1098Starch–lipid complexation induced by mayonnaise addition enhances RS5 formation and modulates digestion behavior in cold-stored mashed potatoes

Yiming Wang1,#, Yuwei Li1,#, Mengwei Yuan2, Mamoru Kimura2 , Lijun Yin1,3, Ryosuke Matsuoka2,*, Yongqiang Cheng1,*

1Beijing Key Laboratory of Functional Food from Plant Resources, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
2R&D Division, Kewpie Corporation, 2-5-7, Sengawa-cho, Chofu, Tokyo 182-0002, Japan
3Center of Food Colloids and Delivery for Functionality, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China

#These authors contributed equally to this work.

Background & Objective: The modulation of starch digestibility through hydrocolloid interactions has garnered significant attention in the design of functional low-glycemic foods. However, the mechanistic role of common food emulsions, particularly mayonnaise, in promoting resistant starch formation during cold storage remains underexplored. This study aimed to elucidate how mayonnaise-induced starch–lipid complexation influences the crystalline structure, enzymatic digestibility, and glycemic potential of cold-stored mashed potatoes, with a focus on RS5-type resistant starch development.

Methods: A model food system was constructed using mashed potatoes with or without mayonnaise (105g potato:24g mayonnaise), subjected to cold storage at 0°C and 10°C for 0–72 hours to simulate commercial cold-chain conditions. Texture Profile Analysis (TPA) assessed product quality, while structural changes were characterized using X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Fourier-transform infrared spectroscopy (FTIR). Starch digestibility and estimated glycemic index (eGI) were determined via the standardized INFOGEST 2.0 in vitro digestion model, with correction based on total starch content.

Results: The results revealed that mayonnaise addition significantly preserved textural integrity and promoted the formation of B+V-type crystalline patterns, indicating the presence of amylose–lipid V-complexes (RS5). FTIR spectra confirmed the interaction between amylose and unsaturated fatty acids, while DSC thermograms exhibited distinct phase transitions corresponding to RS5 formation, differentiating it from retrograded RS3. In vitro digestion data demonstrated that mayonnaise-containing samples exhibited a 15–28% reduction in eGI and a marked increase in resistant starch fractions, particularly after 72h at 0°C. Compared to control samples, these structural transformations correlated with lower enzymatic accessibility and improved nutritional properties.

Conclusion & Innovation:This study provides the first comprehensive mechanistic insight into how mayonnaise—beyond its deliciousness—can actively induce RS5 formation through starch–lipid complexation during cold storage. The findings establish a novel application of food-grade emulsions in modulating the digestion behavior of starch biopolymers and support a practical strategy for low-GI food formulation. The implications extend to both scientific understanding and commercial development of functional starchy foods with improved glycemic performance.

Elsevier Poster Competition: Yes, this poster is based on research led by two current doctoral students and qualifies for consideration in the Elsevier Best Poster Competition.