Color, vitamin C, β-carotene and sensory quality retention in microwave-assisted thermally sterilized sweet potato puree: Effects of polymeric package gas barrier during storage

Abstract

In this study, we investigated the effects of package barrier properties on shelf-life of vitamin C-fortified sweet potato puree (SPP) processed with microwave-assisted thermal sterilization (MATS). Results show a change in SPP color during both processing and storage. The vitamin C in SPP decreased from 201.7 ± 4.7 to 185.8 ± 15.6 mg/100g during MATS and further decreased to as low as 13.6 ± 4.1 and 10.0 ± 0.3 mg/100g the end of 9 or 18 month, depending on the oxygen barrier and temperature. The total β-carotene content after processing and storage was slightly higher than before processing. Pouches with oxygen transmission rates (OTRs) of less than 0.3 cc/m2⋅day showed higher retention of color, vitamin C, and predicted shelf life than other pouches. However, this did not affect the consumer acceptance. Most panelists considered MATS processed SPP as a desirable baby food throughout the 18 months. Efforts are still needed to stabilize vitamin C content for over 3 years for military and NASA missions.