What are the effects of pasteurization on the antioxidants found in beet juice ? Does the process render most of the beneficial nutrients (betaine) useless and make them unable for the body to process as efficiently as it would with raw beet juice? Also, does the pasteurization process do this to most fruit and vegetable juices ? I appreciate any insight, I've seen a lot of conflicting reports and am curious of anyones thoughts. Thank you
So, when they subjected "ready to drink" beetroot juice to thermal pasteurization, they found the betacyanin and betaxanthin (our major antioxidants, and pigment molecules) content to be 39.9 and 42.28% degraded, respectively (1). Their conclusion was as follows:
Standardization of process condition and quality degradation of beetroot juice due to thermal pasteurization was studied. The standardized T2 batch with total heating time (fh) of 720 s thermal in-pack pasteurization leads to the minimal degradation of color, betalain content (Betacyanin and Betaxanthin), antioxidant activity and complete inactivation of micro flora of beetroot juice. The color, betalain content (Betacyanin and Betaxanthin) antioxidant activity and sensory of the beetroot juice was significantly (p < 0.05) reduced during 180 days ambient (27-30°C) storage, but still the quality of the juice was adequate upto 180 days. We concluded that thermal pasteurization of 96 °C for a total heating time (fh) of 720 seconds with P-values of 11.16 would be a good method to produce microbiologically stable beetroot juice with the retention of quality attributes.
So our goal is to get a juice that retains as many "good" attributes as possible, while producing a product that isn't going to get anyone a foodborne illness. As for the net effect of pasteurization on fruit juice in general, im still coming to a conclusion there. The process shouldn't render too much of the fruit/vegetable ineffective, though I'd still expect some degradation either in storage or processing.
If we read the previous statement, we can note two things. Firstly the percentage they mention are not in the quoted material at all. And secondly that the quoted material does not suggest degradation of the health boosting effects from the process of pasteurisation, but rather from long term room temperature (Very warm room) storage for 180 days. "The standardized T2 batch with total heating time (fh) of 720 s thermal in-pack pasteurization leads to the minimal degradation of color, betalain content (Betacyanin and Betaxanthin), antioxidant activity and complete inactivation of micro flora of beetroot juice."