Research On Comprehensive Utilization Of Jackfruit

The cultivation and production of jackfruit in China are increasing,and are mainly distributed over Guangdong,Guangxi,Hainan,Sichuan provinces and other regions.Commercially available jackfruit is mainly sold as fresh fruit,while a small amount of dried fruit is sold after packaging.Jackfruit,a large weight fruit,has less resistance to storage and will cause enormous loss after harvest.Meanwhile,the jackfruit pulp accounts only for about 30% of the total weight.So the remaining fruit,kernels and peels are always discarded as waste,which will pollute the environment and waste resources.In this paper,the vacuum freeze-drying process of jackfruit pulp,the extraction of total flavonoids of jackfruit core,and the preparation process of the fermented feed of jackfruit peel were studied to solve the problem of utilization of whole fruit of jackfruit.The vacuum freeze-drying process of dried jackfruit pulp was studied,and an analytical evaluation system was established.The effects of heating plate temperature,sublimation drying time and desorption drying temperature on the quality of vacuum freeze-drying process of frozen fruit of jackfruit were analyzed and optimized.The influence of three factors on the vacuum freeze-drying process of jackfruit pulp was as follows: sublimation drying time > sublimation drying temperature > desorption drying temperature.Taking the actual production into account,the optimal process for final production was as follows: pre-cooling at-26 °C for 24 h,sublimation at-16 °C for 10 h,desorption for 5 h to reach 50 °C.Under the optimal conditions,the quality of dried fruit of jackfruit and the lyophilized efficiency became better,and the moisture content of pulp was 3.96%.The optimized process of seed peeling and the extraction process of total flavonoids in the preparation process of jackfruit core starch were studied,and the oxidation resistance of crude flavonoid extract was analyzed to provide a theoretical basis for the deep processing of jackfruit seeds.The effects of NaOH concentration,soaking temperature and soaking time on the peeling process of kernel of jackfruit fruit were analyzed,and quantitative evaluation indexes were established as well.Under the optimal peeling conditions,the effects of ethanol concentration,solid-liquid ratio,extraction temperature and extraction time on the yield of total flavonoids in jackfruit seed powder were further analyzed,and the optimal extraction condition of total flavonoids in jackfruit seed powder was obtained by L9(34)analysis.The antioxidant activity of the total flavonoid extract was analyzed by DPPH assay and salicylic acid assay.The results showed that the optimal peeling condition of jackfruit seeds was 2% NaOH,and the soaking temperature was 121 °C,the soaking time was 25 min,and the peeling rate was 80.00%.Under water bath,the factors affected total flavonoids in jackfruit seeds to a different degree and showed as follows: ethanol concentration > liquid-liquid ratio > extraction temperature > extraction time.The optimal extraction condition of total flavonoids was 70% ethanol,solid-liquid ratio was 1: 20(g/mL),water bath at 60 °C for 50 min,and the yield reached 3.30%.The DPPH and ·OH scavenging capacity of crude flavonoids of jackfruit seeds increased by concentration.The scavenging rates of DPPH· and ·OH at 90 mg/mL were 90.20% and 94.10%,respectively,indicating that the total flavonoids in the seeds of jackfruit have strong antioxidant capacity and can be used as natural health food.The processing fermentation of jackfruit peel was studied to improve its palatability.The effects of drying temperature,drying time and material size on the preparation process of jackfruit peel feed were preliminarily analyzed,and quantitative evaluation indexes were established.The cellulose and EM bacteria were mixed and used to ferment,and rice bran and glucose were added simultaneously.The optimal process for the production of high protein feed by the fermentation of jackfruit peel was further studied.Due to the actual cost of production and other reasons,the optimal process was that the jackfruit peel was dried at 135 °C for 3.5 h after the crushed pretreatment.The dried peel powder had a low degree of browning and no odor.Because of the shorter time used,the drying efficiency was higher.Cellulose and EM bacteria were used to ferment pineapple peel(containing sputum)residue and the optimal process was inoculum of 1.5%,and the fermentation temperature was 36 °C,the fermentation time was 9 d,the crude protein content in the fermentation product ranged from 5.21% to 10.59%,which was increased by 103.30%.The fermented cortex was lubricated and lofty,which had better sensory quality and palatability,and the crude protein content was significantly improved.