Abstract
In-season calcium fertilizer application was tested for its effects on the texture of french fries in combination with different blanching conditions during processing. Potato tubers were raised using standard practices with and without calcium fertilization during tuber bulking period. During french fry production, potato strips were treated with either control (without blanching), low-temperature blanching or high-temperature blanching treatments prior to frying process. Our results showed that the in-season application of calcium fertilizer significantly increased the firmness of french fries over the three blanching conditions. Moreover, a combination of calcium fertilization and low-temperature blanching showed the highest firmness of french fries among all the combinations. It was confirmed that calcium fertilization increased calcium concentrations in raw tubers, blanched strips, and its cell walls. Residual activities of pectin methylesterases extracted from potato strips treated by low-temperature blanching were slightly lower than control, but high-temperature blanching inactivated the enzymes as determined by an in vitro assay. Calcium fertilization and low-temperature blanching independently increased content of chelator-soluble pectin extracted from the cell wall. Atomic force microscopy observations suggested that calcium fertilizer application increased the amount of pectins remaining on the primary cell wall even after blanching processes. These results support that the observed increase in firmness of french fries may result from the enhanced formation of Ca2+-induced cross-links between pectin chains in the cell wall based on different mechanisms, i.e., an increase in endogenous Ca2+ available for crosslinking of pectin molecules by calcium fertilizer application and an increase in affinity of pectins to bind Ca2+ through activated pectin methylesterases during low-temperature blanching. Our findings provide potential opportunities to control the firmness of french fries by using different combinations of calcium fertilization and blanching conditions.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
