AbstractsBiology & Animal Science

Diffusion of sugar, acids and pigments during processing and storage of canned berries

by Constantinos Andreas Boziotis




Institution: Oregon State University
Department: Food Science and Technology
Degree: MS
Year: 1963
Keywords: Fruit  – Preservation
Record ID: 1559306
Full text PDF: http://hdl.handle.net/1957/26669


Abstract

Processing and storage of berry fruits is accompanied by various changes, the important ones being the changes in the soluble solids content, titratable acidity, pH, pigments, and texture. A study was made of these changes in processed strawberries, raspberries, blackberries and blueberries, still cooked and stored at 78°F for one and six months in No. 10 cans. Three samples of the above four berries were analyzed before processing, immediately after processing and after one and six months of storage at 78°F. Five samples of syrups were collected from both center and side of the cans by means of 50 ml pipettes. These five samples were from top, 1 3/4", 3 l/2", and 5 1/4" from the top and from the bottom and a mean sample was taken from the drained syrup. The cans were then drained on an 8 mesh 10" screen. 100 gram samples of the drained solids from top, middle and bottom were collected for texture measurements. The results indicated the following: 1. There is a decrease in soluble solids of the syrup and drained weight of the fruit immediately after processing. Softening of berries progresses with storage. 2. There is an increase in titratable acidity, pH and pigments of the syrup immediately after processing. Titratable acidity and pigments increase with storage and pH values were lower. 3. There is a tendency to reach an equilibrium in the can with regards to soluble solids in all berries and pigments in case of strawberries with a lower tendency for raspberries. In the case of titratable acidity equilibrium was almost realized in strawberries and blueberries. All berry packs showed no equilibrium in the pH value after six months. 4. No noticeable differences between samples collected from centers and side of the can.