Effect of high hydrostatic pressure (hhp) on some quality parameters and shelf-life of fruit and vegetable juices

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2005

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Dede, Saner

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The quality and shelf-life of pressure processed (150, 200 and 250 MPa at 25 and 35°C for 5, 10 and 15 minutes) orange, tomato and carrot juices were compared to fresh and thermally pasteurised (60°C for 5, 10 and 15 minutes and 80°C for 1 minute) juices. Treatments were capable of microbial inhibition of juices to non-detectable levels. The change in ascorbic acid content of HHP treated juices was not statistically significant (p>0.05). Both heat treatments at 60 and 80°C, displayed a significant loss and induced a decrease in the free radical scavenging activity but was not affected by HHP treatments. Pressurization at 250 MPa at 35°C for 15 minutes and thermal pasteurization at 80°C for 1 minute and stored at 4 and 25°C for shelf-life analysis. HHP treated juices showed a small loss of antioxidants (below 10%) at both storage temperatures whereas the loss is higher (about 30%) in the heat treated juices through shelf life (30 days). The pressurized juices, stored at 25°C, contained ascorbic acid better than heat treated ones after 30 days. The total color changes were minor (?E=10) for all pressurized juices but for heat pasteurized samples, higher as a result of insufficient antioxidant activity. The pH of juices was not affected by treatment, storage temperature or time. HHP yielded a better product, regarding the studied parameters of the juices compared to the conventional pasteurization. Therefore, HHP treatment (250 MPa, 35°C for 15 minutes) can be recommended for industrial production of fresh fruit and vegetables.

Subject Keywords

Food processing.

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http://etd.lib.metu.edu.tr/upload/12606513/index.pdf
https://hdl.handle.net/11511/15413

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Graduate School of Natural and Applied Sciences, Thesis

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Citation Formats

S. Dede, “Effect of high hydrostatic pressure (hhp) on some quality parameters and shelf-life of fruit and vegetable juices,” M.S. - Master of Science, Middle East Technical University, 2005.