# Production of skimmed yogurt enriched by rice resistant starch: physicochemical properties, microscopic structure and model prediction during storage

## TL;DR

This study shows that adding resistant starch to yogurt improves its texture, stability, and shelf life while lowering its glycemic index.

## Contribution

The study introduces a new method to enhance yogurt stability using resistant starch and validates it with a kinetic model.

## Key findings

- Yogurt with 0.6% resistant starch showed better storage stability and microbial viability over 28 days.
- Resistant starch improved texture, with hardness of 143.32 g and elasticity of 0.75.
- A kinetic model confirmed the enhanced storage stability of resistant starch-enriched yogurt.

## Abstract

Resistant starch (RS) could be considered as a dietary fiber in yogurt, but its association with the shelf-life qualities is not clear. The characteristics and microstructure of low-glycemic yogurt (LGY) during fermentation and storage were investigated. During fermentation, principal component analysis combined with Mantel's test demonstrated that yogurt containing 0.6 % RS was best for storage. Over the 28-day storage, LGY maintained higher lactic acid bacteria count, with comparatively smaller reduction in microbial viability. LGY exhibited superior textural hardness (143.32 g) and elasticity (0.75). Microstructural analysis indicated that larger and looser pores appeared in both LGY and control over time, but the network cross-linking structure formed by RS with proteins resulted in less change in LGY. This structural reinforcement helped preserve the gel matrix and textural integrity. The kinetic model confirmed the storage stability of LGY. This provides a theoretical foundation for the stable LGY.

Unlabelled Image

•Resistant starch effectively reduces the glycemic index of yogurt.•Resistant starch enhances the structure and storage stability of yogurt.•Kinetic models accurately predicts the shelf life of yogurt.

Resistant starch effectively reduces the glycemic index of yogurt.

Resistant starch enhances the structure and storage stability of yogurt.

Kinetic models accurately predicts the shelf life of yogurt.