The Development Of Ginkgo Biloba Milk Cotaining High Level Calcium

Ginkgo biloba,also known as gongsun tree and baiguo in Chinese,belongs to the variety of ginkgo and originates from China.Ginkgo fruits are rich in starch,protein,minerals,vitamin and other bioactive compounds,including flavonoids,ginkgolide,and ginkgolic.Therefore,ginkgo fruits have antiasthmatic,anti-cardiovascular and anticancer activities.In 1992,ginkgo was labeled as both food and medicine by the ministry of public health.However,ginkgo fruits are slightly toxic,which limits their application in food industry.Recently the cultivated area of ginkgo increased rapidly,while the corresponding price decreased dramatically.It is necessary to find a new way for the industrialization ginkgo fruit.In this article,the effects of different industrial processing methods on the bioactive compounds including toxic compounds in ginkgo fruits were studied.After that,boiled ginkgo fruits were used as raw materials for the production of ginkgo milk beverage.The results are shown as follows:The influences of different processing methods on bioactive compounds from ginkgo fruits were explored.It was found that boiling decreased the starch content in ginkgo fruits.After boiling for 15 min,the starch content reached to 13.3175.45 g/100 g.Meanwhile,protein and reducing sugar contents decreased and reducing sugar content firstly increased and then decreased.Microwave treatment for 20 s resulted in the decrease of flavonoid content by 15%.Microwave treatment can also lead to the decrease of contents of phenolics,ginkgolic acid and amygdalin.Similar to microwave processing,hot-air drying at 80? for 24 h resulted in the increase of total flavonoids content to 78.95%.At the same time,contents of phenolics,ginkgolic acid and amygdalin decreased simultaneously during hot-air drying.Lastly,the effect of freeze drying on ginkgo fruit showed no obvious effect on toxic substances.In summary,boiling for 15 min was regared as the best way for ginkgo fruit processing.To produce ginkgo milk beverage,ginkgo fruits were homogenized and enzymatically treated before mixing with fresh milk.Mineral salt was added to increase the calcium content.The ratio of ginkgo slurries,milk and sugar was determined by single factor study and orthogonal study.The formulation was then selected according to a patent from a company.Next,the addition amount and type of stabilizing and emulsifying agents were chosen.In terms of sedimentation rate after centrifugation,the optimal combination of emulsifying agents was avicel and carrageen(3:1,w:w).The total addition was 0.12%.The best combination of stabilizing agents was sucrose ester and monoglyceride(1:1,w:w)with the total addition of 0.1%.The beverages were heated at 50-60?,high-pressure homogenized at 25-30MPa and sterilized at 138? instantaneously before bottling.The results indicated that the microbiological index and heavy metals contents all stayed within the limits of national standards after sterilization at 138? instantaneously.Boling and sterilization can decrease the toxic compounds,such as ginkgolic acid and amygdalin,whereas flavonoids were retained well.