Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: NEW TECHNOLOGIES TO PROCESS VALUE-ADDED, HEALTHY FOODS FROM FRUITS AND VEGETABLES

Location: Healthy Processed Foods Research

Title: Quality Comparison of Apple Cubes Blanched with Infrared and Steam Heating

Authors
item Zhu, Yi - UC DAVIS, DAVIS, CA
item Pan, Zhongli

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: December 4, 2004
Publication Date: July 16, 2005
Citation: Zhu, Y., Pan, Z. 2005. Quality comparison of apple cubes blanched with infrared and steam heating. Meeting Abstract No. 36E-84. IFT Annual Meeting. July 2005. New Orleans, LA.

Interpretive Summary: Blanching process is widely used for inactivating enzymes that are responsible for causing quality deterioration of fruits and vegetables during storage. Typically, it is achieved by using hot water or steam. However, they are energy intensive processes and water and condensed steam can result in leaching of nutrients. This study showed that apple cubes blanched with a new infrared heating method had brighter color and firmer texture than steam blanching. Since the IDB technology can satisfactorily inactivate the enzymes with high product quality, it has a great potential as an alternative to replace current steam, water and/or microwave blanching methods.

Technical Abstract: Blanching process is widely used for inactivating enzymes that are responsible for causing quality deterioration of fruits and vegetables during storage. Typically, it is achieved by using hot water or steam. However, they are energy intensive processes and water and condensed steam can result in leaching of nutrients. It is important to seek alternative blanching technologies with high energy efficiency and without using water and steam. Using infrared dry blanching (IDB) technology could inactivate enzymes with high energy efficiency and no leaching of solids and nutrients compared to hot water and steam blanching. The objective of this research was to study the quality characteristics of blanched apples with IDB and steam. A catalytic flameless gas-fired infrared emitter emitting medium and far infrared radiation energy was used to perform the dry-blanching. 12.7 mm apple cubes were blanched with both infrared and steam at various temperature and time. The heating rates of the samples were measured under different treatments. The product quality indicators including color, texture, total phenols, and residual peroxidase activity were measured right after blanching. The blanched products were also frozen and stored at -18°C. Then, the quality indicators were measured again after the samples were thawed at ambient temperature. Our results showed that IDB could effectively inactivate enzymes of apple cubes with high energy efficiency. It took about 5.5 min to completely inactivate the peroxidase in the samples by using IDB. Samples treated by using IDB had brighter color and firmer texture than steam blanching. Since the IDB technology can satisfactorily inactivate the enzymes with high energy efficiency and product quality, it has a great potential as an alternative to replace current steam, water and/or microwave blanching methods.

Last Modified: 7/23/2014
Footer Content Back to Top of Page