Effect of contact ultrasonic drying on drying kinetics and physicochemical properties of egg whites

Mundada, Vedant Kishor

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https://hdl.handle.net/2142/120579 Copy

Description

Title

Effect of contact ultrasonic drying on drying kinetics and physicochemical properties of egg whites

Author(s)

Mundada, Vedant Kishor

Issue Date

2023-05-02

Director of Research (if dissertation) or Advisor (if thesis)

Feng, Hao

Committee Member(s)

• Lee, Youngsoo
• Wang, Yi-Cheng

Department of Study

Food Science & Human Nutrition

Discipline

Food Science & Human Nutrition

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Egg white
• drying kinetics
• contact ultrasound
• protein
• functional properties.

Abstract

Egg white (EW) is a nutrient-dense food ingredient with a variety of functional properties. However, the limited shelf-life, susceptibility to spoilage, and transportation costs associated with liquid EW have prompted the use of drying as an effective preservation method. While thermal drying is a commonly used food preservation technique, its drawback is that it can cause structural damage and thermal degradation in EW, thereby necessitating the exploration of alternative drying methods for heat-sensitive products. In this study, the use of a variable frequency contact ultrasonic drying (CUD) method to produce EW powders was explored, by comparing it with spray drying (SD), freeze-drying (FD), and hot air drying (HAD) methods. An air stream at a velocity of 5 m/s was used in CUD and HAD to remove moisture. The CUD dryer was equipped with a 20 kHz variable frequency generator/modulator and drying was performed at 3 sound amplitudes (0%, 40%, and 60%) and 2 temperatures (40℃ and 60℃). SD was done at an air inlet temperature of 160℃ with a feed rate of 5-6 ml/min. FD was performed at -40℃ and 0.2 mbar pressure for 48 hours. Compared to HAD, the CUD led to a 240% increase in effective moisture diffusivity, a 66-78% reduction in activation energy, and a 27% reduction in drying time. The CUD process affected the proteins. This is evident by a) increased β-turns and random coil structures, b) increased free sulfhydryl group content, and c) 24-35% reduction in enthalpies for the ovotransferrin and ovalbumin proteins even at 60℃ of drying temperature. When compared to FD, the EW dried by CUD at 40℃ resulted in a 67% higher foaming capacity, while the CUD samples at 60℃ exhibited 37% better foaming stability. The soluble protein content increased by 10-12% in the CUD samples as compared to HAD, and was also slightly higher than in the FD samples. The EW dried by CUD exhibited a brighter color with a browning index 26% lower than the HAD product. This study demonstrates that CUD drying is a promising method for the production of dried EW with improved quality and reduced drying time.

Graduation Semester

2023-05

Type of Resource

Thesis

Copyright and License Information

Copyright 2023 Vedant Kishor Mundada

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