Physical and chemical parameters of strawberry puree
2014
Galoburda, R., Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Food Technology. Dept. of Food Technology | Boca, S., Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Food Technology. Dept. of Nutrition | Skrupskis, I., Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Food Technology. Dept. of Nutrition | Seglina, D., Latvia State Inst. of Fruit-Growing, Dobele (Latvia)
Practice of the world shows, that more and more often a consumer chooses products, which can be used in nutrition without spending much time for their preparation. Use of fruit desserts in nutrition is one of the ways how to consume vitamins and minerals. The aim was to investigate physical and chemical parameters of strawberry puree from different cultivars and the effect of freezing on its quality. The strawberry cultivars - ‘Polka’, ‘Honeoye’, and ‘Senga Sengana’ harvested in Latvia were used in the study. The strawberries were processed in a blender until obtaining a homogenous mass. The strawberry mass was analyzed fresh and after storage at –18 °C. Content of soluble solids was determined according to ISO 2173:2003 using digital refractometer; content of total phenols by spectrophotometer method. Content of total acids was explicit as citric acid. Content of sugars (sucrose, glucose, and fructose) was evaluated by high performance liquid chromatography (HPLC). Content of anthocyanins was evaluated by spectrophotometer method. The pH was measured according to LVS 1132:2001, content of vitamin C - AOAC Official Method 967.21. Colour was measured in CIE L* a* b* system. Content of vitamin C in strawberry puree essentially differs (p is less than 0.01) among the researched cultivars and among the types of thermal treatment. Content of vitamin C in strawberry puree has a close correlation with content of total sugars. Close correlation of a* (r=0.810) and b* (r=0.851) with content of total sugars was established. This could be explained with the changes of the content of anthocyanins in strawberry puree. Content of total acids in fresh strawberry puree from the researched cultivars was from 0.85±0.03 to 0.87±0.03 mg 100 g -1, which increases in average for 4.4% as a result of freezing. The highest content of anthocyanins was in fresh strawberry puree from the cultivar ’Polka’, whereas the lowest – from the cultivar ‘Honeoye’.
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