Study On The Relativity Between Pectin Content In Tomato Powder And Change Of Its Quality In Storage

Tomato powder as a basic material belongs to the Western-style food on the international market, which occupies the large proportion in the field of tomato products. Xinjiang tomato powder has attracted a lot of attention from home and abroad market due to its excellent quality. In general, there still exist some problems concerning the quality change in the process of production and storage of tomato powder. We can draw the following conclusions by researching on the main elements which influence the quality of tomato powder such as the rules of tomato powder agglomeration with raw material of pectin content, storage temperature and packaging skills, the relativity of the change of rules in nutritional components.(1) The spray drying technology is adopted under the same dryness circumstance, the obtain rate of tomato powder results to be in direct proportion to the pectin content of raw tomato paste. The pectin content of raw tomato paste has not too much influence on the particle size distribution.(2) The value L and the value b of the tomato powder show the trend of ascending within the range of same particle size with the increase of pectin content in raw tomato paste, vice versa the value a shows the trend of descending. With the decreasing of the particle size, the value L and the value b of the tomato powder show the trend of ascending within the tomato powder of same pectin content, and the value a shows the trend of descending. Analyzing from sense of intuition, we conclude the relation among value L, value a, value b and the color as follows: with the increase of value L and value b, the color of tomato tends to show much more yellow, with the increase of value a, the color of tomato tends to show much more red and gain the higher price. The experiment result indicates that the raw tomato paste with low pectin content should be chosen judging from the color and quality of tomato powder, moreover, the range of particle size should be controlled between 40~60 mesh.(3) The pectin content of raw tomato paste has an enormous influence on the particle size of spray drying tomato powder; the tomato paste contains less pectin content and the particle size is not equally distributed. We could conclude as follows through the observation of the microstructure, the particle size in tomato powder shows the decreasing trend, and equally distributed with the increasing of the pectin content in raw tomato paste.(4) The moisture content of tomato powder in storage indicates the increasing trend slowly. The change of the moisture content of tomato powder in storage has insignificant (p>0.05) differentiation in the way of packing; the temperature of storage has a great influence on the pectin content of tomato powder, moisture content of tomato powder at 35℃storage environment is always higher than the moisture content of tomato powder at 4℃(p<0.05).(5) The content of Reducing Sugar in tomato powder shows the descending trend in storage, the higher of the storage temperature is, and the faster of descending speed will be. Especially at the storage temperature of 35℃, the change is the most significant one (p<0.05). The change of reducing sugar content in the way of packing is insignificant (p>0.05).(6) The content of total acid in tomato powder shows the ascending trend in storage, and higher the storage temperature is, the more evident the increasing trend shows. It is obvious that the total acid content is increasing dramatically under the temperature of 35℃. The way of packing has insignificant (p>0.05) influence on total acid.(7) The ascorbic acid in the tomato powder shows the obvious ascending trend in storage, the vacuum packing of the tomato powder shows the lowest loss rate at the storage temperature of 4℃.(8) The lycopene shows the descending trend in storage; the loss rate in the vacuum packing is comparatively lower than the common packing. The storage rate of tomato lycopene in tomato powder is the highest at the temperature of 4℃.(9) The loss rate of Reducing Sugar, ascorbic acid and lycopene in the tomato powder in storage have not obvious relation with the pectin content shows the obvious ascending trend, the change of total acid is obvious as the increasing of pectin content.(10) The value L, value a, value b of different particle size in tomato powder which has lower pectin content shows the descending trend in storage, the 60~80 mesh which is stored for 100 days shows the best color; The value L, value a, value b in higher pectin content tomato powder shows the ascending trend at the temperature of 4℃and 20℃, in which the value a and value b show the slowly ascending trend; The value L shows the ascending trend at the temperature of 35℃. The value a and value b show the descending trend.(11) The storage of tomato powder doesn't show any sign of agglomeration under the temperature of 4℃and 20℃. And it shows the agglomeration phenomenon under the temperature of 35℃, and the rigidity of agglomeration has direct relationship between the pectin content and particle size; the rigidity of agglomeration decreases with the increasing of pectin content, and the change is significant (p<0.05) within the same particle size, the rigidity of agglomeration increases with the increasing of particle size, and the change is great significant (p<0.01) within the same pectin content.(12) The storage temperature in tomato powder has relation with the free amino acid; the decrease of total amino acids is prominent at the temperature of 35℃after 100 days of storage; the total amino acids content which is stored at the temperature of 4℃is significant (p<0.01) higher than the one which is stored at the temperature of 35℃in the tomato powder which contains low pectin content and under the condition of vacuum packing; the total amino acids content which is stored at the temperature below 4℃and 20℃is significant (p<0.01) higher than the one which is stored at the temperature of 35℃under the condition of common packing. The total amino acids content which is stored at the temperature below 4℃and 20℃is significant (p<0.05) higher than the one which is stored at the temperature of 35℃tomato powder which contains low pectin content and under the condition of vacuum packing; there is no significant difference (p>0.01)between different storage temperature under the common packing.