Structural characteristics and texture during the microwave freeze drying process of Chinese yam chips

Abstract

Fresh Chinese yam is difficult to store and easily deteriorates during storage, and dehydrated yam chips processed by different methods are widely consumed as a kind of snack food. Freeze drying (FD) is often used to produce high-quality yam chips, but the extralong drying time limits its industrial application. Microwave freeze drying (MFD) has the potential to replace the conventional FD method. Therefore, this research used MFD to dry Chinese yam chips. In this study, the brittleness and hardness of Chinese yam chips during the MFD process were investigated. It was found that the brittleness of Chinese yam chips had a close relationship with the moisture content. The hardness of Chinese yam chips mainly depended on the porosity and moisture content. Moreover, the DoseResp model of the brittleness could effectively predict the brittleness change during the MFD process. The regression equation based on the porosity and moisture content could accurately describe the hardness of the Chinese yam chips during the MFD process.

Keywords:

• Chinese yam
• microwave freeze drying
• texture
• hardness
• brittleness

Acknowledgments

The authors thank the support of the Collaborative Innovation Center of Grain Storage Security, Henan Province, and the support of the National Natural Science Foundation of China under the contract of No. 31671907.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Liuliu Duan, postgraduate student, and her major is food science and engineering.

Xu Duan, Professor, has long been engaged in the research of agricultural product drying technology. Recently, his research field is focused on freeze drying, microwave drying and heat pump drying process of foods.

Guangyue Ren, Professor, has long been engaged in the research of agricultural product drying technology. Recently, his research field is focused on atmospheric freeze drying of foods.

Additional information

Funding

This project was financially supported by the National Natural Science Foundation of China under contract no. 31671907, the Zhihui Zhengzhou·1125 Talents Program, no. 2016XT026, and the Program for Science and Technology Innovation Team in the Universities of Henan Province, no. 16IRTSTHN009.