Ultrasonic cutting of cheese and apples -- effect on quality attributes during storage

Yildiz, Gulcin

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https://hdl.handle.net/2142/45386 Copy

Description

Title

Ultrasonic cutting of cheese and apples -- effect on quality attributes during storage

Author(s)

Yildiz, Gulcin

Issue Date

2013-08-22T16:38:36Z

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

Feng, Hao

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)

• Ultrasonic cutting
• surface topography
• surface appearance
• cheddar cheese
• mozzarella cheese
• Swiss cheese
• peroxide values
• polyphenol oxidase activity
• red delicious apple
• golden delicious apple

Abstract

With advantages such as having excellent cut face, reduced smearing, low product lost, less deformation, less tendency to shatter for brittle products, and being able to handle sticky or brittle foods, ultrasonic cutting has become increasingly popular in the food processing industry in recent years. Although a number of publications have documented the use of ultrasound to cut food with an improved end-product quality, all previous works were focused on ultrasound or mechanical aspects of cutting process. No study has been published to investigating the effect of ultrasound cutting on food quality during storage. My thesis research was conducted to investigate the effect of ultrasound amplitude on the surface appearance and quality of selected cheese (Cheddar, mozzarella, and Swiss cheese) and fresh cut apples (red delicious and golden delicious) during storage. To examine the effect of ultrasonic cutting on quality of cheese products, cheddar, mozzarella, and Swiss cheeses were chosen because of their popularity. The focus of the investigation was on quality changes of cheese samples cut with ultrasound and without ultrasound in three-weeks of storage. Quality attributes such as total color difference, surface topography, peroxide values, pH, and sensory characteristics (taste, odor, and overall acceptability) of the samples were compared. General chemical parameters in ultrasonic cut samples including lipid oxidation and pH value showed significant differences from that of the Control. In addition, the L (lightness) values of samples cut with and without ultrasound were significantly different. Furthermore, all cheeses cut with ultrasound showed shiny and smooth surface appearance, while the surfaces were relatively rough for samples cut without ultrasound. The microscope images indicated that ultrasonic cutting resulted in a smoother surface compared to the Control. In the experiments with apples, red delicious and golden delicious apples were used because of their popular use in fresh-cut apples and the rapid browning of slices (especially red delicious apple which has a high susceptibility to browning) after preparation. The quality of apple samples cut with and without ultrasound was evaluated for a period of two weeks. A significant difference in polyphenol oxidase activity and pH levels was found between samples cut with and without ultrasound. The L (lightness) values of apples cut with ultrasound were significantly higher than that in the Control. Furthermore, both types of apples cut with ultrasound exhibited smooth surface appearance, while the surfaces were relatively rough for samples cut without ultrasound. The environmental scanning electron microscope images indicated that ultrasonic cutting resulted in a smoother surface compared to the Control. Sensory evaluation of cut apples by panelists showed that people favored apples cut with ultrasound.

Graduation Semester

2013-08

Permalink

http://hdl.handle.net/2142/45386

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Copyright 2013 Gulcin Yildiz

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