage time that make the chestnut fresh keeping rate low and the chestnut become putrid . Chestnut storage environment has an effect on pathogenously microbial multiplication and infection which affect chestnut antiseptic and fresh keeping process. On the condition of low temperature, Dothiorella ribis growing can be inhibited; it has difficulty in utilizing cellulose and starch because ultraviolet treatment and dark cultivation make it grow slowly. It is optimal to grow and the weight of dry mycelia is the heaviest at pH6.2 cultures. Pesudomonas vesicularis can also utilize all kinds of sugar very well. Research for the antiseptic and fresh keeping technique indicates that, the 500-fold antiseptic of 75% Tuobujing can effectively inhibit Dothiorella ribis from growing and the 200 mg·L -1 antibiotic of Qingdameisu and 160 mg·L -1 strepotmycin can effectively inhibit Pesudomonas vesicularis from growing. Through storage experiment on nine varieties of chestnut, select Zhuili, Shaoli No.8, Tielituo as better varieties to store, the antiseptic and fresh keeping measures of low temperature(5℃) storage and wood crumb with 75% Tuobujing in sealed bottle are better than those in all the other storage experiments.