瓦伦西亚橘烯生物转化生成圆柚酮

利用固相微萃取-气相色谱-质谱联用技术分析检测黑曲霉(Aspergillus niger)、毛霉(Mucor sp.)和解脂耶氏酵母(Yarrowia lipolytica)转化瓦伦西亚橘烯的产物,并比较3株菌株转化瓦伦西亚橘烯生成圆柚酮的效果。结果表明,3株菌种黑曲霉(A. niger)、毛霉(Mucor sp.)、解脂耶氏酵母(Y. lipolytica)均能对瓦伦西亚橘烯进行转化并生成圆柚酮,同时生成α-松油醇、香芹酮等物质。其中,解脂耶氏酵母转化瓦伦西亚橘烯生成圆柚酮转化量最高,达(252.52±15.79)mg/L,转化率也最高,达(27.45±1.72)%。其次为黑曲霉和毛霉,转化量分别为(140.94±30.26)mg/L和(137.67±14.02)mg/L,转化率分别为(15.32±3.29)%和(15.45±3.36)%。此外,通过正交试验对解脂耶氏酵母的发酵培养基进行条件优化,得到培养基最佳优化组合为α-乳糖40 g/L、蛋白胨15 g/L、FeSO4·7H2O 0.6 g/L。解脂耶氏酵母具有较好的生物转化瓦伦西亚橘烯生成圆柚酮的效果,优化后的该菌培养基转化生成圆柚酮质量浓度可达(457.32±76.11)mg/L,转化率为49%,较未优化的培养基相比,转化率提高21.55%。

彩色甜椒栽培技术(上)

彩色甜椒是我国近几年从法国、荷兰、美国等国家引进的甜椒新品种,果实成熟后果色可由绿色转变成红色、黄色、橙色、巧克力色、橘红色等多种色彩。彩色甜椒的营养价值很高,适合超市、宾馆、酒楼、饭店配菜。

彩色甜椒

彩色甜椒是我国最近几年从法国、荷兰、美国等国家引进的甜椒新品种,经试种,椒皮颜色纯正,椒形整齐美观,食味上乘,适合超市、宾馆、酒楼、饭店配菜,亦可作水果、沙拉。

圆柚酮生物转化菌种筛选及培养基组分优化

为筛选具有特定生物转化功能的菌株,从柑橘果园取得土样,以生长曲线及转化瓦伦西亚橘烯生成圆柚酮的产量为指标,进行菌株的初筛和复筛。利用SPME-GC-MS技术,对菌株转化瓦伦西亚橘烯生成的产物种类及含量进行测定与分析;通过生理生化实验以及16S rDNA测序对所筛菌株进行菌种鉴定,结果表明所筛菌株为伯克霍尔德菌属,将其命名为Burkholderia sp.PZQ14。在LB培养基的基础上,以圆柚酮转化量为指标,进行培养基成分单因素试验,再通过响应面优化试验,探讨培养基成分不同质量浓度组合对圆柚酮转化量的影响。结果表明,最优培养基组分为:葡萄糖38 g/L,蛋白胨25 g/L,FeSO_(4)0.60 g/L。在此条件下进行验证试验,圆柚酮转化量为328.69±17.88 mg/L,转化率为35.73%±1.24%,相比LB培养基,圆柚酮转化量提高了251 mg/L。

Storage Lifetime of Citrus CV ＂Siam＂ from Banyuwangi-East Java-Indonesia

Banyuwangi is one of the citrus centers in East Java, Indonesia with an estimated 27.7 million metric tons produced with growth in 12.804 hectares. The quality of the citrus will be decreased when the retention of storage is too long because of the physiological changes postharvest. The object of the research is to determine the relevancy of shelf life and quality of the citrus. The research was conducted at Laboratory of Mechanization and postharvest in AIAT East Java and the citrus was obtained in Banyuwangi. This experiment used randomized block design as the method, which the factors are temperature of storage （room temperature 27 ~C and cold temperature 15 ~C） and storage time （0, 5, 10, 15, 20 days） with five replication. The physical parameters in this research are weight, texture, flesh color and skin and the chemical parameters include sugar and acid content. The result of the chemical analysis showed that storage temperature had significant effect on sugar content, but did not have significant effect of acid contents. The storage life time have correlation with sugar and acid contents. Citrus that are storage in refrigerator produce a higher sugar content （14, 20 ~brix）, but the acid contents are same. The longer that citrus is stored the highest the sugar content. The highest acid content in citrus is storage for 10 days （0, 30%）. The physical analysis showed that storage temperature affects the weight of citrus, but does not affect the texture and color citrus skin. The result showed that citrus which stored in refrigerator is higher than the others. Storage 20 days at room temperature and storage lifetime has no effect on fruit flesh color. The brightness of the surface （L） that is storage 20 days in room temperature has a same value with citrus that is storage in refrigerator.