Application of Intermittent Drying of Cyclic Temperature and Step-Up Temperature in Enhancing Textural Attributes of Dehydrated Manilkara zapota

Abstract

Uneven hardness and difficulty in masticating dried fruits are common product quality problems. The product rejection rate is relatively high due to these problems. This study found that the textural attributes of dried fruits can be controlled or standardized by applying novel drying techniques, viz. intermittent hot air–dehumidified air drying. In addition, identification of the critical moisture content that contributes to case hardening of dried product is presented in this article. A textural attributes comparison was conducted for the continuous hot air, continuous dehumidified air, and intermittent hot air–dehumidified drying techniques. It was found that samples subjected to 5 h dehumidified air and 19 h hot air (5C-19H) intermittent drying gave the best hardness and chewiness attributes.

Keywords:

• Chewiness
• Dehumidified air
• Hardness
• Intermittent hot air–dehumidified air
• Manilkara zapota
• Textural attributes

ACKNOWLEDGMENT

The authors acknowledge the support given by the Ministry of Science and Technology and Innovation, Malaysia, through the allocation under the e-Science fund (03-02-12-SF0001). The authors also express their gratitude to Nam Foh Yoong Trading (Selangor, Malaysia) for supplying fresh Manilkara zapota.

Notes

Values indicate mean plus or minus (±) standard error. Values within the same column with the same letters are not significantly different.