# Effects of Different Drying Methods on the Quality, Nutritional Components, and In Vitro Bioaccessibility of Kiwifruit

## TL;DR

This study compares different drying methods for kiwifruit and finds that MVD-FD best preserves quality and nutrients while improving nutrient absorption.

## Contribution

The study introduces MVD-FD as a novel drying method that enhances both quality and bioaccessibility of kiwifruit nutrients.

## Key findings

- MVD-FD preserves kiwifruit color, hardness, and texture better than other methods.
- FD and MVD-FD retain the highest levels of nutrients like polyphenols and ascorbic acid.
- MVD-FD significantly improves the bioaccessibility of active compounds compared to FD.

## Abstract

This study systematically compared the effects of vacuum freeze drying (FD), vacuum microwave drying (MVD), hot air drying (HAD), and their combined drying methods (MVD‐FD, HAD‐FD, MVD‐HAD) on the physical properties, nutritional components, and bioaccessibility of active compounds in kiwifruit. Two typical kiwifruit varieties, Zespri Green and Zespri SunGold, were used as raw materials. The results indicated that both FD and MVD‐FD were effective in preserving kiwifruit color, while the MVD‐FD samples additionally possessed moderate hardness and favorable textural properties. The FD samples displayed a uniform porous structure, while the MVD‐FD samples showed variably compressed pores. In terms of nutrient retention, the FD and MVD‐FD methods yielded the highest contents of total acid, total sugar, polyphenols, ascorbic acid, lutein, and zeaxanthin. In vitro digestion demonstrated that MVD‐FD significantly enhanced the bioaccessibility of active compounds compared to FD, including polyphenols, ascorbic acid, lutein, and zeaxanthin. In conclusion, MVD‐FD is considered a suitable method for producing high‐quality kiwifruit dried products with enhanced nutritional value.

FD‐ and MVD‐FD‐treated kiwifruit slices showed optimal quality and the highest nutrient retention, while MVD‐FD further enhanced nutrient bioaccessibility. Overall, MVD‐FD was identified as the optimal drying method.