| Fruit and vegetable are rich in a variety of antioxidant substances, have certain functions such as eliminating free radicals, anti-aging, anti-irritability, improve immunity etc..The strawberry be put into use for raw material in this paper, and evaluated comprehensively of the antioxidant capacity of strawberry powder which spray-dried, Researched the effects of different protein drying aids and spray drying parameters on the extraction rate, the impact of total phenols, flavonoids and anthocyanin content and total antioxidant capacity. And this paper investigated the long-term variability of antioxidant and substance change of antioxidants of spray-dried strawberry powder which was stored under different conditions, and came up with a method of storage condition of the combination of temperature and water activity.Using ABTS+·, FRAP, ·HH clearance method, O2-· clearance method, DPPH·method, determination of spray-dried strawberry powder antioxidant activity, results show that: spray-dried strawberry powder has good antioxidant capacity, and ABTS+·,·OH and O2-·,DPPH free radical has a scavenging ability.Different varieties of spray drying of strawberry powder total phenol content slightly loss, loss to the least of them rose fragrance, was 7.8%, the loss was the most toyonoka, was 37.5%; Flavonoids content loss to the least was the American-13, was 8.0%, the loss was the most sweet treasure, was 22.6%; Anthocyanin content loss to the least was the American-13, was 16.17%, the loss is the most toyonoka, was 37.5%. Using HPLC to determine the different varieties of spray drying of strawberry powder composition and content of phenols, catechin and epicatechin and ellagic acid was a high content of free phenol in strawberry powder. Different varieties of spray drying of strawberry powder significant difference was found in the content of free phenol, the American-13 varieties of strawberry powder has the highest amount of free phenol, was 2.64 mg/g.The spray drying of strawberry powder total phenol, flavonoids, anthocyanins content and antioxidant capacity analysis of the correlation, total phenol content and ABTS+* clearance, clearance of·OH and DPPH· clearance and the correlation of total antioxidant capacity, higher correlation coefficient were 0.995,0.933,0.952,0.933, indicates that the antioxidant activity of spray drying strawberry and its relationship between the amount of total phenolic content have significant effect, it follows the total phenol was its main antioxidants.Choose protein as dry aid study showed that adding whey protein isolates the spray drying of strawberry powder in addition to flour extraction rate is highest, at 51.44%, the total phenol, flavonoids, anthocyanins content is higher, respectively was 3.10 mg/g DW,1.56 mg/g DW,0.42 mg/g DW. Spray drying technology of single factor test results showed that the rise in the temperature of the spray drying in the wind, strawberry powder, such as total phenol content are reduced. With the speeding up of the feed speed, strawberry powder, such as total phenolic content showed a trend of decline after rising first. Dry aid maltodextrin add quantity was less, strawberry powder, the higher the total phenol content, content of less than 30% after the increase was not significant; Whey protein isolated content increases, the strawberry powder such as total phenol content increase, more than 1%, the total phenol content of strawberry powder gradually decreases; Trehalose content increases, the strawberry powder then improve the total phenol content, content of more than 9% after the increase was not significant.Response surface analysis showed that the flour extraction rate as the response value of optimum process parameters for spray drying:inlet air temperature of 164℃,1%whey protein isolated, trehalose 9%, through validation test, the resulting flour extraction rate was 53.86% on average. In FRAP value for the response, the optimal process parameters for spray drying:inlet air temperature of 162℃,1% whey protein isolated, trehalose 10%, under the conditions of strawberry powder from spray drying of FRAP value of 33.02 mmol FeSO4/100 g.Spray drying of strawberry powder in the 4℃, water activity was 0.11,0.22,0.33,0.44,6 months storage total phenol content in environment has fallen by 42.04%,34.16%,38.11%and 42.04% respectively. Storaged at 25℃, water activity was 0.11,0.22,0.33,0.44,6 months total phenol content in environment has fallen by 47.41%,61.94%,51.67% and 47.41% respectively. Storaged at 37℃, water activity was 0.11,0.22,0.33,0.44,6 months total phenol content in environment has fallen by 56.10%,74.56%,37.92% and 56.10% respectively.Spray drying of strawberry powder in the 4℃, water activity was 0.11,0.22,0.33,0.44,6 months storage flavonoids content in environment has fallen by 16.05%,28.85%,37.55% and 16.05% respectively. Storaged at 25℃, water activity was 0.11,0.22,0.33,0.44,6 months total flavonoids content in environment has fallen by 27.46%,35.20%,38.54% and 27.46% respectively. Storaged at 37℃, water activity was 0.11,0.22,0.33,0.44,6 months total flavonoids content in environment has fallen by 29.62%,36.38%,41.70% and 29.62% respectively.Spray drying of strawberry powder in the 4℃, water activity was 0.11,0.22,0.33,0.44,6 months storage anthocyanins content in environment has fallen by 26.91%,42.88%,45.66% and 26.91% respectively. Storage at 25℃, water activity was 0.11,0.22,0.33,0.44,6 months anthocyanins content in environment has fallen by 35.55%,42.55%,44.14% and 35.55% respectively. Storaged at 37℃, water activity was 0.11,0.22,0.33,0.44,6 months anthocyanins content in environment has fallen by 43.54%,49.42%,56.08% and 43.54% respectively.Spray drying of strawberry powder in the 4℃, water activity was 0.11,0.22,0.33,0.44, environment 6 months storage FRAP value has fallen by 12.60%,16.39%,25.58% and 12.60% respectively. Storaged at 25℃, water activity was 0.11,0.22,0.33,0.44,6 months environment FRAP value has fallen by 17.06%,30.12%,35.20% and 17.06% respectively. Storaged at 37℃, water activity was 0.11,0.22,0.33,0.44 environment 6 months FRAP value has fallen by 22.19%,28.39%,39.04% and 22.19% respectively. Water activity and temperature on FRAP value was large, the influence of different water activity during the spray drying of strawberry powder storage FRAP values are felled.Combination of spray drying of strawberry powder under different storage conditions on the composition and content of total phenol, phenol, flavonoids and anthocyanin content and total antioxidant capacity as a result, it was concluded that the spray drying of strawberry powder storage in water activity was less than 0.33, storage temperature below 25℃ under the condition of total polyphenols, flavonoids, the more stable the keep higher antioxidant activity during storage and storage stability. |
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