Abstract
Background: Reciprocating agitation thermal processing (RA-TP) is a recent innovation in the field of canning for obtaining high quality canned food. The objective of this study is to compare RA-TP processing with conventional non-agitated (still) processing with respect to the impact on quality (color, antioxidant capacity, total phenols, carotenoid and lycopene content) of canned tomato (Solanum lycopersicum) puree.
Results: Due to 63-81% reduction in process times as compared to still process, tomato puree with a brighter red color (closer to fresh) was obtained during RA-TP. At 3 Hz reciprocation frequency, the loss in antioxidant, lycopene and carotenoid contents could be reduced to 34%, 8% and 8% respectively, as compared to 96%, 41% and 52%, respectively during still process. In fact, the phenolic content for RA-TP at 3 Hz was 5% higher than in fresh puree. Quality retention generally increased with an increase in frequency, although the differences were less significant at higher reciprocation frequencies (between 2 Hz and 3 Hz).
Conclusions: Research findings indicate that RA-TP can be effective to obtain thermally processed foods with high quality attribute retention. It can also be concluded that a very high reciprocation frequency (>3Hz) is not necessarily needed and significant quality improvement can be obtained at lower frequencies (~2Hz).