Pectin in the potato cell wall plays an important role in strengthening connections of intercellular junctions during thermal processing through in-situ acid-induced gelation (in-situ acid-induced gelation [AIG]). Thus, the variation in the physicochemical and structural characteristics of potato pectin with in-situ AIG was focused in this study. The intra-and intermolecular hydrogen bonding among (d-galacturonic acid) GalA units around 3400 cm -1 (absorbance intensity was increased from 50.9 to 70.7) in Fourier transform infrared spectra were enhanced in the pectin with in-situ AIG. The crystallinity of pectin with insitu AIG increased from 4.02% to 36.63%. Atomic force microscopy revealed that pectin with in-situ AIG was made up of wide linear strands with the length from 0.5 to 4.6 µm. Thermogravimetric and rheological analysis showed that the structure of potato pectin was more stable and resistant to heat processing after in-situ AIG. These observations proved that the complex structure of potato pectin with in-situ AIG linked with its thermal stability. K E Y W O R D Sgelation, hydrogen bond, potato pectin, thermal stability Practical Application: In-situ gelated pectin in the intercellular space caused a helpful structure modification of vegetable to maintain its hardness with heat process. This study will provide novel insights into the physicochemical

Fresh-cut potato slices are very popular in the service of hot-pots. However, the gelatinized starch easily escaping from the potato cells during cooking causes the thickening of beef tallow or soup in the hot-pot. Thus, acetic acid is considered for solving the problem of potato slices. Besides, the nutritional and quality characteristics of potato slices are also evaluated in this study. Results show that 1.0%-1.5% (v/v) acetic acid treatment can decrease mass loss and starch digestion rate, and delay the degradation of ascorbic acid and deterioration of color and texture of potato slices. Such treatment also inhibits membrane oxidation and PPO activity, and increase the total phenolic accumulation of potato slice in 7-day storage. The cell wall integrity of the potato slice is strengthened by acetic acid treatment, providing a strategy for the improvement of the boiling resistance of potato slice, and endowing potato slice with the digesting resistance.