Effect of preconditioning on physicochemical, microstructural, and sensory quality of vacuum-fried jackfruit chips

The effect of preconditioning steps in terms of either freezing or partial drying on the quality of vacuum-fried jackfruit (JF) chips was evaluated. Prepartial drying process of the JF bulb slices resulted in the lowest moisture content in the vacuum-fried chips. The rate of oil uptake by JF bulb slices was found to be almost same in control and prefrozen samples during frying process. However, prepartial drying of slices resulted in a slower rate of oil absorption. The total carotenoid content was found to be 1.81, 0.96, and 1.87 mg/100 g (db) in control, prepartially dried and prefrozen JF chips, respectively. The Hunter L-value of control, prepartially dried, and prefrozen chips was found to be 52.3, 39.4, and 48.5, respectively. The a-value was found to increase, whereas the b-value decreased during vacuum frying in all the JF chip samples, irrespective of preconditioning type adopted. Prefrozen JF chips were found to have highest crispy texture in terms of lowest instrumental breaking force compared to the control and prepartially dried JF chips. Prefrozen JF chips were found to have lowest bulk density and highest porosity. The micrograph of prepartially dried JF chips depicted dense and shriveled structure, whereas a porous structure in prefrozen chips. The preconditioning protocols of partial drying and freezing were found to affect the overall sensory acceptability scores significantly (P< 0.05), with a high acceptability of prefrozen JF chips.